Calcium is one of the essential minerals needed by the body to function properly. It is the most abundant mineral in the human body, with 99% found in the bones and teeth and 1% in the blood. Calcium is used for building strong bones and teeth, cell signaling, blood clotting, maintenance of heart beat, and muscle contraction. Humans get the majority of their calcium from dietary sources. Some dietary sources are excellent. Others are not.
When people think of calcium, they often think of cow's milk, which is unfortunate. Milk has "top of mind" awareness and is widely marketed as a nutritious source of calcium and proteins to people of all ages. The 2010 Dietary Guidelines put out by the United States Department of Agriculture recommends the consumption of three cups of milk daily for persons aged 9 years and older. But here is a paradox: countries with the greatest dairy milk consumption rates have the highest incidence of osteoporosis. Apparently dairy milk does NOT build strong bones. Who knew?
According to data released by the International Osteoporosis Foundation, 51% of osteoporotic fractures in the world occur in the United States and Europe. Surprisingly, the United States Department of Agriculture reports that Europe and the United States are the first and third highest milk-consuming nations in the world. The question that should be going through every logical mind right now is that if dairy milk improves bone health and protects against osteoporosis, why is osteoporosis (a condition that weakens the bone) so prevalent in these high dairy-consuming nations?
The simple truth is that, contrary to popular belief, dairy milk does not protect against osteoporosis or bone fracture. Milk is packed with calcium, cholesterol, lactose sugar, saturated fats, and animal proteins. Like other proteins from animal sources, milk increases the acid load of the body. This milk-induced acidity triggers a homeostatic mechanism that tries to return the pH of the body back to its original slightly alkaline state.
Calcium is an excellent neutralizer of acid. The body pulls out calcium ions from its biggest calcium stores (the bones), uses the calcium to neutralize the extra acid added to the body by milk, and excrete these ions via the urine. Thus, dairy milk promotes the loss of calcium from the bones and the body. Therefore, even though milk contains calcium, its protein content induces the excretion of more calcium than normal through the kidneys, thereby decreasing bone mass and increasing the risk of osteoporosis and fracture.
Healthy Sources of Calcium
We do not need milk (dairy or plant-based) to obtain calcium. Plant foods, such as kale, cauliflower, beans, broccoli, turnip greens, and collard greens, are healthier sources of calcium. Proteins from animal products are so acidic that they leach out the pH-buffering calcium, and thus cause calcium loss (out through the urine). Proteins from whole plant based foods do not. A 1994 study revealed that avoidance of animal proteins can help to reduce calcium loss by 50%. Eating plant foods rich in calcium can help to build up calcium in the bone, thereby enhancing bone health and reducing the risk of osteoporotic fractures. More importantly, not eating animal foods (that cause you to urinate away that calcium) is a more excellent way to preserve bone strength and do your body good.
Additional Information:
(1) Role of Calcium in the Body's Nutrition
(2) The International Osteoporosis Foundation: Facts and Statistics
(3) Does Animal Protein Causes Osteoporosis?
(4) Debunking the Milk Myth: Why Milk Is Bad for You and Your Bone