New research from the University of Gothenburg in Sweden suggests that people who take antioxidant vitamins regularly are twice as likely to experience an increase in their melanoma metastasis.

Martin Bergö, a professor at Gothenburg's Sahlgrenska Academy, led a team of researchers in studying the potential effects of antioxidants on the spread of lung cancer cells in the body.

In a study featured in the journal Science Translational Medicine, Bergö and his team conducted an experiment on mice in which they discovered that antioxidant supplements doubled the metastasis rate of cancer. The vitamins also caused the animals to develop additional and more life-threatening tumors.

Bergö explained that contrary to earlier studies on lung cancer, the initial tumor was not affected by antioxidants, but the supplements enhanced the ability of cancer cells to spread throughout the body. This is considered to be a more serious health issue as metastasis is one of the primary causes of death in melanoma cases.

Bergö added that the initial tumor is not as dangerous compared to the resulting more aggressive tumors from antioxidants and it is often removed.

The recent findings were later confirmed through tests on cell cultures taken from patients with malignant cancers.

The researchers were able to show that antioxidant supplements hasten the development of melanoma in two different ways.

Overall, the conclusion from several cancer studies is that antioxidants can help healthy cells to be protected from free radicals in the body that can turn them into cancer. However, this ability can also protect tumors once they have developed.

"Previous research at Sahlgrenska Academy has indicated that cancer patients are particularly prone to take supplements containing antioxidants," Bergö pointed out.

"Our current research combined with information from large clinical trials with antioxidants suggests that people who have been recently diagnosed with cancer should avoid such supplements."

Skin and Suntan Lotions

According to the Gothenburg study, it is important to explore the role of antioxidants in melanoma cases not only because cells from this particular type of cancer are sensitive to free radicals but because they can also be exposed to antioxidants through non-dietary means.

Bergö said that suntan lotions and skin lotions may sometimes include vitamin E or beta carotene, which could produce the similar effects on melanoma cells as antioxidants contained in nutritional supplements.