I’m a big fan of the New Scientist podcast Change Your Mind, on which my erstwhile colleagues Cat de Lange and Helen Thomson discuss “all the brain health advice you really need to know”. One recent episode is well worth a listen if you’re interested in keeping your brain healthy. Cat and Helen invited JoAnn Manson, who is head of preventative medicine at Brigham and Women’s Hospital in Massachusetts, to the podcast to discuss her research on multivitamin supplements and brain health.

She described how she and her colleagues found that people over 60 who take a daily multivitamin show significantly slower cognitive decline and age-related memory loss over two to three years. For me, that was a marmalade dropper. On the issue of supplements, I’m a hardened sceptic.

Based on a New Scientist feature I edited many years ago, as well as a recent update by another ex-colleague, Alison George, my informed opinion is that very few supplements work and some are positively harmful. I make an exception for vitamin D because I live too far north to make enough on my own from the feeble winter sunshine. But once the clocks have gone forward, I stop taking it.

I would also take folic acid if I were female and trying for a baby (I’m neither), long-chain polyunsaturated fatty acids if I didn’t eat oily fish weekly and vitamin B12 if I were a vegan. But as for the rest, I don’t waste my money. For people who are willing to shell out for supplements, there are myriad opportunities.

One of the thriving markets is in anti-ageing. Although very few if any have been scientifically validated, I’m slightly less sceptical. A few years ago, I took an anti-ageing supplement called alpha-ketoglutarate for six months for a story I was doing.

I had my biological age measured before and after, and it went down. But that is hardly solid data of the sort you get from a clinical trial. Advertisement Of that, there is plenty, and it doesn’t cast anti-ageing supplements in a good light.

I found a gold mine of information in an academic book published earlier this year called Supplements and Drugs for Healthy Longevity. Under the guidance of the eminent biogerontologist Suresh Rattan at Aarhus University in Denmark, an expert panel rated the evidence for more than 250 compounds with supposed anti-ageing effects. These ranged from vitamins and minerals to plant extracts, traditional medicines, probiotics and hormone supplements, plus some much-hyped compounds I often hear bigged up in anti-ageing circles: NAD+, coenzyme Q10, spermidine and D&Q, or dasatinib and quercetin.

Interestingly, they didn’t look at the evidence for alpha-ketoglutarate. Suffice to say that none of them met the highest standard of evidence, which Rattan defines as “solid, reproducible and trustworthy”. A few reached a secondary level, but, on the whole, the authors recommend obtaining these compounds from food.

“At present using one or more nutritional and other supplements… is mostly an act of faith and hope”, rather than being based on strong scientific evidence-based data, the book concludes. But it also says that more research is needed. So, I had a look at Manson’s.