Recently, an article was published in JAMA, a world famous academic journal, which seems decisive about the effect of the supplement.
JAMA: Effect of Omega-3 Fatty Acids, Lutein/Zeaxanthin, or Other Nutrient Supplementation on Cognitive Function The AREDS2 Randomized Clinical Trial
In this study, the participants were randomly assigned to either (1) placebo; (2) DHA/EPA; (3) lutein/zeaxanthin; or (4) DHA/EPA and lutein/zeaxanthin group. They were followed up for four years. Cognitive function was examined in each period. As a result, whether taking supplements or not was proven not to influence the cognitive function.
Since this study is a randomized controlled trial, the validity of the results is much higher than those of cohort studies frequently seen elsewhere. However, there are some questionable aspects.
The participants were at risk of retinal muscle degeneration just I mentioned recently. It seems no direct relationship between cognitive impairment and retinal disease is unknown. Nonetheless, it is possible that the participants are not representative of the whole aged people.
My past entry: Stem cell transportation to regain vision
Cognitive function was examined via a telephone interview in this study. It means that some domains of cognition such as visual memory were ignored in the evaluation. But, in Alzheimer disease, a common cause of cognitive impairment in elder people, recent memory is likely to be damaged firstly. Therefore, telephone interview seems enough to detect the early signs of dementia.
After all, supplements, including omega-3 unsaturated acid as a famous antioxidant, are not likely to prevent you from decrepitude. I am not surprised to see this conclusion. Daily diet for a long time is more important in protecting your body and brain.
There are some diet styles that may be beneficial in terms of anti-aging. The Mediterranean cuisine is potentially powerful to keep you healthy. For example, Greek people frequently eat fish and fruits, and they always use olive oil. Compared to them, British cuisine contains lots of fats and red meat. I have to say British are eating more harmful food than Greek. Some British people are fond of vegetarian cuisine while I am not sure they are aware of this fact.
USA Today: Diet, not pills, may still be the best bet for brain power
How is Japanese cuisine? Japanese food contains little fat, in general. We also eat a large amount of fish. On the other hand, rape oil commonly used in Japan is said not to be good for health. Unfortunately, rice is also inferior to whole grain in terms of nutrition. I like Japanese cuisine the most, nonetheless.