Tornado Science, Facts and History
Across the United States and even deep in the beef belt of the Midwest, word has spread of the health benefits from omega-3 fatty acids. They lower the risk of heart disease, help clear up varicose veins, boost brain power, beat back depression, and do just about everything useful except for washing your windows.
The beef-and-pork-themed diet of America, however, is high in omega-6 fatty acids. Although this type of fat is essential for health, Americans get too much of it. The ideal ratio of omega-6 to omega-3 should be about 4 to 1, which is likely the ratio humans evolved with. Today that ratio has been distorted to about 20 to 1.
The perception is that fish — particularly the big, overfished and heavy-metal-rich kind — are the only sources of omega-3s and that you have to forego beef and other meats in order to get omega-3s in your diet.
While many fish, pound for pound, are the best source of the healthiest omega-3s, any animal that eats grass has omega-3s. The reason why most beef, chicken, milk and eggs are so devoid of omega-3 is that we feed cows and chickens a factory diet of corn and other foods these animals don't normally eat.
Up until about 100 years ago, these foods were natural sources of omega-3s — and they still are, provided the animals have access to pasture.
Fish get their omega-3s from grass — that is, sea grass, algae, other sea vegetables and plankton. In fact, wakame, a seaweed ubiquitous in Japanese cuisine, is the highest vegetarian source of omega-3s. Wakame has an omega-6-to-omega-3 ratio of about 1 to 18.
As a result of a grass-heavy diet, oily fish such as sardines and anchovies — as well as the fish that love to eat them, such as mackerel — have the highest amounts of the two healthiest forms of omega-3s, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
Corn, for all its merit in keeping the Aztecs alive, is a horrible source of omega-3s. Corn oil, for example, has an omega-6-to-omega-3 ratio of about 45 to 1. As a result of an unnatural lot-feed diet of cheap corn, cows have very little omega-3s in their milk, cheese or meat.
Back to basics
A diet devoid of fish can still be rich in omega-3s provided you eat food products from pasture-raised animals along with vegetables high in omega-3s. Lamb is almost entirely pasture-raised, being such a non-American industry, and thus has decent amounts of omega-3.
Milk, cheese and meat from grass-fed cattle are now once again commonplace, particularly at farmers' markets. Some grass-feed cattle have about a 1-to-1 ratio. Chickens permitted to scratch for grass, seeds and insects produce eggs rich in DHA. For fish lovers, sardines offer among the highest levels of DHA and EPA with the least toxins or worry of overfishing.
Agribusiness, of course, is hearing all this clamor about healthy fats. Its solution has been to feed animals fishmeal, which for now seems to have no ill consequences. But if you've ever seen a cow or chicken in water, it quickly becomes clear they aren't very good at catching fish and thus haven't evolved to eat fish. Cows weren't meant to eat other cows, either; that's how we got mad cow disease.
Vegetarian sources of omega-3s include tofu, walnuts, flax seed and oil and, perhaps surprisingly, the Chia pet. This corny Christmas gift, with the shortest song in the English language (Ch-ch-ch-chia), contains three times more omega-3 than omega-6.
Vegetarians need to be a little careful, because excellent omega-3 sources such as flax seed are mostly alpha-linolenic acid (ALA), which is converted by the body into the necessary DHA and EPA with poor efficiency, about 20 percent.
And we all need to be little careful because this is all about ratio. Too many omega-3s, like a blood thinner, can lead to hemorrhagic stroke. That's not the free-flowing blood circulation most people are after.
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Benjamin Radford is managing editor of the Skeptical Inquirer science magazine. He wrote about psychological fallacies and alternative medicine in his book "Hoaxes, Myths, and Manias: Why We Need Critical Thinking." This and other books can be found on his website.