The US is going grey: Recent estimates by the Census Bureau show that within the next two decades, there will be just as many seniors as there are children under 18.
As the population ages, dementia rates are also set to increase. By 2060, there will be almost 14 million people living within the country with severely impaired cognition.
Adults concerned with cognitive decline have given rise to a dubious memory supplement market. Between 2006 and 2015, memory supplements sales increased from $353 million to $643 million—despite the fact that there’s no concrete evidence that these pills can actually ward off cognitive decline.
More worryingly, though, some of these pills may not even contain the ingredients they advertise. On Thursday (Nov. 14), the US Government Accountability Office (GAO) publicly released a report on three memory supplements that had been tested in a lab. Only one pill contained the ingredients it was supposed to; the other two contained either half or none of the marketed active ingredient. Instead, these pills contained unknown chemical substitutes, the safety of which has not been assessed.
Researchers still don’t understand why some people develop dementia and others don’t. There are some known genetic risk factors, and limited evidence that lifestyle factors like diet, exercise, and social engagement may play a role. But because there’s no way of knowing what definitively causes dementia, there’s no way of knowing how to prevent it.
Dietary supplements capitalize on the idea that there may be a nutritional component to long-term neurological health. Ginkgo biloba comes from a tree originating in China; its powdered extract has been shown to increase blood flow to the brain, which is likely why some researchers thought it may protect cognitive abilities. Additionally, there’s some evidence that diets rich omega-3 fatty acids from foods like salmon have been linked to lower rates of dementia.
So far, though, there’s no large-scale evidence that these chemicals in supplemental forms are actually useful for neurological health. In one study with almost 3,000 participants, gingko supplements weren’t protective at all against developing Alzheimer’s disease (paywall), the most common form of dementia. Similarly, studies comparing adults taking omega-3 supplements versus a placebo have shown that the pills don’t significantly improve memory or impulse control, another measure of cognitive function.
It’s possible that these compounds are merely a benign waste of money. However, unlike medications, dietary supplements are only loosely regulated by the US Food and Drug Administration (FDA). Supplements don’t have to have any data behind their claims, Lon Schneider, a psychiatrist at the Keck School of Medicine at the University of Southern California, told Consumer Reports. The FDA can only intervene when there’s reason to believe that supplements don’t contain the ingredients they say they do.
Last year, researchers at the GAO identified three memory supplements from a previous survey conducted on supplements marketed toward senior citizens. They picked three (pdf) that were some of the top 10 most-advertised, and most commonly sold in retail stores. Two of these supplements contained ginkgo biloba, and one contained fish oil, or omega-3 fatty acids.
Of the two gingko supplements, one had a label claiming it was “ultra pure.” In the lab, however, researchers were unable to find any of the 120 milligrams of ginkgo biloba advertised on the package in each pill. Instead, they found a new compound, which they did not identify and therefore has unknown health effects. The second gingko supplement had a label claiming it contained gingko biloba and two other herbs; although the team found some evidence of each, it was less than the amount listed in the ingredients. The rest of the pill was made up with other chemical substitutes, which have not been tested for safety, either.
The third supplement stated it contained 600 mg of omega-3 fatty acid per serving. It actually contained slightly more, between 650 mg and 680 mg. Although there are some risks linked to taking too much fish oil, this amount likely wouldn’t cause any harmful effects.
The GAO is not a regulatory body; its only job is to provide information to Congress or other federal agencies and advise them on how they should be spending taxpayer dollars. Its study focused on just three supplements and was not peer-reviewed or published in a scientific journal, so it doesn’t provide sufficient evidence of a trend within the supplement industry as a whole.
However, it is alarming that the supplements sampled were some of the most prominently advertised, and readily available in stores. Although they may not necessarily be harmful to health, consumers still need to know what makes up the supplements they’re taking.
The GAO has sent reports to the FDA and the Federal Trade Commission, which regulates advertising on the internet, where most such compounds are promoted. It’s unclear how these regulatory bodies will respond, and when they will take action.
In the meantime, this work shows why it’s important for scientists to find the actual causes of cognitive decline and dementia. Not knowing means that consumers could be vulnerable to unknown substances as they search for their own forms of protection.