Think about the fats in your diet for a minute. Think about their variety.
Some of these fats are integral to food, like those in nuts, olives, fish, meat, and avocados. Others are added deliberately or used in cooking, like oils, butter, margarine, dressings, or cream. Still others are added to processed foods, and among these are man-made ones like interesterified fats and some types of trans-fats.
Now think for a minute about the types of fats people were eating a millennium ago. Most of these were the integral kind, with maybe a few exceptions like oil from crushed olives or fat rendered from cooking meat.
Better omega balance
Does it matter that we now eat a lot more in the way of processed fats? According to research, it’s made a big difference in human health over the last 150 or so years.
Here’s a little perspective. Human ancestral diets—the ones we evolved with, and which shaped human immunity—had a natural balance between two basic types of fat: omega-3s and omega-6s (named so for their chemical structure). But the modern food supply has been shaped by modern agriculture and food processing, which has introduced many novel, refined fats into our diets.
One result of these changes has been a big shift in the omega-6-to-omega-3 balance. Humans (and human immunity) developed with an even 1-to-1 ratio between omega-6 and omega-3 fats. In the 20th and 21st centuries, this balance shifted strongly towards omega-6, and now the ratio is around 15-to-1 in favor of omega-6. That’s a lot of change, and it happened at a speed that greatly outpaces human evolution!
Food fats aren’t the only thing changed by modern living, but they are an important part of the story. In fact, a lot of research has focused on how the types of fats you eat affect immune balance and overall health. The shift towards omega-6 fats has been linked to maladies that used to be rare, including obesity, heart disease, chronic immune issues, diabetes, asthma, skin conditions, and mood changes.
Omega-6 and omega-3 fats are incorporated into the body—especially the ever-vigilant immune system—in different ways. Omega-3s have more “joints” in their molecules and are less rigid than most omega-6s, so cells made with omega-3s tend to be more fluid, and more adaptable to changing conditions within the body.
Human chemistry transforms omega-6s into a variety of substances, some of which can encourage inflammation. Omega-3s, on the other hand, are changed into compounds (like pro-resolving mediators) that may help maintain better immune balance.
Here are some ways of restoring better omega balance:
Emphasize whole foods over processed ones
Enjoy more nuts, seeds, and sustainable cold-water fish
Consider supplementing with sustainably-sourced omega-3s, especially the longest and most limber ones, EPA and DHA
For a deeper dive
Curious to know more? This article describes how increased consumption of common oils has led to lower body levels of EPA and DHA. These oils aren’t necessarily bad, and some contain essential fats that the body could potentially use to make EPA and DHA, except for one little problem …
Humans don’t create enough of the enzymes needed for building EPA and DHA. So instead of ending up with more EPA and DHA when you eat these oils, you have less! The authors also describe many other interesting facts about 20th-century food habits.