Warning of the Risks of Most Brain Health Supplements!
The British newspaper The Telegraph quoted Dr. Joan Manson, a professor of medicine at Harvard Medical School, warning that the safety of most dietary supplements marketed for brain health has not withstood high-quality clinical trials.
This warning comes at a time when one in four adults over the age of 50 takes dietary supplements with the aim of improving memory, concentration, or preventing cognitive decline.
According to the report, Manson explained that after nearly three decades of leading some of the world’s largest clinical trials, she has become more cautious about the absolute claims made by brain health products, emphasizing that evidence for the effectiveness of many remains weak. She noted that two recent studies have cast further doubt on fish oil pills and the glucosamine supplement. A clinical trial published in the journal eBioMedicine found that omega-3 supplements did not improve memory or slow brain changes associated with Alzheimer’s, while another study observed that glucosamine may accelerate disease progression in individuals with cognitive impairment.
In contrast, the expert stressed that the best available option for brain health is multivitamins, describing them as a “nutritional insurance” that covers potential gaps in micronutrients. She cited the COSMOS study, which involved 5,000 people over the age of 60, showing that daily multivitamin use slowed the rate of cognitive decline by up to 60 percent over three years. She explained that many older adults suffer from deficiencies in one or more vitamins and minerals, and obtaining all nutrients is more effective than focusing on a single one.
Regarding fish oil, Manson affirmed that the evidence is “mixed,” noting that the VITAL trial, which included more than 25,000 people over five years, found no clear benefit from taking one gram daily of EPA and DHA acids to slow cognitive decline. However, she pointed out that omega-3 is an essential nutrient and that what benefits the heart usually benefits the brain as well, adding that priority should be given to consuming fatty fish twice a week as part of a Mediterranean diet rich in vegetables, fruits, whole grains, and nuts.
According to figures from the UK’s National Health Service, one in 20 people aged 65 to 74, and one in 10 over the age of 75, suffer from a deficiency in this vitamin. Nevertheless, she stressed that taking it does not improve cognition in those with normal levels, and that multivitamins are sufficient for most healthy individuals, while vegans and those taking medications such as metformin should consult a doctor.
For her part, a neurological study involving more than 1,600 people showed that those with moderate vitamin D deficiency were more than 50 percent more likely to develop Alzheimer’s disease or dementia, with the rate rising to 125 percent among those with severe deficiency. However, Manson confirmed that the major VITAL trial found that taking 2,000 international units daily of vitamin D3 did not slow cognitive decline in those with sufficient levels, explaining that benefits appear only when deficiency is corrected. She noted that the UK recommendation is to take 10 micrograms daily during the autumn and winter months.
Within the list of supplements Manson believes money should not be spent on, the report identified four common products as follows:
• Vitamin E: No consistent benefits for preventing dementia have been shown, and high doses may cause bleeding.
Manson emphasized that supplements cannot replace a healthy lifestyle, stressing that the evidence linking a balanced diet, physical activity, social and mental engagement, and the management of cardiovascular risk factors is far stronger than that for any pill. She noted that whenever she is asked whether to spend money monthly on supplements or to improve one’s lifestyle, she always recommends investing in healthy habits, describing regular physical activity as “the true magic bullet for the brain.”
