Spanish tenant Monica Briceno, 70, suffering from Alzheimer’s disease, sits on her home’s couch as she waits for a bailiff to execute her eviction in Madrid on April 5, 2013.(AFP/Getty Images/Dominique Faget)
Some of the most widely used treatments for dementia — including certain drugs, hormonal therapies, vitamins and supplements — are ineffective at preventing cognitive decline in healthy elderly adults, according to a review published in the Canadian Medical Association Journal. But while the science doesn’t support the use of chemical interventions, brain exercises could help older adults maintain their mental acuity, the researchers say. Dr. Raza Naqvi, a resident at the University of Toronto and lead author of the paper, said in a statement that he hoped the review would help both doctors and patients determine the best course of action for older adults worried about cognitive decline.
As the population ages, the threat of dementia is becoming reality for many families — in a report released earlier this year, researchers estimated that the incidence of Alzheimer’s would triple by 2050. Many people take vitamins or supplements like gingko biloba, which are marketed as natural memory enhancers, in attempt to stave off cognitive decline. To test these claims, researchers from St. Michael’s Hospital in Ontario examined the evidence from 32 studies on several common treatments for dementia, and found that most interventions were unsuccessful. The researchers noted that their review was limited by the quality of the studies they assessed: many had short or non-existent follow-up periods, or did not report all of their data. The studies also used different methods and outcome measures, making them difficult to compare.
Doctors commonly prescribe two types of medications, cholinesterase inhibitors and memantine, to treat the symptoms of dementia. Both kinds of drugs regulate neurotransmitters involved in learning and memory and are thought to slow the march of Alzheimer’s, but the studies included in the review indicated that they did not substantially improve patients’ memory and cognition. The researchers also looked at studies testing the ability of hormones like estrogen and testosterone to prevent age-related cognitive impairments. Though one three- month study on testosterone suggested improvements in memory, longer-term studies found no effect.
Vitamins and supplements with antioxidant properties, such as Vitamin B, Vitamin E, gingko biloba, folic acid, and omega-3 acid, protect and repair cells from damage caused by agents called free radicals, and are often touted for their health benefits. Despite the assertions made by health supplement vendors, however, none of the studies included in the review found evidence that people taking these products fared better in memory tests than people in control groups.
The one bright spot in the review involved the studies on cognitive training, which found that participants who engaged in mental exercises experienced significant improvements in memory and attention compared to people in control groups. And in a 2006 study of 2,832 people, the cognitive improvements were sustained over a period of five years. A 2011 Cochrane review corroborated the findings of the earlier studies, suggesting that mentally-stimulating activities could prevent some measure of cognitive decline in older adults with normal brain functioning or mild impairment.
In spite of the evidence, older adults looking to ward off dementia will probably continue to buy vitamins and supplements, and vendors will continue to profit off of their anxiety. But, as the review demonstrates, the best bet for preventing cognitive decline might have nothing to do with eating food rich in antioxidants or taking medication. Instead, people eager to stay sharp might consider trying mentally stimulating activities like crossword puzzles or sudoku — it certainly couldn’t hurt.
