Over at Retrospectacle, Shelley titled her blog post “Fish Oil Reduces Alzheimers Risk.” Who can blame her? ScienceDaily did it, too. I haven’t seen the title of the original article in the Journal of Neuroscience, but I suspect the researchers might have even included something about fish oil, too. But in their attempts to frame science, they’re encouraging fish consumption for no good reason.
What all these authors really mean is that eating omega-3 fatty acids reduces risk of getting Alzheimers. But wild fish is just one of many good sources of omega-3. Flax seeds, for instance, have six times more omega-3 than your average fish. Kelp, walnuts, and acai palm fruit also have high levels. So do meat, cheese, and eggs from animals fed primarily grass (problem is, most animals are now fed corn instead of grass).
Michael Pollan has more on why our omega-3s are out of whack–because of the corn-fed animals we eat–and a great description of a shifting baseline. From The Omnivore’s Dilemma:
One of the most important yet unnoticed changes to the human diet in modern times has been in the ratio between omega-3 and omega-6, the other fatty acid in our food. Omega-6 is produced in the seeds of plants; omega-3 in the leaves. As the name indicates, both kinds of fat are essential, but problems arise when they fall out of balance. (In fact, there’s research to suggest that the ratio of these fats in our diet may be more important than the amounts.) Too high a ratio of omega-6 to omega-3 can contribute to heart disease, probably because omega-6 helps blood clot, while omega-3 helps it flow. As our diet–and the diet of the animals we eat–shifted from one based on green plants to one based on grain (from grass to corn), the ratio of omega-6 to omega-3 has gone from roughly one to one (in the diet of hunter-gatherers) to more than ten to one. (The process of hydrogenating oils also eliminates omega-3s.) We may one day come to regard this shift as one of the most deleterious dietary changes wrought by the industrialization of our food chain. It was a change we never noticed, since the importance of omega-3s was not recognized until the 1970s.
Pollan believes omega-3 is to today what oat bran was to the 1980s. But fish didn’t suffer greater demand thanks to the oat bran hysteria. Fewer fish thanks to “efficient” meat devoid of omega-3. Just another shifting baseline…