Can a multivitamin slow the aging process? Not really
Experts say healthy people who eat a varied diet don't need vitamin suppliments. (Getty image: d3sign)
In short:
A new study found taking a daily multivitamin supplement slowed two markers of biological aging.
But the study's own authors and Australian health experts are urging people to be "cautious" in interpreting the research's findings, with more evidence needed before making any recommendations.
What's next?
Australians wanting to care for their bodies as they age are encouraged to eat a balanced diet, get enough sleep and limit alcohol intake.
The idea of slowing down the aging progress is an alluring prospect.
A new study published in the journal Nature Medicine this week — and gaining traction online — claims taking a daily multivitamin can help slow markers of biological aging.
But don't rush to the supermarket to fill your shopping trolley with supplements just yet.
Based on his own study, not even the senior author recommended taking a daily multivitamin.
Howard Sesso, an epidemiologist at Boston's Brigham and Women's Hospital, said although his team's findings were "incredibly encouraging", more research was needed.
"We are not yet in a position to recommend a daily multivitamin for all older adults,"he said.
The other catch is that the study only looked at people about 70 years old.
So, what can — and can't — the study tell us? And what's the general advice around multivitamins?
The study's authors are unsure why daily consumption of multivitamins may have impacted health markers. (Unsplash: freestocks.org)
What did the study tell us?
The 958 healthy participants in the study were assigned to take either a multivitamin supplement; a cocoa-extract supplement; both supplements; or neither supplements, for two years.
Researchers analysed five epigenetic clocks — tools which measure tiny changes in DNA — to calculate how the study participants' biological age changed over time.
They found that participants who took the multivitamins had slightly slower biological aging for two out of the five markers, both of which were biomarkers for disease and mortality.
The changes equated to about four months less biological aging over the course of two years.
Dr Sesso said his team were not sure why the daily multivitamin may have had an impact across the two measures it did.
"We do not have a specific reason why the multivitamin — a common, safe, broad-based collection of essential vitamins and minerals, plus selected bioactives, at usual levels — was so effective," he said.
As participants in the trial were aged about 70 and mostly white, the researchers said the results could not be generalised to other populations.
The research also excluded any participants with major chronic illnesses, cancer or cardiovascular conditions.
"We really need more randomised clinical trials like [this trial] across the entire age spectrum, and not just among older adults," Dr Sesso said.
The current trial, called the COSMOS trial, was funded by Mars and the US National Institutes of Health, with Pfizer providing support via donating supplements.
Experts urge 'caution' about results
Luigi Fontana, professor of medicine and nutrition at the University of Sydney and not part of the research team, urged people to be "cautious" in interpreting the study's findings.
"The change was very, very small,"Professor Fontana said.
In addition, he said, the science behind epigenetic clocks was still young.
"The study is interesting, very, very experimental, we don't know what these biological clocks are measuring," he said.
More research is needed to see if the results apply to people of other ages and ethnicities. (Getty Images: Riska)
While the study showed that multivitamins could modify epigenetic clock measurements, whether they could increase life span "remained an open question," epidemiologist Daniel Belsky and evolutionary biologist Calen Ryan of Columbia University, wrote in an analysis of the study in Nature Medicine.
"There is no gold standard measurement of aging," they wrote.
They said that, even if they did change people's epigenetic clocks, there still was no evidence that multivitamins would reduce disease risk or increase survival.
"An observed effect on a clock cannot be interpreted as evidence that the intervention [taking the multivitamin] has modified healthspan."
Should you ever take multivitamins?
Professor Fontana said people who were eating a healthy diet did not need supplements.
He recommended anyone who suspected they had a vitamin deficiency to see their doctor, who may be able to recommend if supplements were right for them.
Experts say most people who eat a balanced diet shouldn't need vitamin suppliments. (Unsplash: Anna Pelzer)
Jenny Gunton — director of the centre for diabetes, obesity and endocrinology at the Westmead Institute for Medical Research, who did not contribute to the study — agreed people eating a healthy diet did not need multivitamins.
Loading...But Professor Gunton also pointed out many people did not have a healthy diet.
"If you manage the recommended five serves of veggies, two serves of fruit, some dairy, some low-glycaemic-index carbs and some low-fat protein each day, congratulations, you are doing a fabulous job and probably don't need supplements," she said.
"Most Australians don't manage that, though.
"But if your diet isn't as good as it should be, then taking one multivitamin per day is very reasonable."
However, she warned, too much of some vitamins was not a good thing.
"It is important to note that more is probably not better; for some vitamins, excess doses are harmful," Professor Gunton said.
"An example of this is vitamin B6, which at high doses causes nerve damage."
But for Australians who wanted to care for their bodies as they aged, Professor Fontana's advice was simple: eat a balanced diet, remain active, get enough sleep, try to look after your emotional health and limit alcohol intake.