A new study shows that older men and women who got the most calcium from food and supplements had a 16% lower risk of colorectal and other cancers of the digestive system than those who got the least calcium.
Among women, those cancer-fighting benefits were even stronger. Women who got the most calcium from food and supplements had a lower risk of all cancer and a 23% lower risk of cancers of the digestive system than those who got the least.
Calcium is already known to boost bone health, but researchers say previous studies on calcium’s effect on cancer have produced mixed results.
“Our study suggests that calcium intake is associated with a lower risk of total cancer and cancers of the digestive system, especially colorectal cancer,” write researcher Yikyung Park, ScD, of the National Cancer Institute and colleagues in the Archives of Internal Medicine.
Calcium May Lower Cancer Risk
The Institute of Medicine recommends 1,200 milligrams of calcium per day for men and women over age 50. Dietary guidelines also call for adults to eat three cups of fat-free or low-fat dairy foods, such as milk, yogurt, and cheese to meet their daily calcium needs.
One 8-ounce serving of skim milk or yogurt contains about 300 milligrams of calcium. Other nondairy sources of calcium include beans, broccoli, spinach, and other green, leafy vegetables.
In the study, 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. Participants answered a questionnaire about the foods and supplements they ate, and cancer rates were linked through state cancer registries over seven years of follow up.
The results showed that total calcium intake was not associated with a lower risk of cancer in general in men, but women who got up to 1,300 milligrams of calcium per day had a lower risk of cancer overall.
However, total calcium intake from both food and supplements was linked to a lower risk of colorectal cancer and other cancers of the digestive system in both men and women.
Men who got the highest levels of total calcium per day through food and supplements had a 16% lower risk of these cancers than those who got the least amount per day. Women who get the most calcium per day had a 23% lower risk than those with the least reported intake per day.
Researchers conclude that "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."