Super-food supplements may raise the risk of developing diabetes, experts have warned.
In fact, the supplements, thought to help fight cancer, can even shorten lifespan, the boffins added.
According to research, the supplements, known as antioxidants, may interfere with blood glucose levels, which can increase the risk of type 2 diabetes.
Antioxidants, including vitamins A, C and E, and selenium are believed to "mop up" cancer-causing compounds known as free radicals.
However, a report published in the journal Cell Metabolism shows low levels of these free radicals appear to protect against diabetes by helping the body respond to insulin signals.
Professor Tony Tiganis, an expert in cell biology at Australia's Monash University who led the study, said: "We think there is a delicate balance and that too much of a good thing - surprise, surprise - might be bad.
"I would advise people not to take these supplements because they could be detrimental."
Prof Tiganis's team carried out their research on mice but he said: "There is other evidence antioxidants might be bad for you."