Britons are taking more health supplements than ever before, often because of advice from social media influencers, a survey has found.
Products range from traditional supplements like daily multivitamin and mineral tablets to more unusual ones, such as capsules made from lion’s mane mushrooms.
Nearly three-quarters of people take at least one supplement and a quarter are using three or more supplements, according to the survey by Bupa.
The NHS does recommend some supplements: Adults are advised to take vitamin D for six months over winter, as we cannot make enough of it when sunlight is weaker. Pregnant women and those trying to conceive should take vitamin D all year round, as well as folic acid.
But some others have little good evidence to support them – yet still have strong adherents online. Here are four widely used supplements that you probably can safely do without.
The turmeric myth
The yellow spice turmeric, widely used in cooking, has gained the reputation of a superfood. Its key ingredient, curcumin, is claimed to be anti-inflammatory and even to have anti-cancer effects.
But many of the original studies these claims were based on have been retracted due to concerns that they were flawed, the New Scientist reported in June.
It is also implausible that curcumin could have much effect on the body because it is poorly soluble and is mainly excreted. A study of men taking the supplement found it was barely detectable in their blood.
Special formulations of curcumin designed to boost absorption may even have caused liver injury, according to the US National Institute of Diabetes and Digestive and Kidney Diseases.
“These high-bioavailability forms of purified curcumin were linked to several cases of liver injury and mentioned as a possible cause of outbreaks of acute hepatitis with jaundice in Italy,” the institute said.
Limited research on lion’s mane
Lion’s mane mushrooms may be consumed in the form of fashionable coffees, but these fungi are also sold as powders and capsules.
In mushroom form, lion’s mane is a large white fungus with long dangling fronds. In traditional Chinese medicine, it is used for relieving stress and improving mood.
Today, lion’s mane is sometimes claimed to be a cognitive enhancer. This stems from the fact that it contains two groups of compounds, called erinacines and hericenones, which boost a molecule in the brain called BDNF that supports brain cells.
But experts say the research doesn’t support the claims made about it. “The research is really limited at the moment,” said Dr Ellen Smith, a nutritional researcher at Northumbria University. “There needs to be a lot more evidence before we can start making the kinds of claims that we’re seeing.”
Fishy claims about fish oil
Fish, especially oily fish like salmon, mackerel and sardines, has long been thought to be good for us because of its omega-3 fatty acids. Many studies have shown that people who eat more fish tend to have better health and live longer – with omega-3 assumed to be the reason.
Omega-3 is a key component of brain cell membranes and has been said to protect the heart in some way, perhaps by lowering blood pressure or levels of harmful fats in the blood called triglycerides.
But when it was tested in randomised trials – the best kind of medical evidence – the results were disappointing.
Fish eaters live longer but trials of fish oil supplements fail to show much benefit (Photo: Alexander Spatari/Getty)
Cochrane reviews, which combine evidence from multiple trials, found omega-3 supplements have little, if any, benefit for lifespan or the heart or brain.
“The most trustworthy studies consistently showed little or no effect of long-chain omega-3 fats on cardiovascular health,” said Dr Lee Hooper, a nutrition expert at the University of East Anglia, who led one of the Cochrane reviews.
Mixed results for multivitamins
A daily tablet containing all the main vitamins and minerals is one of the most popular supplements – taken by four in 10 people who take any supplement, according to the Food Standards Agency.
It is also among the least controversial. Many people see it as a sort of insurance policy, assuming it would make up any deficits in their diet.
But the NHS does not recommend that most adults take this kind of supplement. Randomised trials have shown they don’t make any difference to how long people live, nor to common conditions like heart disease or cancer.
The use of some vitamin supplements, including vitamins A and E, has even been linked with a slightly higher death rate in some trials. The explanation remains a mystery.
However, a large trial from 2022 – part-funded by the manufacturer of a multivitamin and mineral pill – found that people taking their supplement did somewhat better on memory tests than those taking a dummy pill.
The trial was large, involving about 3,500 people. But the effect was modest, roughly equivalent to the typical decline in memory abilities over three years of ageing.
Bupa’s poll of 8,000 people in the UK found that people are increasingly getting their health information from influencers on platforms like TikTok and Instagram.
“The sheer volume of health information available brings significant opportunities, but also makes it harder to distinguish trustworthy sources,” said Dr Caroline Wood, head of customer intelligence for Bupa Global, India & UK.
But the NHS says: “Most people should get all the nutrients they need by having a varied and balanced diet.”