As Far as Fish Are Concerned, Smaller Is Better By E. Dylan Mayer This article was inspired by Patagonia Provisions’ journal found here. Even though the majority of people have stuck to their traditional habit of enjoying red meat as their main protein source, in the last 40 years, an increasing number of Americans have been moving away from red meats and transitioning towards vegetarian, vegan or so-called pescatarian diets.1 The science is telling us this is probably a good thing not only for our own health but for the environment’s health as well. The only caveat to this transition is that overfishing as well as farming fish has been growing too, in order to satisfy the increasing appetite for seafood. According to the Independent, “fewer big, predatory fish are swimming in the world’s oceans because of overfishing by humans, leaving smaller fish to thrive and double in force over the past 100 years.” (I won’t go too in depth on the negative sides of farming fish in this article, but if you’re interested in learning more, I’d recommend watching Patagonia’s film Artifishal). Because of overfishing, some may argue that farm-raised fish are the better alternative for a growing number of people that are seafood enthusiasts. Farm-raised fish are now frequently found in grocery stores and are bought up by fish-loving customers. However, we know that farm-raised fish are fed a diet which is similar to that of farm-raised cattle (hormone-packed & not fed their natural diet), leaving the wild option almost always the healthier choice. One of the most significant differences between farmed and wild fish is the omega-3 fatty acid content. Wild fish generally have a more favorable omega-6 to omega-3 fatty acid ratio compared to their farm-raised counterparts.2 We all know and love our salmon, tuna and swordfish, and can definitely still enjoy these delicacies as long as they are responsibly harvested and wild, but let us turn our attention to the smaller guys: the sardines, anchovies, squid, herring and mackerel. Not only are these smaller fish more plentiful and have much lower mercury levels than fish higher up on the food chain, they are also excellent sources of protein, omega-3 fatty acids and vitamin B12.3 Because of this, when you make the switch from big to small fish, you’re not only doing something good for your own health, you’re also benefiting the environment, allowing wild food…

Why Do Humans Continue to Eat Meat When It Is Not Good for Us By Emeran A. Mayer, MD Personal and environmental health are closely interconnected. Increasing evidence suggests that diets inextricably links human health and environmental sustainability as recently described in great detail in the Eat-Lancet Commission report.1 The authors of the report state that “unhealthy diets are the largest global burden of disease and pose a greater risk to morbidity and mortality than does unsafe sex, alcohol, drug and tobacco combined.” The report goes on to propose a dramatic shift from the current lose-lose diets to worldwide acceptance of “win-win” diets which are both healthy and environmentally sustainable. What are these unhealthy lose-lose diets? The term is generally used to refer to the modern Western diet, a dietary pattern with high consumption of red meat (including beef, lamb and pork), ultra-processed foods and sugar, as well as low consumption of fruits, vegetables, legumes and fish, which are typically consumed by people who are overweight or obese, and who have growing rates of chronic metabolic diseases. So even if people claim to feel better, have less “brain fog”, lower rates of obesity and metabolic disease on diets predominantly based on animal products, such as the ketogenic diet, the environmental impact of such diets are shocking. To use a quote from a conversation I recently had with Dr. Walter Willett, Professor of Epidemiology and Nutrition and chairman of the Department of Nutrition at the Harvard School of Public Health, and the first author of the Eat Lancet Commission report:”… what kind of world population could our earth support if everyone adopted …. the animal based keto diet. And the response I got was about 200 million people, which means that about 7.2 billion people need to find another planet. If we can only support 200 million people with this almost completely animal source kind of diet, it's just not realistic for the world.” So why is it that so many Americans cling so desperately to their Western diet and their meat-eating habits despite a growing body of research that eating a lot of meat is not only bad for our bodies, but for the environment? One answer to this question has to do with the image that society, with the help of the advertisement industry, has attached to eating a meat based, protein rich diet as masculine, while eating a…

A Personal Experience from 2 Months of Time-Restricted Eating By E. Dylan Mayer with Emeran Mayer, MD The Science You may have heard the terms intermittent fasting and time-restricted eating being used interchangeably; however, there is an important difference between the two. By definition, intermittent fasting is an energy restriction on 2-3 days per week, or alternate days, while time-restricted eating is compressing the daily period of food intake to 10 hours or less on most days of the week, without restricting calorie intake.1 Two studies , I came across from the Salk Institute for Biological Studies in La Jolla, CA reported several amazing effects of time-restricted feeding on metabolism, systemic inflammation and on the gut microbiome. In these animal studies, the time restriction was from 9-15 hours per day while the animals had unrestricted access to food the remainder of the 24 hours. In one study,2, 3 led by Amandine Chaix, the researchers showed that the effects of time restricted feeding were proportional to the fasting duration with few benefits being observed with less than 12 hours of fasting. However, the positive effects of the time restricted feeding paradigm included a protective effect against excessive body weight gain when the mice were put on a “Western” diet high in fat and sugar and remarkably this effect was seen without a change in 24-hour caloric intake. In other words, the mice could enjoy their high fat high sugar diet, as long as they consumed their unhealthy diet in a window of less than 12 hours a day. The investigators also found a reduction in whole body fat accumulation and associated inflammation, an improvement in glucose tolerance and a reduction in insulin resistance in the time restricted diet group. In a second study, led by Amir Zarrinpar, the group showed that the normal diurnal fluctuations in the gut microbiome were abolished when animals were put on a “Western” diet, high in fat and sugar, and that the rhythmic 24 hour oscillations were restored when these mice were put on a time restricted feeding schedule. Consistent with this healthy system behavior, these microbial oscillations were accompanied by a greater diversity of the gut microbes, and by changes in the relative abundance of microbes known to be involved in obesity. What is most remarkable about these experiments is the fact that they didn’t really involve any fasting, e.g. reduction in calorie intake, but…

Treating Chronic Gastrointestinal Symptoms with Digital Therapeutics By E. Dylan Mayer and Emeran Mayer, MD Chronic disorders of the intestinal tract, such as inflammatory bowel diseases (IBD) and irritable bowel syndrome (IBS) are common, affect both children and adults, greatly impact patients’ quality of life and contribute significantly to the economic healthcare burden. About 1.6 million Americans suffer from IBD and the prevalence of these disorders has increased by 200,000 since 2011. Ten to fifteen percent of the US population meet the symptom criteria for IBS. Despite their different disease mechanisms, scientific and clinical evidence point towards alterations in the bidirectional interactions between the brain and the gut, and the important role of the brain in influencing symptom severity.1, 2 The great majority of patients are treated symptomatically with medications which do not always provide satisfactory symptom relief or are limited by side effects. It has been more than 7 years since our group published the results from a small clinical trial on the effectiveness of a psychoeducational treatment program for IBS patients which showed significant clinical benefits.3 A plan to move this treatment program to an online format did not materialize as not enough patients regularly used the internet at the time. A recent large clinical trial from Dr. Jeffrey Lackner’s group at the University of Buffalo show a persistent clinical benefit of a patient-centered cognitive behavior therapy (CBT) approach in IBS patients.4 And our two groups showed in a recent study that CBT not only improves symptoms in IBS, but that this clinical benefit is associated by changes in the brain and the gut microbiome, a finding that qualifies CBT as a biological therapy.5 Even though CBT has been shown to be one of the most effective treatments for IBS patients, the widespread application of CBT in gastrointestinal (GI) disorders is greatly limited by two major factors. Even though it is not a new treatment, there are still a very limited number of CBT therapists with expertise in GI disorders, in particular in non-metropolitan areas. The other issue is that when you do find someone, the duration and cost of traditional face to face CBT has prevented this therapy from being adopted widely. Welcome to 2020 and the age of digital therapeutics. Digital therapeutics or prescription digital therapeutics (PDTs) are clinically validated software treatments prescribed by a doctor and have the potential to greatly improve life outcomes for…

Are Probiotics Good for You? By Emeran Mayer, MD A recently published report by the American Gastroenterological Association (AGA) on Clinical Practice Guidelines for the role of probiotics in the management of gastrointestinal disorders, based on an in depth Technical Review of the published literature concludes that probiotics have little if any evidence based value in treating digestive diseases (including irritable bowel syndrome [IBS] and inflammatory bowel diseases),1 a statement that is not surprising to somebody who has long followed the scientific debate about probiotics and who gets the question from nearly all of my patients which probiotic is best to take. The only disease populations that the report exempts from their negative assessment were children and adults on antibiotic treatment, preterm infants with low birthweight and patients with pouchitis, a postoperative complication in patients following a colectomy. According to the World Health Organization, “Probiotics are live microorganisms which when administered in an adequate dose confer a health benefit on the host.” This is an ambiguous definition, as it includes both the possible benefits of ingested microbes on gut and overall health in individuals without any specific gastrointestinal (GI) disorder (probably the majority of people who take probiotics), as well as the possible benefits in treating or preventing a specific disease (a small fraction of the overall market). Even though there are a number of clinical trials which have aimed to demonstrate an effect on GI disorders (most of which according to the report have not been conclusive, were of low quality or have been negative), there is a small number of studies which have shown that certain probiotics are effective in reducing common digestive symptoms such as rumbling and abdominal discomfort in otherwise healthy people.2 Unfortunately, for most probiotics such well designed and controlled studies do not exist. Even though I generally agree with the conclusions of the AGA guidelines, there are several important points to consider before we close the curtain on the benefits of probiotics: The same microbes may not be effective in everybody, and based on current knowledge, the effectiveness of a particular microbe is likely to depend on the unique composition and function of the gut microbiome of a particular individual. Until we are able to design custom cocktails of probiotic strains which match an individual’s microbiome, and evaluate the effectiveness in such selected populations it may be impossible to demonstrate significant benefits in clinical…