Is It Time to Eat? A Surprisingly Important Question

'Tis the season for making New Year's resolutions.  Perhaps your resolutions include healthier eating and losing weight.  There is certainly plenty of info in my past articles on how to construct a healthy diet that will help you live longer and prevent chronic diseases. One element that may have been overlooked in all the scrutiny over what to eat is when to eat. There is growing evidence that restricting our eating to certain times of the day leads to more easily maintaining a healthy body weight.

Several authors and experts have been touting so-called "intermittent fasting," which consists of only eating between the hours of 10 AM and 6 PM, for example. Another version of this approach involves eating normally five days per week, but essentially fasting (taking in less than 500 calories) on the other two days.  The idea behind this is that a more prolonged period without food discourages fat storage, and allows our body to switch its metabolism over to burn our stored fat supplies.

A recent study in mice (1) seems to support this idea. In this study, two groups of mice were allowed to eat as much as they wanted. One group had food available at all times, while the other group only had food available for a 12-hour period each day. The group with the more restrictive time ate about the same number of calories as the other group, and yet maintained a healthy body weight, while the unrestricted group became obese.  The time-restricted mice were even able to reverse obesity and prevent type-2 diabetes.  Cholesterol balance improved within two weeks, and blood sugar control improved within a few days.

A related study (2) showed how this intermittent fasting can change the composition of the gut microbiome.  A healthier blend of friendly intestinal bacteria leads to leaner body weight.

It's too soon to translate these results directly to humans, but there have been some small human studies that point to the benefits of this approach.  One study found that intermittent fasting led to the same amount of fat loss as traditional calorie-restricted diets, but preserved much more healthy lean tissue. (3)

In a way, all of this seems to hearken back to traditional Chinese and Ayurvedic medicine: these systems used more poetic language to recommend against eating late into the evening or at night.  Whatever the reasoning, the outcome seems to be the same -- better health when we pay more attention to eating at the right time of day.

Listen to an interview with one of the researchers:  You Are 'When' You Eat 

1.  Amandine Chaix, Amir Zarrinpar, Phuong Miu, Satchidananda Panda.  Time-Restricted Feeding Is a Preventative and Therapeutic Intervention against Diverse Nutritional Challenges.  DOI: http://dx.doi.org/10.1016/j.cmet.2014.11.001

2.  Amir Zarrinpar, Amandine Chaix, Shibu Yooseph, Satchidananda Panda.  Diet and Feeding Pattern Affect the Diurnal Dynamics of the Gut Microbiome.  DOI: http://dx.doi.org/10.1016/j.cmet.2014.11.008

3.  Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings.  Transl Res. 2014 Oct;164(4):302-11. doi: 10.1016/j.trsl.2014.05.013. Epub 2014 Jun 12.

Healthy Food? Blech!

One of the main impediments that many people cite in avoiding healthy foods is taste.  When the average American is faced with the choice between a Frappuccino and a kale salad, it's no mystery which one will be chosen.  Our brains are hard-wired to seek out fats, sugar, and salt for survival -- but with the modern food-industrial complex, these once-scarce resources are available in virtually endless supply in our country.  I've gone into a lot of detail previously on what constitutes a healthy diet:  Mediterranean-style eating, high in fiber, low in refined flours and sugars, with moderate amounts of healthy fats (such as olive oil and nuts) and lean proteins (such as legumes and fish).  So how do we get over the hurdle of transitioning to this style of eating... and more importantly, how do we adopt this on a permanent basis?  It can be easy to stick with any "diet" for a few weeks, but long-term health requires a lifestyle change.

Kids.  As a parent, I know how challenging it can be to introduce healthy foods in the face of the "beige diet:" chicken nuggets, corn, bananas, pizza, cereal, cookies.  The key here is persistence and repetition:  Food experts tell us that it can take 10-12 times of encountering a new food before young children will accept it.  Just keep putting that broccoli on their plates, and requiring at least one "thank-you bite."  Eventually, they'll get used to it.

Adults.  Are we just "in the habit" of eating unhealthy foods -- or are we actually addicted to them? While this term is controversial, there have been studies that show the same brain areas light up on functional MRI in response to refined sugar as they do for cocaine (1).  In 2007, a rat study found that the animals actually preferred the sweet stuff over cocaine when given a choice (2).

So how do we break this addiction?  Mark Hyman, MD, recommends approaching it the same way you would with any other addiction:  go cold turkey.  In this case, it means absolutely no sugar or refined grain products for at least 10 days.  This gives a chance for the taste buds and (more importantly) the reward centers of the brain to hit the reset button, so that we are not so sensitized to the sweet stuff.  We can then actually start tasting other foods, and they taste better by comparison.

A small pilot study by researchers at Harvard and Tufts Universities (3) used functional MRI to measure brain reward response in overweight and obese individuals before and after a structured low-glycemic index diet.  This plan, called the iDiet (or "instinct diet"), overcomes the natural tendency toward sweets by substituting healthier ingredients in familiar dishes, encouraging more frequent eating of healthy meals to avoid hunger, and involving interpersonal support.  After 24 weeks, the reward centers of the brain showed less reponse to high-calorie foods, and more response to low-calorie foods.  In plain English, this proves that on a neurological level, the brain can be rewired to enjoy healthier foods.

So it takes some effort, but it shows that old habits can be changed.  Dr. Hyman emphasizes that willpower is not the issue here:  the combination of our neurobiology with what K. D. Brownell (4) calls a "toxic food environment" creates a trap for us.  A structured kick-start might be just what we need to turn over a healthier leaf.

1. Avena N et al.  Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake.  Neurosci Biobehav Rev. 2008; 32(1): 20–39.  Published online May 18, 2007. doi:  10.1016/j.neubiorev.2007.04.019
2. Lenoir M, Serre F, Cantin L, Ahmed SH (2007) Intense Sweetness Surpasses Cocaine Reward. PLoS ONE 2(8): e698. doi:10.1371/journal.pone.0000698.
3. Pilot randomized trial demonstrating reversal of obesity-related abnormalities in reward system responsivity to food cues with a behavioral intervention.  Nutrition & Diabetes (2014) 4, e129; doi:10.1038/nutd.2014.26.  Published online 1 September 2014.
4. Brownell KD, et. al. Personal responsibility and obesity: a constructive approach to a controversial issue. Health Aff (Millwood). 2010 Mar-Apr;29(3):379-87

Are You Sitting Down? Think Again...

Imagine two co-workers:  one slim, the type who can seem to eat anything without gaining a pound -- and therefore does not feel the need to exercise; the other one overweight, but who works out regularly.  In spite of your latter colleague's efforts, he has found it very difficult to lose weight.  Which one is at greater risk for health problems down the road?

The answer is not so clear-cut, since both obesity and physical inactivity have been linked to chronic diseases:  cardiovascular disease, diabetes, osteoarthritis, etc.  If you were forced to choose, though, it appears more and more that keeping physically active is the more important variable for decreasing health risks.

• Australian researchers (1) recently found that being sedentary accounts for about half the risk for cardiovascular disease in middle-age women -- more than obesity, high blood pressure, or even smoking.
• Recent studies in BMJ (the British Medical Journal) found that for older adults, light daily physical activity decreased the disability associated with knee arthritis (2), and poor physical fitness nearly quadrupled the risk for all-cause mortality (death by any cause) (3).
• While many studies have focused on light-to-moderate exercise, a new study in the Journal of the American College of Cardiology looked at something a bit higher impact -- namely running -- and found that running, even as little as 5-10 minutes per day, decreased cardiovascular and all-cause mortality risk by 30-50%. (4)
• Author Nilofer Merchant has compiled the research, and calls sitting the "new smoking" -- the big public health scourge that needs to be addressed in the 21st century.

What can you do today to incorporate more physical activity?

• Park a little further from your destination
• Walk the dog a little further each morning
• Jog in place during each commercial break on TV

Our bodies are designed for exercise throughout life -- so keep it moving!

1. Br J Sports Med. Published online May 8, 2014.
2. Relation of physical activity time to incident disability in community dwelling adults with or at risk of knee arthritis: prospective cohort study.  BMJ 2014;348:g2472
3. Physical capability in mid-life and survival over 13 years of follow-up: British birth cohort study.  BMJ 2014;348:g2219
4. Leisure-Time Running Reduces All-Cause and Cardiovascular Mortality Risk.  J Am Coll Cardiol. 2014;64(5):472-481. doi:10.1016/j.jacc.2014.04.058

Another Secret to a Smaller Waistline

There has been a lot of speculation about the increasing rates of obesity over the last few decades.  Many of the causes of this phenomenon are well known, and I have covered them in past articles: the move from whole foods to more processed foods, a decrease in physical activity with the rise in technology, and the increasing intake of both regular and diet soda pop.  One factor that often gets overlooked in this equation is the importance of a good night's sleep.

Researchers in the UK (1) recently published the results of a survey of over 100,000 women covering a 10 year period.  They found that light exposure at night disrupted the normal circadian rhythm (day-night cycle), and led to increased body mass index, and increased waist circumference.

If you are trying to shed pounds by increasing exercise, then bravo!  Just don't exercise late in the evening.  Night should be a time for winding down, decreasing activity, and definitely minimizing exposure to light (no falling asleep with the TV on).  The infographic below is a handy reminder of what's known as good sleep hygiene.  Use it to optimize your sleep, and maintain a healthier body weight.

1.  McFadden E et al.  The Relationship Between Obesity and Exposure to Light at Night.  Am J Epidemiol. 2014;180(3):245-250.

Coffee: Pain Reduction, Weight Loss, and More

For decades, it's been a given in natural health circles that coffee is a no-no. It's commonly one of the first things that people are asked to give up when going on a detox program, or any other recommendations for improving their health. Over the past decade or so, though, evidence has been mounting that there are actually many health benefits for that morning cup of joe.

One of the latest findings is that coffee may help to reduce pain.  In 2012, Norwegian researchers found that coffee drinkers reported about a 25% lower pain score than non-coffee drinkers in a simulated office work environment. This difference was true whether participants had chronic pain or not.

Other benefits that have been reported for coffee in recent years include:

• decreased risk of endometrial cancer, Parkinson's disease, Alzheimer's disease, and type 2 diabetes
• enhanced muscle growth
• assistance with weight loss (with green coffee bean extract)

The research on green coffee extract for weight loss was a small human trial, involving only 16 subjects. Doses used were in the range of 700 to 1000 mg per day.  However, the results were striking, and so far, and this supplement seems safe. It is inexpensive, and worth a try for a few months.

The main benefits of coffee seem to be related to its phytonutrient content-- those health promoting compounds found in plants that have antioxidant and other beneficial effects on the human body. These benefits seem to hold true whether the coffee contains caffeine or not. So if you're concerned about caffeine, due to its acute blood pressure raising effects, or its detrimental effects on sleep, you can drink decaf, and still enjoy the preventive medicine aspects of coffee.

One last thing to keep in mind: many of the health benefits of coffee can be counteracted if you add a lot of milk and sugar to it. The high saturated fat and empty calories would be more than enough to outweigh the phytonutrient effects.

For me, I'll be enjoying my cup of black half-caf in the morning all the more.

Good Bacteria = Smaller Waistline?

Research in the area of normal flora -- the "good," or beneficial bacteria that live in our gut -- has been exploding in recent years.  It has been known for a long time that supplementing with probiotics (those friendly bacteria like Lactobacillus and Bifidus) can help with conditions ranging from eczema to allergies to irritable bowel syndrome.  But the list of benefits of proper microbial balance keeps growing -- and it seems like the more we know, the more we realize how much we don't know yet.

Recently, Chinese researchers (1) found a connection between the microbes in our gut and the problem of obesity.  Mice that were bred to be resistant to obesity, in spite of a high-fat diet, rapidly gained weight when injected with a bacteria from the human gut called Enterobacter cloacae.  They hypothesize that a harmful substance produced by these bacteria, called endotoxin, contributes to insulin resistance.  Insulin resistance is a major contributor to overeating and obesity, and the hallmark of type 2 diabetes.  Think of insulin as a key to open the door to your cells so they can take in blood sugar for energy; insulin resistance is where the lock on the cell doors gets worn and rusty, making it more difficult for insulin to do its job.  Insulin levels rise, which contributes to widespread inflammation in the cardiovascular system, and promotes fat storage.

In the same article, the researchers report a case study of a man who lost 66 pounds in 9 weeks by switching to a diet that promoted good bacteria growth in the intestinal tract.  The harmful Enterobacter was reduced to undetectable levels.

Now before you pop an acidophilus supplement or grab a Yoplait, expecting miraculous weight loss, we need to look a little more closely at the diet supplied to this test subject.  It was very high in fiber, to feed the good bacteria in the gut, and also included traditional Chinese fermented foods that might seem challenging to our palates.  Fermented foods are beginning to look more important than probiotic supplements, simply because of sheer numbers:  supplements might have anywhere from 1 billion to 20 billion bacteria per serving, which sounds like a lot, until you realize that there are about 100 trillion bacteria in your gut!  Traditional fermented foods have much higher levels of good bacteria than supplements.  We're not talking about most commercial yogurts, which are crammed with sugar and have questionable amounts of active bacterial cultures; we're talking about plain yogurt, kefir, miso, traditional sauerkraut, and kimchi, to name a few.

We've barely scratched the surface on research into our normal flora -- not just in the gastrointestinal tract, but also on the skin, respiratory tract, and genitourinary tract.  It makes sense that they would have such a huge influence on our health:  there are ten times as many bacterial cells as human cells in our bodies!  We are really more of an ecosystem rather than a single organism.  Perhaps in the future there will be much less emphasis on therapeutic nutrition, except as it applies to how it influences our flora.

1.  An opportunistic pathogen isolated from the gut of an obese human causes obesity in germfree mice.  The ISME Journal advance online publication 13 December 2012; doi: 10.1038/ismej.2012.153

Another Nail in the Coffin for Diet Soda

All right, Dr. Peters, will you lay off the diet-soda-bashing melodrama?

No.  The answer is no.

You've read my articles before about how diet soda actually promotes weight gain rather than weight loss, and more seriously, raises the risk of stroke significantly.  Is that Diet Coke fix worth a brain attack that could lead to permanent neurologic deficit, or even death?

Now French researchers have published findings (1) that consumption of lots of diet soda more than doubles the risk of developing type 2 diabetes, compared to non-soda drinkers.  This is an even higher risk than regular soda drinkers!  As you know, type 2 diabetes is like aging on fast forward, accelerating the development of cardiovascular disease, nerve problems, kidney disease, eye problems, and other complications.  But wait -- how much is "a lot" of diet soda?  More than about 600 ml per week.  Or for us Americans, about 20 fluid ounces.  Yes, just one 20 oz. bottle per week.  Know anyone who drinks more pop than that?

So let's look at the arguments of the beverage industry:

• "Diet soda is a good choice for those trying to lose weight, since it contains zero calories."  FALSE
• "Diet soda is a good choice for diabetics, since it contains no sugar."  FALSE

Consider the alternatives:

• Get a reusable water bottle, and make pure water your go-to drink.  Add a squirt of real lemon or lime juice for a little flavor, if you miss it.  No need to replace one highly processed food (diet soda) with another ("designer" waters).
• Green tea:  go beyond the Lipton -- there are many different varieties, with flavors that should appeal to everyone.  And how about a 20-30% lower risk of cardiovascular disease as a bonus?

1.  Consumption of artificially and sugar-sweetened beverages and incident type 2 diabetes in the Etude Epidémiologique auprès des femmes de la Mutuelle Générale de l'Education Nationale–European Prospective Investigation into Cancer and Nutrition cohort.  January 30, 2013, doi: 10.3945/​ajcn.112.050997.  Am J Clin Nutr March 2013 ajcn.050997

Why I'm Still Eating Organic Foods

A study about organic food published this month in the Annals of Internal Medicine (1) made big headlines, mostly along the lines of "organic food is no better for you than conventionally grown food."  As usual, the headlines tend to gloss over the details of the research that was conducted.  Several points are worth noting, to decide whether or not organic fruits, vegetables, eggs, and meat are worth the extra cost:

• This was a review study, not primary research.  That is, the authors combed through existing articles from the past 15 years to extract the data.  This can confuse the issue, since the previous studies were done in different settings and for a variety of purposes.
• Organic produce does not contain significantly higher levels of vitamins or minerals than conventionally grown produce.
• Eating organic food leads to lower exposure to synthetic pesticides and fertilizers, but the authors point out that the exposure from conventional foods was mostly within the "allowable limits" set by the US government.
• Organic chicken and pork have a greatly reduced risk of carrying antibiotic-resistant bacteria ("superbugs" that are particularly dangerous and difficult to treat).

My view on some of the conclusions reached:

• It has been well known for a long time that organic fruits and veggies are not superior in vitamin or mineral content.  However, some studies have suggested that they do have a higher content of phytonutrients -- those compounds produced by plants that help protect us against cancer, cardiovascular disease, and other chronic health conditions.  Plants are basically chemical factories; without the "protection" of synthetic pesticides, they must cook up their own natural protective compounds, and we get the benefits when we eat those plants.
• Even though pesticide residue on conventional produce is within "safe" limits for daily consumption, we must remember that those chemicals are lipophilic (literally, "fat-loving").  They can stay in our fat tissue for a very long time.  How long?  A by-product of the pesticide DDT (which was banned in the US in 1972) was still present at significant levels in adults' fat tissue two decades later (2).  So it's not about keeping the daily dose in a "safe" range; it's thinking long-term about these carcinogenic compounds (3) building up in the body.
• While we're on the topic, those synthetic chemicals can even contribute to obesity and diabetes (4).
• Avoiding antibiotic-resistant bacteria is always a good idea; avoiding the residue of antibiotics in meat is also a good idea, since that may disrupt the normal, beneficial microorganisms in our digestive tract.

So for many fruits, vegetables, and meat, I'm sticking with organic.  If you need to budget your grocery dollars, check out the Environmental Working Group's analysis of which foods are highest and lowest in pesticide residue.

1. Are Organic Foods Safer or Healthier Than Conventional Alternatives?: A Systematic Review.  Ann Intern Med. 4 September 2012;157(5):348-366
2. Organochlorine pesticides and polychlorinated biphenyls in human adipose tissue.  Rev Environ Contam Toxicol. 1991;120:1-82.
3. Adipose tissue levels of organochlorine pesticides and polychlorinated biphenyls and risk of non-Hodgkin's lymphoma.  Environ Health Perspect. 2004 Jun;112(8):854-61.
4. Obesity and persistent organic pollutants: possible obesogenic effect of organochlorine pesticides and polychlorinated biphenyls.  Obesity (Silver Spring). 2011 Apr;19(4):709-14. Epub 2010 Jun 17.