Healthy Food & Healthy Living by Dr. Ayala

No, it doesn't just go through

A new study finds that a common food additive, ubiquitous in processed foods, changes the microbiome and the gut of healthy people

The introduction of highly processed food upon a society reliably predicts a decline in people’s health.

Highly processed food is linked to rising obesity rates and high blood pressure. A large study found a 10 percent increase in ultra-processed food was associated with a 10 percent higher risk of overall cancer and breast cancer. A study in Public Health Nutrition following 12,000 Americans with no underlying illness for more than 20 years, found that a highly processed diet is linked to a 30 percent higher chance of dying early.

Why is processed food harmful?

The convenient, flavorful, ready to eat array of processed foods are low in important nutrients: micronutrients, fiber, and the whole array of what’s in whole foods.

On the other hand they contain much of the things we try to eat less of: sugar, fat and salt.

And then, on top of that, they contain ingredients that the human intestine had never ingested until the advent of these technological innovations: Hydrogenated oils, food coloring, chemical preservatives and emulsifiers are just some of them. The nutrition label lists many ingredients foreign to human food, which up until recently came solely from nature. 

A new study in the journal Gastroenterology looks at emulsifiers – these are a hallmark of highly processed foods, added to improve texture and increase shelf life. Besides natural emulsifiers, such as lecithin, which was originally derived from egg yolk and can also be extracted from plants, there are synthetic emulsifiers such as carboxymethylcellulose (CMC) which are commonly used in industrialized foods. CMC was approved for use in the 1960s, despite no extensive testing, and was presumed to be safe because it’s poorly absorbed and is eliminated in our stool.

In the 60 years since the introduction of this emulsifier we’ve learned that even when something passes through our gut without entering our blood stream it still leaves its mark. Our gut bacteria encounter this substance and it may change the composition of the microbiome; the lining of the gut, the mucosa, which comes in contact with whatever’s just passing through, might also be susceptible.

And indeed, CMC has been shown to promote inflammation, metabolic syndrome and obesity in mice, to induce colitis – bowel inflammation – in predisposed mice, and also to change the mice’s microbiome. But that’s mice. Researchers set out to check CMC’s effect in humans.

The randomized controlled feeding study was conducted at the University of Pennsylvania, and included 16 healthy volunteers. After an 80 hour emulsifier-free diet at home, the participants were randomly assigned to an emulsifier free or one with 15 grams per day of CMC, in a residential setting in order to assure all elements of diet and exercise. 

And the results: CMC clearly changed the composition of gut bacteria, reducing select species and overall diversity, and there was a significant depletion of some of the beneficial bacterial metabolites that are known to help maintain a healthy gut.

Besides looking at fecal composition and metabolites, the researchers also performed sigmoidoscopies before and after the trial, and took biopsies of the distal colon in order to study the gut lining microscopically. In two volunteers on the CMC-containing diet, they found that bacteria were encroaching into the lining – a finding reminiscent of what you can see in people with inflammatory bowel syndrome and metabolic syndrome. This may suggest that when the health of the microbiome is compromised, or due to the CMC exposure, the altered gut bacteria start invading the lining – which when healthy is normally close to sterile.

Emulsifiers ubiquitous in processed foods

This is a small study, and just one chemical component is examined here. In real life people consume many food additives and their precise quantities are unknown. But even in this very short study there were stark changes in gut bacteria, reduction in beneficial fecal metabolites and in a few of the participants, even changes in the lining of the gut.

The authors conclude: “our observations argue that a particular food additive might perturb the host-microbiota relationship to promote disease in a subpopulation of individuals.”

So while individual susceptibility to processed foods’ ingredients may play a part, the highly processed diet is not good for anyone, for the other reasons listed above, and it’s probably one of the worst diets one can eat.

Because besides the low nutritional value, and the unnatural non-food stuff in it, it’s also built for overeating, crafted to please us and to manipulate our reward system. Food chemists design these products with a perfect sugar-fat-salt and flavor combinations, great mouthfeel, chuggability and crunch, making them so pleasing and easy to eat that they’re hard to resist or to moderate.

If there’s one small dietary commitment you want to sign on to for the coming year I suggest it’s to look more carefully at over-processed foods, and replace at least some of them with wholesome ones. A recent study in JAMA shows that two thirds of calories American kids eat now come from highly-processed foods, so we really do have our work cut out for us. 

Dr. Ayala

 

Is healthy vs. unhealthy food a myth?

When we head out we figure if the weather's rainy or dry, and then decide on the umbrella. 

Assigning things into binary categories is a useful way to help us make fast decisions. When it comes to food, something we choose constantly, we'd like to do the same thing, especially since there’s such variety and abundance around us – a quick shortcut is tempting.

And while most of us can see that the people we know are neither saints nor devils, most days are neither incredible nor horrible, and that the last movie we watched was neither a masterpiece nor a flop, food is all too often judged in a binary way: healthy vs. unhealthy.

A new study, led by Paul Rozin of the University of Pennsylvania, looks at the primary division of foods that first comes to mind in three countries: US, France and India.

The study included about 300 people in each country, and started with an open question: “If you had to divide all the things we eat and drink into two categories, what would they be?” In another part of the study the questionnaire participants ranked the importance of 5 binary divisions of the food world: animal vs plant origin, food vs. beverage, healthy vs. unhealthy, natural vs. processed, French/Indian/American (depending on  the  country of the participant) vs. other. 

Obsessed with health foods

The most common default way in which Americans categorized food was according to healthy vs unhealthy. This was the way they categorized most often when they were asked this as an open question. It was also the most important way to categorize foods when they had to rank the different dichotomies. It was the second most important to Indian participants, and the third for the French. 

For the French participants the most important categorization was natural vs. processed.

There was surprisingly no big difference between men and women among all participants. The authors also note that the animal vs. plant was rarely selected (animal vs. plant is actually the only factual binary way in which food can be categorized).

The authors conclude: “Our findings suggest that the food–health link is very salient for many individuals, especially Americans. Insofar as this strong mental link does not translate into lower food intake and more healthy choices, it may be counter-productive.” 

Can you really divide foods to healthy and unhealthy?

By definition, any broad categorization will be simplistic. I am often asked whether a food is healthy or not, and I admit that sometimes I will give an answer as short as “yes” or “no”, especially if I sense that there’s no patience or interest in a broader lesson about nutrition and wellness.

Food's healthfulness, however, exists on a grey scale.

The truth is that for most foods the quantity you eat determines its effect on health. You can gain unhealthy weight on perfectly nutritious foods that are minimally processed, and that boast many beneficial micronutrients – too much nuts, which are the epitome of healthy food, can do that. On the other hand, small amounts of indulgences such as chocolate or ice cream aren’t a threat to health. It’s this black and white way of training us to see food as good vs. evil that enables some processed foods to create a halo of ‘healthy’ that diverts us from thinking of the benefits and drawbacks of food as a continuum.

So yes, there are a few things that are pure junk foods, and that can easily be categorized as unhealthy – soda comes to mind. But most foods can’t be divided this way. On the continuum of healthfulness, there are sustainable ways in which you can improve your diet. If your dinner plate that once had a large steak, potato fries and a half cup of leafy greens transforms into one in which the leafy vegetables occupy half of that plate, the meat portion halved its size and the potato fries are replaced by roasted sweet potatoes, your food is healthier. We can’t characterize either version of that dinner as healthy or unhealthy, but one is more nourishing than the other, and if you repeat these choices again and again your diet improves. 

Food is many things, it's communal, traditional, sensual, cultural, it's our connection to the natural world. But even if your main goal is to support optimal health, thinking about food primarily as healthy vs. unhealthy may be, as the authors suggest, counter-productive.

Dr. Ayala

The inconvenient science-based truth about the upper limit of sugar and alcohol

Covid times have brought two conflicting realizations to the fore. We’re ever more aware that our general health is key to the way our body deals with a medical challenge – such as an infection with a virus. On the other hand, it’s been hard not to double down on the very things that undermine our wellbeing, which is understandable, given the stress and isolation of the recent year, and how hard it is to change our habits. 

As pubs and restaurants closed, people stocked up on alcohol at home. According to Neilsen, alcohol sales from stores grew 21 percent, while online alcohol sales skyrocketed and are up 234 percent. People gravitated to larger sizes and to higher alcohol content. Alcohol consumption is up especially among people prone to alcohol abuse, and binge drinking rose about 20 percent for every week on lockdown according to a recent study.

Unhealthy eating patterns also rose, especially in already at-risk populations. In a recent study about a third of participants reported that they’re eating less healthfully and have gained weight, 44 percent reported increases in unhealthy snacking, as well as increased intake of sugary drinks and candy. 

A guiding hand

Unrelated to the pandemic, the 2020-2025 Dietary Guidelines were recently published. These recommendations are developed using a report by a scientific advisory committee of 20 nationally recognized experts in the field of nutrition and health. After reviewing the relevant science, the committee’s advice, published last summer, was to cut back further on sugar and on alcohol. Alcohol intake is on the rise the committee notes “excessive alcohol consumption is a leading behavioral risk factor for a variety of morbidity and mortality outcomes, social harms, and economic costs”, and “consuming higher average amounts of alcohol is associated with increased mortality risk compared to drinking lower average amounts.” Men who drink alcohol, the expert panel advises, should limit their alcohol intake to 1 drink a day – the upper limit for women – down from the 2-a-day upper limit in the 2015 guidelines. 

Likewise, the scientific committee had new advice regarding the upper limits of added sugar. Previous dietary guidelines had the upper limit at 10 percent, a tall order by itself, as per the committee’s data, the average American consumes about 13 percent of daily calories as added sugar. The committee’s added sugar conclusion: “Evidence suggests that adverse effects of added sugars, particularly from sugar sweetened beverages, may contribute to unhealthy weight gain and obesity-related health outcomes... the Committee suggests that less than 6 percent of energy from added sugars is more consistent with a dietary pattern that is nutritionally adequate while avoiding excess energy intake from added sugars than is a pattern with less than 10 percent energy from added sugars."

The committee’s advice regarding cutting back on alcohol and added sugar was not incorporated into the 2020 guidelines, however.

Although the 2020 guidelines admit that added sugars, and especially sugary drinks, can add to our alarming obesity rates, and that alcohol is linked with certain cancers and cardiovascular disease, the guidelines remained unchanged.

Drinking less sugar and alcohol is better

To which one can say, who listens to the guidelines anyway? Well, it’s true that years of recommending 5-a-day of fruits and veggies achieved the common knowledge that we should eat more veggies and fruit, but not the actual practice of doing so – only 1 in 10 Americans eat enough fruits and veggies. Most Americans don’t follow the guidelines, and the average American scores 59 out of 100 on the Healthy Eating Score.

But the Dietary Guidelines for Americans are the basis of educational materials and policies, such as the federal nutrition assistance and school lunch programs, so the guidelines do have real-world consequences. People are also aware, like never before, that poor diets are linked with chronic diseases and bad outcomes, so communicating the science matters.

And for people struggling to improve upon an unhealthy habit, vague or ambivalent advice, especially from a voice of authority, is permission to struggle less. It’s all too easy to read the current guidelines as entitling men to 14 drinks a week under the guise of moderate drinking, and shooting for a diet of 10 percent added sugar as a recipe for health – and we know we're already cheating ourselves when we count our dietary indiscretions.

So yeah, alcohol and junk food can give some comfort, and a little indulgence shouldn't be denied, especially when we’re deprived of many other things we used to enjoy. Alcohol sales have also been a bright spot for many retailers and food service businesses struggling in these hard times.

But the truth is still the truth.

The fact that health food stores like Whole Foods Market have several aisles devoted to alcohol doesn’t mean that alcohol is a whole food that nourishes you. It reflects consumers’ desire to buy the retailers' need to sell. Wine is delicious, so is cake, but these, evidence shows, should be consumed in moderation; moderation can't be defined by our desire to consume or by the wishes of those who profit from sales, but by evidence. 

I, too, wish that ice cream could become the new kale nutrition-wise, unfortunately, this is not the case.

Dr. Ayala

Can certain foods rev up your metabolism?

We want our appliances to run efficiently. Our body, on the other hand, we’d like to run inefficiently and waste excess energy. If we had it our way we’d like to consume lots of ice cream and for the extra calories to evaporate.

Regrettably, our bodies are frugal. Our internal machinery runs economically and excess energy is stored for the next famine in the form of fat.

But fat tissue actually offers a glimmer of hope for burning off extra calories.

You see, we have two types of fat tissue in our body, white fat, which is the fat that stores extra energy in the form of fat droplets, and brown fat, which is much richer in blood supply and has many more mitochondria (hence its color). Mitochondria are intra-cellular tiny organs that utilize fuels (glucose, fats) to produce energy. In brown fat inefficiency occurs through the “uncoupling protein” – a protein in the mitochondrial inner membrane – that converts the cell’s fuel into heat rather than energy. Brown fat burns off calories, especially when we’re exposed to cold temperatures. While white fat stores energy while brown fat uses it.

Brown fat, however, is something we have very little of. Babies are born with brown fat dispersed throughout their body – it helps them maintain their small body’s temperature. The amount of brown fat diminishes with age, with small amounts persisting in the upper chest and neck.

But brown fat can be revived, we’ve discovered, and there’s actually a third type of fat: beige fat. Beige fat is white fat that’s turning brown after stimulation.

Can fat tissue transformation help combat obesity and metabolic syndrome?

Waking up the brown fat

Exposure to cold temperature can stimulate brown fat, but shivering in the cold isn’t fun.

Coffee, according to a new study in Scientific Reports that received lots of media attention, can stimulate brown fat into action. Drinking coffee is certainly more tempting than subzero temperatures.

The researchers, led by Michael Symonds, started off with cell cultures. They added caffeine to fat stem cells (adipocytes), and showed an increase in in the concentration of the mitochondrial uncoupling protein, and in the “leak” and waste of energy.

Next, they moved on to testing the idea on 9 healthy volunteers. The volunteers were given either a caffeinated beverage or water. After 30 minutes the heat emitted from their upper body was measured through thermal images.

Drinking coffee significantly increased the temperature measured in the area between the chest and neck – the area where brown fat supposedly lives.

So according to this small study a single cup of coffee can increase brown fat activity.

Browning fat with food

Coffee isn’t the only food that activates brown fat and cause white fat “browning”.

A recent review article in the Journal of Nutritional Biochemistry looked at several food components’ effect on brown fat.

Green tea increased brown fat and energy expenditure in mice. Resveratrol, a polyphenol compound found in red wine, cabbage, berries and spinach initiated fat browning in tissue cultures and also in live mice. Capsaicin, the spicy component in hot peppers, activated brown fat in rodents and humans in other studies. Curcumin, a component of turmeric, induced fat browning in mice. Thymol, a component of several aromatic herbs, such as thyme and oregano stimulated browning in cell cultures.

These ingredients are all plant-derived phenolic compounds, and there's now some evidence ­– most of it from test-tube and animal models – that these phytochemicals can induce fat to turn into an energy-consuming tissue.

How many calories will this waste? Probably not that many.

Weight is lost by a simple formula: You need to consume fewer calories than you expend. The consumption side of the equation is the most practical approach.

Calorie expenditure is usually addressed through exercise, which is super important in and of itself, but burns fewer calories than you might hope, and physical activity builds an appetite.

Can fat browning help us burn calories? That would be nice, any recruit to our fight against obesity and metabolic syndrome is very welcome, I love coffee, and recommend using herbs and turmeric for many other -- flavor and health -- reasons anyway.

But I suspect that brown fat will not enable us to endlessly indulge without consequence. Nothing will.

Dr. Ayala

Coffee and cancer?

You might have been surprised by the news coming out last week, announcing that the World Health Organization (WHO) found that coffee isn’t carcinogenic after all. If I were in the coffee business I’d want this news item to get as little publicity as possible, as I doubt anyone was worried about coffee’s carcinogenicity before they were told not to fret.

So what’s this all about?

The last time the WHO’s International Agency for Research on Cancer (IARC) evaluated coffee was in 1991, and at that time it gave it a “possibly carcinogenic to humans“ classification because of limited evidence associating coffee and bladder cancer in case-control studies (which are not the best evidence).

For this evaluation 23 scientists from 10 countries met in Lyon, France, and evaluated 1000 observational and experimental studies that have accumulated in the meantime.

Overall, cancer risk and coffee seem to be unrelated, they concluded.

The group also evaluated mate, a drink popular in South America and steadily gaining popularity elsewhere. Hot mate was classified as “probably carcinogenic to humans” in 1991 based on limited evidence. The new evaluation, based on the latest knowledge, concludes that while the high temperatures in which some people drink their tea or mate might act as a tumor promoter, the researchers think the mate itself is not a problem. Beware of very hot drinks, they advise:

“Drinking very hot beverages at above 65°C was classified as “probably carcinogenic to humans.”

Should we worry?

The WHO’s findings are a scientific evaluation, not a set of recommendations on what to eat.

The categories used by the IARC can be quite confusing.

The highest, most dangerous category, category 1: Carcinogenic to humans, includes processed meats (bacon, ham, hot dogs, sausages). And also cigarettes. Does this mean that meat is as carcinogenic as smoking tobacco? It definitely doesn’t. More than 85 percent of lung cancers result from tobacco smoking, yet according to the WHO’s report 50 grams (about 2 ounces) of processed meat daily might increase colorectal cancer by 18 percent -- smoking is much more likely to cause cancer than eating processed meat, even though both are in the same category. In this same category 1 you can also find ethanol in alcoholic beverages, secondhand smoking, engine exhaust, air pollution, and sun exposure. The sun’s rays, X rays and gamma radiation are all in the same category 1, but that doesn’t mean that beach vacations are as risky as getting a weekly CT scan.

Now, lets visit the category coffee’s in, it used to be 2B: Possibly carcinogenic to humans, and now it’s group 3: Not classifiable as to its carcinogenicity to humans. Coffee shares this distinguished category with tea.

This is science speak, so the best, most benign score you can get is category 4: Probably not carcinogenic to humans – scientists are very careful, and will never declare certainty.

Once the “can it cause cancer” question is raised to the IARC the best possible outcome can be: Probably not. When you ask a scientist: Is this – pertains to practically anything -- 100 percent safe? the answer can never be a simple: Yes.

A better place to look for practical dietary advice is the Scientific Report of the 2015 Dietary Guidelines Advisory Committee, which concluded:

“Currently, strong evidence shows that consumption of coffee within the moderate range (3 to 5 cups per day or up to 400 mg/d caffeine) is not associated with increased long-term health risks among healthy individuals. In fact, consistent evidence indicates that coffee consumption is associated with reduced risk of type 2 diabetes and cardiovascular disease in healthy adults. Moreover, moderate evidence shows a protective association between coffee/caffeine intake and risk of Parkinson’s disease. Therefore, moderate coffee consumption can be incorporated into a healthy dietary pattern, along with other healthful behaviors…However, it should be noted that coffee as it is normally consumed can contain added calories from cream, milk, and added sugars. Care should be taken to minimize the amount of calories from added sugars and high-fat dairy or dairy substitutes added to coffee.”

I wouldn’t be at all surprised if one day we’ll discover that worrying about cancer may cause cancer.

Dr. Ayala

Better health by cutting sugar for just 10 days

The recent prevailing mood regarding sugar swings between worry that it’s not particularly good for you, to conviction that it’s downright poison. 

There’s no doubt that sugar makes food more appealing – some say even craveable and addictive – and that a sugar-amplified diet has a role in overeating and obesity. But what several researchers are finding is that regardless of weight gain, regardless of caloric intake, sugar – especially fructose – in excess is detrimental to health.

A rigorous new study in Obesity, led by Robert Lustig, shows that reducing overconsumption of fructose is metabolically beneficial in and of itself.

The study involved 43 obese 8-18 year-olds, all of whom were heavy sugar consumers (28 percent of their diet was added sugar!) and also had at least one metabolic risk factor, such as high blood pressure, glucose intolerance or high triglycerides.

For 9 days this group ate an added-sugar restricted diet, while still aiming to maintain the same amount of total carbohydrates and calories. 

Short explainer about sugar, fructose and glucose; I promise it’s short and necessary in order to understand what this experiment teaches. Foods and drinks are usually sweetened with sugars that are a combination of the simple sugars glucose and fructose. Sucrose (table sugar) is a two-sugar molecule with 1 glucose and 1 fructose bound together, and is therefore exactly 50 percent glucose, 50 percent fructose. High Fructose Corn Syrup (HFCS) is about 45 percent glucose, 55 percent fructose. Practically all forms of caloric sweeteners used in food processing are glucose/fructose mixes. So how does one maintain the sugar level while reducing fructose? The answer is starches, which are pure glucose chains.

The study didn’t change the kids’ diet to a kale, hemp seed and quinoa retreat, but rather just replaced foods with lots of added sugars with other processed foods such turkey hot dogs, pizza and baked potato chips, that have little or no added sugar, and instead contain carbs in the form of starches.

Just 10 days later there were significant metabolic improvements: Glucose tolerance, blood lipids and other markers of liver health changed for the better.

As mentioned before, the study aimed to keep caloric intake steady, and for the kids' weight to stay the same. However, despite the effort, and even though the researches even added calories to that effect, the kids lost about 1 kg on average (2.2 pounds) in the 9-day study. Could this mild weight loss explain these metabolic improvements? The researchers performed regression analysis and claim it’s unlikely -- I won’t go into that complicated explanation. 

So, is sugar toxic?

This study is further proof that reducing added sugar to more reasonable amounts benefits kids at risk of metabolic syndrome and diabetes.

Dr. Lustig often warns about the dangers of fructose, emphasizing that glucose isn’t the problem. In practicality, since added sugars are almost always at least 50 percent fructose, the sensible advice it to cut all added sugar.

Sugar in large amounts is definitely associated with weight gain, and likely also independently with diabetes and metabolic and heart disease. Reducing it (even without intentional caloric restriction) usually leads to weight reduction, and to improved health outcomes.

So cutting on added sugar and aiming for the World Health Organization's and the American Heart association’s target of no more than 6 teaspoons a day for women, 9 teaspoons a day for men, is very sound advice. The first step towards that not-easy-to-achieve goal is to know how much sugar is added to our food, which is what’s proposed by the FDA, and fought mightily by the food industry.

Dr. Ayala

Brain zapping for weight loss

Here’s a prediction: It’s only a matter of time before people start zapping their brain to shed weight.

In the last few years, electrical brain stimulation (transcranial direct current stimulation or tDCS) has become a hot topic. The principle behind this area of research is that a small electric current, delivered through electrodes attached to the head, can increase or decrease the activity of the brain for several minutes. The initial results are promising: Such treatment has been shown to help train pilots faster, make math calculations easier and even aid in the rehabilitation of stroke patients. The currents tested are a tiny fraction of those used for electroconvulsive therapy (a proven therapy for severe depression, a brutal version of which was memorably portrayed in One Flew Over the Cuckoo’s Nest) – just 1 to 2 milliamps, less than what’s needed to light a typical LED. Although exciting and plausible, the researchers in the field freely admit these are early days, and both the efficacy and long-term safety are yet unknown.

Can this method also address our oh-so-tough and ever-persistent weight control problem? A few small studies suggest that tDCS can diminish feelings of hunger and reduce craving for sweetness, and now a German group published a new study in The American Journal of Clinical Nutrition that shows this method can make people eat less.

Shocked into reduced appetite 

In the new study, 14 healthy-weight male students were alternated between 20 minute treatments with either electric stimulation or sham stimulation for 8 consecutive days – the electric and sham treatment assignment was known to the researchers, but was easily confused by the students as the zap is so mild. The area stimulated was in the prefrontal cortex, thought to modulate our behavior around food. While the volunteers thought what was tested was their mood, what was actually checked was how much they ate at a subsequent buffet.

The response to the repetitive electric treatment was about 14 percent reduction in food intake by day 8 of the experiment, compared to the sham treatment, and the diminished eating was mainly of carbs. The short treatment didn’t lead to weight loss. 

The $20 slimming cap?

Commercial companies have jumped into the improved-mental-performance arena with devices that they claim increase the plasticity of your brain and make your synapses fire faster – they admit these devices are not FDA approved or proven to cure disease. For the handy, there’s no need to shell out hundreds of dollars: the components needed – a battery, a resistor a few wires, sponges etc. – are available and cheap, and devising a DIY kit isn’t that difficult. YouTube has many tutorials.

And although none of us would mind a bit of cognitive enhancement, the humongous diet industry proves we’re absolute suckers for half-baked, magic weight loss solutions. Just a hint of weight loss success unleashes a tide of demand, and I won’t be surprised if those in possession of electrodes will now be searching for that elusive dorsolateral prefrontal cortex that supposedly controls our food cravings and appetite.

Hence my prediction.

But not only is this method far from proven for any condition yet, it also isn’t necessarily harmless. Here are a few words of caution: Google hasn’t yet mapped the brain for DIY navigation, and even researchers with MRI and EEG machines can’t neatly pinpoint to the area they want to treat, so we might be awakening anger rather than self control; 2 milliamps may seem harmless, and we can agree that that amount of juice won’t drill a hole in your skull, or make neurons fire, but the currents that transmit information within human cells are even smaller, and just ask yourself this: if you believe 2 milliamps are enough for a positive effect, then why shouldn’t they suffice for nasty side effects?

There’ll also, no doubt, be those who think – following the prevailing logic regarding vitamins -- that if 2 milliamps are good, 20 must be better. 

The science definitely isn’t ready, but if you’re itching to try brain stimulation for weight loss in a controlled setting – and at the same time help advance the knowledge – the National Institutes of Health is recruiting volunteers for a clinical study. 

Dr. Ayala

Crazy diets, silly food science and absurd food inventions 2013

This year had its remarkable share of senseless diets, bizarre research and odd inventions. Here’s what you might’ve missed. Feel free to add your chuckle-worthy items to the comments below.

Lose weight; stop eating

The Breatharian Diet holds much promise. For one: It can solve world hunger. According to believers, much like plants, humans can live on fresh air and sunlight’s vital life forces if they work on it. The British Dietetic Association lists this diet as the number one “Top 5 Worst Celebrity Diets to Avoid in 2014”; ridiculous as this might sound, there are people who actually tried this, and some who lived to tell the tale. 

Why do onions make us cry?

The silliest of research is celebrated yearly at the Ig Nobel awards.  The ceremony, held at Harvard University each fall, spoofs the Nobel prizes and is presided over by real Nobel winners.

Among this year’s achievements were the discovery that people who think they’re drunk feel more attractive, and that the longer a cow lies down, the more likely she is to stand up. The important food chemistry prize went to Shinsuke Imai from Japan, who discovered why onions make us cry – it is actually more complicated that previously thought.  Imai’s group discovered a previously unknown enzyme, lachrymatory-factor synthase, which apparently has nothing to do with onion’s taste profile or nutritional value. So there you have it: we can potentially develop a perfectly tasty onion that doesn’t protect itself with tear gas. 

Must have: watermelon stroller

I love watermelons and really miss them right now – I won’t touch watermelons out of season. Would you like to take your watermelon for a walk in a fitted cooler, or are you going to carry this heavy baby in your arms forever? Head over to this site and you can purchase this lovely Japanese device for about $200. What do you do with twins?

A tablet on every table

Applebee’s announced it will install tablets on every table by the end of 2014, enabling diners to read the menu, pay the bill and play games. Chili’s will be doing much the same, empowering customers to order drinks and desserts and to play interactive games. Both companies deny this will cut jobs. If you are to believe the chains, the computers will enhance rather that replace human servers, who are poised to get larger tips due to better customer satisfaction.

Yippee! With TV screens already in every corner, Instagram, Facebook and text luring us to our personal smartphones, and now a tablet to fill odd-moments-when-family-finds-silence-unbearable with video streaming and social media interaction, we can finally fully enjoy a leisurely meal. This really brings these so-called family friendly eating establishments to new levels of kindliness to what it means to eat and to be in company. Next: your meal will be delivered by drone.

Looking forward to see what 2014 brings.

Dr. Ayala

Is there scientific basis for the blood type diet?

Why are so many of us struggling with our weight and suffering illness? According to naturopath Dr. Peter D’Adamo knowing your blood type, and eating and exercising according to it, is the key to avoiding health and weight problems. His bestseller, Eat Right For Your Type, which was published in 1996, has been translated to more than 50 languages, and has 7 million copies in print.

I know my blood type only too well. The Red Cross is extra excited with my O negative donations (O negative blood is considered a universal donor), but as a pregnant woman I had the pleasure of receiving plenty of shots to prevent hemolytic disease of the newborn.

So how should I be eating? “Type Os thrive on intense physical exercise and animal protein”, according to Eat Right For Your Type. Uh-oh! Although I exercise regularly, I’ve never run a marathon and I’m a vegetarian; I eat lots of grains and legumes, which according to D’Adamo contribute to weight gain in my ‘type’. According to his diet I should eat a lot of lean meat, which I don’t, and avoid gluten, oranges, mushrooms, cauliflower, coffee and tea, black pepper, all vinegars and beans, which I certainly don’t. I thought I was doing fine, but imagine how much better I could be feeling.

The science behind blood type diets

Blood types are perfectly scientific. There are about 30 different antigens than can be present or absent on the surface of a red blood cell. The ABO system for typing blood, which deals with just two of these antigens (A and B), is the most well known and useful, since ABO compatibility is the most important for blood transfusion – getting incompatible blood can be fatal.  Most people have never heard of other blood types such as M, N and Kell.

But do blood types really inform about our disease susceptibility and gastrointestinal fitness?

The book offers plenty of anecdotal ‘evidence’ of people whose symptoms improved when they learned to eat for their blood type. Stories of success sound very convincing, and nothing makes as memorable an impression as personal testimony. But anecdotes are not proof.

A new study in the American Journal of Clinical Nutrition assessed the evidence for blood type diets in the scientific literature. The researchers looked for studies that grouped people according to blood type and studied whether adherence to a certain diet made a difference. Combing the entire life science and biomedical databases, the researchers could not find even one study showing an association between ABO blood type diets and health related outcomes.

Not even one!

Is it possible that blood type affects susceptibility to disease and should predict your optimal diet? It is also perfectly possible that eye color and the curliness of hair could be associated with certain dietary outcomes, and that these traits are inherited together with traits that affect gastrointestinal differences. Much like the belief that blood type is predictive of personality, the notion that blood type affects metabolism and should determine your optimal diet is a belief, in this case, based on no facts whatsoever.

I have not given birth to any children of my blood type – a bit of good news: according to D’Adamo my kids can thrive as vegetarians – so after proving I’m too lazy for  ‘intense physical exercise’ you won’t be surprised I’m also too lazy to cook seperate, individual meals for my husband and three kids.

Dr. Ayala

Silly diets, silly food inventions, and other 2012 follies

As this year comes to a close I look back with appreciation, and recognize that research and technology are generally moving us forward, and that we people are quite remarkable – despite our many flaws we strive to better ourselves and improve our world. 

There are of course plenty of exceptions, and this end-of-year post is devoted to some of the silliest food-related science and innovation that came my way in 2012.

Who wants a bride with no common sense?

There were many contenders for this year’s prize for stupidest diet. The desire to shed weight seems to breed an endless stream of particularly magical claims, supernatural devices and silly, dangerous plans. 

But I do have a clear winner. The K-E diet, or nasogastric diet was a hit among brides-to-be looking to shed 20 pounds in 10 days. The plan is simple. You put nothing in your mouth for the duration of the diet. Instead, you insert a feeding tube through the nose into the stomach, and through it a slow drip of carb-free nutrients supply your body with 800 calories a day. Since your body’s starving, and has no carbs to run on, you’ll be converting fat to ketones, which will make you stink. (Know that smell coming from hungry people? It can be described politely as sweet and fruity, and more accurately as rotting fruit mixed with nail polish remover – it’s not pretty.) You’ll also be constipated (avoiding fiber will do that) and look sick.

Don’t be surprised if you find your groom has a change of heart. I wouldn’t blame anyone who has second thoughts about sharing a life and raising kids with someone whose priorities and common sense are so, shall we say, unusual. Nasogastric tubes are an unpleasant medical necessity for patients who can’t eat, but I’m pretty certain most of us hope we’ll be able to introduce every morsel of food into our body the traditional – healthy -- way, through the mouth. Stephen Colbert already imagined an upgrade to the feeding tube diet: why stop at the stomach? Why not bypass the entire digestive tract and thread the tube all the way to the bottom? That would make any food you eat zero calorie and “You won’t just hit your goal weight, you’ll hit you birth weight”.

Why does coffee spill?

The silliest of research is celebrated yearly at the Ig Nobel awards.  The ceremony, held at Harvard University, spoofs the Nobel prizes and is presided over by real Nobel winners.   

One of this year’s coveted awards went to Rouslan Krechetnikov and Hans Mayer, who investigated one of life’s greatest mysteries: when you walk with a cup of coffee why does it always spill? Brownish trails in most office carpets will attest that the problem is epidemic and real: coffee always spills! 

Mayer and Krechetnikov are experts of fluid dynamics, and are the perfect pair to tackle this important question, and they systematically tried various walking speeds and coffee levels. Their analysis shows three competing motions at work in the walked-with-coffee-cup: side to side sloshing, forward-back sloshing, and up and down motion of the walker. All this adds up to a swirling around in the cup, as well as an up and down wave of coffee, resulting in spills. And what matters most is not the speed of walking, but how you get to that speed: your acceleration.

Bottom line: fill the cup a little less and put a lid on. Then, be ready for a spill. 

Your car as a mini kitchen

Drivers love fancy technology, and new safety features in cars are credited with large declines in accidents and fatalities on the road. 

But new technology has also made the car into a mini office, complete with text, email and phone calls. And if car food and drink were limited to pre-made options, this year’s hot innovations promise to transform the car into a mini kitchen.

The Handpresso Auto plugs into the 12V cigarette lighter, and promises a delightful, creamy cup of espresso, just add water, a coffee pod, press a button and wait a bit. Fiat’s new 500L model will include a built in espresso machine.

This sounds like a great idea. Until you ponder how often drivers stop in a safe place for their phone calls and texts. Since most drivers think they’re above average, how likely are they to park the car before making coffee? Remember how coffee always spills? How hot it is when it’s just brewed? Do we need another gizmo to occupy drivers while operating a heavy machine at high speed, a machine whose operation requires two hands, a clear head, and all our senses?

I’ll stop here, and invite you to share what fascinated you this year.

To a happy, healthy, progress filled 2013!

Dr. Ayala

To see my previous years' notable silly science choices go here, here and here.

Is organic food healthier? New study fuels the debate

What makes a food healthy? The definition of healthy food and nutritious food is absolutely essential in order to answer the question: “is organic food healthier”.

But a new widely publicized study published in the Annals of Internal Medicine this week answers this question without digging deeper into what defines “healthy”. The study reviewed research comparing organic and conventional foods and concluded that there’s “limited evidence for the superiority of organic foods”.

Let’s see what the study actually found. 

Fewer pesticides, more phenols, no more vitamins

The researchers, led by Dena Bravata and Crystal Smith-Spangler identified 237 of the most relevant organic vs. conventional studies. Those included 17 studies (six of which were randomized clinical trials) of humans consuming organic and conventional diets, and 223 studies that compared either the nutrient levels or the bacterial, fungal or pesticide contamination of various products including fruits, veggies, grains, meats, milk, poultry, and eggs grown organically and conventionally. There were no long-term studies of health outcomes of people consuming organic vs. conventionally produced food – these would be difficult and expensive to do, and have not yet been attempted.

There were two types of nutrients organic food had statistically higher levels of: total phenols in organic produce, and beneficial omega-3 fatty acids in organic milk.

As expected, organic food had fewer pesticide contaminants: conventional produce has a 30% higher risk for pesticide contamination than organic produce. Another study found kids switched to an organic diet for 5 days had significantly lower levels of pesticide residue in their urine.

As for vitamins, overall there wasn’t a significant difference in the vitamin content of organic and conventional plant or animal products.

There was no difference in the risk for contamination of produce or animal products with pathogenic bacteria (yes, organic produce does need to be washed!), but conventional chicken and pork had a higher risk for contamination with bacteria resistant to antibiotics than were organic alternatives.

Obsessed with vitamins 

So is the meta-analysis’ conclusion that organic has little health benefit correct? 

If eating healthy is about getting as much vitamins as possible I guess you can conclude just that. But if eating healthy is about maxing on vitamins your route to health can easily be a vitamin supplement with a fast food meal (an abundant source of protein!). 

Our obsession with vitamins has been fueled for years by nutritionists and marketers. But getting enough vitamins is hardly a central health issue in modern societies. Eating healthy isn’t about getting your vitamins.  Even devoted junk eaters gets plenty of vitamin C and don’t need a vitamin boosted organic strawberry to save them from scurvy. 

What is healthy eating? This is a complicated question. It’s hard enough to even define health; is health the absence of detectable disease, or a state of physical, mental, and social wellbeing? I can’t really answer this question (especially not in a blog post), but healthy food has to be more than the sum of all its vitamins.

Why organic

More and more people are choosing organic. One popular reason is avoidance of chemicals. Conventional food is grown using a multitude of chemical fertilizers, pesticides and herbicides. We now know that these remain in the food, and are absorbed by and present in our body. Although conventional growers and food producers make every effort to convince us that these chemicals are safe and harmless in these amounts, common sense says that they definitely add nothing good to our health, and we’re probably better off without them. This study shows that organic food does have fewer pesticide residues and fewer antibiotic-resistant bacteria -- organic delivers on its promise!

But organic farming is about so much more than our personal health and safety. Organic agriculture is an ecological production management system that has deep environmental implications. Organic production is about respecting the land and all its inhabitants. 

An organic farm doesn’t contribute to the growing problem of chemical fertilizers’ run-off contaminating our rivers, lakes, oceans and drinking water. This contamination is persistent, and affects us as well as wildlife.

An organic farm doesn’t contribute to our worrying dependence on dwindling oil supplies (fertilizers are fossil fuel products). Farm workers on organic farms aren’t subjected to a work environment heavily contaminated by pesticides. Soil fertility is maintained for future generations by organic practices. An organic farm recycles its waste, and doesn’t fill landfills with hazardous waste.

An organic farm promotes biodiversity. Organic practices lead to crops that are more resistant to drought and pests, and probably are more complex in phytochemical composition. (Phytochemicals are chemical compounds derived from plants and fruits; there is evidence from epidemiological studies that phytochemicals in fruits and vegetables can reduce the risk of disease. This is one of the findings this study demonstrated by the higher level of phenols in organic produce). 

And the list goes on and on.

Organic food delivers products with fewer chemicals, preservatives, additives, antibiotics and hormones, and the environmental reasons to go organic are compelling. I doubt informed buyers opt for organic strawberries for their superior vitamin C level anyway.

Dr. Ayala

Full disclosure: I’m vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician, an early adopter of organic practices and foods, and have been promoting good nutrition and healthy lifestyle for many years.

Non-caloric sweeteners on the rise: Should we be concerned?

Americans eat a lot of sugar – 15 percent of daily calories are from added sugar alone. Sugar’s high caloric price as well as its rising market cost are moving consumers and food makers to replace sugar with ever rising amounts of low-calorie sweeteners such as Equal, NutraSweet, Splenda, Sweet'N Low, Stevia and many others. Replacing sugar with no-calorie sugar substitutes potentially saves many calories, but also raises concerns about what happens when you dissociate sweetness from energy: how does non-caloric sweetness affect appetite, eating habits and weight?

And since the sugar-substitute experiment is long underway, it’s a good idea to stop and see how the trial is faring: are low caloric sweeteners helping in the obesity fight?

Food and nutrition experts met in the spring of 2011 in Washington DC to do just that in a workshop called: “Low-Calorie Sweeteners, Appetite and Weight Control: What the Science Tells Us”. The presentations of this workshop are summarized in a upcoming supplement of the Journal of Nutrition and make for some interesting reading.

Does sweetness promote overeating?

Tasting something sweet activates pleasure centers in the brain.  Do you know what else activates these neural reward pathways? Addictive drugs such as alcohol and opiates work on the same brain mechanisms. That of course doesn’t mean that drug addiction and our affection for sweet food are the same thing – but it does help explain how strong and well conserved our sweet preference is.  Loving sweet is innate and present even before birth. It probably served our species well, leading babies to crave mother’s milk and all other aged humans to seek ripe fruit.

A few interesting findings from the article about sweetness and food preference:

• Sweet taste makes pain go away: a Cochrane review showed that sweet tasting solutions reduced the reaction to pain in babies. Sweetness continues to act as an analgesic in childhood.

• We sense sweet taste through taste receptors in the mouth, but receptors are present also in our intestine and our pancreas. Stimulating these receptors leads to a cascade of physiologic reactions, including insulin and other hormone secretion, stomach emptying, appetite control and gut motility. These receptors can’t tell caloric sweeteners and non-caloric sweeteners apart -- they react to both, to a degree that isn’t completely understood. 

• Young kids prefer super sweet -- the sweeter the better. They’ll always gravitate to sweet rather than plain. Kids can also discriminate between sweet-tasting foods differing in energy content, preferring those that are more energy dense. 

• Preferring sweetness is natural, but also learned: babies and young kids exposed to sweet foods and drinks prefer sweet foods, and eat more of them. Through their experience with food kids ‘learn’ what should and shouldn’t taste sweet. Repeated exposure to sweet drinks leads to preference of sweet drinks. 

• The ready availability of sweet, highly rewarding foods, can promote overeating and weight gain. Adding sweetness (caloric or non-caloric) to foods that are not naturally sweet -- think cereal, water, yogurt or milk -- creates dietary habits of overconsumption. It’s just human nature.

The science of non-caloric sweeteners

Thanks for hanging in there up until now. I bet you’re curious to know the bottom line verdict of this workshop. Two years ago, the new Dietary Guidelines for Americans concluded that:

“The replacement of sugar-sweetened foods and beverages with sugar-free products should theoretically reduce body weight. Yet many questions remain, as epidemiologic studies show a positive link with use of nonnutritive sweeteners and BMI. Additionally, whether use of low calorie sweeteners is linked to higher intake of other calories in the diet remains a debated question.”

I’m afraid not much has changed.

The workshop concluded that the bulk of epidemiologic, observational studies, but not all of them, reported that use of low-caloric sweeteners is associated with obesity and weight gain. However, association doesn’t prove causality. Real evidence, the experts say, can only come from well-performed randomized controlled clinical trails, in which people will be assigned randomly to consume either non-caloric sweeteners for long periods of time, or serve as controls.

Until then, the large-scale non-randomized population experiment is ongoing, we’re all part of it, and I don’t think it’s going too well. I choose to be in the control group.

Dr. Ayala

Full disclosure: I’m vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years.

 

Fat burning miracles?

A few years ago billboards announced the arrival of “negative calorie” food.  Drinking three 12-oz. cans a day of Enviga, the Coca Cola and Nestle carbonated tea drink, will burn an extra 60-100 calories daily, claimed the products’ packaging.

The Center for Science in the Public Interest (CSPI) filed a lawsuit against Coke for Enviga’s false weight-loss claims. Coke and Nestlé agreed to add language to the labels and marketing materials stating that the product will not promote weight loss without diet and exercise and Enviga is slowly vanishing from shelves.  But supplements and foods claiming to slim you down have not – they are alive and thriving.

A new paper in Obesity Reviews looks at the dynamic market of nutritional supplements claimed to increase fat metabolism, and explores how much evidence – or lack of it – is behind some of these popular supplements.

What is a ‘fat burner’?

A fat burner is a substance that is claimed to increase energy expenditure, make you lose weight, or somehow promote fat breakdown.  Many fat-burning supplements combine several ingredients, claimed to work in concert.  Is there such a thing as a fat burner?  The article examines some of the most popular such miracles, and I’ll discuss just a few of those.

Fat burners on the market

Caffeine

The ultimate functional ingredient, caffeine appears naturally in coffee, tea and cocoa and is also added to many foods and drinks.  Anyone who drinks coffee knows that coffee does have active ingredients that increase alertness – that’s why I love my morning cup.  It makes loose dreamy words stick into lucid sentences.  But does it increase energy expenditure and promote weight loss? 

A few studies showed that high doses of caffeine increased metabolic rate, however, longer-term studies tracking dieters taking caffeine or placebo showed caffeine performing no better than the dummy pill.  Overall, the authors conclude:

“Caffeine on its own has not been shown to be effective in reducing body weight and if caffeine increases fat metabolism, the effects are generally small”

Carnitine

Carnitine, which occurs naturally in meat, and is produced by our own liver and kidneys, is claimed to improve fat metabolism and increase muscle mass. 

Most of the carnitine in our body is in our muscles, and our muscle takes up carnitine from our blood against a huge concentration gradient (sorry for the flashback to high school chemistry, but it’s needed in order to understand how little sense this makes).  Studies have shown that the enzyme that is responsible for transferring carnitine into the muscle is at maximum capacity, and therefore ingesting extra carnitine doesn’t raise muscle carnitine at all.

The only way in which muscle carnitine could be elevated was by increasing blood levels of both carnitine and insulin at the same time – by insulin intravenous drip or very large amounts of ingested sugar.  This impractical scenario is quite counterproductive from the weight-loss point of view.

Carnitine supplementation for weight-loss just doesn’t make sense!

Tea

Tea contains catechins, which are thought to stimulate fat metabolism.  Green tea, which is non-oxidized and non-fermented tea leaves, has especially high levels of catechins, the most interesting of which is EGCG (epigallocatechin 3-gallate).  The authors review the green-tea weight burning studies and find them inconclusive:

“Green tea has the potential to increase fat metabolism at rest, also during exercise, and may help to lose body fat and body weight.  As with caffeine, the effects appear to be relatively small…”

Chromium

Chromium is added to many “functional” foods and drinks (Vitamin Water, Fuze) and is sold as part of many supplements as a fat burner and muscle builder.  Chromium occurs naturally in broccoli, red wine, mushrooms, brewer’s yeast, wheat germ and other foods, and was reported to increase lean body mass during exercise. 

The excitement was dampened by further, better studies that found chromium had no effect – overall, the majority of studies find it useless – and the authors also caution that a few studies on cell cultures found chromium can cause chromosomal damage.

Want to burn calories?

The authors, A. E. Jeukendrup and R. Randell, conclude with an overall impression that most of the supplements marketed as fat burners have little or no science to support their claims, and that among the group, caffeine and green tea have some effect, but it is small, and more consistent in habitual caffeine users.  They write:

“The ever increasing list of fat-burning supplements is industry driven, and is likely to grow at a rate that is not and cannot be matched by similar increase in scientific underpinning” 

In other words, marketers are quick to announce miracle solutions based of the flimsiest of evidence collected on a few lab mice or a cell culture; if and when the science manages to amass enough research that more often than not doubts the substance’s merit, sellers are already quick to market with the next new fat-burning sensation.

How can we end this? Silly and optimistic as I am, I’m hoping for an end to health claims on foods and supplements.  Health claims were introduced in 1994, have been so miserably abused and have become so utterly misleading that it’s just time to say goodbye. 

The other more realistic way is that consumers will start rejecting the hype and express their skepticism with their wallets.

Let’s end with the age-old solution to fat burning.  We know it works.  It’s healthy and inexpensive, too.  It’s called exercise.

Dr. Ayala

 

Can super-sizing fruits help you shed weight?

I'll be taking a few weeks off to spend time with my family and travel and will be writing infrequenly during August. Meantime, I'll be reposting some of the most popular posts I’ve written over the past years so that new readers have a chance to catch up.  Happy summer!

I’m very skeptical of promises that sound too good to be true.

No field is as rife with these as the diet industry, where new dream diets are invented daily and claim to have found a magic trick allowing us to eat as much as we want yet lose weight.

But here’s one worth checking out: Can eating more fruit help you shed weight?

This diet is worth a second look because we have many other good reasons to increase our fruit consumption—fruit and vegetables are an important component of a healthy diet and have a protective effect against many chronic diseases, such as heart disease and diabetes.

There’s also a plausible explanation for why eating fruit may protect against weight gain: Fruits have a relatively low-energy density, they have a lot of water and dietary fiber, and add lots of bulk. Studies show that food intake may be regulated by the weight of the food, and how long it takes to consume, therefore filling your plate with fruits would lead to greater satiety and less consumption of other foods.

A recent paper in Obesity Reviews analyzes the published studies on the association of fruits and weight loss. The authors specifically sought studies which look at fruit only, and not fruit and vegetables as one category (there are many studies showing that fruit and vegetable intake has an inverse relationship with overweight and obesity).

Of the sixteen human studies that met the inclusion criteria, eleven showed that increased fruit intake facilitated a significant reduction in body weight, decreased the risk of overweight or obesity or was associated with less overweight. The remaining five studies found no significant association, and no studies showed increased weight related to increased fruit consumption.

The studies included in this review were of three different types: Intervention studies, in which a study group is randomly assigned to receive an intervention—in this case increased fruit—and compared to a control group which receives a placebo or no intervention, prospective observational studies, in which a cohort with known exposures (in this case fruit intake) is followed for a health outcome over time (in this case weight), and cross-sectional studies, in which a population is observed at a certain point in time, looking for possible connections between, in this case, fruit consumption and weight. Each kind of study has its strengths and weaknesses.

Results from all three types of studies pointed towards an association between high fruit intake and lower weight. The authors call for large behavioral, randomized, controlled intervention studies to further clarify this issue. 

Can supersizing the fruit serving increase fruit intake?

I think we’re all sold on the idea of including more fruit in our daily diet for a multitude of reasons, but many parents struggle with just how to do it—less than ten percent of kids consume their daily recommended number of fruit and veggie servings.

This brings me to another recent fruitful study, this one from the scientific journal Obesity. 

Many studies show that increasing the size of the serving of food—entrees, snacks or soda—leads to increased intake, and supersizing the portion leads to supersized eating and supersized people. The authors asked the interesting question: Will supersizing the fruit and vegetables portion lead to higher intake of those in kids?

Forty-three Philadelphia-area kids aged five and six years were included in the study. They were twice fed dinner consisting of pasta with tomato sauce, broccoli, carrots, unsweetened applesauce and milk, with the portions of broccoli, carrots and unsweetened applesauce doubled in one of the meals randomly, while the pasta and milk portions stayed the same.
The results are pretty interesting:

Doubling the portion of fruit and vegetables side dishes resulted in a significant increase of 43 percent in the intake of the fruit—applesauce—but not the vegetables.

Doubling the portion of fruit and vegetables side dishes resulted in a significant decrease in the intake of the pasta dish, with the extra fruit displacing the more energy-dense pasta.

Overweight kids showed a bigger response to over-sizing the fruit and vegetables portion than normal weight kids; they ate more of the fruit and vegetables offered. 

The study shows doubling the size of fruit and vegetables portions as a valid method for increasing fruit intake, but also maybe of controlling weight gain, as the fruit displaced a higher calorie food (pasta).

What about the vegetables?

A more careful look at how the vegetables were presented might offer an explanation: the broccoli and carrots were thawed from a frozen pack and served plain, with no seasoning or fat. I think even the most ardent vegetable lovers wouldn’t get too excited by those. Perhaps a more appealing preparation (broccoli sautéed with some olive oil, garlic, fresh ground pepper and salt anyone?) would have gotten a different result.

I think that if you’re plating a meal for yourself or for others increasing the size of the vegetable and fruit component is worth trying. It may very well be that the most obvious way to increase fruit and vegetables consumption is by making them show up in plenty! If they’re on the table, prepared in an appealing way, ready to eat and constantly available they’ll be what we eat when we’re hungry. That’s part of the way manufacturers of sugary drinks and junk foods make sure we consume more—they’re just everywhere and in plenty.

Food for thought!

Dr. Ayala

 

Study shows a daily can of soda has measurable harmful effects

There is very little doubt that drinking sugary drinks regularly is associated with obesity, type 2 diabetes, hypertension and heart disease. 

Since sugary drinks are the leading source of added sugar in the American diet, and it’s quite easy to take in lots of calories in beverages without much effect on satiety, a lot of the harm done by consuming sugary drinks can be explained by the weight gain associated with their consumption.

But there’s another school of thought, and growing supporting research, that believes that sugars -- and especially the fructose component of sweeteners -- are especially harmful to our health, and have direct adverse effects on fat metabolism and inflammation. 

Our metabolism on sugary drinks 

A previous study from the University of California at Davis showed that drinking 25 percent of daily calories in fructose for 10 weeks increased triglycerides and cholesterol and caused insulin resistance in people, while drinking the same amounts in glucose didn’t. And while both the fructose and the glucose groups gained weight during the study, the fructose group gained more belly fat.

Indeed, a concerning finding, but drinking 25 percent of calories in fructose is something very few of us do (although many teens do take in about 20 percent of their calories in added sugars, and do so daily for many years).

Now, a new study, led by Isabelle Aeberli, and published in the American Journal of Clinical Nutrition, looked at 29, young, healthy, non-overweight men, who drank more reasonable amounts of sugary drinks containing different levels of fructose, glucose or sucrose (which is a glucose/fructose mix). 

(Quick reminder: Our foods and drinks are usually sweetened with sucrose (table sugar) or high fructose corn syrup (HFCS); both types of sweeteners are a combination of the simple sugars glucose and fructose.) 

Each participant spent 3 weeks on each of the following 6 beverage regimens, with a 4-week washout between interventions: 

• Medium fructose: 40 g of fructose a day

• High fructose: 80 g of fructose a day

• Medium glucose: 40 g of glucose a day

• High glucose: 80 g of glucose a day

• High sucrose: 80 g of sucrose a day

• Control: No sugary drinks at all

Just to put the sugar content in perspective: The medium sugar interventions are equivalent to drinking 1 can (12 oz.) of coke/day; the high sugar interventions are equivalent to drinking 2 cans (24 oz.) of coke/day. 

The experiment lasted about 44 weeks; here are some of the main findings:

• Waist-to-hip ratio increased in the medium fructose, high fructose and high sucrose interventions (higher waist-to-hip ratios indicate abdominal obesity, which is associated with an increased risk of heart disease and type 2 diabetes)

• Fasting glucose levels increased in all five sugary drink interventions

• C-reactive protein, a marker of inflammation, increased in all 5 sugary drink interventions, with the highest values seen in the high fructose intervention.  Inflammation is a key factor in the development of both heart disease and type 2 diabetes

• There was a reduction in large, buoyant LDL particles when participants were consuming fructose drinks (high and medium fructose and high sucrose interventions).  A regular lipid profile measures only total LDL, which didn’t change between interventions; we now know that there are subclasses of LDL, and the smaller LDL molecules pose more risk and have a higher tendency to block arteries.  The large buoyant LDL is, as the name implies, flexible and bouncy, and causes less lumps and blocks.

• All sugary drink interventions lead to some increase in caloric intake

• Leptin (a hormone that regulates appetite and metabolism) increased in the medium and high glucose interventions, but not in the fructose and sucrose interventions

What can we learn from this study?

The first conclusion we can draw from this study is that fructose does seem to cause more damage than glucose – fructose leads to lipid abnormalities and more belly fat accumulation.  On the other hand all sugary drink regimens, including the moderate glucose exposure, had pretty unhealthy results: all 5 interventions increased markers of inflammation and increased caloric intake.

The practical, real-life understanding is that all sugary drinks, even in what many would consider “moderate” amounts, seem to have a measurable undesirable effect after as little as 3 weeks. 

As far as I know there are no popular drinks in the market sweetened by glucose; practically all forms of caloric sweeteners used in food processing are a glucose/fructose mixture.  Cane or beet sugar are sucrose (table sugar), which is a two-sugar molecule with exactly 50 percent glucose, 50 percent fructose. HFCS is about 45 percent glucose, 55 percent fructose. Fruit juice concentrate's sugar composition will depend on the fruit source: Apple juice concentrate is about 30 percent glucose, 70 percent fructose, while orange juice concentrate is about 50 percent glucose 50 percent fructose.  Agave syrup is about 70-75 percent fructose.

All sugary drinks contain fructose, and if this study’s findings are confirmed in larger and repeated studies, there’s reason for worry.

Dr. Ayala

Full disclosure: I’m vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years. 

Reposted as part of Food Renegate's Fight Back Fridays.