Time to dump those pills: antioxidants found to hasten spread of cancer

    9 October 2015

    In 1999 a book called The Antioxidant Miracle was released. Its publicity material stated:

    ‘A pill that strengthens your heart, sharpens your mind, keeps your body young, extends your life, prevents cancer, and keeps your skin wrinkle-free? Sounds like a joke or a dream, doesn’t it? According to molecular cell biologist Lester Packer, these pills exist.’

    Or not. The hype, 16 years on, is now well and truly over. Yesterday further evidence emerged that antioxidants actually hasten the spread of cancer.

    A study published in Science Translational Medicine found that the compound doubled the rate at which melanoma spreads in mice. The finding bolsters previous evidence of antioxidants speeding up the spread of lung cancer.

    Supplements containing antioxidants are widely marketed as helping to prevent cancer. They were believed to do so by protecting healthy cells from free radicals that can turn into cancer.

    Not surprisingly, Professor Martin Bergö, the study author, has urged people who have cancer or have a high risk of developing the disease not to take any such supplements. He said:

    ‘Previous research has indicated that cancer patients are particularly prone to take supplements containing antioxidants.

    ‘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.’

    Both of the studies were carried out at the Sahlgrenska Academy, part of the University of Gothenburg. The first, published last year, found that mice with cancer developed additional aggressive tumours if given antioxidants. This was confirmed by a study of human lung cancer cells.

    The latest research shows that antioxidants have a similarly disturbing effect on melanoma, the most dangerous form of skin cancer.

    Professor Martin Bergö, the study’s author, said:

    ‘As opposed to the lung cancer studies, the primary melanoma tumour was not affected.

    ‘But the antioxidant boosted the ability of the tumour cells to metastasise, an even more serious problem because metastasis is the cause of death in the case of melanoma.’