More on Improving Aging

July 20, 2009
Victor G. Dostrow

Much data of note are coming to light of late regarding factors which diminish some of the ravages of aging. I posted on this recently. However, several abstracts from the ongoing Alzheimer's Association International Conference on Alzheimer's Disease, in Vienna, Austria, deserve comment.

Much data of note are coming to light of late regarding factors which diminish some of the ravages of aging. I posted on this recently. However, several abstracts from the ongoing Alzheimer's Association International Conference on Alzheimer's Disease (ICAD), in Vienna, Austria, deserve comment.

There were two studies presented evaluating Omega 3 fatty acids (O3FA), which are often added to the diet through fish oil supplements. O3FA are promoted by the supplement industry as possesing near magical powers. O3FA have been touted as being of value for the treatment of a very wide variety of disorders, ranging from obesity to gingivitis, although sound data really only exist for hypertriglyceridemia and a few cardiac disorders. The potential for benefit in Alzheimer's Disease (AD) is not clearly established. Docosahexaenoic acid (DHA), one of several O3FA, is the principal O3FA in the brain. [Disclosure: I take O3FA daily, for reasons not related to cognition.]

The first ICAD study about O3FA was the Memory Improvement with DHA Study (MIDAS), a randomized, double blind, placebo controlled trial of 6 months' duration, sponsored by a manufacturer of an O3FA product. This study looked at supplementation with DHA in healthy older persons without a formal dementia diagnosis. 485 persons, with an average age of 70 years old, were enrolled. The primary outcome measure was change from baseline in a visual spatial neuropsychological measure. At six months, the DHA group showed significant improvement over baseline compared to the placebo group (error score -1.63 ± 0.76, p<0.03). It is not clear from the abstract whether this was also a finding of clinical significance. Interestingly, there was also a small, but statistically significant, decrease in heart rate (-3.2 v. -1 beats per minute, p<0.03).

The second trial evaluated DHA supplementation in patients with mild to moderate AD. This was also a randomized, double blind, placebo controlled multicenter trial. This 18 month study enrolled 402 patients with an mean age of 76 ± 8.7 years old. Patients had a low dietary DHA intake at enrollment. Several neuropsychological measures were obtained. No significant treatment effect was noted on any of the measures. So, DHA did not show the same benefit in AD patients as in healthy older persons.

Other investigators presented data on moderate ethanol intake and AD risk. Subjects were taken from a larger, community-dwelling cohort. The cognitive function of participants was studied in detail, and they were then classified as normal or suffering mild cognitive impairment (MCI). Of the persons enrolled, 2,587 were cognitively normal and 482 had MCI at baseline. Patients were evaluated every six months for up to six years. Alcohol intake was self-reported, and divided into none, light, moderate and heavy categories, based on weekly intake. 523 patients progressed to a diagnosis of dementia. The study found that moderate ethanol consumption was associated with a relative risk of 0.63, or a 37% risk reduction, of developing dementia. In contrast, MCI patients who were heavy users of alcohol had a much increased risk (RR 1.84; 1.03-3.30) of developing fr ank dementia compared to abstainers with MCI.

These new data demonstrate that those fish oil capsules may modestly retard cognitive decline in otherwise health older persons, but don't help in the setting of established Alzheimer's. Perhaps this is another example of data suggesting that intervention very early in the course of dementia is required to have any material effect.

Also, moderate intake of ethanol (up to, but not exceeding 2 drinks per day for men) is associated with improved cognitive function in aging. Obviously, excessive ingestion of ethanol is toxic, and the medical and societal problems associated with alcoholism are clear. But, it is reassuring to know that, as is the case with cardiac health, moderate alcohol intake may have benefit for cognitive functioning.