US researchers have claimed that taking a daily multivitamin pill may lower the risk of developing cancer in men.
Their study followed nearly 15,000 men, aged over 50, for more than a decade.
The findings, published in the Journal of the American Medical Association, reported a small reduction in cancer cases in men taking vitamin pills.
But experts warned that other studies had found the opposite effect and that eating a diet packed with fruit and vegetables was a safer bet.
Vitamin supplements are recommended for some groups of people, such as vitamin D in the over 65s.
However, the benefits of multivitamins on general health have been mixed. Some studies suggest they cause more harm than good when taken by healthy people while others have shown no benefit in cancer.
Doctors at the Brigham and Women’s Hospital and Harvard Medical School analyzed data from men who were given either a multivitamin or a sugar pill every day.
There were 17 cancers per 1,000 people taking multivitamins per year compared with 18 cancers per 1,000 people taking the dummy pills per year.
One of the researchers, Dr. Howard Sesso said: “Many studies have suggested that eating a nutritious diet may reduce a man’s risk of developing cancer.
“Now we know that taking a daily multivitamin, in addition to addressing vitamin and mineral deficiencies, may also be considered in the prevention of cancer in middle-aged and older men.”
The researchers do not know if a similar effect would be seen in women or in younger men.
Experts have found that a blood test that reads genetic results like a barcode can pick out the most aggressive prostate cancers.
The test, which looks at the signature pattern of genes switched on and off in blood cells triggered by the tumor, can sort the “tigers” from the “pussycats”.
London’s Institute of Cancer Research trialled the test in 94 patients.
The findings are published in the Lancet Oncology medical journal.
Prostate cancer is a very diverse disease – some people live with it for years without symptoms, but for others it can be aggressive and life-threatening.
Currently, doctors take a small sample of the tumor – a biopsy – to examine under a microscope to get a better idea of how dangerous
Experts hope that ultimately the barcode blood test could be used to make a more accurate estimation.
In the study, the scientists were able to split the patients into four groups based on the results of the barcode test. One of these groups fared far worse, surviving for significantly less time than the other patients.
The researchers then confirmed their findings in another 70 US patients with advanced cancer, which revealed that nine genes could accurately spot who had the least chance of survival.
Patients with this “bad” gene signature survived for an average of nine months compared with 21 months for those without it.
US researchers at the Dana-Faber Cancer Institute and the Memorial Sloan-Kettering Cancer Centre have also been testing a similar prostate cancer blood test.
Their six-gene test could split patients into high and low risk groups.
Prostate cancer is the most common male cancer in the UK, accounting for almost a quarter of male cancers.
Each year, nearly 35,000 men are diagnosed and more than 10,000 die from the disease.