Donna Kaye Hill realized that her 80-year-old mother was faltering cognitively when her phone suddenly stopped working. When Ms. Hill called the phone company, “they told me she hadn’t paid her bill in three months.”
Finding other alarming evidence of memory gaps, she took her mother, Katie, to a memory clinic. A geriatrician there diagnosed dementia and recommended two prescription drugs and a dietary supplement, a form of vitamin E.
Katie Hill dutifully took vitamin E capsules, along with a host of other medications, until she died four years later. As she declined, her daughter didn’t think the vitamin, or the two prescription medications, was making much difference.
“But if it doesn’t hurt, if there’s a chance it helps even a tiny bit, why not?” she reasoned. Ms. Hill, 62, a retired public employee in Danville, Va., takes fish oil capsules daily herself, hoping they’ll help ward off the disease that killed her mother.
The elder Ms. Hill was unusual only in that a doctor had recommended the supplement; most older Americans are taking them without medical guidance. The Food and Drug Administration estimates that 80 percent of older adults rely on dietary supplements, many purporting to prevent or treat Alzheimer’s and other forms of dementia.
Last month, the F.D.A. cracked down on this burgeoning market, sending warning letters or advisories to 17 companies selling about 60 supplements with names like Cogni-Flex and Mind Ignite.
The warnings pointed out that the companies had touted these products as working like Alzheimer’s drugs, “but naturally and without side effects.” Or as “clinically shown to help diseases of the brain, such as Alzheimer’s.” The pills, oils and capsules were said to treat other diseases, too, from stroke to erectile dysfunction.
Claiming that these products were intended for “the cure, mitigation, treatment or prevention of disease” meant that they were drugs, the agency’s letters said.
And since they were drugs the F.D.A. had never reviewed or approved for safety and effectiveness, the companies now must submit applications for approval or stop making such claims. Over the past five years, the agency has taken action against 40 other products making Alzheimer’s claims.
The supplements’ appeal is understandable. A growing older population with longer life spans means more people with dementia, though in population-based studies in this and other Western countries, its prevalence has fallen.
More of us have seen the devastation up close and would do almost anything to evade it. But so far, the news about drugs and supplements has been discouraging.
Although scientists have learned much more about dementia, the research literature and large pharmaceutical trials have mostly served to tell worried Americans about the many substances that don’t appear to prevent, treat or slow dementia.
Vitamins, various antioxidants, concoctions derived from animals and plants — “we see plenty of ads on TV, but we have no evidence that any of these things are preventive,” said Dr. Steven DeKosky, a neurologist and deputy director of the McKnight Brain Institute at the University of Florida.
Dr. DeKosky led a federally supported study of Ginkgo biloba extract, for instance, following more than 3,000 people for seven years to see if it reduced dementia. It didn’t.
“No effects at all,” he said. “But look on the shelves. Many companies still sell ginkgo — if there’s really any in there, because supplements don’t always have the contents they say they have.”
Moreover, “some of these supplements are biologically active and can cause toxicity when you take other drugs,” said Dr. DeKosky. Supplements can be costly, too.
But there are other ways people can reduce their risk of dementia. Two prestigious panels, reviewing many prevention studies, recently came up with several recommendations.
Dr. Kristine Yaffe
University of California, San Francisco
The more conservative report, from the National Academies of Sciences, Engineering and Medicine in 2017, relied primarily on large randomized clinical trials.
There aren’t many of those, so the panel endorsed just three interventions “supported by encouraging but inconclusive evidence,” to prevent, delay or slow cognitive decline.
Increased physical activity;
Blood pressure management for people with hypertension, particularly in midlife;
And cognitive training.
That last recommendation doesn’t necessarily refer to commercial online brain games, said Dr. Kristine Yaffe, a neuropsychiatrist and epidemiologist at the University of California, San Francisco, who served on the panel.
“It’s really the concept of being mentally active,” she said. “Find something you enjoy where you’re learning something new, challenging and stimulating your brain.”
Though the evidence to date doesn’t establish which mental workouts have the greatest impact or how often people should engage in them, “they’re not expensive and they don’t cause side effects,” Dr. Yaffe pointed out.
The blood pressure recommendation got a boost in January with the latest findings from the Sprint trial, a multisite study stopped early in 2015 when intensive treatment of hypertension (a systolic blood pressure goal of less than 120, compared to the standard 140) was shown to reduce cardiovascular events and deaths.
The investigators continued the trial, however, with 9,361 participants who had hypertension (average age: 68) and completed follow-up cognitive assessments.
Their results, published in JAMA, showed the intensive treatment group less likely to develop dementia than those in standard treatment, though not by a statistically significant margin. Intensive treatment did, however, significantly reduce participants’ risk of mild cognitive impairment, a frequent precursor to dementia.
“To me, it was one of the most exciting findings to come along in years,” said Dr. Yaffe, who noted in an accompanying editorial that this was the first large trial to demonstrate an effective strategy for preventing age-related cognitive impairment.
“The same things we recommend for heart health turn out to be important for cognition,” she told me. “It’s a blossoming field.”
The Lancet Commission on Dementia Prevention, Intervention and Care also recommended hypertension treatment for the middle-aged, along with exercise, social engagement and smoking cessation, as well as management of obesity, diabetes, hearing loss and depression. Such steps could prevent or delay a third of dementia cases, the commission estimated.
When Dr. Yaffe gives talks on dementia prevention, she also mentions good sleep hygiene and urges listeners to protect themselves against brain injuries.
It’s important advice, but disappointingly undramatic. Where’s the magic bullet? Don’t we already know to stay physically and mentally active, maintain a normal weight, treat high blood pressure and so on?
Moreover, “it’s not foolproof,” Dr. Yaffe acknowledged. In the lottery of dementia, “there’s a role for genetics. There’s a role for bad luck.”
Still, she added, “The concept is important. You can do something about this. You can lower your risk.”
That’s why the most helpful approach Donna Kaye Hill uses to protect herself from dementia probably isn’t taking fish oil.
It includes using medication to control her blood pressure. And reading biographies and mysteries and joining a book group with friends. And taking a four- or five-mile walk, five days a week, with a yellow Labrador named Annie.