DHA omega-3 ‘not useful’ for Alzheimer’s patients

02-Nov-2010 - Last updated on 02-Nov-2010 at 16:33 GMT

Related tags Dha Alzheimer's disease Docosahexaenoic acid

Daily supplements of docosahexaenoic acid (DHA) were ‘not useful’ in reducing cognitive decline associated with mild-to-moderate Alzheimer’s disease, says a new study.

Writing in the Journal of the American Medical Association (JAMA), researchers report that DHA at a dose of 2 grams per day did not affect cognitive and functional abilities after 18 months of supplementation.

“Despite enrollment of the target population of individuals with low baseline DHA, increase of plasma phospholipid and cerebrospinal fluid DHA in the group treated with DHA, and ample progression of randomized participants on the primary outcome measures, there was no evidence of benefit of DHA supplementation in this population,” wrote the researchers, led by Joseph Quinn, MD, of Oregon Health and Science University.

“The hypothesis that DHA slows the progression of mild to moderate Alzheimer disease was not supported, so there is no basis for recommending DHA supplementation,” they added.

Response

The study’s findings should not diminish the important benefits of DHA, however, said the Council for Responsible Nutrition (CRN), and that more research should be done. “The concern with this study is that it focused on supplementing DHA in individuals who were currently coping with Alzheimer’s disease,” said Duffy MacKay, ND, vice president, scientific & regulatory affairs, CRN.

“It didn’t answer the question of whether DHA—taken over long periods of time and several years prior to disease onset—could have helped prevent these participants from developing the disease.

“Further, the study only tested DHA under the assumption that it could be used as a treatment, which is highly unlikely given how little we know about Alzheimer’s disease. There is still much to be learned about the potential of DHA—and all omega-3 fatty acids—and the many health benefits they offer consumers,” added Duffy.

Study details

The results echo those presented at the Alzheimer's Association 2009 International Conference on Alzheimer's Disease (ICAD 2009) in Vienna, which suggested that DHA may improve both memory function and heart health in healthy older adults, but the omega-3 had no general impact on the cognitive health of people with mild to moderate Alzheimer's.

Quinn and his co-workers randomly assigned individuals with mild to moderate Alzheimer’s disease to receive either the daily DHA supplement (2 grams per day, Martek) or placebo for 18 months. A total of 295 participants completed the trial.

Assessing the participants’ cognitive and functional abilities using the Alzheimer's Disease Assessment Scale showed no significant difference in ADAS scores between the placebo and DHA group.

Furthermore, the rate of brain atrophy – determined by volumetric magnetic resonance imaging (MRI) – was no different between the groups, said the researchers.

“Because part of the rationale for the trial was epidemiological evidence that DHA use before disease onset modifies the risk of Alzheimer disease, it remains possible that an intervention with DHA might be more effective if initiated earlier in the course of the disease in patients who do not have overt dementia,” wrote the researchers.

Comment

In an accompanying editorial, Kristine Yaffe, MD from the University of California, San Francisco called the trial ‘well-conducted’ but said it added to the “continued frustration over lack of effective interventions and prognostication” for Alzheimer’s disease.

CRN’s Duffy added: “Whether through diet or through the use of dietary supplements, individuals should ensure they are receiving adequate amounts of DHA and EPA, and they shouldn’t wait until they begin to experience symptoms of a health concern.

“Should consumers choose to get the recommended amounts of DHA through dietary supplements, they should also remember that supplements are not a cure or treatment for any disease—but when incorporated into a healthy lifestyle, they can play an important role in maintaining overall health and wellness.”

Source: JAMA
2010, Volume 304, Number 17, Pages 1903-1911
“Docosahexaenoic Acid Supplementation and Cognitive Decline in Alzheimer Disease: A Randomized Trial”
Authors: J.F. Quinn, R. Raman, R.G. Thomas, K. Yurko-Mauro, et al.

Editorial : JAMA
2010, Volume 304, Number 17, Pages 1952-1953
“Treatment of Alzheimer Disease and Prognosis of Dementia”
Author: K. Yaffe

3 comments

wrong title

Posted by dr chris quigley, 10 November 2010 - 15:59 GMT

Your title should be that 2 grams of DHA is not useful. My refrences state that to improve brain function you need at least 7.5 g and as much as 15 g of both EPA and DHA to improve brain function.

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Another Main line medicine critisism of Nutritional intervention

Posted by RKS Nair, 03 November 2010 - 15:42 GMT

There seem nothing big in this report. As it is known, the main line medicine thinks that it can cure everything with only prescription items.This attitude itself is the result of frustration among the neurologists who are not able to do any thing with the problems of the neurons.All treatments are only assumptive. If Stains can be claimed to have benefits in reducing the levels of APP in the brain of Alzheimer's then a better choice will be to combine both Fish oil or Omega 3 or DHA to the regime and do a genuine trial with the intention of getting the correct benefits instead of trying to Project the Prescription drugs by the Pharma giants who are not able to contribute any thing to improve the condition of the Alzheimer's. These companies are just silent spectators with some molecules with all the hype because basically we know less than 0.00000001 % of the brain function and there is ample difference in the in vivo and in vitro response and changes.
These trials are for some to present a p[aper and get some name. Frankly speaking there is nothing done to the degenerative neuroinflammatory problems with any of the modern molecules. They try all the possible combination but they are not willing to trust the food and natural substances with which our body is created. We cannot be born with a deficiency of Statins but definitely we can have a deficiency of DHA or EPA or other EFA which has to be obtained from the food.
In addition to all these points ,statstics and interpretation is one thing according to the gift of the ability to express the wrong things thing in the right way.
We are natural creation of the Great designer and he never created food with things not available in the nature.
Trying to prove nature wrong is wrong and we are limiting our scope of finding the solution. Frankly who wants the solution even some one develops? That will be immediately branded as false claim and later some one will prove it right and we have plenty of evidence with our medical scientists- The mockery they made on the scientist who found out H.pylori which is now the accepted cause of GI ulcer and Gastritis.
So change the attitude to finding out a solution instead of converting a solution to a problem in the interest of Real contribution to Heal through nutrition and all our health problems are due to abuse of food, lifestyles, and bad habits.
So this to me is something like another trial for not searching for a benefit but to search for a problem to discount.
Do this mean that all those volumes of reports of EFAs and health benefits reported are all bunk. This is some thing which i feel manipulated.
Now with the proof that all placebos are having pharmacological effects how can the Placebo controlled trials be accepted. All these should be canceled in the drug evaluation.

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Exciting new study

Posted by davidr19, 02 November 2010 - 19:27 GMT

On a positive note, an exciting new study adds to the increasing evidence that special anti-inflammatory therapeutics may improve cognition in a variety of brain disorders including Alzheimer’s. See http://www.ncbi.nlm.nih.gov/pubmed/20796174 and http://nrimed.com/pub.html Together these findings suggest that continued investigation of inflammation as a therapeutic target in Alzheimer’s disease is urgently needed.

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