Identifying which nutrients may cause or protect against prostate cancer

Sarah Lewis’s team hypothesise that folate, vitamin B12, and iron may increase prostate cancer risk or progression, and that selenium, vitamin D, vitamin E and lycopene may protect against prostate cancer risk or progression

  • Topic: Prostate cancer
  • Institution: University of Bristol
  • Country: United Kingdom
  • Status: Completed
Researcher: Sarah Lewis

Background

Prostate cancer is the second most common cancer in men worldwide. It has been estimated that around 1.3 million new cases are diagnosed every year.

Aims

In this study we aimed to find out which diet and lifestyle factors cause prostate cancer and to review the evidence on potential biological mechanisms between vitamin D and prostate cancer and body fatness and prostate cancer.

How it was done

Mendelian randomisation to determine whether 24 dietary factors and lifestyle factors cause prostate cancer risk, we used genetic data from up to 80,000 prostate cancer cases and controls, and used methods developed with WCRF to review the published literature to determine whether vitamin D protects against advanced prostate cancer risk via testosterone and changes in body fatness influence prostate cancer via effects on insulin.

Findings

Weak evidence for a protective effect of calcium and folate on prostate cancer risk, and stronger evidence of a protective effect of iron on prostate cancer risk. Evidence that physical activity protects against prostate cancer risk. Men with a higher body mass index were less likely to be diagnosed with prostate cancer and we found some weak evidence that mono-unsaturated fat might increase the risk of prostate cancer. High vitamin D levels increased testosterone levels, although evidence linking testosterone to advanced prostate cancer risk was weak. There was also weak evidence that body fatness reduced insulin sensitivity, although the evidence linking this to prostate cancer risk was inconclusive.

Grant publications