Findings of the Martek funded study were published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association and showed that 24 week supplementation with 900 mg/d DHA improved learning and memory function in age-related cognitive decline (ARCD) and is a beneficial supplement that supports cognitive health with aging.
Cassie France-Kelly, director of corporate communications for Martek Biosciences, told Nutraingredients.com that DHA and its role in brain health throughout the lifecycle, and particularly in aging adults, continues to be an area of interest to Martek and its long-term strategy may include additional further clinical studies.
“We believe that the MIDAS results confirm the brain health benefits of DHA consumption for older adults and we plan to support the launch of consumer products for this population both through our own consumer products channel at Amerifit and through trusted partners,” she added.
Ageing process
The researchers said that the Memory Improvement with Docosahexaenoic Acid (DHA) study (MIDAS) is the first large, randomized and placebo-controlled study demonstrating the benefits of algal DHA in maintaining and improving brain health in older adults.
According to the study, age-related cognitive decline is defined as “decline in cognitive functioning consequent to the ageing process that is within normal limits given a person’s age. Individuals may report problems remembering names or appointments or may experience difficulty solving complex problems.”
Estimates indicate that as many as 5.4 million older Americans (22.2 per cent) have cognitive impairment without dementia, and approximately 12 per cent of these will develop dementia annually.
The authors claim that DHA plays an important role in neural function. Several epidemiological studies, they report, associate decreases in plasma DHA with cognitive decline in healthy elderly people and in patients with Alzheimer’s disease.
The study
Scientists examined 500 older adults with a mild memory complaint who took 900mg of algal DHA for six months.
The participants, said the researchers, took numerous computerized tests during the surveillance period that measured their ability to learn new information. The test of memory and learning used is called the CANTAB Paired Associate Learning (PAL), they continued.
CANTAB PAL is an assessment of visual memory and new learning, and is a useful tool for assessing patients with age-related memory loss, said the researchers.
The authors said that to minimize the potential confounding effect of high DHA consumption before study entry, subjects who consumed greater than 200 mg/d DHA in the two months before randomization or consumed omega-3 containing supplements, or medications for AD, major antipsychotics, or anti-depressants were excluded.
Futhermore, they said, a history or presence of major medical conditions, including a diagnosis of dementia or a geriatric depression, and current or past alcohol or drug abuse also excluded subjects from eligibility. Eligible subjects were stratified by age and randomized into blocks of four to active or placebo groups, said the researchers.
The study, explained the team, consisted of a screening visit, followed one week later by a baseline visit, and three follow-up visits, with safety and compliance measures assessed at every visit. Efficacy assessments were obtained at baseline, week 12, and week 24, they stated.
“All capsules were orange-flavoured and orange colour to protect the study blind. Subjects were instructed to take capsules with food at the same time each day (e.g., 1 capsule meal), starting at the baseline visit, and to not alter their normal diet during the study,” added the authors.
Outcomes
The results show that healthy people with memory complaints who took the algal DHA capsules had nearly double the reduction in errors on the tests than those who took the placebo (corn/soy) over the course of six months, a benefit equivalent to having the learning and memory skills of a person three years younger, claim the authors.
According to the researchers, the study also showed that DHA was well-tolerated and subjects taking it also experienced a lower heart rate, thus showing that the supplementation also provided a cardiovascular benefit.
Approach validated
France-Kelly, when asked whether conclusions can be drawn from a 24 week study said: “The length of treatment is an adequate time span to look for an improvement in memory in healthy older adults. To examine rate of decline, the test would need to be conducted over a longer period of time,” she added.
And she maintains that the study cohort is wide enough to support the findings: “A study using nearly 500 participants from 19 sites from across the country is credible. A statistical power analysis was conducted and indicated that the sample size was adequate to see a significant difference if one existed.”
Transparency
With the exception of three consultants, the researchers involved in the study were employed by Martek.
France-Kelly stressed that Martek ensures transparency is maintained throughout the process of studies supported by the company. She said that this clinical trial and all the other Martek sponsored studies, are registered on the website of the National Institutes of Health (NIH) – www.clinicaltrials.gov.
This means the methodology and design of the study were made available from initiation (prior to recruitment) through to its completion and results.
France-Kelly said Martek publishes the results of all its studies, whether positive or negative in terms of the benefits of products analysed: "We cannot guarantee publication of study results as the peer review process of journals is involved.
However, it is common within scientific clinical research today to publish all results, whether positive or negative. The NIH has guidance on this and Martek Biosciences follows these principles,” she reported.
Source: Alzheimer's & Dementia: The Journal of the Alzheimer's Association
Published online ahead of print doi:10.1016/j.jalz.2010.01.013
Title: Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline
Authors: K.Yurko-Mauro , D. McCarthy, D. Rom, E. B. Nelson, A. S. Ryan, A Blackwell, N Salem, Jr, M. Stedman