What Are Fish Oil Supplements Good For? Here’s Your Crash Course

Docosahexaenoic acerb (DHA), an omega-3 fatty acerb recovered successful abundance successful oily food specified arsenic mackerel and sardines, is thought to amended cognitive relation by supporting connections betwixt encephalon cells. However, it has ne'er been conclusively demonstrated that DHA taken arsenic a dietary supplement really reaches the encephalon oregon provides measurable benefits against dementia.

Against this backdrop, a probe squad astatine the USC School of Medicine has published the results of a large, two-year objective proceedings involving older adults astatine elevated hazard of processing Alzheimer's disease. The survey recovered that portion high-dose DHA supplements bash so scope the brain, they did not amended representation oregon cognitive function, nor did they dilatory encephalon atrophy.

“Everyone hopes for a metallic slug to forestall Alzheimer's disease, but we can't accidental that food lipid supplements support encephalon health,” said Hussein Naji Yassine, manager of the Personalized Brain Health Center astatine USC. “While omega-3s play an important relation successful forming encephalon compartment connections needed for cognition, our results bash not enactment food lipid supplements arsenic a preventive measurement against Alzheimer’s.”

DHA Reached the Brain, But ...

Yassine and his colleagues conducted a randomized, double-blind, placebo-controlled proceedings involving 365 men and women betwixt the ages of 55 and 80 who seldom ate fish. Nearly fractional of the participants (47 percent) carried the APOE ε4 allele, the strongest familial hazard origin for late-onset Alzheimer's disease. All participants consumed little than 200 mg of DHA per time done their diet.

Participants were randomly assigned to 1 of 2 groups. One radical received a regular supplement containing 2,000 mg of DHA, portion the different received a placebo for 24 months. The placebo consisted of a substance of maize lipid and soybean lipid and was indistinguishable from the DHA supplement successful appearance, taste, and smell. Neither the participants nor the researchers knew which attraction each idiosyncratic received.

The researchers archetypal wanted to find whether DHA really reached the brain. Measurements of DHA levels successful the cerebrospinal fluid, which surrounds the encephalon and spinal cord, showed that concentrations accrued by 17 percent aft six months successful the DHA group. There was nary quality betwixt carriers and noncarriers of the APOE ε4 allele, providing nonstop grounds that high-dose DHA supplementation reaches the brains of cognitively steadfast older adults careless of APOE ε4 status.

The results were precise different, however, erstwhile it came to cognitive relation and encephalon structure. After 24 months, participants completed the Repeatable Battery for the Assessment of Neuropsychological Status, a standardized trial of representation and cognitive performance. No important differences were recovered betwixt the DHA and placebo groups. Likewise, determination were nary important differences successful changes successful hippocampal volume, a encephalon portion captious for representation and an aboriginal biomarker of Alzheimer's disease.

Why Didn’t It Work?

The researchers suggest respective imaginable explanations for wherefore DHA reached the encephalon but failed to nutrient measurable objective benefits. One anticipation involves an enzyme that disrupts DHA metabolism successful the brain. When an enzyme known arsenic calcium-dependent phospholipase A2 (cPLA2) becomes activated, it whitethorn interruption down DHA earlier it tin beryllium incorporated into synaptic membranes—the structures wherever DHA is thought to play its astir important relation successful supporting cognitive function.

Another imaginable mentation is that galore participants had cardiovascular hazard factors specified arsenic obesity, hypertension, and carnal inactivity. The chronic inflammation associated with these conditions whitethorn person blunted the effects of supplementation, making it hard for a azygous nutrient to nutrient measurable benefits.

The researchers besides enactment that the participants were comparatively young, with an mean property of 66, and experienced lone minimal cognitive diminution implicit the people of the two-year study. As a result, determination whitethorn simply person been excessively small diminution during the proceedings to observe immoderate protective effect from DHA supplementation.