Sombre news from the National Institutes of Health, it appears that supplements of omega-3 and carotenes have no benefit over a placebo in terms of cognitive decline in people in their twilight years.
Supplements of the carotenes lutein and zeaxanthin had previously been shown to help slow age-related macular degeneration (AMD), a degeneration of the eye. The researchers decided to add omega 3 to the list of supplements and run another study, also monitoring cognitive decline.
The study involved over 4,000 patients and lasted for 5 years. Unfortunately, none of the supplements were able to slow the cognitive decline, i.e. there was no difference between the cognitive decline across the treatment groups.
Still, it’s probably best not to give up on healthy eating yet. As the authors point out, the omega 3 in the supplements used in this trial were derived from fish oil. There is also omega 3 present in walnuts, chia and linseed (and at favourable omega 3: omega 6 ratios) and these sources have not yet been tested.
Also, why do we think omega 3 could help? Because people eating a diet rich in omega 3 seemed to have better cognitive abilities in their later years. Maybe it is not the omega 3 on its own that is giving this effect but the balanced diet as a whole.
I for one will be happily eating my piece of salmon for dinner tonight, and even it is turns out it will not help me keep my marbles for longer as least it tastes damn good.