Dairy products are rich in calcium, are often enriched with vitamin D and may contain probiotics. All of these nutrients can play a role in cancer prevention, though according to the American Cancer Society (ACS), the reasons are not always clear and the benefits are not always consistent. Certain dairy foods might prevent one type of cancer, such as colon cancer, while increasing the risk of prostate cancer, according to the National Cancer Institute (NCI). Nevertheless, eating a healthy diet that includes calcium and other nutrients is beneficial to everyone.
Milk
Milk is one of the richest food sources of calcium, and might be able to prevent colorectal and ovarian cancers in some populations. The National Cancer Institute summarizes findings from a study called the Nurses' Health Study and reports that women who drank low-fat milk had a lower risk for both ovarian and breast cancer than those who did not, or those who drank whole milk. The American Cancer Society additionally reports that women who consumed low-fat milk and also took oral contraceptives were much less likely to become diagnosed with ovarian cancer. The NCI theorizes that the calcium in milk attaches itself to bile and fatty acids in the digestive tract and prevents damage to the colon's lining, which could lead to cancerous growths. Milk is rich in vitamin D as well as calcium. Though vitamin D did not make a difference in cancer risks in the ACS findings, it helps the body metabolize calcium effectively.
Yogurt
Yogurt that contains live, or active cultures like L. casei may have cancer prevention benefits. According to the National Center for Complementary and Alternative Medicine (NCCAM), live cultures, also called probiotics, can reduce the risk of bladder cancer recurrences. Probiotics are healthy bacteria that can boost the immune system and promote digestive regularity. The University of Michigan Health System's (UMHS) nutritional charts regarding calcium lists yogurt at the top of the lists, with a 1 cup serving containing 415 mg. The high calcium count of yogurt, like milk, may keep people from developing other forms of cancer as well as bladder cancer.
Cheese
Certain types of cheese may hold cancer prevention benefits due to the calcium content. Hard cheese like cheddar can contain up to 300 mg of calcium, According to UMHS, softer cheeses such as ricotta, cottage cheese and mozzarella are less rich in calcium, but still good sources of the nutrient. To place the calcium content of cheese in perspective, the NCI reports findings from the Calcium Polyp Prevention study of the late 1990s that shows a correlation between 1200 mg to 2000 mg of daily calcium--or several servings of cheese-- and a reduced occurrence of colon polyps.
