Something Fishy About My Diet
My family and I are just back from vacation in Maui. It was fabulous.
For one thing, my wife and I really enjoy spending time with our kids. Now that four out of five are grown and out of the house, it's challenging and rare to get them all in the same place at the same time. Turns out, an invitation to Maui works wonders!
For another, it was, well, Maui. Gorgeous beaches, gorgeous water, glorious sunshine, occasional rainbows and great activities. We snorkeled, we surfed, we hiked in the rain forest, we went to a luau and we watched the sun rise on top of the Haleakala volcano, requiring a wake-up alarm at 2 a.m. We cultivated memories to last a lifetime. As our oldest daughter said -- rejuvenated for her first day back on the job -- "Vacation really works!" Amen to that.
In addition to those many wonderful activities, we ate well. We ate very, very well. Inevitably, for a family that eschews mammals, eats mostly plants, but does include fish and seafood in our diets, that meant quite a lot of fish and seafood, as these figure prominently in the native Hawaiian diet, and on the menus of the island's best restaurants. I ate some of the best fish I have ever tasted in my life last week.
Even so, all that fish left a funny taste not so much in my mouth, but in my conscience. Enjoying my wife's vegetarian cooking since getting back home, I have been left to chew on the notion that there may be something just a bit, well, fishy about my diet.
Historically, I have considered the inclusion of fish in my diet a good thing. The evidence from nutritional epidemiology is decisively in favor, consistently demonstrating health benefits associated with routine fish consumption.
To some extent, such benefits may appear because traditional diets that include fish routinely, such as Mediterranean and Asian diets, are health-promoting in various ways, and conducive to good health outcomes because of the whole rather than any given part. To some extent, it may be because people who eat more fish eat less meat, and benefit both from what their diets include, and what they exclude. To some extent, it may be because health-conscious people who have received the memo about fish go out of their way to include it in their diets, and are healthier both because of eating fish, and because of being health-conscious in general. To some extent, it may be the omega-3 content of fatty fish. Omega-3 fats are essential nutrients, most of us have intake below the ideal, and fish provides the most physiologically important varieties (i.e., EPA and DHA).
Because the benefits of fish ingestion are seen in a wide variety of studies, including observational studies in large populations over long periods of time, and controlled interventions designed to elucidate mechanisms of action, it is likely that all of the above pathways to benefit are relevant. The health benefits of fish consumption are seen despite valid concerns about contaminants. Unfortunately, we have mucked around considerably with this beautiful planet of ours, and almost everything here is tainted in some way, to some degree. Large, predatory fish do contain mercury. Salmon, particularly farm-raised salmon, do contain PCBs. Perfectly pure fish is only available now on other planets. Fortunately, on this planet, the health benefits decisively eclipse any adverse effects of trace contaminants.
Those benefits are contextual, however. We have consistent and compelling evidence that fish-eating is better for health than non-fish-eating against the backdrop of the prevailing, rather dubious, modern diet. We have no direct comparisons, however, of an optimized vegan diet, and such a diet modified to include just fish but no other animal products. Would fish confer a benefit there? We don't know, and such a study is perhaps unlikely; no committed vegan would be willing to be randomized to fish consumption. Such a study is possible among ambivalent omnivores, and would be enlightening. Until or unless it gets done, we cannot infer that fish would do to all diets what it does to the diets that prevail. Some diets may be as good, or better, without fish as any diet is with them. The most popular, modern diets are not good, however, and reliably benefit from the inclusion of fish.
Why, then, my tainted conscience on the subject? We can blame it on the times, and maybe on the snorkeling.
The times we live in shine an increasingly bright and painful light on the implications of our dietary patterns and other behaviors for the fate of the planet. I have long argued that whatever the adaptations of Homo sapiens to meat, they simply become moot when addressing the aggregate appetite of some 7 billion or more of us. At some point, whether or not questions about the nutritional implications of meat are complicated, related questions about the environmental implications get very simple, very fast. A horde of 7 billion Homo sapiens simply cannot be substantially carnivorous if we hope to have a food supply, and planet, left to bequeath to our children and grandchildren.
Increasingly, that same thinking applies at sea. Fisheries are depleted, and in some cases, facing irrevocable collapse. That means any one of us might eat the last specimen of any given variety of fish. I don't want that to be me! It also means we are potentially denying maritime predators -- from dolphins to marlin, whales to sea lions -- their native food supply. We have choices; they really don't.
Then, there was the snorkeling. I was beguiled by the graceful beauty of fish in their every anatomical arrangement and color as I was with them in the water. Then, their cousins were on my plate. Having thought about it, I must confess it bothered me. Much the same thinking removed all mammals from my diet decades ago. I simply could not reconcile calling a dog a beloved member of my family, while calling a pig with equal or greater intelligence...breakfast.
Such thinking may take hold slowly, but it is rather relentless. You can't unknow something. My thinking about animals in my diet changed forever after reading John Robbins' Food Revolution. There is no recourse to the bliss in the absence of the ignorance.
I am not there yet with fish, but I am detecting a similar inclination. As I was working out in the gym on Maui, the elliptical screen showed a recurring reel from the Maui Visitor Channel. One of the segments profiled island restaurants. The hauling of fish out of the water, their placement on ice, and then the elegantly plated dish were meant to be an appetizing sequence, highlighting how fresh the fare at the island's premier restaurants. Indeed it was, and delicious. But I kept thinking: How many of those animals can we haul out of that water before there are none left?
For now, I still eat fish. There are many arguments in favor. But there are increasingly valid arguments against as well. I return from Maui happily restored to my wife's wonderful, plant-centric cuisine. I return, too, convinced that failure to apply comparable considerations about food on land and at sea -- including attention to sustainability, and effects on biodiversity -- is just a bit too fishy to justify.
David L. Katz, MD, MPH, FACPM, FACP, is the founding director of Yale University's Prevention Research Center; President of the American College of Lifestyle Medicine; Editor-in-Chief of the journal, Childhood Obesity; Chief Science Officer for NuVal LLC; and director of the Integrative Medicine Center at Griffin Hospital. A clinician, researcher, author, inventor, journalist, and media personality, Dr. Katz is the recipient of numerous awards and recognitions, including an honorary doctoral degree; widely supported nominations for the position of U.S. Surgeon General; recognition by Greatist.com as one of the 100 most influential people in health and fitness in the world for the past 3 years; and inclusion by LinkedIN as one of the original 150 INfluencers. He has authored over 200 scientific papers and chapters, 15 books, and well over 1,000 columns and blogs- with a resulting social media following of roughly 500,000. A two-time diplomate of the American Board of Internal Medicine, and a board-certified specialist in Preventive Medicine/Public Health, he is recognized globally for expertise in nutrition, weight management and the prevention of chronic disease. Dr. Katz has delivered addresses in numerous countries on four continents, and has been acclaimed by colleagues as the "poet laureate" of health promotion.
