Recent discoveries have shown calcium plays an integral role in regulating adiposity (fat deposition), insulin resistance, and hypertension–all risk factors for coronary vascular disease (heart disease).
How might calcium help prevent cancer? According to the National Cancer Institute, the exact mechanism how calcium may help reduce the risk of colorectal cancer is unclear, and most research has been done on colorectal cancer. We do know calcium binds to bile acids and fatty acids in the gastrointestinal tract to form insoluble complexes known as calcium soaps. These “soaps” reduce the ability of the acids (or their metabolites) to damage cells in the lining of the colon and stimulate cell proliferation to repair the damage. Calcium may also act directly to reduce cell proliferation in the lining of the colon or cause proliferating colon cells to undergo differentiation, i.e. to not become cancerous. Calcium also may improve signaling within the cell itself and cause cancer cells to differentiate and/or die (1, 2).
On average, Americans consume only 600 mg of calcium daily despite recommendations by the National Academy of Sciences for adolescents to consume 1300 mg/d and adults under age 50 to consume 1,000 mg/d, while adults over 50 should consume 1,200 mg (3). The best calcium supplement is calcium citrate, as it is most easily absorbed.
|Food sources for Magnesium
Low magnesium intake has been associated with adverse cardiovascular events, including atherosclerosis, cardiac arrhythmias, hypertension and even sudden cardiac death. There has also been an association noted with diabetes. Severe magnesium deficiencies are reportedly rare, however certain medical conditions, such as electrolytes imbalances, diuretic therapy, malabsorption, pancreatitis, postsurgical stress, vitamin D-resistant rickets, diabetes, and parathyroid gland disorders, are associated with more acute depletions (4). Good food sources of magnesium are listed above, and include seeds, legumes, cereal grains, dark green leafy vegetables, milk and other dairy products. The best form of supplementation is magnesium glycinate, as it has the least bowel side effects.
- Whereas not all evidence has been supportive, a number of clinical studies appear to support a role for adequate magnesium intake for reducing the risk for CVD. It is hypothesized that magnesium may be protective against atherosclerosis and thrombosis. There are numerous studies that address the role of magnesium in different types of cancer prevention, and research is ongoing.
The current recommended daily intake for adult males age 19-30 is 400 mg/d and 420 mg/d for males over age 30. Adult females age 19-30 should consume 310 mg/d while females over age 30 should take in 320 mg/d (5).
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- Milner JA, McDonald SS, Anderson DE, Greenwald P. Molecular targets for nutrients involved with cancer prevention. Nutrition and Cancer 2001; 41(1–2):1–16.
- Lamprecht SA, Lipkin M. Cellular mechanisms of calcium and vitamin D in the inhibition of colorectal carcinogenesis. Annals of the New York Academy of Sciences 2001; 952:73–87.
- Committee to Review Dietary Reference Intakes for Vitamin D and Calcium, Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.
- Anderson and Braun, Pathophysiology: functional alterations in human health. Lippincott Williams &Wilkins: Philadelphia, 2007.
- Trumbo et al, Dietary reference intakes: vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. J Am diet Assoc. 2001 Mar;101(3):294-301.
By, Georgia Tetlow