Omega-3s and cognitive health: From memory and moms and babies, and from mood to the military

Depending on the specifics of this question, the science says many different things. There are multiple randomized clinical trial that show clear benefits, for example, for cognitive performance and reducing the rate of age-related cognitive decline.

The data has not always been consistent in this area, with experts noting that some studies have performed in diseased patients (for example, Alzheimer’s disease) or have used insufficient doses.

Despite these limitations, many clinical trials have shown clear benefits to cognitive health, with a 2015 meta-analysis of randomized, controlled trials showing that daily DHA doses over 1 gram were required to improve some aspects of cognitive function in older adults (PLoS One​​).

A key area for many is the role of omega-3 fatty acids in the healthy development of a fetus during pregnancy.

A study from Canada, for example, reported that an increased intake of the omega-3 DHA during pregnancy could produce improved motor function in the offspring in later life (The Journal of Pediatrics​​).

And increased levels were linked to improved visual, cognitive, and motor development in the offspring, report the researchers from Wayne State University School of Medicine, Detroit and Laval University.

Results of a meta-analysis of 15 gold standard randomized controlled trials presented at the Experimental Biology 2016 event in San Diego, CA by scientists from Tufts University and Harvard indicated that EPA+DHA supplementation during pregnancy or infancy was associated with improved motor skills in the children (The FASEB Journal​​).

Mood and behavior​

Linked to cognitive performance are reports that omega-3 supplements may improve mood and behavior. Several studies have reported that supplementation with EPA and DHA may result in improvements in behavior and learning of children, although such studies have their critics.

In terms of mood, several studies, such as the French study published in the American Journal of Clinical Nutrition​​, have reported benefits for EPA and symptoms of depression.

Moreover, a joint Anglo-Iranian study reported that depression ratings were cut by 50% following daily one gram supplements of EPA, an effect similar to that obtained by the antidepressant drug fluoxetine (Australian and New Zealand Journal of Psychiatry​​).

Researchers have also reported a potential role for EPA in lowering the severity of symptoms of post-traumatic stress disorder (PTSD). According to data published in the Journal of Affective Disorders​​, increased levels of EPA+DHA (docosahexaenoic acid), EPA only, and the ratio of EPA to the omega-6 arachidonic acid (AA) were all associated with low PTSD severity symptoms in patients receiving omega-3 supplements at 3 months.

A recent study published in the Journal of Affective Disorders​​ found that omega-3s may benefit people suffering from post-traumatic stress disorder (PTSD), which is known to produce psychophysiological symptoms such as a pounding heart.

Such findings are of obvious interest to the current and former members of the armed forces. Indeed, military interest in omega-3 is nothing new, with the Military Medicine​ focusing on the fatty acids as “nutritional armor”.

Interest has focused on several different endpoints, including improving mood and reducing suicide rates among serving and ex-military personnel, speeding recovery from traumatic brain injury, and improving reaction times of fighter pilots.

An expert panel convened at the Nutritional Armor for the Warfighter Conference, jointly hosted by the Samueli Institute through the Metabolic Defense Program and National Institute on Alcohol Abuse and Alcoholism, concluded: “[B]ased on studies analyzing omega-3 and omega-6 FA balance, it would be unethical to not attempt elevating the omega-3 status among U.S. military personnel.”​

The US Army is currently studying if omega-3 supplementation (krill oil) can improve cognitive processes in high-performing warfighters in the Ranger Resilience and Improved Performance on phospholipid bound Omega-3s (RRIPP-3)​ study.

“The purpose of this study is to investigate whether supplementation with krill oil concentrate can improve specific cognitive processes that underlie key elements of soldier performance that may have a measureable impact on performance and mental health under the extreme psychophysiological stress of military officer training,” ​said study lead Bernadette Marriott, PhD, Professor and Director, Nutrition Section, Department of Medicine and Military Division, Department of Psychiatry and Behavioral Sciences, MUSC​.

Benefits for others​

The science will continue to grow, but intriguing results published recently in the journal Aggressive Behavior​​ suggested that the potential brain benefits of omega-3 supplements may even extend to people who don’t take them.

Scientists from the University of Massachusetts-Lowell, the University of Pennsylvania, and the National Institute on Alcohol Abuse and Alcoholism reported that omega-3 supplements may calm aggressive behavior in children and this has the knock-on effect of reducing the psychological aggression among adult caregivers not receiving supplements.

“This study is the first to show that omega‐3 supplementation in children can reduce inter‐partner psychological aggression among adult caregivers not receiving supplements,” ​wrote the authors.

“Findings suggest that improving child behavior through omega‐3 supplementation could have long‐term benefits to the family system as a whole.”​