Omega-3 is supposed to reduce Alzheimer’s risk by up to 65 percent

Meta-analysis from prospective cohort studies attests to high protection

In view of rising numbers of Alzheimer’s and other neurodegenerative diseases worldwide, prevention is playing an increasingly important role, in addition to the development of effective therapies and diagnostic early detection options.  Many scientific circles are therefore taking a more intensive look at the potential of our diet and possible supplementation with food supplements.

Omega-3, i.e. polyunsaturated fatty acids, has long been on the list of preventive measures discussed, for example to prevent heart disease, but also Alzheimer’s, dementia and other neurodegenerative diseases.

Recent research now indicates that a daily dose of more than 1 gram of omega-3 fatty acids can reduce the risk of Alzheimer’s by an impressive 65 percent or so. In addition, a comprehensive meta-analysis of 48 long-term studies found that omega-3 fatty acids can also reduce the likelihood of dementia and cognitive decline by up to 20 percent.

Omega-3: Simple protection against cognitive decline

Omega-3 fatty acids, a group of polyunsaturated fatty acids, are long-chain hydrocarbons with a carboxyl group (-COOH) at one end and a methyl group (-CH₃) at the other. The name “omega-3” indicates that the first double bond in the molecule occurs at the third carbon bond, counting from the methyl end.

The most important omega-3 fatty acids for the human body are: Alpha-linolenic acid (ALA), an essential fatty acid that the body cannot produce itself and therefore must be obtained from food. It is found mainly in vegetable oils such as flaxseed oil, hemp oil and walnut oil. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are both found mainly in fatty fish and certain algae oils. The human body can produce EPA and DHA from ALA to a limited extent, but this conversion process is not very efficient.

Omega-3 fatty acids play an important role in various bodily functions, including the formation of cell membranes, the production of signaling substances, and the regulation of inflammation. Numerous studies have long pointed to the health benefits of omega-3 fatty acids, but a meta-review has yet to be conducted.

A study group from Qingdao University, Qingdao, China, evaluated the longitudinal relationships of omega-3 polyunsaturated fatty acid intake with the risk of developing Alzheimer’s disease (AD), dementia and other cognitive diseases. The results of their meta-study were recently published in The American Journal of Clinical Nutrition.

High evidence to reduce risk of developing Alzheimer’s dementia

Previous data had already linked omega-3 fatty acids to the risk of developing dementia. The scientists:goal was to also assess the longitudinal relationships of omega-3 polyunsaturated fatty acid intake as a blood biomarker with risk of Alzheimer’s disease (AD), dementia, or other cognitive diseases.

For this purpose, longitudinal data were derived from 1,135 participant:s (mean) who did not have dementia. The mean age of the subjects was 73 years. For analysis, the Alzheimer’s Disease Neuroimaging Initiative (ADNI) cohort was applied to compare associations between omega-3 fatty acid supplementation and blood biomarkers with Alzheimer’s disease dementia outcomes during a 6-year follow-up.

In addition, a meta-analysis of published cohort studies was conducted to assess the long-term relationships of dietary omega-3 intake in relation to peripheral markers with dementia of any cause or cognitive decline. As a causal dose-response relationship, analyses were performed using the robust error meta-regression model.

According to the Alzheimer’s Disease Neuroimaging Initiative (ADNI), in the cohort of long-term users:of omega-3 fatty acid supplements, there was a reduction of approximately 65% for the risk of developing Alzheimer’s dementia (hazard ratio: 0.36, 95% confidence interval: 0.18, 0.72; P = 0.004).

Dementia and other cognitive diseases can also be prevented with omega-3

After analysis of 48 longitudinal studies involving 103,651 participant:s, there was also a moderate to high level of evidence that regular, daily dietary intake of omega-3 fatty acids can reduce the risk of dementia of any cause or cognitive decline by about 20 percent.

Conclusion: long-term dietary supplementation with omega-3 fatty acids may help significantly reduce the risk of Alzheimer’s dementia or other cognitive disease.


B.-Z. Wei, L. Li, C.-W. Dong et al, The Relationship of Omega-3 Fatty Acids with Dementia and Cognitive Decline: Evidence from Prospective Cohort Studies of Supplementation, Dietary Intake and Blood Markers, American Journal of Clinical Nutrition 2023; 117: 1096-1109.