Healthy Food & Healthy Living by Dr. Ayala

Healthy eating lessons from the new glycemic index data

Carbs have been demonized.  Understandably, it’s much easier to target an entire major nutrient group than to understand the intricacies of how our body interacts with the multitude of foods out there, so some lump all carbs in the to-minimize category, whether they’re an apple or a sugary drink.

But when it comes to how our body works, the quality of a food is what matters. We’ve been there before with blanket warnings about fat, only to realize that you just can’t view them all as the same thing, and you can’t develop a sensible food philosophy that aims to replace one entire major nutrient group – of which we have just three. This is nutrition reductionism to the point of silliness.

To better understand carb quality people may look at the dietary fiber content of the food and to the “added sugar” in it. Another indicator is the Glycemic Index, which measures how a food raises blood sugar. The glycemic index used to be reserved to diabetes management but it's now part of several popular weight-loss programs (South Beach, Zone) and disease prevention plans. The low glycemic index health claim is also a selling point advertised on food labels.

What is the glycemic index

The glycemic index ranks carb-containing foods on how they affect blood glucose levels when eaten in isolation. The glycemic index charts were developed by testing people’s blood sugar after ingestion of 50 grams – almost 2 ounces – of carbs from the food tested.

Carbs that break down quickly, like white bread and potatoes, have a high glycemic index. Those that release sugar into the bloodstream more gradually, like fruit, have a low glycemic index. Foods are scored on a scale of 0 to 100, and a glycemic index of ≥70 is high, 56–69 is medium, ≤55 is low.

Is the glycemic index absolute?

As you can imagine, since there are so many foods in the world, since food varies in its nutritional composition depending on cultivar and growing conditions, since foods are not eaten in isolation, because different labs are doing the testing, and due to people’s unique physiology, glycemic indexes are not and exact science.

The glycemic index also measures the response to 50 grams of carbs. Eating 50 grams of carbs from white bagels is commonplace. But although watermelon has the high glycemic index of 80 you’d have to eat almost 2 pounds of watermelon to load yourself up with 2 ounces of carbs, and therefore watermelon’s high glycemic index is irrelevant for most. To guess blood sugar responses you’d also have to take into account the glycemic load, which tallies the amount of carbs consumed.

On top of that, although the type and proportion of sugar or starch in a food affects glycemic index, so do a lot of other factors in the meal—the way the food’s been cooked, the presence of fiber, protein, fat, alcohol or acid in the meal will all affect the glucose response. Exercising and activity around a meal will affect it, too. Your own glycemic response will change from day to day.

The new glycemic index charts

Since the glycemic index’s popularity and usage are rising, and previous data is incomplete and inconsistent, a refresh of the information is overdue.

A new study in The American Journal of Clinical Nutrition looked at the glycemic index studies published to see if the older tables could be improved upon from the 2008 table. The authors reviewed published and unpublished studies and tabulated the glycemic index of about 4000 foods, more than double that of the previous table.

To generalize the 4000 results with a very broad brush:

• Fruit, legumes, pasta and dairy products have low glycemic indexes that are pretty consistent across countries.
• Cereal and cereal products, however, show a very wide variation in glycemic index, depending on the grain processing (whole grain has a lower glycemic index) and the preparation.
• Potatoes, generally a high glycemic food, varied from 84, all the way to 49, depending on the origin and cooking method. Such was the case with rice: from 73 for white rice, to 65 for brown rice.

These detailed tables will no doubt serve researchers and clinicians, as well as the general public. The glycemic index can be useful as there are studies linking low-glycemic index diets to better management and prevention of diabetes, to weight loss, and the prevention of other illnesses.

But rather than relying on a 4000 item glycemic index chart, understanding its basic themes can help us develop a healthy lifestyle pattern – no tedious counting and reference checking needed.

What the glycemic index chart teaches us is that whole plant-based foods are better, fruits and vegetables are excellent, and that lack of processing really matters. Naturally occurring carbohydrate foods also supply fiber, which is very important for health– it lowers the glycemic index, helps with satiety and promotes a healthy microbiome. Bread and rice and even potatoes won’t necessarily spike blood sugar if they’re eaten in moderate amounts and combined with other healthy foods.

For the non-diabetic, it’s much easier to follow the well-proven guidelines of limiting added sugar (sugary drinks are especially harmful), eating more plants and whole grains, and minimizing hyper-processed foods.

These dietary principles yield a low glycemic diet as an added bonus.

Dr. Ayala

Why does losing sleep make you overeat?

We’ve all missed a good night’s sleep at one time or another, so we know first hand how important sleep is. Chronic lack of sleep is a bigger issue, it can make us moody and anxious, it reduces mental acuity, and it’s associated with increased likelihood of several diseases – such as viral infections, diabetes and heart disease.

Insufficient sleep is also associated with weight gain and overeating. 

A recent meta-analysis including 11 interventional studies – in which people with partial sleep deprivation were compared to controls who slept normally – found that shortened sleep is associated with eating an extra 385 calories.

Lack of sleep is now considered an established risk factor for childhood obesity, even though the data is mostly observational. An analysis of seven studies, including 14738 participants finds that from infancy into adolescence, sleeping less is linked with the development of obesity.

Sleep and weight gain are linked, but that doesn’t explain how one affects the other. What is it about sleeplessness that triggers weight gain? 

It may be that the lack of sleep activates hunger through a cascade of hormones. Lack of sleep may also just move people to eat in the absence of hunger – an emotional kind of eating that has more to do with comfort or mindlessness, not with real hunger urges.   

Not hungry, still eating

A new study in the American Journal of Clinical Nutrition including 105 kids aged 8-12 looks at what sleep deprivation does to eating in the absence of hunger, ie: eating for the sake of eating.

The kids, who all had normal sleep (8-11 hours a night), were assigned to 2 weeks of sleep restriction in which they went to bed one hour later, and the same kids were also tested with 2 weeks of sleep extension, in which they went to bed one hour earlier, the sleep settings done in random order. On the last day of each week the kids were given a buffet style meal, and told to eat until they were full. After a 15 minute break the kids were asked back into the dining room and given a free range of things like ice cream, chips, cookies and chocolate. Each kid’s consumption was measured in both the meal and the after meal by weighing what’s missing from the serving plates.

The authors found that the kids – who are basically compared to themselves – didn’t increase caloric intake when they lost an hour of sleep compared to when they gained one. What they did find is that after the first meal experiment the kids lowered their consumption during the first course, leaving more room for the dessert session for the remaining 3 weeks of their experiment. In other words, the kids learned that there’s sweet and salty stuff coming later, and adjusted accordingly.

When the researchers looked at all the kids together, after just the first week, before kids could learn that dessert was coming, they found that the mild sleep deprivation did increase the eating-while-not-hungry intake by a little, but the study sample wasn’t big enough to prove this point.

In this respect, this experimental model failed to prove that sleep deprivation leads to a greater tendency of eating while not hungry.

Eating while sleep deprived

This is, however, just the way science moves on. The observational data finds that sleep deprivation is clearly linked with overeating. Designing and implementing randomized controlled studies and manipulating sleep to further understand the mechanism and to establish causality is still needed, and obviously challenging. And we can never completely control for biases such as screen time and socioeconomic factors even though the statistical models take those into account. Questions remain.

But we can already say with some confidence that chronic sleeplessness is a common trigger for overeating.

It may simply be that being awake longer gives us more time to engage in our favorite activity.

And being tired may also make us more susceptible to the temptations of the kinds of foods that make us overeat: fast and energy dense ones – tired people aren’t likely to chop kale and dress it in lemon juice in the middle of the night.

Solving sleep isn’t easy, but being aware of the connection between sleep deprivation and overeating can make us a little more mindful of what we do when we don’t get enough sleep.

Dr. Ayala

Student health: Why cooking matters

Healthy eating is mostly about habits. It’s the recurring actions that are repeated mindlessly day in and day out, month after month, year after year, that matter the most. What you eat on vacation or at a wedding party isn’t going to change things that much, but overeating just a bit each day makes for significant weight gain over the years, and poor diets take a toll on health if sustained.

So habits really matter – establish a healthy routine and you’re on autopilot towards a healthy destination. There are critical times in life in which habits are formed, and for young adults the transition from home to independent living is such a period.

Unfortunately, for many college students who are at that exact juncture, fast food courts, alcoholic drinks, junky snacks and midnight deliveries are the default. The lure of convenience, low price, student food culture and maybe also no parental food oversight (at last!) make unhealthy eating real easy for college students. Lifestyle habits shaped over these formative years may last a lifetime and can be hard to root out.

College students are reportedly on the lowest end of fruit and vegetable consumption in a world in which most people don’t get their 5-a-day. A recent review of 71 scientific papers from around the world found that on average only 40 percent of students ate vegetables daily and that being female was the most reliable predictor of higher vegetable intake, as was living at parents’ home and higher socioeconomic level.

Gender and economic background aren’t changeable and need to be controlled for when understanding the barriers towards better nutrition at this important life phase. But there’s another really important parameter that influences what people eat: the ability to cook.

When it comes to whole plant-based foods and especially vegetables, knowing what to do with these leaves and roots, and having the equipment, time and wherewithal to do it is what it all hinges on.

A new study in the journal Appetite looked at the veggie consumption and cooking skills of university students in Brazil. Less than half the students ate vegetables regularly. Knowing how to cook was significantly associated with eating veggies daily. These results are in agreement with another recent study in more than 1000 freshmen in the US that found that confidence in the ability to cook from basic ingredients and to follow a recipe was associated with eating more fruits and vegetables. “Cooking more frequently, cooking with greater skills, and practicing meal planning behaviors are associated with greater fruit and vegetable intake and lower BMI in first-year college students. Interventions aimed at improving health in college students may be enhanced by incorporating cooking and meal planning components,” the authors conclude.

And it make sense: Although eating a baby carrot from a bag requires no skill at all, making kale delicious requires equipment, skill and other pantry staples, such as oil, vinegar and seasoning.

Life skills

Kids are never too young, nor too old, to start cooking. Learning how to cook is a valuable life skill that will enable kids to eat healthier — no matter what you make at home it will usually be healthier than what you buy — and it can also be a great tool in helping them eat their veggies. 

Whether this summer is the last one before your kid leaves the nest or not, it’s never too late to dig into veggie and fruit prep skills. And I do know that it’s not just kids that don’t cook: Many of them are second and third generation non-cooks, but again, it’s never too late.  

This is the summer to fall in love with salads: It really takes very little skill to make a delicious green salad from scratch, and a green salad is a basic recipe that can include any number and variety of grains, seeds, fruits and nuts – the things that we should be eating more of daily.

Practice salads.

Another basic technique that will add lots of veggies to the diet is stir frying. It’s fast, you only need a few tools, and you can include many vegetables and protein sources.

The third one isn’t a summer dish (at least not in my home) but it’s another basic technique that any budding vegetable cook needs in their arsenal: vegetable soup. A big pot of vegetable soup can sustain a hungry student for many days, supplying lots of vegetables, as well as whole grains and pulses.

Cooking isn’t hard, it isn’t necessarily time consuming, it’s fun, and it’s something everyone should be able to do.  You wouldn’t imagine releasing kids into the world not knowing basic money management, or what to do with dirty laundry.

It should be the same for food skills.

Dr. Ayala 

Can good food make you younger?

Diet quality affects health, and eating well is associated with lower incidence and later-in-life emergence of chronic diseases such as diabetes, heart disease and stroke, and with longer lifespans. There are several mechanisms – diet influences lipid profiles, sugar metabolism, inflammation and obesity rates for example, which are all culprits – that can account for the life extending traits of food. 

Could food also change how our genes are expressed?

Food doesn't change our coded DNA sequence – it isn’t gene therapy. But food and other lifestyle habits as well as our environment can modify how our genes are expressed and which areas of the genome get more active. This biomedical field is called epigenetics. Gene expression can be controlled through chemical changes such as methylation which is the addition of a methyl group to the DNA chain in an area that doesn’t code for the gene itself. There are millions of places where methylation can occur, and thousands of these sites correlate with aging. In this way the gene’s control switch is either repressed or activated. These changes can be stable over time and over many replications of the cell.

Methylation is the most studied of epigenetic mechanisms. Methylation status can predict lifespan; it’s like a biological clock that reflects biological age, as opposed to our chronological one. These methylation clocks predict mortality as well as disease better than knowing one’s birthdate. Previous studies looked at how certain foods change methylation patterns, suggesting that high intake of plant-based foods slows the clock, and high intake of poultry predicts an accelerated aging. Another small study of 120 65-79 year olds showed cellular slower aging when people ate a Mediterranean-style diet for a year.

A new study in the American Journal of Clinical Nutrition looks at the overall diet quality of a large group of almost 2000 people, to see if aging is affected on the molecular level.

Diet and aging

The diet of the participants was assessed by the DASH score, which evaluates the intake of dietary components: You get high scores for consuming more vegetables, fruit, nuts, legumes, whole grains and low-fat dairy, and for consuming less red and processed meat, sugary drinks, sweets and salt.

Blood tests were drawn for methylation profiling using 3 different verified epigenetic aging measures.

And the results:

During a 10-year follow up 297 participants died. The DASH score and the 3 epigenetic age acceleration measures were significantly associated with all-cause mortality. 

As you might have guessed, participants with high DASH scores tended to be women, thinner, not smoke, drink less alcohol, and use less medications for hypertension. But after adjusting for age, sex, smoking status, BMI, physical activity, alcohol consumption, and energy intake, eating lower quality diets was still clearly associated with a DNA methylation pattern that was “older” than the chronological age.

“Our study emphasizes that improving diet quality is important to delay the aging process,” the authors conclude.

Anti-aging the safe way

Some predict that tremendous technological and biomedical breakthroughs on the horizon are going to enable major gains in average human life expectancy. The anti-aging marketplace is already capitalizing on a bounty of (unproven) wrinkle defying creams, placentas, donkey milk, resveratrol and anti-aging pillows. But we actually already know that certain habits are associated with delayed aging. Chief among them are eating well, exercising, avoiding smoking and nurturing social ties.

What does eating well mean? There are very many ways to eat healthfully, and all of them center on emphasizing whole plant-based foods (vegetables, fruits, nuts, legumes, whole grains) and minimizing highly processed foods (fast-food, processed meats, sugary drinks). 

Dr. Ayala

Can fruits and veggies relieve anxiety?

If you mention that grey skies make you sad you won’t get much pushback – many believe that rainy days bring about miserable moods and know at least one person who’s predictably affected – yet there’s genuine skepticism about food’s effect on our mental wellbeing.

Nutritional psychiatry is still an emerging field.

There’s growing evidence, however, that certain foods bring about better moods, and that other foods can bring you down.

Several studies have shown that a healthy diet, rich in fruits and vegetables, may impact mental health and is associated with lower rates of depression. Besides numerous studies that show a link between eating fruits and veggies and psychological benefits, there are also studies that actually put it to the test: a study of 171 young adults who usually don’t eat their 5-a-day were assigned to either start doing so or continue as usual. After 14 days the participants on the fruit and vegetable boosted diet reported greater psychological wellbeing.

De-stress with salad?

A new study in the journal Clinical Nutrition examines the connection between eating fruits and vegetables, and perceived stress levels. The researchers looked at a large population of more than 8600 25-91 year olds from the Australian Diabetes, Obesity and Lifestyle cohort. Diet and perceived stress were assessed by validated questionnaires. The stress questions were things like: “you feel rested”,“you feel that too many demands are made on you”, and “you are irritable or grouchy” on a sliding scale. 

And the results: Those eating the most fruits and vegetables (more than 470 grams a day, about 16 ounces, which is close to the recommended minimum of 5 servings a day) felt less stressed than those who ate the lower end of fruits and veggies (less than 240 grams or 8 ounces a day). These findings held after adjusting for confounding factors such as exercise, smoking and caloric intake. 

An inverse relationship between plant-based foods and stress has been shown in other studies. A recent systematic review of studies in the journal Nutrients, which included 61 studies, and looked at fruit and vegetable intake and a whole array of psychological symptoms, from depression to general mental wellbeing, quality of sleep, stress, nervousness and happiness, concludes that eating 5-a-day “seems to have a positive influence on mental health, as stated in the vast majority of the included studies.”

The inflammatory connection

This association doesn’t prove causality. The connection is plausible, though, and could be explained by the fact that fruits and vegetables contain antioxidant phytochemicals that reduce inflammation and cellular oxidative stress.

The connection between inflammatory foods and mood disorders was examined in a recent meta-analysis in Public Health Nutrition, which included four studies and about 50,000 people, looking to see if the inflammatory profile of their diet is linked with developing depression.

The diet was scored using the Dietary Inflammatory Index, an index based on thousands of scientific articles, which enabled scoring most foods and nutrients.

The study found that a pro-inflammatory diet (a diet low on fruits and veggies, high on highly processed food, meat, refined grain, desserts and sugar) was associated with a higher incidence of depression, and that people eating diets with the highest inflammatory score had a 23 percent higher risk of becoming depressed.

As mentioned above, mental nutrition research is relatively new. The 5-a-day fruit and vegetable recommendation is already exhaustingly verified and established as a way to support health and wellbeing. The mental-health benefits, if they pan out, are just another added bonus.

Dr. Ayala

Why soda may increase the risk of early-age colon cancer

Chadwick Boseman's death from colon cancer at the shockingly young age of 43 was a wake up call. Colon cancer, like most cancers, is more common in older people, and early detection has been focused on the over-50 population. Rates of colon cancer have indeed been declining in the older population – the development of cancer in the gut can be prevented when polyps are removed during colonoscopy before they have a chance to turn into a cancerous tumor – but the rates have risen sharply in younger adults. For people born in the 1990s the risk of colon cancer is twice that of people born in the 1950s.

What explains the rise in cancer among Millennials and Gen Xers? 

The most likely explanation is lifestyle risk factors: Colon cancer risk factors include poor diet, obesity, smoking, alcohol consumption and lack of exercise. In other words, as fast food, obesity and unhealthy sedentary practices rise, so would the risk of colon cancer.

A new study in the journal Gut looks at the leading source of added sugar in the US diet – sugary drinks – and the risk of early-age colon cancer. The researchers analyzed data from almost 120,000 women who were part of the Nurses’ Health Study II between the years 1991-2015, with a 24 year follow up, looking at diet and health outcomes. 

Among this large group there were 109 cases of early-age (before the age of 50 years) colon cancer.

Women who drank more sugary drinks were more likely to be less physically active and have lower diet quality – eat less fruits, vegetables and fiber, and eat more processed meat. But even after adjusting for all the above colon-cancer risk factors, as well as for obesity, alcohol intake etc., higher sugary drink intake was associated with an increased risk of early colon cancer.

Women who drank more than 2 servings of sugary drinks had more than double the risk of developing early onset colon cancer, with a dose-response additional risk with each additional sugary drink. The increased risk was associated with sugary drinks, and not with fruit juices.

Added sugar and your gut

Americans’ consumption of sugary drinks rose dramatically in the second half of the 20th century, with kids drinking soda earlier in life and in greater quantities. 

We already know that sugary drinks are linked with obesity, as well as with several chronic diseases such as type 2 diabetes and heart disease.

This study shows a link between sugary drinks and early-age colon cancer in a large women cohort. What could explain that? We already know that sugary drinks promote weight gain by the sheer fact that they introduce plenty of calories, yet lead to very little satiety, and therefore can result in overeating and weight gain. They can also make blood sugar rise quickly, leading to a rise in insulin, which can long-term result in insulin-resistance, inflammation, type-2 diabetes and weight gain. All of these are known risk factors for colon cancer.

But beyond that, the authors write:

“By causing dysbiosis and endotoxaemia, fructose can impair gut barrier function and increase gut permeability, which could promote colorectal carcinogenesis. A recent experimental study demonstrated that HFCS-treated mice had substantial colon tumour growth with aggressive tumour grade, independent of obesity and metabolic syndrome,30 which lends additional support to the link between SSBs (sugar sweetened beverages) and CRC (colorectal cancer) risk.”

Allow me to explain. Fructose is part of most of the added sugars we consume, including table sugar and high fructose corn syrup. Fructose in sugary drinks overwhelms the small intestine’s absorption capacity and reaches the large intestine where it can cause imbalance in the microorganisms living within the gut (the microbiome), and lead to the production of bacterial toxic materials, resulting in further changes in the gut that promote the formation of cancer cells.

Colon cancer rates are rising among young people, but fortunately this disease is still relatively rare. 

The other afflictions associated with the soda habit are much more common, and much more evidence connects the sugary-drink habit with outcomes such as hypertension, type 2 diabetes and heart disease.

Dr. Ayala

Two proven ways to halt aging and disease

A milestone birthday, a forehead wrinkle and a temporary bout of morning stiffness lead many to seek all kinds of creams, supplements and regimens in search of lasting youth. Less hopeful individuals sigh and accept these as a sign of inevitable decline.

There’s no sound scientific support for those youth-in-a-bottle miracles.

There is, however, plenty of evidence that the decline and disease associated with age can be dramatically altered.

Several metabolic risk factors are known to lead to type 2 diabetes, heart disease and cognitive decline: abdominal obesity, high blood pressure, abnormal lipid profile, insulin resistance and high blood sugar. The clustering of three of these metabolic risk factors (abdominal obesity measured by waist circumference, elevated blood glucose at fasting, high blood pressure, unfavorable cholesterol and high triglycerides) is defined as the metabolic syndrome. And these risk factors, when present in people’s thirties, forties and fifties, can lead to deteriorating health later in life.

Age-associated diseases are lifestyle dependent

These risk factors, however, are highly amenable to lifestyle choices. Diet and exercise are super important. Many studies show that adhering to a healthy diet lowers the risk of the metabolic risk factors of disease mentioned above. Many studies prove that exercising regularly, and avoiding a sedentary lifestyle help prevent this myriad of metabolic risks. 

And now, a new study in the Journal of the American Heart Association looks at the effect of each modality, and, more importantly, at the protection they offer when combined.

The researchers followed almost 2400 people aged 18 and up from the Framingham Study, looking at their adherence to diet and exercise recommendations. Physical activity was assessed by wearing an accelerometer for eight representative days, to assess moderate and vigorous physical activity. Diet was assessed by questionnaires, and compared to the recommended Dietary Guidelines for Americans.

Among the participants, only 28 percent followed both diet and exercise, while almost half followed just one of them, diet or exercise.

When the participants achieved the desired minimum of 150 minutes of moderate to vigorous activity per week, the risk of metabolic syndrome was reduced by half. 

When the participants adhered to the dietary guidelines, the risk of metabolic syndrome was reduced by a third.

Metabolic syndrome risk was 65 percent lower in people who adhered to both fitness and diet recommendations!

And for all these lifestyle choices, there's a dose response link: the more people exercise and the better they eat, the better the outcome.

Bear in mind that this study doesn’t define adherence to a healthy lifestyle too ambitiously. Two and a half hours of moderate to vigorous activity per week and eating according to the American Dietary Guidelines – which are no more than a sensible dietary pattern that emphasizes nutritious choices, while allowing moderate amounts of pretty much everything else – isn’t a tall order.

While according to this study you don’t need to be a health fanatic to reduce your risk of disease, we know that sadly, very few American’s eat well and exercise, and metabolic health is pretty rare in the US. According to a recent study of 9000 Americans whose metabolic health was assessed by measuring five parameters (blood pressure, waist circumference, fasting blood glucose, triglycerides and cholesterol) only 1 in 8 people had optimal levels of all five.

Joyful prevention 

We’ve been focusing on lowering our disease risk at considerable sacrifice this year – preventing Covid-19 spread kept us to ourselves and six feet apart for more than a year.

Now that we’ve been practicing preventive measures to improve our health, here’s some good news: The measures needed for keeping our arteries and brain supple don’t involve the type of deprivation we engage in to prevent Covid-19 spread. They don’t involve isolation; quite the contrary! Most exercise activities can be social, and usually keep you social with the sort of people that will keep you young. And eating healthfully can be super delicious – look at the Mediterranean Diet with all its mouthwatering fresh delights, look at the colorful bounty of the markets.

Dr. Ayala

Is chocolate good for your heart?

When it comes to chocolate, I’m well aware that confirmation bias may be playing tricks on many of us – on me specifically. New evidence of chocolate’s benefits is searched for, interpreted favorably and given space in the busy brains of all of those who wish it to be true.

The evidence, if somewhat tenuous, is adding up though. Many of the better studies about the health benefits study cocoa, not chocolate as such.

But a new study in the American Journal of Clinical Nutrition is actually about chocolate. The study looked at the chocolate consumption of almost 190,000 US veterans – veterans all receive care in a national integrated healthcare system, so their medical data is comprehensive and uniform.

Chocolate consumption was associated with an 8-12 percent lower incidence of cardiovascular disease. The lower risk odds remained when adjusting for age, sex, hypertension or diabetes.

This study finds that consistent intake of chocolate is associated with lower risk of heart disease. Which chocolate works? This study didn’t differentiate between milk and dark, has no information about cocoa or flavonoid content, nor does it draw any conclusions on the amounts linked with benefits. 

This study’s results are similar to those of another in a European population of about 20,000, which found that higher chocolate intake is associated with a 12 percent lower incidence of heart disease.

A recent meta-analysis of 14 studies also found lower risk of cardiovascular illness among chocolate eaters, but the linear dose-response benefits maxed at about 100 grams a week (about 3 ounces), and higher levels didn’t confer further benefits. 

These are observational trials, but there are also randomized trials that substantiate the benefits of chocolate. A meta-analysis of 13 randomised controlled trials of cocoa products showed that they reduce blood pressure when compared to the control group.

Good news is always welcome 

Chocolate lovers devour proof of chocolate’s health benefits.

Chocolate and candy manufacturers like it even more. They like it so much they spend generously on research to find links between chocolate and health. An expose in Vox  describes how millions of dollars in corporate-sponsored research produced scientific, peer-reviewed papers about the benefits of cocoa. 

And indeed, cocoa has been found to lower the risk of heart disease, autoimmune disorders, cognitive decline and diabetes, and is even linked with lower body weight. 

But by the time these studies are presented in popular media in bite-size portions, cocoa turns into chocolate, and associations turn into wellness advice. 

Want an example? There are several studies that demonstrate cocoa’s ability to improve cognitive function. A study in Nature Neuroscience finds improved cognitive functioning in middle aged people, who drank a mixture rich in cocoa’s flavonols for three months. A study in the American Journal of Clinical Nutrition in 90 elderly people free of cognitive impairment tested the effect of  three cocoa drinks: with high, medium or low flavonol content. The intermediate and high flavonol drinks improved cognitive performance, as well as blood pressure and insulin resistance. Another similar study in 90 people with cognitive decline demonstrated that intermediate and high cocoa flavonol drinks improved verbal fluency and increased the speed of mental processing when compared to the volunteers tested with a low flavonol drink.

These are encouraging, interesting findings about cocoa, not about chocolate. The cacao bean is just one – and the most nutritious – of the ingredients in chocolate, and people usually don’t eat plain cocoa. Headlines such as  “Chocolate Protects Against Alzheimer’s” and “Chocolate Makes You Smarter” take these studies’ findings a little far.

When you need a treat

Chocolate contains varying amounts of nutritious plant-based food. It’s almost guaranteed that when you study a whole plant-based food you discover health benefits. Cocoa beans are seeds, and seeds are ordinarily sources of beneficial phytochemicals that protect the seed and enable its development into a full-grown plant. In the case of cocoa, much of the research centers on cocoa flavonols. Flavonols are abundant in many plant-based foods, including onions, kale, grapes tea and apples.

That's why we should eat lots of whole plant foods. 

As to treats – and I for one do need them – I like them sweet. 

If you enjoy chocolate rest assured that it’s a healthier choice than a donut or Starbursts, or Skittles. It definitely makes my own heart sing. If your goal is to aid heart health, however, there are clearer – sugar-free – ways to get the beneficial nutrients.

Dr. Ayala

The best foods for love

Every day’s a good day to celebrate love, and a holiday that prompts us to pay attention to our loved ones and to the magic they bring to our lives is very welcome indeed, every year and this one especially.

A favorite way to say I love you is through food, now why’s that?

Food is love

Love is as yet impossible to completely define. The physiologic manifestations of falling in love and the early days of infatuation have been characterized as a kind of obsessive madness; other types of love are hard to explain biochemically and emotionally. 

Food, like undefinable love, elicits complex emotions. Consuming food elicits pleasure, and sometimes longing, and unease. Offering food, gifting food and sharing it lead to closeness between people. “The people who give you their food give you their heart,” wrote Cezar Chaves.

Food is the language of affection. Food may feel like love because it releases similar neurotransmitters, such as dopamine and norepinephrine. 

Food also brings us back to our original love, our earliest feelings of contentment and safety – our parents giving us sustenance and relieving the discomfort of hunger with sweet milk and gradually varied foods while holding us close. 

No wonder food, comfort and love are so entangled.

Aphrodisiac offerings

Are there foods that elicit love and desire better than others? 

“Eat oysters love longer” goes the saying. Aphrodite, the goddess of love, is the root of the term aphrodisiac, and the search for substances that enhance desire, pleasure and performance is as old as human history. Many of the traditional aphrodisiacs are herbs and foods, among them are maca root, ginseng, nutmeg, saffron, and cacao.

Do they work? There is some supporting evidence for their use. A double blind placebo-controlled study in men found that maca (a root plant from the South American Andes, not to be confused with matcha green tea) enhances perceived desire. Saffron, the golden hued spice made of the stigma of crocus flowers, has demonstrated aphrodisiac properties in male rats. Results in a pilot study of 20 men were promising, but a later study in 346 men failed to show improved sexual desire. Red ginseng was found to increase arousal in a double blind placebo controlled study of 32 menopausal women, and other studies have shown benefits in men.

Chocolate, regarded as an aphrodisiac since ancient times, is reported to release phenylethylamine and serotonin, lifting mood and desire, and it's no doubt delicious. A study of 153 Italian women reports significantly higher sexual desire in chocolate eaters, but no differences were found in arousal or satisfaction, and the effect disappeared when adjusted for age.

The evidential support for these aphrodisiacs is indeed scant, and the FDA doesn’t recognize any of over-the-counter ingredients as safe or effective love potions. 

Salad as love gesture

Nothing’s as critical for setting the mood for love as plain overall good health. To that end, a healthy diet, physical fitness and getting enough rest are the most effective aphrodisiacs. 

So chopping a big bowl of salad and letting your loved one sleep in could work, and a basket of colorful fruit is an excellent love offering – it’s not just chocolate in a heart-shaped box that says I love you.

And any food that’s shared is romantic.

Valentine’s Day food gifts aside, cooking and presenting healthy foods communicates love every day of the year, warmth that we can sense in our bones. 

Dr. Ayala

What to eat to save your teeth

Beware of sticky candy and starchy foods that get trapped between your teeth, brush and floss. You must have heard this annoying advice endless times. 

It’s good advice, though. That much of the advice is targeted at sugar and carbs makes sense. Sugars have long been established as a major contributor to the formation of cavities. Bacteria in tooth plaque ferment sugars and produce acids that lead to tooth damage.

But to keep teeth healthy diet advice goes well beyond just sugar control.

Because beyond cavities, there’s a more serious dental disorder: periodontitis. Periodontitis is a chronic inflammatory disorder that slowly destroys the gums and the tissues that support the teeth. Untreated, it eventually leads to tooth loss. Severe periodontitis affects more than one in ten people worldwide, while mild disease may affect up to 90 percent. Gum disease starts with gingivitis: Plaque along and under the gum line can get gums infected, red, tender and prone to bleeding. Gingivitis, left untreated, can advance to periodontitis. The inner layer of the gum and bone pull away from the teeth to form pockets, which collect debris and become infected and activate an immune response, which together with the bacterial excretions, breaks down the supporting structures of the teeth, leading to their loss.

Periodontitis is a major public health issue, and preventing its development can help avoid a lot of suffering and expense. Gum disease is influenced by many factors beyond dental hygiene, including genetics, smoking, and alcohol consumption. An association between a balanced diet and periodontal health has been observed for centuries.

Sailors leaving the ports of Europe felt just fine, but after a few months at sea their gums were bleeding and inflamed, so painful that they couldn't eat. They became extremely fatigued, their limbs swelled up and bruised easily, and soon after, their teeth fell off like the leaves of autumn. The discovery that fresh citrus prevented this deadly syndrome led to the recommendation that sailors on the Royal Navy drink lemon or lime juice on long journeys at sea. Many other fresh fruits and vegetables prevented this clinical syndrome, called scurvy; later on the etiology of the syndrome was revealed: vitamin C deficiency. Vitamin C is critical for gum health, but isn’t the only one: vitamin D and B-12 deficiencies also increase the risk of periodontitis.

Fortunately, vitamin deficiencies – and vitamin C deficiency especially – are now uncommon in the developed world. Despite that, rates of periodontal disease and its severity continue to rise.

We know that other chronic inflammatory conditions – such as cardiovascular disease, type 2 diabetes and cancer – are influenced by diet. Is periodontal disease linked with dietary patterns in the same way? We also know that periodontitis is correlated with the chronic inflammatory conditions listed above, among others. Is diet-related inflammation a common mechanism for all of these diseases?

Ideal dental diet isn't just about candy and soda

A new study in the American Journal of Clinical Nutrition looked at the connection between whole diet – not just specific nutrients such as sugar and vitamins – and periodontitis.

The researchers looked at a large cohort of 10,000 people and investigated the association between their overall diet and periodontitis, which was evaluated with a full-mouth periodontal exam. They didn’t look at any one single nutrient, but rather at foods and general dietary themes. The dietary pattern associated with healthy gums was a varied diet, rich in fruits, vegetables, salad, plain water and tea. People who adhered to this pattern most had less than half the periodontitis occurrence than those who followed this pattern the least. 

Could it be that people with periodontitis avoid fruits, vegetables and green salad in response to their weakened chewing ability? The authors think it’s highly unlikely, since periodontitis is symptomless until very late in the process – when teeth are falling off – and adjusting the study population to exclude people with advanced tooth loss did not change its findings.

Why would these foods matter? 

“One hypothesis is that high intake of carbohydrates, especially sucrose and fructose in added sugars, may influence periodontal health through chronic systemic inflammation,” the authors suggest.

So refined sugar may not just act locally inside your mouth, but systemically, raising inflammation and thus increasing the risk of periodontitis in the same way that it raises the risk of heart disease and stroke.

That periodontitis tracks with heart disease is pretty well established. It very well may be that the same risk factors that increase the risk of heart disease increase the risk of severe gum disease.

Studies like this should of course be followed by prospective, careful trials to further investigate the diet-periodontitis link. 

But since this dental diet is in concordance with what’s recommended to eat anyway, why wait? We already have too many reasons to limit added sugar and eat more salad.

Dr. Ayala

 

Further evidence that eating right lowers blood pressure

Most nutrition studies rely on people reporting about what they eat. The reliability of such reports is limited by people’s memory and dependability – even with the best intentions people often delude even themselves regarding their diet and weight. Nevertheless, when large sets of data, from many different studies, continue to point in the same direction, the connection between diet components and outcomes becomes more and more robust despite these limitations.

But proving a dietary connection through objective measurements offers extra support.

One of the most important risk factors all over the world is high blood pressure. Hypertension is a risk factor for heart disease, stroke and dementia. Hypertension worries are getting some extra attention these days – people with high blood pressure may be at greater risk of severe Covid-19. Abnormally high blood pressure is responsive to several lifestyle changes, chief among them are changes in the food we eat.

Certain plant foods contain bioactive molecules that are associated with lower blood pressure. Flavonoids are a large family of plant beneficial compounds, and they occur naturally in fruits, veggies, herbs, spices and plant-based drinks such as wine and tea. Flavan-3-ols are a major class within the flavonoid family, and are found in tea, berries, nuts and cocoa.

How to keep your blood pressure in check

A new study in Scientific Reports looked at a new nutrition marker that reflects plant food intake –  the flavan-3-ol and (–)-epicatechin biomarker – in more than 25,000 people, and its correlation with blood pressure. The researchers found that high flavan-3-ol intake was associated with a significantly lower blood pressure, both systolic and diastolic. People with higher the flavan-3-ol levels also had lower blood lipids.

Many studies already show a correlation between plant-centered diets and lower blood pressure. A review in JAMA Internal Medicine, analyzing 39 studies finds that vegetarian diets – emphasizing plant-foods such as veggies, fruit, grains and legumes – are associated with lower blood pressure. A Mediterranean diet is associated with improved blood pressure. The DASH (Dietary Approaches to Stop Hypertension) diet – which emphasizes vegetables, fruit, and low-fat dairy, while limiting salt – has been successful in delivering on the promise of its name: It's proven to reduce blood pressure in randomized controlled trials.

So the findings of this study are not surprising. The news here is the confirmation of the outcome (lower blood pressure) by verifiable measurements of a plant biomarker.  

And this is a fine reminder that to maintain healthy blood pressure what you do eat (plant foods) is as important as what you limit in your diet (alcohol, salt, highly processed food), and that a simple regimen of tea, apples, berries and cocoa can have measurable benefits.

Food, however, is only one modifiable variable that affects your blood pressure. Exercise, and maintaining a healthy weight are also important. 

As is controlling stress.

In this election season, topped by a global pandemic, it’s ever more important to Keep Calm and Eat Your Plants.

Dr. Ayala

Who should remind kids to eat their fruit?

Most kids don’t eat enough fruits and vegetables. On the other hand, they’re all too happy to eat junk food, candy and sweetened drinks. The allure of sweet foods is understandable. We humans have an innate preference for sweet flavor and high-calorie foods – a fondness that served us well a long long time ago when food was scarce and we had to hunt and gather it. It’s biological.

But it’s not just the inborn preference that’s leading kids to the cookie jar. Kids also see lots of unhealthy food in media content directed at them, and marketers present these unhealthy foods in a way that’s cleverly persuasive. Food products are placed in entertainment directed to kids, in ads online, on billboards, in games and practically everywhere their eyes go.

So on one hand, parents might be modeling healthy eating behavior and placing fresh produce on the counter, yet on the other, kids see celebrities, athletes and cartoon heroes drinking soda and eating candy bars. Do parents and the people who care about kids’ health even have a chance against cute animals pushing the opposite message?

Whose behavior do kids most emulate?

Kids imitate behaviors encountered in real life, as well at what they see on screens and in fictitious characters. 

A new study in the journal Appetite tests three social endorsers making an argument for fruit. Based on previous studies, endorsers are categorized as either experts (such as a dietician or medical doctor), celebrities (famous or admired people) or peers (a child-like character).

The study recruited 340 6-11 year olds through schools. Kids were shown a cartoon promoting grapes and mandarins, in which the presenter was either an expert (physician), a celebrity (actress or football player) or a child. The arguments for eating fruit were the same in all conditions, and were things like: “it is important to eat a lot of fruits because they help you stay fit,” and “to stay healthy, it is important to eat a lot of healthy foods, such as grapes.” A control group saw no videos.

After viewing the cartoon (or no cartoon in the control group), the kids could select just one of four types of snacks: grapes, mandarins (both appearing in the video), fruit gummies and fruit chews. These snacks were chosen because they are similar in size, shape and color to the fruit.

And the results: The kids in the expert condition – those who saw a doctor making an argument for eating fruit – selected fruit over candy significantly more than in the celebrity, peer and control groups.

The authors conclude that the effectiveness of a health-related message depends on the source who’s presenting the information, and experts perform better than other social endorsers. 

Ads sell. That’s why companies spend so much money on them, and most of the marketing efforts targeted at our kids promote junk foods and sugary drinks.

But persuasion and reasoning work, too. Kids do care about their health, weight and fitness. And this is where input from experts, as well as the parties interested in kids' health – parents, family and friends – come in. Kids are in front of screens like never before, due to Covid-19, so inserting reasoned nutrition public service announcements can help. 

And what works best, in my experience, as well as according to the scientific literature, is setting an example. Eat your fruits and vegetables, show genuine excitement for these truly delicious foods, and kids will – eventually – follow.

Dr. Ayala

 

A wholesome diet adds healthy years and years of health

Would you like to live longer?

I wouldn’t be surprised if you’re not entirely sure. Modern medicine has enabled prolonging the lives of people with debilitating chronic conditions, and if you witnessed the protracted suffering, diminished existence and slow decline of a loved one you might be less excited about extending your own time on earth.

But additional good years – extra time in which you’re disease-free and functioning fully, physically and mentally – are the best gift ever. We can all agree that extending disease-free life expectancy would be fantastic.

At what price, though? Upfront steep payment – as in near-starvation diets, which actually aren’t even proven to lengthen human life – resulting in lower quality years for a chance of tacking on bonus time at the other end of life is a precarious bet I’m not willing to even entertain.

There are reasonable measures, however, that are proven to slow the clock on disease and aging. Not smoking, exercising, keeping a normal weight and eating healthy food are all associated with disease-free extra years, and can be achieved while having a good time.

Healthy diet, extra years

A new study in the American Journal of Clinical Nutrition looks at disease-free years after the age of 50 in 8000 people. The study finds that people who adhered to the dietary guidelines the most had 23.9 healthy years and were disease free until almost 74 years. Those who observed the food guidelines the least lost 2.5 healthy years, and started experiencing heart disease, stroke and diabetes at about age 71.4 years. These findings were independent of smoking, obesity and exercise, and the findings were similar across all socioeconomic groups.

Diet quality was scored according to the Alternative Healthy Eating Index, which looks at 11 dietary components, and defines a high quality diet as one that has high intakes of things like vegetables, fruit, whole grains, nuts, legumes, and a low intake of sugary drinks, trans-fats and processed meats.

Similarly, a recent study in BMJ following 73,000 female nurses and 38,000 male health professionals for 34 and 28 years respectively, found that a healthier diet adds about 4 healthy years to men and women.

Four extra good years – years free of heart disease, diabetes and cancer – just for eating better.

The BMJ study looked at four other lifestyle parameters: smoking, weight status, exercise and alcohol consumption. Adhering to the recommendations on each one of these independently was associated with adding healthy years.

Combining the low-risk choices added 10 healthy years to the women and 7.6 years to men. Women in the study, who at age 50 adhered to four or five of low risk behaviors (didn’t smoke, ate healthy, exercised at least 30 minutes a day, drank alcohol no more than moderately and had a healthy weight) were likely to be free of the major chronic diseases until the age of 84.4, men until the age of 81.1 years.

The combination of beneficial lifestyle choices multiplies the health benefits, and there are dozens of studies supporting that.

Modern medicine can cure, treat, alleviate suffering and extend your life once you become sick, its medications and procedures are powerful and fast acting – this biological potency is also the very reason why side effects are not unusual.

But delaying the time in which you’ll need the gifts of modern medicine is in your control ­– healthy aging is in your hands and in your plate.

Healthy diets don’t just add years – they add healthy ones.

Dr. Ayala

Flavor comes first

“Imagine if a startup came up with a new invention, a perfect bite of finger food that explodes in your mouth when you chew on it, releasing juicy, sweet, acidic flavors, with afternotes of sun and the mysteries of wine lingering in your mouth after you swallow,” my oldest son said while popping a grape into his mouth.

Because that’s what a grape is; it’s one of the most perfectly delicious products on earth.

Not to insult the apple, or the avocado, or the carrot. They are all marvels of flavor, with endless culinary potential.

So why aren’t people excited?

Could it be because we’ve pushed fruits and veggies as good-for-you chores? Are we marketing vegetables all wrong?

We eat with our mind, not just with our taste buds. Our perception and state of mind, the surroundings, the presentation, and what other people think all affect what food will actually taste like to us. There’s a whole body of evidence to show this, but I’m sure you already know it from personal experience.

What would happen if we emphasized the tastiness of healthy food? Would people find them more enticing?

What’s in a name

In a new study in Psychological Science researchers from Stanford University examine how a focus on pleasure and taste, rather than on health attributes, affects students’ choices.

The researchers displayed taste-focused labels – the intervention – against health-focused names and basic labels. The flavor focused titles included “Herb n’ Honey Balsamic Glazed Turnips”, “Sizzlin’ Szechuan Green Beans with Toasted Garlic”, “Twisted Citrus Glazed Carrots”, and “Ultimate Chargrilled Asparagus” – the kind of names used in restaurant menus. The names were designed to communicate flavor, preparation method and a positive experience. Health focused titles included “Healthy Choice Turnips” and “Nutritious Green Beans.” Basic, neutral labels were non-descriptive, i.e., “Turnips” or “Green Beans.”

The randomized controlled study took place over 185 days, across 5 university dining halls, included about 140,000 diner decisions, 71 vegetable dishes and 24 types of veggies.

Taste focused labels increased veggie selection by about 30 percent, compared with the health-focused label, and by 14 percent compared with the basic label. Take note: the health-focused label performed worse than the basic label!

Taste focused labels increased vegetable consumption by about 40 percent.

The catch: a tasty sounding name has to also deliver on the promise of deliciousness. Taste focused labels worked when the cafeteria also prepared the dish well; since the experiment was conducted in several dining halls the culinary level wasn’t uniform, and in the school in which the veggie failed to deliver on expectations a mouthwatering name made little difference. Adding more words and listing ingredients works to create an expectation, but expectations do need to be met.

Get excited about veggies

You don’t need a marketing consultant to get your family excited about veggies, but you can get some inspiration from restaurants.

Famed chef and philanthropist José Andrés – who can’t be suspected of veganism –writes in his new cookbook, Vegetables Unleashed:

“We need to find ways to get people excited about things that sprout from the earth. We need to show the world just how sexy plants can be.”

Excitement comes from using good produce, from interesting and varied preparation, nice presentation, a sprig of herbs and a few crunchy nuts used as a garnish.

How about a mouthwatering name? Giving dishes at home chef-y names may sound fake and unnatural, up to you, but do please consider skipping the good-for-you saves-your-eyesight advocacy. Most kids find it boring and aren’t the least bit interested in aging gracefully.

I’m with Andres: get kids’ tastebuds excited about veggies.

Dr. Ayala

How to get babies to love their veggies

Parents know how important vegetables are to their kids’ health, yet only 1 in 10 kids eat enough of them, leading to another worrying statistic: Only 1 in 10 US adults eat enough fruits and veggies to support good heath. How do you create good vegetable-eating habits? How do you get kids to like vegetables and eat them out of choice, without a struggle?

All habits are easier to form earlier in life, but that’s even more pertinent when it comes to food preferences. Generally, a baby’s first 20 months are the time he or she is most open to new flavors and textures – bear in mind that babies are fed nothing but milk until age 4-6 months. Acceptance of new foods diminishes after that, food neophobia peaks at age 5 years, after which interest in new food usually recovers.

So how do you take advantage of this window to get kids into broccoli, tomatoes and spinach?

A new review, published in the journal Appetite, collected all 46 relevant scientific studies on promoting intake of vegetables in kids under 3 years of age. Among these there were 25 interventional studies and 21 observational ones.

Strategies that work

Repeated exposure

There were 27 studies exposing babies to the same vegetable repeatedly, for 8-10 repeats. All 21 experimental studies find that recurrent exposure increases intake, usually by at least about an ounce a day, and that the younger the baby, the greater the increase in veggie consumption. The 6 observational studies confirm the same trends. Some of these studies had up to 6-month follow up, demonstrating that repeated exposure let to a stable increase in veggie consumption.

How many exposures are needed to change a baby’s initial aversion? Some studies showed an effect already at the third exposure, and by the eighth exposure about 70 percent of babies liked a veggie they previously disliked.

Variety

Exposure to a variety of veggies seems to increase veggie intake in young kids in the 15 studies examining this strategy. When variety is piled on to repeated exposure the advantages are magnified.

Start early

Mom’s diet during pregnancy and after birth if she’s breastfeeding may expose her baby to the flavor of veggies very early, well before they eat their first mashed carrot. All the observational studies reviewed in this paper support a relationship between breastfeeding and veggie acceptance.

As to the age in which babies were fed their first veggies, this seems to have just a small effect on veggie affection, hardly detectable when the kids are 4 years old, so no rush  feeding eggplants to a 4-month-old.

Visual exposure 

Does showing a picture of a veggie in a book increase a baby’s affinity to the veggie? Four studies investigated this question and suggest that exposing babies to unfamiliar veggies through books, play and touch moves them to try that veggie.

Setting an example

Parents who eat vegetables in the presence of their kids tend to have kids that eat vegetables. Three observational studies in this review confirm that setting a good example of eating and enjoying vegetables is associated with higher frequency and intake in their young kids.

Things that don’t seem to work

Acclimatizing to a veggie’s taste

Parents may combine a veggie that their kid doesn’t readily want with a flavor they like, for instance, sugar can be added to green beans, masking its flavor. Although young kids initially prefer a sweetened veggie puree or a high calorie veggie soup the effect doesn’t last.

Bottom line

Repeated exposure to a variety of veggies and fruit is the most effective way to get babies and young kids to eat them. This method is the most proven scientifically, and makes intuitive sense – we’re all subject to the persuasive power of repetition, that’s why we’re served the same messages and ads again and again.

Don’t give up!

Serve veggies in a positive, calm, no pressure way – another clear takeaway from other research is that pressuring kids to eat is counterproductive and it certainly isn’t fun for anyone involved. It also follows common sense that better-tasting, nicely prepared veggies will be better liked.

Dr. Ayala