Study Title:

DHA Helps Cognitive Function in Older Adults

Study Abstract

Background
Docosahexaenoic acid (DHA) plays an important role in neural function. Decreases in plasma DHA are associated with cognitive decline in healthy elderly adults and in patients with Alzheimer's disease. Higher DHA intake is inversely correlated with relative risk of Alzheimer's disease. The potential benefits of DHA supplementation in age-related cognitive decline (ARCD) have not been fully examined.

Objective
Determine effects of DHA administration on improving cognitive functions in healthy older adults with ARCD.

Methods
Randomized, double-blind, placebo-controlled, clinical study was conducted at 19 U.S. clinical sites. A total of 485 healthy subjects, aged ≥55 with Mini-Mental State Examination >26 and a Logical Memory (Wechsler Memory Scale III) baseline score ≥1 standard deviation below younger adults, were randomly assigned to 900 mg/d of DHA orally or matching placebo for 24 weeks. The primary outcome was the CANTAB Paired Associate Learning (PAL), a visuospatial learning and episodic memory test.

Results
Intention-to-treat analysis demonstrated significantly fewer PAL six pattern errors with DHA versus placebo at 24 weeks (difference score, −1.63 ± 0.76 [−3.1, −0.14, 95% CI], P = .03). DHA supplementation was also associated with improved immediate and delayed Verbal Recognition Memory scores (P < .02), but not working memory or executive function tests. Plasma DHA levels doubled and correlated with improved PAL scores (P < .02) in the DHA group. DHA was well tolerated with no reported treatment-related serious adverse events.

Conclusions
Twenty-four week supplementation with 900 mg/d DHA improved learning and memory function in ARCD and is a beneficial supplement that supports cognitive health with aging.

From press release:

A study published in the November edition of Alzheimer's & Dementia: The Journal of the Alzheimer's Association suggests that taking docosahexaenoic acid (DHA) may improve memory and learning in older adults with mild cognitive impairments. This is promising news for many aging Americans who are searching for options to maintain memory and support overall cognitive health.

The "Memory Improvement with Docosahexaenoic Acid Study" (MIDAS) was a randomized, double-blind, placebo-controlled study to evaluate the effects of DHA -- the principle omega-3 fatty acid in the brain -- on improving cognitive functions in healthy older adults with age-related cognitive decline. The study found that DHA taken for six months improved memory and learning in healthy, older adults with mild memory complaints.

"The results of this study are very encouraging for those consumers concerned about maintaining memory. We know that lower DHA levels are associated with cognitive decline in healthy elderly and Alzheimer's patients, and higher DHA levels help reduce the risk of Alzheimer's disease," said Duffy MacKay, N.D., vice president, scientific & regulatory affairs, for the Council for Responsible Nutrition (CRN). "Memory loss, dementia and the development of Alzheimer's disease are prominent health concerns for older individuals. The more we learn about the valuable role DHA plays in supporting brain function, the more options aging Americans have towards managing cognitive decline."

These findings underscore the importance of early DHA intervention. While the MIDAS study focused on a population of healthy adults with age-associated memory impairment, a study recently published in the Journal of the American Medical Association (JAMA), conducted in a population that had previously been diagnosed with Alzheimer's disease, did not indicate DHA provided a statistically significant benefit to cognitive function. The lead author of the JAMA study also highlighted that their results may have been different had DHA been administered before the participants' disease progressed.

"This study reinforces the principle that consumers will reap the most benefit from their DHA supplements -- and many supplements -- when they are taken over time and before a health concern is imminent," continued Dr. MacKay. "When included as a part of a proactive health regimen that includes a well-balanced diet, regular physical activity and routine visits with a healthcare professional, dietary supplements offer an important tool to help support many systems in the body, including memory and cognitive function."

The MIDAS study was conducted in a total of 485 subjects, aged 55 and older with a subjective memory complaint and who met criteria for age-related cognitive decline (or "age-associated memory impairment"). Subjects were randomly assigned 900 mg/d of algal DHA orally or a placebo for 24 weeks.

DHA is an omega-3 fatty acid and is available as a dietary supplement. Many Americans turn to dietary supplements each year help manage age-related challenges. According to CRN's Consumer Survey on Dietary Supplements, among Americans aged 55+ who take supplements, 13 percent report they do so for "memory" and 39 percent for "healthy aging."

Study Information

1.Karin Yurko-Mauro, Deanna McCarthy, Dror Rom, Edward B. Nelson, Alan S. Ryan, Andrew Blackwell, Norman Salem Jr., Mary Stedman.
Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline
Alzheimer's and Dementia
2010 November
Clinical Research Department, Martek Biosciences Corporation, Columbia, MD, USA.

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