A new study from Columbia University Medical Center certainly isn’t the first to link omega-3 fatty acids with brain health, but it is the first human study to link them with lower blood levels of beta amyloid, the protein used to mark Alzheimer’s risk. The more omega-3s someone consumed, the lower their blood level of beta amyloid, the researchers found. That means a diet high in omega-3s could help stave off dementia and Alzheimer’s disease.
“There is no threshold here,” says study author Dr. Nikolaos Scarmeas. “The more omega-3s one eats, the less the beta amyloid levels are. Previous studies have found this association in animals, but not in humans. It’s a good thing we see it in humans.”
The findings, published in the journal Neurology, were part of an analysis of 10 different nutrients and their relationship to beta amyloid in the blood. Of all the nutrients studied—saturated fatty acids, omega-3 and omega-6 polyunsaturated fatty acids, monounsaturated fatty acids, vitamin E, vitamin C, beta-carotene, vitamin B12, folate and vitamin D— only omega-3 was linked with less beta amyloid.
Consuming 1 gram of omega-3s per day — the equivalent of eating about half a fillet of salmon a week — was associated with 20% to 30% lower blood beta amyloid levels.
Researchers only looked at dietary intake of omega-3s, not supplements like fish oil taken for their omega-3s. Of the 1,200+ participants, most of the omega-3s consumed came from fish, chicken, margarine, nuts and salad dressing, On average, people weren’t getting the recommended 1 gram per day of omega-3s.
Despite increasing evidence of the importance of omega-3s for (all sorts of) health, most Americans continue to get way too little, along with way too many omega-6 fatty acids. Even people who eat a healthy diet may be omega-3 deficient, as raw foods chef Victoria Boutenko explains here:
Because the unique flexibility of the omega-3 molecule makes it highly perishable, in recent years genetic engineers have been manipulating the DNA of seeds, trying to develop strains with higher omega-6 and lower omega-3 content in order to prolong the storage life of seeds and the oils made from them.
In addition, most farm animals, such as cattle, sheep, pigs and chickens, have increasingly been fed soy, corn and other grains instead of grass and hay, which has altered the balance of omegas present in meat. People who consume animal products would benefit from knowing that the meat from animals that consume grass is high in omega-3s while the meat from animals that consumer corn and other grains is high in omega-6s.
Even fish aren’t guaranteed to be a good source of omega-3s anymore. Omega-3 fatty acids are the main reasons doctors recommend eating fish regularly, but farmed fish are now fed a grain heavy diet, vastly reducing their levels of fish oils. A very popular fish in recent years, tilapia, contains twice the level of omega-6 as omega-3s.
I’ve written a lot about omega-3s recently—enough to know that there are really simple and surprising ways to sneak more omega-3s into your diet (even if you don’t eat meat or fish). Nuts are one good source, though some are much better than others. Greens like spinach, arugula and purslane are also good source, as are seeds like flax, chia and hemp.