Land Food Versus Seafood

The omegas battle it out in our budgets and our bodies.

Published May 18, 2017

This spring, two striking things happened in the United States: one on land, the other at sea.

On land, farmers planted a record area of soybeans—almost 2.5 million hectares (about the size of Maryland)—and a near record of over 36 million hectares (approximately the equivalent of three Mississippis) of corn. That new production was supported by US $25-billion in farm subsidies—also close to an all-time high—that covered everything from crop insurance to debt relief and enabled farmers to till more land for, yes, more corn and soy. Because of all this, the top five calorie sources in the American diet are a mélange of processed treats sweetened by high-fructose corn syrup and corn-fed meats. Soy oil is used in 75 percent of all American processed food, and corn, as either an additive or a substrate, is equally omnipresent. Collectively, this makes for a diet extremely high in what are known as omega-6 fatty acids—polyunsaturated fats that some nutritionists believe can play a critical role in causing many of the so-called “Western” diseases.

With seafood, meanwhile, investment is going in the opposite direction despite the belief of nutritionists that omega-3 fatty acids are healthier than omega-6s. In March, US President Donald Trump proposed a budget that would cut financing for the National Oceanic and Atmospheric Administration (NOAA) by 17 percent. NOAA, which oversees all US government fisheries and aquaculture programs, has already seen its budget cut significantly since Republicans insisted on a general cut in government spending. Over the past few years, the United States has slid to 17th place in world farmed seafood production, slipping behind Myanmar and pulling up just short of Malaysia. And while American seafood consumption recently increased by about half a kilogram per person, fish and shellfish rich in omega-3s still represent a tiny portion of the overall American diet: 6.8 kilograms of seafood per person per year compared to around 70 kilograms of terrestrial meat. In the future, seafood consumption could fall even more.

This is significant because, according to a study published last year in the Journal of the American Medical Association, approximately 56 percent of the calories consumed by Americans are the direct result of subsidized commodity land crops such as corn and soy. The researchers found that these crops could be linked to high body mass index, glucose-related abnormalities such as diabetes, and cholesterol imbalances. In short, the authors concluded, “overall better alignment of agricultural and nutritional policies may potentially improve population health.”

The chorus to fix the misalignment between agricultural and nutritional policies has been steadily rising in the past decade. But this misalignment, particularly exemplified by a dietary imbalance of omega-6s and omega-3s, has been on the agenda of certain scientists for more than five decades.

“It begins with puzzling why some people around the world have different severity and different incidences of disease, and what ethnic food and lifestyles they have,” says William Lands, a biochemist who did some of the early work on omega-3 fatty acids back in the 1960s and ’70s. Building on research focused on the anti-inflammatory effects of omega-3s in the human diet, Lands’s work went on to suggest that omega-6 fatty acids interfere with the ability of the human body to “elongate” vegetable sources of omega-3s into healthy long-chain omega-3 fatty acids. Omega-6s, meanwhile, seem to give rise to compounds that are pro-inflammatory in the human body, potentially affecting cardiovascular and neurological health.

This makes sense if you consider what omega-3s and omega-6s do in nature. Omega-3s work in the body of fish to increase flexibility and speed up the transfer of energy across cell membranes. That’s why they are so present in cold-water fish such as salmon and mackerel. But the purpose of omega-6s is to help store energy rather than spend it. It is for this reason that seed crops such as corn and soy are so rich in omega-6s.

And while omega-6s are every bit as essential to the human body as omega-3s, the way we eat them today is out of sync with the foods with which we evolved. Early hominid diets, in the absence of farmed cereals, would have consisted primarily of some seafood, but also large amounts of leafy greens rich in omega-3s and animals that browsed on grasses rich in omega-3s. This is borne out when one compares the fatty acid profile of grain-fed animals with the Paleolithic equivalent: grass-fed meat and dairy. A 2016 study in the British Journal of Nutrition found that grass-fed meat and dairy had an omega-3 level 50 percent higher than grain-fed animals. Some physicians, including Washington-based clinician Artemis Simopoulis, suggest that pre-agricultural humans had blood lipids with an even balance of 1:1 omega-3 to omega-6 whereas today that ratio is as unbalanced as 1:15.

This unbalancing is also being played out ecologically. Over the past century, as the production of omega-6-rich soy, corn, and livestock has grown exponentially, the amount of nitrate and phosphate fertilizer and manure wastes that have been flushed into American waterways has grown similarly apace. Omega-3-rich seafood has undoubtedly suffered as a result. Numerous oxygen-poor areas resulting from all that terrestrial pollution now exist throughout the United States, including a dead zone in the Gulf of Mexico that is among the largest in the world.

As the present planting season comes to a close and all that corn and soy comes to market, we seem likely to continue this misalignment at least for the coming year. But as more and more clinicians consider the American model and find a lack of balance, a different approach may be on the menu—one where land and sea find a more equal representation in the body politic as well as in the actual human body.