Prostate cancer is the most common cancer in men in the UK, with over 40,000 individuals diagnosed with the disease every year, and more than 250,000 currently living with it. Furthermore, four out of five men with a higher than average risk of being diagnosed with the ailment are unaware of its danger and are not having vital conversations with their GPs, which could save their lives. This means that thousands of men are at risk of missing out on being diagnosed at an early stage, when treatment for the disease is most effective.
The majority of early cases are symptomless, and a lack of accurate tests for life-threatening forms of the disease means there is no national screening programme. As a result, awareness of risk and speaking to a health professional about it is a man's chief defence against this form of cancer. Individuals at an increased risk of prostate cancer include men with a family history of the disease, men over the age of 50, and black men.
A recent study from Northwestern University in the US, lead by Dr. Adam Murphy, found that a lack of vitamin D increases the chances of men at high risk of prostate cancer being diagnosed with an aggressive and potentially deadly form of the disease. The link is so strong that scientists believe blood levels of the vitamin could provide a way of screening patients with vitamin D deficiency being used as a biomarker of advanced prostate tumour progression.
The scientists examined data from a wide-ranging group of more than 600 men who had risk factors for prostate cancer, including raised levels of the blood marker Prostate Specific Antigen (PSA). Each man was screened for vitamin D deficiency before having a sample of his prostate removed for analysis. The biopsy samples showed that lacking vitamin D was strongly associated with aggressive forms of prostate cancer, even after adjusting for influences such as diet, smoking habits, obesity, family history and calcium intake.
American men of European origin were 3.7 times more likely to have aggressive prostate cancer if they were vitamin D deficient, while for those of African origin, lacking vitamin D increased their risk 4.2 times. African-Americans with severe vitamin D deficiency were also more than twice as likely as those with normal levels of the vitamin to be diagnosed with prostate cancer. Vitamin D deficiency is more common and severe in people with darker skin and it could be that this deficiency is a contributor to prostate cancer progression among black men.
Vitamin D is the only nutrient where the main source for most people is exposure to UVB light rather than diet. In order to produce vitamin D, UVB exposure must be at 290-315nm, which means that in the UK we only make vitamin D from sunlight between April and September between the hours of around 11am and 3pm. During the winter months we rely on dietary intake and storage that we build up during the summer. But recent evidence shows the majority of the population has a low storage. This can be for a variety of reasons, including lack of exposure to the sun due to work and lifestyle choices, sunscreen use and poor diet.
It is suggested that men with fairer skin need at least 20 minutes sunlight exposure to their face and forearms on a daily basis during the summer months to ensure sufficient storage for the winter months. Black and Asian men need longer exposure. After this time, sunscreen should be used as necessary to prevent sunburn. Few foods provide vitamin D, the main sources in diet include oily fish, eggs, meats, butter and spreads and mushrooms. Many more foods are now being fortified with vitamin D such as breakfast cereals. This means there is a clear role for supplements. In addition, it is also prudent to get vitamin D levels checked on a yearly basis.
A number of other risk factors are associated with prostate cancer. The most important of which, include:
A diet high in animal products: Eating a lot of meat, eggs and dairy products, especially early in life, causes the body to produce a growth factor. Growth factors help the body grow, but they also help tumors grow. Dairy products contain calcium and cholesterol. These products may also increase the risk of prostate cancer.
Calcium: High amounts of calcium, either from diet or supplements may be a risk factor.
Cholesterol: High cholesterol levels are linked to an increased risk of prostate cancer. Cholesterol does not appear to affect risk of other cancers.
An active lifestyle with time spent outside and a healthy diet that includes vitamin D rich foods, plenty of fruit and vegetables, wholegrain and moderate amounts of dairy products seems to be an important strategy in preventing vitamin D deficiency and improving prostate health.