This post comes to you from about 30,000 feet en-route from Detroit to Portland, Oregon. I’m heading out there for a scientific conference on diet and nutrition, where I will be presenting some of my own work on omega-3 fats.
Since this is fresh in my mind, I thought I’d catch you up on some of the work that is going on. Realize that this is fresh out of my lab and has not yet passed through the scrutiny of scientific review.
First, a little review – then, I’ll get to the new stuff. Omega-3s work in concert with another class of omega fats, called omega-6s. It is important to keep these two classes of fats in balance because, although they both are important, they actually compete with each other for many physiological processes – kind of like the yin and yang of fats. You can’t really think of one as good and one as bad. It’s the same way the brake and accelerator are both important in your car. You need them both working well but they have opposing functions.
Historically, up until about 100 years ago our diet consisted of approximately equal amounts of omega-3s and omega-6s. However, today we get about 20 times more omega-6s than omega-3s. This is because omega-6s are high in all the standard oils that we find in our processed foods, like corn oil, safflower oil, sunflower oil and soybean oil. And omega-3s are mostly in fish, some nuts, flax and hemp seeds. Most people today just eat far more of the foods high in omega-6s and low in omega-3s – thus, the imbalance.
In fact, omega-3 deficiency has now been implicated in some forms of major depression, schizophrenia, Alzheimer’s, diabetes and heart disease. That’s why so many products today are pushing their omega-3 content as a health benefit.
So now for the new stuff. We are starting to generate some data in my own lab that suggest a diet high in omega-6s (similar to the typical western diet) actually increases weight gain. When we put certain types of rats that are ‘pre-diabetic’ on a balanced omega-3 : omega-6 diet, they don’t gain much weight. But when we put them on the high omega-6 diet they gain a lot of weight. The kicker is that the two diets are identical in the amount of calories and the rats eat the same amount. That means that it’s not just the calories from fat, but the type of fat (high omega-6s) that is really causing the weight gain.
The other thing about a high omega-6 diet that we are finding is that if the rats get a little stressed on the high omega-6 diet then they tend to start eating a lot more. In contrast, a little stress while eating the balanced omega-3 : omega-6 diet does not cause them to overeat.
So there may be a viscous cycle here: The combination of a high omega-6 diet (typical western diet) and stress (who does feel that) make you eat more AND pack on more pounds relative to a balanced diet. So we are eating diets that make us fat and make us want to eat more.
The bottom line for you is, try to increase your omega-3 intake by eating stuff high in omega-3s, and cut back on the omega-6s by limiting the processed foods that have oils from corn, safflower, sunflower or soy as major ingredients. But please don’t confuse soybean oil with soy protein. Soy protein is associated with lower risk of certain cancers and general cardiovascular health.
If you think about it, this all makes a lot of sense. We evolved as a species growing up mostly next to large bodies of water and ate lots of fish through most of our history. It was only the advent of agriculture that drove us farther in land, and this happened relatively late on the physiological evolution scale.
Today, we are warned about the dangers of too much fish because of the potential for high mercury and PCB content. If you are going to take a fish oil supplement, as I do, make sure you check the back of the label to make sure it state that these contaminants have been purified away. But you can also do well by cutting back on the omega-6s and getting some more non-fish sources of omega-3s, like walnuts and flaxseed.
These strategies will help you heart, liver and brain and help you regain control of your weight.
