Harvard article derides supplements' memory-support claims
The article, titled Dietary Supplements for Mind and Memory: What Works, and What Doesn’t, said that “trustworthy” evidence to support the function of dietary supplements in supporting mental functioning and memory is insufficient. It recommends that a heart healthy diet and exercise are the best ways to preserve memory.
“My patients and their families ask a lot about supplements, and I try to point them to whatever evidence we have," says Dr. Gad Marshall, an assistant professor of neurology at Harvard Medical School who was quoted in the article. He also helps to run clinical trials for Alzheimer's disease at Harvard-affiliated Brigham and Women's Hospital.
No solid evidence
A number of supplement ingredients are mentioned in connection with cognitive support. Dr. Marshall said the ones he is asked about most often include three B vitamins (folic acid, vitamin B6, and vitamin B12) and antioxidants such as vitamin C, vitamin E, and coenzyme Q10. In addition, the article mentions herbal supplements huperzine A and ginkgo biloba, along with nutraceuticals like fish oil (containing omega-3 fatty acids), curcumin, and coconut oil.
For now, you can cross most of these products off your shopping list for lack of evidence he said. "There are a lot of things out there for which we have no data on whether they are safe or do anything to help," Dr. Marshall said.
According to Dr. Marshall, diet and exercise are the only proven ways to preserve cognitive functioning as we age. "My strongest recommendations are a Mediterranean-style diet and regular physical exercise," he said. "There's good evidence from multiple studies showing that these lifestyle modifications can prevent cognitive decline and dementia and also slow down existing cognitive decline."
The one nutraceutical that the article named as having demonstrated benefits in Alzheimers patients was vitamin E.
Not enough studies
Omega-3s expert Bill Harris, PhD, agreed that there is a lack of a solid body of evidence for the memory-supporting effect of omega-3s, but that’s mostly for lack of trying.
“There is some evidence that omega-3s in randomized trials does improve memory in some studies. But it just hasn’t been studied very much. There is some evidence for it but there is not enough evidence for a Harvard neurologist to say, ‘do it,’” he said.
Harris noted that while there is less evidence for the effect of omega-3s on cognitive health, there is strong evidence for their benefit in other areas, such as cardiovascular health.
“If there is any evidence for benefit at all and no evidence of risk, I would say do it,” he said.
Where's the evidence for drugs?
Loren Israelsen, executive director of the United Natural Products Alliance, said the article seemed to be tinged with the familiar anti-dietary supplement bias common to many medical school publications.
The drugs in the memory-support field don’t appear to be blockbusters, either, he noted.
As Israelsen put it: “Many of the drugs approved for Alzheimer’s, as I understand it, were approved on pretty close votes of advisory committees, meaning the evidence of showing statistically significant benefits in these approved drugs was pretty soft.”
Israelsen said a number of different botanicals and other nutrients have been studied for cognitive support benefits. “I have certainly seen a lot of literature that is both promising and indicative of benefit,” he said.
“You will find critics who say there is very little evidence and you will also find equally credible sources who will say this is a very promising and useful area,” he said.
