Low Omega-3 Levels Impair Cognitive Ability
Brain: low Omega-3 levels impair cognitive functions
Blood levels of Omega-3 below the average reduce cognitive abilities, but diet and supplements could help counteract the problem. Low Omega-3 levels in the body impair cognitive functions, but increasing the intake of foods or supplements rich in these molecules could help restore them to normal. This hypothesis is supported by the authors of a study published in Nutritional Neuroscience, who demonstrated that having blood levels of these fatty acids below the population average reduces cognitive flexibility, i.e., the ability, when necessary, to shift attention from one subject to another. At the same time, reduced Omega-3 levels are associated with a decrease in executive functions, i.e., the ability to plan, control, and coordinate cognitive activities.
The importance of Omega-3 for the body
The Omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are important both for the development and the functioning of the nervous system. Moreover, the benefits of these molecules for other organs and tissues, especially those of the cardiovascular system, have been known for a long time. However, the human body cannot fully synthesize them independently. In particular, cells can obtain DHA from EPA, but their ability to synthesize EPA from its precursor (alpha-linolenic acid or ALA) is limited. ALA, in turn, cannot be produced by the body, so it is very important to ensure an adequate Omega-3 intake through diet.
Effects of Omega-3 deficiency on the nervous system
Previous research showed that low DHA levels are associated with an increased risk of suicide among military personnel on missions. The authors of the Nutritional Neuroscience study also involved a group of soldiers, discovering that the amounts of EPA and DHA in their red blood cells were lower than those found in the US population of the same age. Specifically, the percentage of these Omega-3s in the soldiers’ red blood cells was 3.5%, compared to the typical 4.5% of their peers. The researchers were not surprised by this difference, which is justifiable by the generally poor Omega-3 diet followed by soldiers on deployment. More surprisingly, low levels of these nutrients were associated with reduced cognitive flexibility and executive functions. Data analysis from psychosocial and neurocognitive tests further revealed that the link between low Omega-3 levels and reduced cognitive ability was particularly strong in those reporting sleep disturbances. Moreover, soldiers who had poor sleep but higher-than-average Omega-3 levels appeared to have a greater capacity for recovery from fatigue and better cognitive flexibility and executive functions.
Feeding the brain with Omega-3
The authors hypothesize that the decrease in cognitive abilities could be countered by increasing EPA and DHA levels in the body, either by eating more Omega-3-rich foods or by taking fish oil supplements. The study aimed at testing this hypothesis has already been conducted, with results expected by the end of this year.
Source:
1. Johnston DT, Deuster PA, Harris WS, Macrae H, Dretsch MN, “Red blood cell omega-3 fatty acid levels and neurocognitive performance in deployed U.S. Servicemembers,” Nutr Neurosci. 2012 Jun 28 2. Lewis MD, Hibbeln JR, Johnson JE, Lin YH, Hyun DY, Loewke JD, “Suicide deaths of active-duty US military and omega-3 fatty-acid status: a case-control comparison,” J Clin Psychiatry. 2011 Dec;72(12):1585-90. Epub 2011 Aug 23
