Abstracted by Greg Arnold, DC, CSCS, January 18, 2012, from “Associations between n23 PUFA concentrations and cognitive function after recovery from late-life depression” printed online January 4, 2012 in the American Journal of Clinical Nutrition. Researchers found benefits with blood levels of omega-3 fats and cognitive function in a study involving 132 patients with a previous diagnosis of major depressive disorder but not depressed in the last 3 months. Posted June 21, 2012 r/km.
As the U.S. population continues to age (with an estimated 1 in 8 Americans (36.9 million) over the age of 65 as of 2009 (1)), increasing concern is paid to the numerous mental health issues that can affect U.S. seniors. These include Alzheimer’s Disease (currently affecting 4.5 million Americans (2)) at a cost of $100 billion per year (3)) and Parkinson’s Disease (affecting 1.5 million Americans (4) and costing $5.6 billion (5)).
A third mental health issue is late-life depression, which affects an estimated 3% of U.S. seniors (6) and has actually been found to increase the risk of falling in seniors (7) which in 2000 cost the U.S. health care system over $19 billion dollars or $28.2 billion in 2010 dollars (8). While the exact changes in brain chemistry that cause late-life depression are not exactly known (6), research has continued to link low levels of omega-3 and altered brain chemistry (9). Now new research (10) continues to suggest an link to mental health in the elderly.
The study involved 132 patients with a previous diagnosis of major depressive disorder but not depressed in the last 3 months. They provided blood samples and completed 6 different cognitive tests that included general intelligence (11), word list recall (12), timed recall (13), visual and spatial recall, and fluency of recall in the form of fruit naming.
The researchers found direct associations between both EPA (one type of omega-3 fat) and total omega-3 fatty acid levels of higher scores on the cognitive tests. They found “the strongest and most consistent correlations” in those with repeated depressive episodes having higher total omega-3 fatty acid levels in addition to lower levels of alpha linolenic acid (found in vegetable oils) (14). Because the researchers only measured blood levels and did not obtain any data on food intake, no beneficial omega-3 doses were discussed and no risk reductions for depression were stated, just that an association existed in the study between omega-3 intake, depression and memory.
For the researchers, “our findings suggest that [blood levels of omega-3 fats] are positively associated with cognitive function, particularly immediate recall, in older people with previous major depression.”
- “Profiles of Americans: 2010” – http://www.aoa.gov/AoAroot/Aging_Statistics/Profile/2010/3.aspx
- Hebert, LE; Scherr, PA; Bienias, JL; Bennett, DA; Evans, DA. “Alzheimer Disease in the U.S. Population: Prevalence Estimates Using the 2000 Census.” Archives of Neurology August 2003; 60 (8): 1119 – 1122
- Ernst, RL; Hay, JW. “The U.S. Economic and Social Costs of Alzheimer’s Disease Revisited.” American Journal of Public Health 1994; 84(8): 1261 – 1264
- “About Parkinson Disease” posted on the National Parkinson Foundation Website www.parkinson.org
- “Ten Frequently Asked Questions About Parkinson’s Disease” posted on the Parkinson’s Disease Foundation Website www.pdf.org
- “Late Life Depression: What You Need to Know’ – http://www.wpic.pitt.edu/research/depr/depression.htm
- “Late Life Depression Linked to Falls” – http://psychcentral.com/news/2008/06/18/late-life-depression-linked-to-falls/2474.html
- “Cost of Falls In Older Adults” – http://www.cdc.gov/HomeandRecreationalSafety/Falls/fallcost.html
- Lin PY. A Meta-analytic review of polyunsaturated fatty acid compositions in patients with depression. Biol Psychiatry 2010;15:140–7.
- Chiu CC. Associations between n23 PUFA concentrations and cognitive function after recovery from late-life depression. Amer Jou Clin Nutr 2012. Printed online January 4, 2012. doi: 10.3945/ajcn.111.015784.
- Wechsler D. Wechsler Adult Intelligence Scale-III. San Antonio, TX: The Psychological Corporation, 1997.
- Wechsler D. The Wechsler Memory Scale. San Antonio, TX: Harcourt Brace: The Psychological Corporation, 1997.
- D’Elia LF. Color Trail Test: psychological manual. Lutz, FL: Psychological Assessment Resources, Inc, 1994.
- “Omega-3 fatty acids, fish oil, and alpha-linolenic acid” – http://www.mayoclinic.com/health/fish-oil/NS_patient-fishoil