People with the highest levels of calcium intake had significantly fewer cancers of the digestive system compared with people with the lowest intake, researchers at the US National Cancer Institute wrote in the Feb. 23 issue of Archives of Internal Medicine.

 

The Institute of Medicine recommends 1,200 milligrams of calcium per day for men and women over age 50. Adults should eat three cups of fat-free or low-fat dairy foods, such as milk, yogurt, and cheese to meet their daily calcium needs. Calcium can also be found in green and leafy vegetables, sardines and salmon, orange juice, almonds, sweet potatoes, tofu and lentils.

 

Previous research has shown that calcium reduces abnormal growth and induce normal turnover of cells in the gastrointestinal system, but “testing has been incomplete, inconsistent and limited,” said Yikyung Park, a staff scientist at NCI who led the study.

 

For the current study, the researchers analyzed data from nearly 300,000 men and 200,000 women 50 to 71 who participated in the National Institutes of Health -AARP Diet and Health Study. They were followed for a period of seven years. The participants were asked about the foods and supplements they ate. After seven years, a total of 36,965 men and 16,605 women were diagnosed with cancer. There were more than 10 different kinds of cancer, the most common being prostate, breast, lung and colorectal.

 

The study found that men who consumed the most calcium both from dairy products or supplements had a 16 percent lower risk of colorectal cancer and other cancers of the digestive system than those who got the least amount per day. Also, women who got the most calcium per day had a 23 percent lower risk to develop cancer than woman with the lowest consumption of calcium.

 

“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 cancer, in both men and women,” the researchers concluded.

 

As other studies have shown, calcium intake had no effect on the risk of breast cancer in women or the risk of prostate cancer in men.

 

This is not the only study published in the same issue of Archives of Internal Medicine to assess benefits and safety of vitamins on the human body. A second study reveals that vitamin D might reduce the risk of catching a cold. The study showed that people with the lowest levels of vitamin D had a 36 percent increased risk of catching a cold compared with those with the highest levels. For those suffering from asthma with the lowest vitamin D levels, the risk of catching a cold was six times higher, while for those with chronic obstructive pulmonary disease, low levels of the vitamin more than doubled the risk of cold.