Omega-3, part 2 of 2
Regarding recommended intakes for omega-3 and omega-6 fats, research has focused on relative, not absolute, amounts. The reasons for this are historical; currently Americans are consuming an approximate ratio of 15:1 (omega-6 : omega-3). Generations and generations ago, our ancestors consumed a ratio much closer to 1:1 and a ratio of 4:1 is what is recommended today based on the latest research. The theory goes that we’re not feeding our bodies as evolution designed us to eat, and this is the reason the onslaught of many new health issues has arisen – type 2 diabetes, heart disease, asthma, and others. For a brief discussion and some data about this ratio, visit the Whole Health Source blog.
Not all researchers agree that relative amounts should be the only focus. Two Harvard papers, both written in part by WC Willett, concluded that the issue is more about raising omega-3’s, and that lowering omega-6’s showed no appreciable benefits. But still, even though there’s disagreement over the ratio, everyone seems to agree that omega-3’s have importance. Abstracts here and here.
So finally, what food sources contain which kinds of fats? These two PUFA’s come from a range of meats, vegetables, nuts, and their oils, often both in one kind of food. But still there are certain foods that are clearly dominated by one and not the other.
Good sources of Omega-3’s:
ALA: flaxseed and oil, walnuts and walnut oil, canola oil, leafy green vegetables like broccoli and spinach, grains
EPA/DHA: wild fish (especially salmon), grass fed beef, eggs. In general the more natural the animals eat, the better.
Good sources of Omega-6’s:
LA: safflower, sunflower seeds, vegetable oils, corn oil
AA: animal meats, farmed fish, eggs. In general, animals that have a heavily processed and corn derived diet have higher omega-6 to 3 ratios.
The bottom line behind all this research and nutrition hype seems to be that we should eat what evolution carved us out to eat. More omega-3’s, less omega-6’s. More real food, less processed and overly preserved.
What do you think?