Healthy Food & Healthy Living by Dr. Ayala

Do scented candles improve the atmosphere?

The past two years turned us into mini experts on aerosols and indoor air quality as we educated ourselves about viral transmission and Covid spread. Which makes this a perfect time to consider other particles that we breathe indoors, especially the ones we have more control of. 

I'll open this discussion with an admission: Scented candles are a pet peeve of mine. Most people love them, I know. They're a favorite gift, they’re often beautiful, and it’s a personal annoyance that I know isn’t shared by many. The scented candle industry is big and growing and worth billions. Scented candles are marketed as mood enhancers, destressors and also as (aroma)therapeutic. 

But in my personal opinion scent preference is highly personal – simply a matter of taste. A scent that’s pleasing to you may be nauseating to someone else. If you’re baking cookies or sautéing garlic your home will naturally carry these ingredients’ scent for a while as a side effect. But lighting a chocolate cinnamon candle is a deliberate scent-adding decision, and while you may like that scent others may not.

And here’s the thing with smelling stuff: Unlike our vision and hearing, in which only waves stimulate our receptors and nothing material enters our body, with smell you’re actually internalizing molecules. If you’re smelling something, these are actual particles that enter your nose, and it’s not just aroma that’s delivered. Burning stuff around the house produces combustion gasses that may affect the quality of the air – and modern homes are better insulated so what’s indoors lingers.

So let’s examine what’s carried in the air with these scents.

What’s burning?

Candles are made of fuels for burning, such as wax, a wick, and to that are added fragrances and sometimes colors.

The fragrance is what we seek, but a lit candle releases not just fragrance but also solvents (the oils in which the aroma is dissolved) and these solvents’ emissions – which are many times odorless – may be air pollutants. Even a completely natural and safe-to-eat material changes when it’s burned, it transforms into something else.

A recent study in Environment International examines 24 types of candles with different fuels and fragrances that represent the candles currently in the market. The candles were tested in a ventilated and well mixed 8 meter (26 feet) square emissions test chamber. The 4 types of candle fuels tested were palm, paraffin wax, soy and stearin, each of these with five different scents, including floral, fresh, fruit, oriental and spice, and edibles, or in an unscented version. Candles with scent had a 5 percent fragrance load, which is the industry average.

And the results: There were multiple combustion products emitted, and while most of these molecules’ concentrations were below the levels considered concerning, several scented candles produced nitrogen dioxide (NO2), acrolein and benzopyrenes above the levels considered safe by groups such as the World Health Organization and the US Environmental Protection Agency. Unscented candles emitted lower emissions of combustion byproducts than candles with fragrance. As to the fuels of which the candle burns: There was no fuel that showed a better emissions profile.

A study in the Journal of Hazardous Materials testing 12 samples from 6 candle types (5 scented, 1 unscented as control) in the unlit and lit condition found that toxic compounds like formaldehyde were emitted in large quantities from some scented candles, especially when lit. The researchers measured a number if emitted pollutants known to have deleterious effects on human health, and compared these to the recommended upper limit set by OSHA (Occupational Safety and Health Administration) and ACGIH (American Conference of Governmental Industrial Hygienists), and for most compounds the level was below that upper limit, but for formaldehyde the level in three of the samples exceeded it considerably. The authors conclude: “The use of scented candles was found to have serious consequences as a significant source of certain pollutants, especially some light hydrocarbon species. The 76 of the most commonly released compounds from scented candles appear to vary greatly in their emission profiles by a simple criterion – whether the candle is lit or not.”

Another study of unlit vs, lit candles finds that an unlit candle emits weak odor, which increases as much as ten fold when lit, and the lit candles also release volatile organic compounds, especially benzene, benzaldehyde, and benzophenone. The authors note that measuring the exact quantity of the compounds is fraught with artifacts, and that the benzene emissions were low.

A study published in 2014, which was financed by the Research Institute for Fragrance Materials Inc. tested 9 scented candles in small and large chambers, to resemble a bathroom or a living room, respectively. There were measurable non-fragrance combustion chemicals such as benzene and formaldehyde in the chambers after burning the scented candles, but those were below the concentration limits set by the World Health Organization. The formaldehyde and benzene formed as a result of combustion are considered a carcinogen – so it’s perhaps small comfort that the levels measured in these experiments were low and considered safe by research financed by an affiliated industry. 

Does the benefit outweigh the risk?

The issue of diffused scent is not limited to candles. Scents and air fresheners are all around us, and are part of the identity of many retail environments. That lovely aroma that you associate with a hotel chain, a fashion brand and an ice cream parlor are actively diffused into the air, to make your stay pleasant and to make you stay longer. To compensate for our Covid masks blocking the aroma some retailers nowadays pump more scent into the air. Scent, its designers argue, plays a significant role in marketing just about anything.

We can’t really control the scents or air quality outside our home. At home, however, products designed to fragrance the air have no essential role. We’re intentionally releasing into our home a mostly unknown chemical mix, especially when we burn these aroma sources.

There’s risk in that, and it’s real, even if it’s small. 

The benefits of a burning scented candled are highly subjective. Do they outweigh that risk for you and others sharing your space? That would really depend on how much you enjoy scented candles. When it comes to inhaling toxic chemicals, less, I think, is always better, even if the amounts are rather small.

Dr. Ayala

No meat, low meat, and what really matters for health

The calls to cut back on meat are coming from many directions. The meat industry is a major contributor to greenhouse gasses, climate change, and environmental degradation. Billions of animals suffer and die to satisfy our eating choices.

These altruistic reasons to cut down on meat come on top of the self-serving rationale to do so: Eating less meat is good for you.

Studying the outcomes of a lifetime of dietary habits is difficult – the range of what and how much a person eats is extensive and diets change over time – but decades of research show that the risk of cardiovascular disease is overall lower among vegetarians and vegans. Vegetarians and vegans tend to be thinner, have lower total LDL cholesterol, and lower blood pressures. 

A link between meat and cancer is also well studied. The American Cancer Society recommends limiting or avoiding red and processed meats in order to lower the risk of cancers. The World Cancer Research Fund states that if you eat red meat, shoot for no more than 3 portions (12-18 oz cooked weight) a week, and consume very little if any processed meat.

Low meat, fish, and vegetarian diets and cancer risk 

As noted from the above recommendations, it’s not just vegetarians that can lower their disease hazard, as the risk from meat is cumulative and dose dependent.

A new study in BMC Medicine analyzed the nutrition data from almost half a million British adults, aged 40-70 years, and looked at the incidence of cancer over 11 years, also controlling for diabetes, socioeconomic factors, smoking and obesity.

About half (52 percent) of the cohort ate meat more than 5 times a week, 44 percent ate meat less than 5 times a week, 2 percent ate only fish but no meat, and 2 percent were vegetarian or vegan.

The study finds that those who ate meat less than 5 times a week had a 2 percent reduction in cancer incidence, fish eaters had a 10 percent reduction, and vegetarians and vegans had a 14 percent reduced risk. Low meat, fish and vegetarian eaters had lower risks of all-cause cancer, and especially colorectal, prostate and breast cancer.

But although the study controlled for confounders such as weight status and exercise, the authors note that: “Vegetarians and fish-eaters differ from meat-eaters in many non-dietary lifestyle factors such as lower smoking and alcohol consumption, and higher physical activity. Although relevant potential confounders were added to the multivariable models to adjust for these differences, imperfect measurements and/or changes in these confounders over time may result in incomplete adjustment for these variables.”

Not all meat-free diets are created equal

Not all foods of plant origin are healthy though: French fries, chips and soda are utterly vegan, and obviously don't promote health.

Meat avoidance, in and of itself, doesn’t tell us enough about what people actually eat, therefore studies that look at the content of plant-based diets are informative.

The longest living group of Americans are probably The Seventh Day Adventists, whose health habits—promoted by their religion—include vegetarianism, as well as avoiding alcohol and smoking. Adventists as a group aspire to these rules, and are generally health conscious, but individual adherence is variable, and not all adventists avoid meat. Studying and subgrouping this diverse cohort is revealing.

A new study in the American Journal of Clinical Nutrition following about 77,000 members of the Adventist church for about 7.5 years looked at their rates of death from any cause, and correlated it with how much ultra-processed foods and meat they ate. 

And the results: Eating more ultra processed foods was associated with a 14 percent higher incidence of death. Eating more red meat was also linked with an 8 percent increase in all cause mortality.

The quality of any diet is determined by what you eat more of, and also what you eat less of. 

Instead of categorizing a food just as plant-based you should also question its nutritional quality.

A recent study in the American Journal of Clinical Nutrition including almost 130,000 people, followed for 20 years, sought to see if  plant-based diets affect weight gain, which is an important risk factor for many chronic diseases.

The study uses three indexes of plant-based diets. The first is an overall plant-based index, in which plant-based foods receive a positive score, and animal foods receive a negative one. The other two are subcategories of the first one and rate the healthfulness of of the plant based components of the diet, adding points for healthful plant based foods (whole grains, fruits, vegetables, nuts, legumes, vegetable oils, tea/coffee) and reducing score for less healthy plant foods (sweetened beverages, refined grains, sweets/desserts).

Participants gained on average 2 to 4.5 pounds every 4 years. Diets that were more plant-based mitigated weight gain. But not all plant-foods and meat avoidance regimens fared equally: People who ate a more healthy plant based diet gained 1.5 pounds less. People who ate an unhealthy plant-based diet gained about 1 pound more.

Similar results are seen studying type 2 diabetes: Overall a high plant-based diet and especially healthy plant-based diets are linked with lower the risk of diabetes. Unhealthy plant-based diets, however, are actually associated with higher rates of type 2 diabetes.

And the same goes for cardiovascular disease: although sticking to a more plant-based diet seems to be protective, when examined more carefully the subgroups of plant-based eating patterns diverge – healthier plant-based diets are linked with lower heart disease risk, but an unhealthy plant-based diet confers a higher risk.

Watch out for highly processed food

As plant based meat and milk alternatives expand – clearly a blessing for animal rights and environmental benefits – make sure that you’re not replacing an eat-less-of ingredient with yet another one that we should watch for: highly processed food.

Many in the meat avoiding population are health conscious, and their wellbeing can be attributed to the myriad of healthy routines they practice, in diet, physical activity, mental wellbeing, smoking avoidance etc., all working in conjunction. 

Vegetables and plants are the essence of a healthy vegetarian lifestyle, meat avoidance alone doesn’t do the trick – and meatless burgers are hardly a plant.

Dr. Ayala

Can gadgets accurately count your calories?

There are very many ways to approach weight control and loss. Tracking calories, our body’s energy coin, is front and center of many of them, as energy deficits will result in weight loss, and energy surplus will result in fat accumulation. Diets that don’t count calories also work on getting to a caloric deficit through other methods. Estimating caloric balance requires knowledge of input and output.

How many calories do you consume?

The traditional way of calculating caloric or energy intake relies on weighing and measuring your food, and knowing the caloric value of each specific food item. There are now apps aplenty – MyFitnessPal, Lose It, and Fitbit to name just a few – that help with assessing portion size and identifying food’s caloric value. It's still tedious, time consuming, and in real life we know that people’s assessments tend to be inaccurate and wishful, erring on the side of underestimating intake.

How many calories do you burn?

Assessing caloric output used to rely on charts taking into account age, gender, body size and activity level – sedentary people burn fewer calories than active ones.

Electronic activity devices are in wide use and are an advanced version of the pedometer, able to measure steps, distance, altitude, and some of them also heart rate. They come in all sorts of wearable and clippable forms. Many of them calculate caloric expenditure by an algorithm that uses our movement and our personal health information, such as gender, height and weight. Most smart phones have a built in health app that provides this info. The Fitbit calculates how many calories you burn, based on what you burn at rest – the calories that are used to maintain vital bodily functions such as breathing, heart and blood circulation, digestion etc. – and the extra calories burned during exercise. The Apple watch provides similar information, dividing calories to active and total calories. 

Is the caloric expenditure accurate? A study from Stanford University looked at six devices (Apple Watch, Basis Peak, Fitbit Surge, Microsoft Band, Mio Alpha 2, PulseOn and the Samsung Gear S2) used by 60 volunteers, and although heart rate measures were pretty accurate, energy expenditure measures were off. When compared to metabolic rate assessments measuring oxygen and carbon monoxide in breath – which are a more accurate way to assess energy expenditure – even the most accurate measures were almost 30 percent off, and the least accurate device was off by more than 90 percent. A recent 2020 study looking at four popular wearables (Apple Watch Series 4, Polar Vantage V, Garmin Fenix 5, and Fitbit Versa) also found that heart rate measures were pretty accurate, while energy expenditure measures were unreliable.

So these devices are pretty good at counting steps and heart beats, but not as good at knowing how many calories went by. Mind you I still can’t explain the Samsung bonus: My husband's phone consistently registers an additional 15 percent mileage compared to what my iPhone calculates when we hike together. 

Devices that do the counting for you?

So, the search for an easy, objective way to measure caloric intake is still on.

A promising way to measure caloric intake relies on a simple math equation: Spare calories are stored as fat, so if you knew the energy storage, and you also knew how much energy you expend, you could calculate energy intake. 

As mentioned above, consumer devices that measure physical activity are ubiquitous. 

And there are now devices that claim to measure body composition. Electric scales that use bioelectrical impedance measure not just weight but also body composition (the scale sends an electrical signal through your body that measures the amount of fat vs. lean body mass) and can load this information to your personal account.

Combine the scale information, with the resting and activity energy measures, and you can potentially assess caloric intake without employing tedious food diaries and portion measurements.

How accurate are these measures?

A new study in the Journal of Nutrition compared the results of calculating caloric intake using the commercially available wearable devices for measuring caloric expenditure combined with a smart wi-fi weight scale (Fitbit Alta HR + Fitbit Aria), comparing them to the “gold standard”, the most accurate ways to measure energy expenditure and energy storage. For energy expenditure the most accurate method is doubly labeled water. For measuring storage of fat it’s Dual X-ray Absorptiometry for body composition. These accurate methods are difficult, expensive and require expertise, and are used only in specialized academic centers. This comparison was done for 2 weeks in 24 adult volunteers.

And the results: The Fitbit Aria’s ability to accurately measure fat storage was low. Energy expenditure measurements by the Fitbit device fared better in this recent study, and were quite accurate when compared to the doubly labeled water.

Alas, without an accurate measure of fat storage, the equation cannot be solved, and caloric intake cannot be reliably calculated by the existing electronic devices. 

So it’s back to scales, measuring cups and nutrition labels in order to know how many calories you consume, if you choose to go this route. You can’t base food decisions on these devices – at least not yet.

What’s all this counting good for?

Accurate and convenient automated calorie counting isn’t feasible yet – electronic devices have yet to deliver a reliable solution, even as they’re getting better at it. 

For people trying to eat better, tracking food may be a worthwhile exercise, at least for a while, because it helps you learn what’s in your food, and allows you to moderate caloric intake.

Until you actually count, you may not realize the caloric burden of frappuccinos, sugary drinks and fried foods, and the disproportionate portion sizes served in some establishments.

But once that exercise is over, there are easier and more practical ways to eat well, maintain weight and enjoy life. 

A balanced plate of food (see MyPlate) can be assembled without scales, measuring cups and nutrition charts. And being glued to a digital screen even when you’re out and about outdoors, counting distance and steps rather than looking at the sky and registering birdsong diminishes wellbeing even if it can motivate you to exercise.

Much like with attaining financial literacy, some counting and accounting might be necessary in order to build good habits, but carrying a money or calorie tally in your mind – or on your devices – takes away time and attention that can be better used.

Dr. Ayala

 

An end to the gluten-free fad?

 

May is Celiac Awareness Month. Celiac disease can have very subtle manifestations, and its relatively non-specific and sometimes almost invisible symptoms make awareness of it critical. Awareness should make patients and physicians consider the possibility, and then diagnose it; or rule it out.

It doesn’t mean that everyone should avoid gluten, just in case.

It’s estimated that up to 1 percent of the American population has celiac, most of these people don’t yet know they have it. Others may have gluten sensitivity, a less clearly defined clinical entity. But there is now a widespread belief that gluten is just bad for your health, and the rise in gluten-free food adoption has been meteoric. A survey shows a third of Americans are trying to avoid gluten.

The anti-gluten movement has been greatly beneficial for the people whose health depends on gluten-free food – at last there are breads, grains flours and even restaurants that cater to their needs.

But the belief that gluten-free foods are better for the general population has many downsides.

The downside of the gluten-free fad

One of the obvious ones is that pointing at the wrong target makes you miss more important, more proven-to-harm ones.

Another downside is that by avoiding gluten you might actually be eating worse.

A new study just published in BMJ, that included about 6500 people who were followed up for more than 20 years, found that avoiding gluten not only didn’t improve heart hearth, it may have also increased their risk, as it led to reduced consumption of beneficial whole grains, known to reduce the odds of coronary artery disease.

Eating more gluten was associated with a lower risk of type 2 diabetes in a recent study presented at the American Heart Association meeting.

Another study, presented at the at the 50th Annual Congress of the European Society for Pediatric Gastroenterology Hepatology and Nutrition demonstrated what careful nutrition-label readers might have already suspected: Gluten-free foods often have more calories than their gluten-containing counterparts. The researchers gathered 655 gluten-free foods, and found that across the board, from pasta to cookies to ready meals, these foods had more fat and calories, and less protein than their 654 ordinary, gluten containing equivalents.

The authors warn that the gluten-free craze might be fueling obesity, as the gluten-free halo might be giving the impression that these highly-processed cookies and cereals are healthier than the wheat containing equivalents. In fact, those gluten-free products were even more energy-dense.

Bottom line

A gluten-free diet is essential for people who suffer from celiac, and might help people with gluten sensitivity.

As for the rest of us, we should be moderating our intake of all highly refined and highly processed grain-based foods -- not just gluten-containing ones. On the other hand, whole grains are foods that are good for our health, and there's no reason to deny ourselves the pleasure of a good whole-wheat or barley based bread in favor of one made with corn and tapioca starches.

Here, you have my permission to enjoy a good loaf of bread.

Dr. Ayala

Healthy food trends to take advantage of in 2017

Eating your veggies is suddenly hip.

You might accuse me of being biased – and for full disclosure, yes, I’ve always been a huge veggie and plant-based food fan and proponent – but look around you and see the signs.

In restaurants, veggies are taking center plate; menus are listing more plant-based offerings as many Americans declare they are trying to eat less meat. Pinterest reports a 336 percent rise in the search for veggies in comfort foods.

And this trend will only expand next year.

The market research agency, Mintel, recently announced 2017's food trends, predicting further expansion of vegetarian, vegan and other plant-focused interest.

The Baum and Whitman consultancy's trend predictions follow the same lines:

“Vegetables in 2017 will extend their domination of the dinner plate, shoving animal protein to the edges ... or off the plate altogether… It is no secret that Americans are eating less meat (26% of consumers said so last year) ... that vegetarian/flexitarian diets going mainstream ... and that vegans increasingly are gaining respect.”

Trends shape health

These current trends are sure to please health and sustainability advocates – and grandmas -- who have been drumming the fruit and veggie advice into everyone’s head forever. Plant-centered diets are not only healthful and nutritionally adequate, they have also been shown to prevent and treat many diseases, and people practicing them are among the longest lived and most vibrant people on this planet.

Yet nothing seemed to move for the longest time. And that’s understandable: habits are very hard to change.

It seems that a message needs to come from many different directions, in several modalities and forms, in order to affect action, and in that respect trends help greatly. Just look at what the cool factor – or lack of it – did to cigarettes, spinning, yoga and running.

Greens are in, and 2017 is the perfect time to jump on this trend and adopt healthier habits.

To a healthy 2017

New year resolutions are often broken by the end of January, but a trend, by definition, is something that people are ‘dragged’ into without much resistance, or with minimal effort.

If you’ve been trying to eat a little bit better, chances are, this will be a good year to clinch a few good habits.

A few tips:

• As you continue to hear the “eat more plants” message from health experts, notice how attractive this option is becoming, by looking at recipes, menus and Instagram posts.

• Make plant-centered options convenient, tasty and attractive; this will make this choice easier for you and for your family. Place that pretty, ready-to-eat fruit bowl a little closer and it will be as convenient as a bag of chips.

• Remember: Making small steps in the right direction helps a lot, and this isn’t an all or nothing game. By eating more fruits and veggies you'll be benefiting your health, and displacing less healthy items – such as added sugar, highly processed food and processed meat -- from your dish and cup.

Wishing you happy and healthy holidays, and a peaceful 2017.

Dr. Ayala