Some months ago, we presented a review of 3 anti-inflammatory diet books. One of the major points on which all three authors agreed was that Omega 3 fatty acids were good for you (so eat plenty of fish and take a fish oil supplement they advise), but unfortunately most of us eat more Omega 6 fatty acids. New research takes that idea one step and four generations further.
Many scientists agree that humans evolved to eat roughly equal amounts of Omega 3 to Omega 6 fatty acids. Unfortunately, the modern Western diet that many Americans eat has roughly 15 times as much Omega 6 as Omega 3. This is partly because of modern agricultural practices including feeding corn to meat animals. According to one metastudy (emphasis added):
In the secondary prevention of cardiovascular disease, a ratio of 4/1 was associated with a 70% decrease in total mortality. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. A ratio of 2-3/1 suppressed inflammation in patients with rheumatoid arthritis, and a ratio of 5/1 had a beneficial effect on patients with asthma, whereas a ratio of 10/1 had adverse consequences.
Research to be published in a few days paints an even more bleak picture:
To perform their experiments, the researchers exposed four generations of mice to a Western-style diet, characterized by these same omega 6/omega 3 ratios. As a result, they saw a gradual increase in fat mass over several generations. They also observed the onset of metabolic disorders such as insulin resistance, which is the first step in the development of type 2 diabetes and a stimulation of the expression of the inflammatory genes involved in obesity.
Each generation of mice was fatter than their forebears while eating a diet high in Omega 6 fatty acids. There was no change in diet or activity level over the 4 generations; more of the same resulted in fatter mice with each generation. Scientists speculate that they may have found just one cause of the increasing obesity epidemic.
This is not to say that there is no point in putting your dietary house in order today. On the contrary, it’s a reason for parents to be more diligent in selecting quality, healthy foods for their families.
Her take: I do take issue with the last sentence of the press release on this research: “The agrifood industry needs to take greater account of the implications of these findings.” The “agrifood industry” is in the business of making money, and the existence of some of the chemistry sets sold as food — particularly to children — should alert you to the fact that our health is not their primary goal. It is our responsibility as consumers to make our best effort to be informed and choose healthy food. If more consumers demanded healthier products such as grass-fed beef, the “agrifood industry” would find a way to make it available to us.
