Finding coincides with NY Times reports concluding that fish really is brain food 01/09/2006
The human brain is rich in DHA—a long-chain “marine” omega-3 fatty acid found only in fish and algae—and the findings of population studies and of clinical trials support its importance to brain health and mood.
But until now, the effects of marine omega-3s had never been tested thoroughly in healthy adults.
Italian team tests effects of fish oil on mood and mental performance
To determine whether omega-3s enhance the performance of normally functioning brains, a group of researchers at the Italy's University of Siena conducted a 35-day placebo-controlled trial in 49 healthy men and women aged 22 to 51 years.
Every day for 35 days, 33 of the study participants consumed four-gram fish oil capsules containing 2.4 gm of omega-3s each (1.6 g EPA and 0.8 g DHA) daily, while the other 16 participants took capsules containing four grams of if olive oil.
The participants were all in good health, free of medications, had no history of psychiatric or hormonal disorders, and exercised at least four hours a week.
All participants took the Profile of Mood States test and four attention tests on the first and last days of the trial. The attention tests included assessments of alertness, ability to repress an unsuitable response, ability to react to different stimuli, and sustained attention.
Key measures of participants' electro-physiological status—e.g., electroencephalogram, electromyography, heart rate, and reaction times—were also recorded during the attention tests.
Fish oil group shows gains in mood and brain speed
Participants in the fish oil group showed significant improvements on all the components of the mood tests, compared with baseline values, but there were no significant changes in the olive oil (placebo) group.
For example, perceptions of vigor increased while negative states such as anger, anxiety, fatigue, and depression diminished significantly.
The fish oil group also enjoyed significantly reduced reaction times in the attention tests, but reaction times were unchanged in the olive oil placebo group.
The authors noted that tests in which reaction times were shorter were those that involve central processing of information: findings consistent with previous reports that linked consumption of long-chain marine omega-3s with enhanced cognitive performance.
None of the outcomes measured was associated with the sex or age of the participants. The fish oil group also experienced a large, beneficial decrease in the ratio of omega-6 arachidonic acid to omega-3 EPA, from about 14:1 at baseline—a ratio that reflects the typically imbalanced dietary intakes of omega-6 and omega-3 fats in industrialized countries—to about 4:1 after the experimental period.
We should note that the participants consumed at least four times more long-chain marine omega-3s every week than you'd get by eating two meals of fatty fish per week, which is the typical dietary recommendation, intended to reduce the risk of heart disease.
Two "Times" agree evidence supports old fish-is-brain-food saying
As Dr. Andrew Weil told Time magazine this week, in a special section on brain health, “The reason fish is so good for the brain is the so-called omega-3 fatty acids it contains. Oily fish, like salmon, sardines, mackerel, herring, bluefish and black cod, are the best sources of those special fats…"
"In my diet I stick to sardines, herring, Alaskan black cod and Alaskan sockeye salmon. All sockeye (red) salmon are wild—fish farmers haven't yet been able to domesticate them—and since those fish are less carnivorous than other types of salmon, they have lower levels of the environmental contaminants that accumulate as you work your way up the food chain.”
And as The New York Times concluded in a recent edition of their recurring “The Bottom Line” column, “… when it comes to one piece of dietary advice that many of us were brought up on, the old wisdom prevails: fish is apparently food for the brain.”
The New York Times article noted that some scientists believe humans and their immediate ancestors gravitated to oceanic and inland coastal areas where protein food (i.e., fish and shellfish) was plentiful and easy to catch, and that the resulting fish-rich diet gave them the ample supply of omega-3 fatty acids necessary to development of the large, quick brains that gave humans a huge competitive edge.
We witnessed an extremely compelling presentation of this hypothesis from the eminent British brain-nutrition researcher Michael A. Crawford, Ph.D. of London Metropolitan University, at the Seafood & Health Conference we attended last November, and we'll explore it in more depth in a future issue of Vital Choices.
As the author of the New York Times column noted, evidence from many studies provide support for the idea that fish is brain food:
“One study this year at Harvard, which looked at 135 mothers and their infants, found that the more fish the mothers ate during their second trimesters, the better their infants did on tests when they were 6 months old. … Another recent study … found that elderly people who ate fish at least once a week did better on tests of memory and mental acuity than their peers who did not, and had a 10 percent slower decline in mental skills each year. … THE BOTTOM LINE: Fish is good for the brain.”
- Fontani G, Corradeschi F, Felici A, Alfatti F, Migliorini S, Lodi L. Cognitive and physiological effects of omega-3 polyunsaturated fatty acid supplementation in healthy subjects. Eur J Clin Invest 2005;35:691-699.
- O'Connor A. “Really? The Claim: Fish Is Brain Food” New York Times, January 3, 2006. Accessed online January 3, 2006 at http://www.nytimes.com/2006/01/03/health/03real.html