In a study published in the journal Applied Physiology, Nutrition, and Metabolism, researchers at the University of Alberta say they have discovered a potential explanation for why a diet high in DHA, an omega-3 fatty acid found in fish, improves memory.

In an animal study, lead researcher Yves Sauve and colleagues discovered mice that consumed a diet high in DHA had 30% higher levels of DHA in the hippocampus region of the brain, compared with mice fed on a regular, healthy diet.

Sauve, a researcher in the Faculty of Medicine & Dentistry, who works in the department of physiology, the department of ophthalmology and the Center of Neuroscience, explained:

“We wanted to find out how fish intakes improves memory. What we discovered is that memory cells in the hippocampus could communicate better with each other and better relay messages when DHA levels in that region of the brain were higher. This could explain why memory improves on a high-DHA diet.”

The researchers confirmed that when DHA is added to a diet, additional stores of DHA are deposited in the brain. Sauve explains that consuming more fish or taking supplements could prevent DHA levels decreasing in the brain as we age.

In an earlier study, Sauve found that consuming DHA stops a toxic molecule at the back of the eye that causes age-related vision loss from accumulating.

DHA stands for Docosahexaenoic acid – it is an omega-3 fatty acid that is a main structural component of the retina, sperm, testicles, and human brain cerebral cortex.

Cold-water oceanic fish oils are rich in DHA. DHA can also be manufactured commercially from microalgae.

The following foods are rich in DHA:

  • Algae
  • Anchovies
  • Bluefin or Albacore Tuna
  • Breast milk (also infant formula milk)
  • Caviar or Fish Roe
  • Herring
  • Salmon
  • Sardines
  • Swordfish

DHA fish oils and alzheimer’s disease – experts have long believed that DHA fish oils taken regularly can help alleviate the signs and symptoms of people with Alzheimer’s disease. However, a recent study published in JAMA (Journal of the American Medical Association) found that over an 18-month period, regular consumption was no better than placebo. (Link to article)

DHA and male fertility – researchers from the University of Illinois found that regular fish oil DHA consumption helps construct the arch that turns a round, immature sperm cell into the streamlined super swimmer with an extra long tail, thus improving male fertility. (Link to article)

Low DHA linked to higher suicide risk – scientists at the Uniformed Services University of the Health Sciences (USU) and the National Institute of Alcoholism and Alcohol Abuse (NIAAA) at the National Institutes of Health (NIH) found that low levels of DHA may be linked to a higher risk of suicide among military personnel. Their study was published in the Journal of Clinical Psychiatry. (Link to article)

Written by Grace Rattue