Omega-3 and the brain: fish oil preserves structure and size

The consumption of fish oil rich in Omega-3 appears to promote positive changes in the structure of the human brain. Supplements could thus preserve brain volume and function, reducing the risk of neurodegeneration and cognitive decline.

This is reported in a study published in the journal Alzheimer and Dementia. The work, aimed at investigating the relationship between fish oil supplement use and cognitive deficits in the elderly, was conducted by researchers from Brown University and Rhode Island Hospital in Providence (USA).

Omega-3 against cognitive decline

Omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are essential for the formation and activity of the central nervous system. In particular, DHA is a major component of neuronal membranes and is associated with proper brain development during fetal life, also playing a fundamental role in nerve impulse transmission in adulthood. Various studies reveal the association between Omega-3 deficiency and neurodegeneration, and many researches suggest that polyunsaturated fatty acids may protect against Alzheimer’s disease, reducing the risk of developing it.

Positive effects for supplement users

In this new study, researchers led by Lori Daiello analyzed data from 819 people with and without cognitive problems (229 normal subjects, 397 with mild cognitive impairment, and 193 with Alzheimer’s disease). Among them, 117 regularly used fish oil supplements. All subjects were evaluated with neuropsychological tests and brain MRI every 6 months.

The researchers compared cognitive function, observing that fish oil supplement users in all three groups showed better cognitive performance. This effect was not observed in subjects carrying the ApoE4 gene, already known as an Alzheimer’s risk factor. Furthermore, scientists found a clear association between fish oil use and average volumes of the cerebral cortex and hippocampus. These two areas, involved in memory and thinking, showed less shrinkage in elderly supplement users compared to others. This association was also significant only for ApoE4-negative individuals.

According to scientists, the neuroprotective role of Omega-3s may largely be due to vascular effects. However, other mechanisms have been proposed, including the action of a molecule called neuroprotectin D1, formed from DHA during periods of oxidative stress.

Fish oil consumption is associated with greater brain volume

The results indicate that the use of Omega-3-containing supplements may be associated with better cognitive function, reduced atrophy, and maintenance of brain volume. This study is the first to report an association between supplements and structural brain changes in groups of people with different cognitive conditions. It highlights the need for future research on the long-term effects of supplements for preventing cognitive decline and dementia in middle-aged and older adults. Importantly, researchers emphasize the need to identify ApoE4 carriers in these studies.

Source: Daiello L, Gongvatana A, Dunsiger S, Cohen RA, Ott BR; Alzheimer’s Disease Neuroimaging Initiative. "Association of fish oil supplement use with preservation of brain volume and cognitive function." Alzheimers Dement. 2014 Jun 18. pii: S1552-5260(14)00079-X. Doi:10.1016/j.jalz.2014.02.005.