Higher DHA Levels Associated with Slower Decline in Alzheimer’s Disease

by | Aug 1, 2022 | Alzheimer's Disease, Brain Health, DHA, EPA (Eicosapentaenoic Acid), Omega - 3

Written by Jessica Patella, ND. Study observations show an association between higher omega-3s, DHA and EPA and slower cognitive decline in patients with Alzheimer’s disease on acetylcholinesterase inhibitors.

Aging woman An estimated 5.8 million Americans are living with Alzheimer’s disease (AD) and the number of people with the disease doubles every five years after the age of 65 1.  The cost of treating AD in the United States is an estimated $159 to $215 billion annually 1.  With increasing prevalence and the many challenges of the disease, researchers are interested in how to slow the progression of AD 2.  Recent research found an association between levels of omega-3 DHA and AD 2.

Most available drugs for AD (acetylcholinesterase inhibitors, N-methyl-D-aspartate receptor antagonists) act on symptoms only and are not able to prevent or slow the progression of AD 2,3.  Omega-3 fatty acids (EPA & DHA) have been researched and shown that higher concentrations of blood levels are associated with a decreased risk of dementia 2,4.  The omega-3 fatty acids have different roles in the body.  DHA is found in the brain, while EPA is found primarily in the body with decreasing inflammation and improving immune functioning2,5.

Researchers for the first study of its kind measured EPA & DHA blood levels, recorded dietary habits and monitored cognitive changes in patients with AD receiving medication (acetylcholinesterase inhibitors).  A total of 127 patients were included in the initial data collection of the study and were then followed for two years.

During the two-year follow-up, patients were divided into a decline group (n=42, worsening clinical dementia rating (CDR)) and a stable group (n=87, unchanged CDR).  There were no significant differences in age, gender or cognitive testing between the groups.  In relation to diet, the only significant difference between the groups was a higher daily intake of total fat in the stable group, compared to the decline group (57.4 +/- 11.9 vs 49.4 +/- 11.8, p=0.042) 2.

Laboratory findings showed the only difference between the stable group and the decline group was that the stable group had significantly higher levels of omega-3s, DHA and EPA compared to the decline group:

  • Stable group: omega-3, 10.0 ± 13.8; DHA, 5.2 ± 7.1; EPA, 1.2 ± 0.9 and
  • Decline group: omega-3, 3.6 ± 7.2; DHA, 1.8 ± 3.6; EPA, 0.4 ± 1.0. All p < 0.05) 2(1).

When dividing the omega-3s, researchers found baseline DHA to be a protective factor for cognitive decline (OR:1.131, 95%CI: 1.020-1.254, p=0.020) in Alzheimer’s patients taking medication 2.

In conclusion, an association between higher omega-3s, DHA and EPA and slower cognitive decline in patients with AD on acetylcholinesterase inhibitors was observed.  Future research should examine baseline levels in Alzheimer’s patients who are not on medication and try to determine mechanisms of action 2.

Source: Chu, Che-Sheng, Chi-Fa Hung, Vinoth Kumar Ponnusamy, Kuan-Chieh Chen, and Nai-Ching Chen. “Higher Serum DHA and Slower Cognitive Decline in Patients with Alzheimer’s Disease: Two-Year Follow-Up.” Nutrients 14, no. 6 (2022): 1159.

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

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Posted August 1, 2022.

References:

  1. Prevention CfDCa. Alzheimer’s Disease and Related Dementias. 7/27/22, https://www.cdc.gov/aging/aginginfo/alzheimers.htm
  2. Chu CS, Hung CF, Ponnusamy VK, Chen KC, Chen NC. Higher Serum DHA and Slower Cognitive Decline in Patients with Alzheimer’s Disease: Two-Year Follow-Up. Nutrients. Mar 9 2022;14(6)doi:10.3390/nu14061159
  3. Fink HA, Hemmy LS, Linskens EJ, et al. Diagnosis and treatment of clinical Alzheimer’s-type dementia: a systematic review. 2020;
  4. Thomas A, Baillet M, Proust-Lima C, et al. Blood polyunsaturated omega-3 fatty acids, brain atrophy, cognitive decline, and dementia risk. Alzheimer’s & dementia : the journal of the Alzheimer’s Association. Oct 8 2020;doi:10.1002/alz.12195
  5. Su KP. Biological mechanism of antidepressant effect of omega-3 fatty acids: how does fish oil act as a ‘mind-body interface’? Neurosignals. 2009;17(2):144-52. doi:10.1159/000198167