New research suggests that eating fish at least once a week can slow typical age-related mental decline by three to four years.
10-13% Slower Rate of Decline
Over 3,700 Chicago residents aged 65 and older took three memory tests over the course of six years, and also filled out a questionnaire about their food choices. Those who had fish once a week had a 10 percent slower annual decline in cognition, and those who ate fish twice a week showed a 13 percent slower decline.
No Link to Omega-3s?
The researchers failed to find a connection between omega-3 fatty acids and the prevention of brain decline, although previous studies found such a link. A researcher not involved in the study, however, argued that the questionnaire was too broad to allow for an accurate estimation of omega-3 intake.
Previous studies have found that people who eat fish lower their risk of Alzheimer's disease and stroke, and that fish rich in omega-3 fatty acids can prevent heart disease.
Beware of Mercury
However, the FDA has warned pregnant women, nursing mothers, and children to avoid some fish, such as shark, swordfish, king mackerel, and tilefish, because they contain high levels of mercury.
Since I am a Chicago native (I was born here and went to kindergarten through a three-year post-graduate residency training program all within the city limits), this study has special relevance to me. But I believe the results are just as important for those of you who did not grow up in Chicago.
However, it is most surprising these researchers failed to find a link many other studies have between fish rich in omega-3 fatty acids and improved brain functioning.
Possibly this was because, as at least one expert believed, the food questionnaire was faulty. Apparently, it only included four broad seafood categories -- tuna fish sandwich, fish sticks/fish cakes/fish sandwich, fresh fish as a main dish, and shrimp/lobster/crab -- which did not really allow for distinctions to be made between seafoods that were high in omega-3s and seafoods that were not.
As the article notes, most fish are too high in mercury to be safe, so if you want to get the beneficial, brain-protecting effects described, I would recommend you use a high-quality fish or cod liver oil instead. Most fish oil supplements, like the Carlson brand of fish oil/cod liver oil that I highly recommend and offer on this site, go through a molecular distillation process to clean out the mercury.
The Carlson brand also is routinely tested using standard international protocols in an independent, FDA-registered laboratory; this testing not only ensures freedom from detectable levels of mercury, but also cadmium, lead, PCBs and 28 other contaminants.
Fish or cod liver oil is really the only "supplement" I routinely take. I put supplement in quotes because I really don't believe that fish or cod liver oil is a supplement at all, but rather is a food.
It is also important to recognize that the time of the year has come for those of us that live in most of the United States to shift to taking cod liver oil and not fish oil. And be sure to avoid the mistake most people make when taking cod liver or fish oil.
You need a hefty dose for it to work. Most people need from one teaspoon to one tablespoon every day. Please remember, folks, this is a food, not really a supplement. So if you swallow a few capsules don't fool yourself into thinking you are getting all the benefits.
Capsules are OK for travel but for regular replacement they are not that good. Most adults would need 10 to 15 every day, which is not only inconvenient but more expensive than using the liquid. Fortunately, for most of us this is cod liver oil season and liquid cod liver oil is far less expensive than liquid fish oil.