By Dr. Barry Sears
I have often said that if you’re fat, it may not be your fault. Recent research goes further to illustrate this point. In particular, an article published in Cardiovascular Psychiatry and Neurology (2009;2009:867041) demonstrates what happens when you take genetically identical mice and put them on different diets for three generations. The diets were equal in calories and total fat, but only differed in the ratio of omega-6 to omega-3 fats. By the third generation, the mice on the high omega-6 fatty-acid diet were considerably fatter, had higher levels of arachidonic acid (i.e. Toxic Fat) and had more damage to their organs.
What this means is that a seemingly minor change in the diet can have dramatic genetic consequences. This is called epigenetics. It appears to be the underlying cause of our current obesity crisis. Our children represent the third generation of Americans who have been exposed to high omega-6, low omega-3 diets. Even though the total fat consumption has remained the same since 1960, obesity has skyrocketed. These epigenetic changes caused by changing the ratio of omega-3 to omega-6 fatty acids in the diet may explain this. It also suggests that it may take another three generations of high omega-3, low omega-6 fat diets to reverse the existing genetic damage.
Thus all the cries for more exercise and eating fewer calories by nutritionists (and politicians) may have little effect on our obesity epidemic. To make the situation even more ominous, the author of this study told me that his group will present more even more disturbing research at the International Fatty Acid Conference I am attending next week in the Netherlands.