Women with high calcium intake appear to have reduced cancer risk
US scientists have found that women who consume plenty of calcium-rich foods appear to have a reduced risk of cancer.
Men with a high calcium intake were found to have a lower risk of specific cancers of the digestive system, including bowel cancer, but their overall cancer risk was not lower.
The findings are published in the Archives of Internal Medicine and are based on an analysis of data on 293,907 men and 198,903 women, all of whom had participated in the National Institutes of Health-AARP Diet and Health study.
The participants provided information on their dietary habits between 1995 and 1996, as well as whether or not they took dietary supplements.
Researchers at the National Cancer Institute in Bethesda, led by Dr Yikyung Park, then obtained data from state cancer registries which told them whether or not any of the participants had developed cancer over the next seven years.
During that time, 36,965 of the men and 16,605 of the women developed cancer.
The researchers noticed a link between calcium intake and total cancer risk in women, but not in men.
Among women, the risk of cancer fell as their intake of calcium increased up to 1,300mg per day, but an intake higher than this did not reduce their risk any further.
The study also revealed that while men do not appear to benefit from a reduction in overall cancer risk, a high calcium intake does seem to reduce their risk of certain kinds of cancer.
Men who consumed the most calcium - either in food or supplement form - were found to have a 16 per cent lower risk of cancers of the digestive system than those who consumed the least.
For women with a high calcium intake, the risk of digestive cancers was reduced by 23 per cent.
The study authors wrote: "In conclusion, our findings suggest that calcium intake consistent with current recommendations is associated with a lower risk of total cancer in women and cancers of the digestive system, especially colorectal (bowel) cancer, in both men and women."
Dr Jodie Moffat, health information officer at Cancer Research UK, said: "This study agrees with previous studies which have found that dairy foods protect against bowel cancer, although the overall effect is quite small.
"This interesting study is one of the largest to investigate the effects of dairy foods on the risk of many different types of cancer. The best advice is still to eat a healthy, balanced diet high in fibre, fruit and vegetables and low in saturated fat and red and processed meat."