For years and years, most of us at one time or another have heard that calcium is the key to preventing osteoporosis, and that the consumption of dairy products, particularly milk, is the way to protect your bones as you age. There is some truth to that, since calcium is one of the components of your skeleton. However, as you will see below, there are many other nutrients that build strong bones, and sadly enough, since calcium is the only one that has been mentioned, (partly due to strong lobbying from the dairy industry), many of us do not get sufficient amounts of the other nutrients, especially those of us not following a hunter-gatherer type diet.
Furthermore, dairy products, although high in calcium, might not be the best method for protecting your bones. In fact, a large review article from the American Journal of Clinical Nutrition concluded that the only subset of people who might benefit from dairy products to prevent osteoporosis is women under 30 years of age. The problem with dairy products is twofold. First, dairy products such as milk and cheese contain high amounts of calcium, but low amounts of magnesium, which is also a crucial nutrient in strengthening the skeleton as will be discussed below. Thus you get a very high ratio of calcium to magnesium, which can lead to increased urinary loss of magnesium. Second, most calcium containing dairy products, including milk, but especially cheese, also contain significant amounts of sodium. Sodium causes urinary calcium loss, and so you’re literally peeing your calcium away, especially if you consume significant amounts of other processed foods like breads, snack foods, processed meats, soy products, and junk food.
More and more evidence now shows that protecting your bones is more a function of retaining calcium in your bones rather than the amount you consume. Thus eating large amounts of calcium alone won’t do the trick. If anything, it will make you deficient in magnesium, which will hurt you in the end. You should try to consume adequate amounts of calcium, but dairy might not be optimum. Try increasing your intake of sardines, halibut, ocean perch, pike, trout, canned salmon, almonds, brazil nuts, oranges, prickly pears, blackberries, black currants, figs, kumquats, spinach, leafy greens, and if you want, a cup or so of calcium fortified orange or grapefruit juice. These are all healthy, natural, foods that will ensure good calcium intake without the unhealthy effects of dairy products. Furthermore, they are all good sources of other essential nutrients.
One of those essential nutrients is magnesium, a mineral found in nuts, seeds, vegetables, and in smaller amounts in fruit and meat. Magnesium is essential not only for bone health, as it is one of the components of bone, but also for heart health and the prevention of hypertension. Unfortunately, the vast majority of us who live on processed food are grossly deficient in this important nutrient, which is contributing to poor health.
Potassium, found in high amounts in fruits, vegetables, and meat, also is crucial for the prevention of osteoporosis, but not because it is a component of bone, but rather because it is important in preventing urinary losses of calcium and magnesium. As was stated above, preventing urinary losses of calcium, especially as we age, is the key to preventing osteoporosis, and thus eating a diet rich in potassium and low in sodium is of the utmost importance.
The next component in our bone health discussion is protein, or more specifically animal protein. Many nutritionists have bashed protein, claiming that a high protein diet will cause weak bones because protein can lead to increased urinary excretion of calcium. However, the scientific evidence speaks for itself. One large study published in the Journal of Bone and Mineral Research showed that both elderly men and women who consumed the most animal protein had the lowest rate of bone loss, whereas those who consumed little protein had much higher rates of bone loss. Another study published in the American Journal of Clinical Nutrition, has shown that postmenopausal women (the group of people at highest risk for osteoporosis) who consumed the highest amount of protein, particularly animal protein, had the strongest bones, and were the least likely to suffer from hip fractures. Other studies have shown that low protein diets hamper recovery from fractures (as well as illness in general).
If we think about it, it makes sense. Bone is a living, active tissue, just like any other in the body. It contains large amounts of cells that are made up partially of protein. A lot of these cells have functions essential to maintaining bone health. Furthermore, eating low amounts of protein usually puts the body in a catabolic state, where muscle is cannibalized for its protein. It could be that in such a state, the body is producing lower amounts of anabolic, bone-building hormones such as testosterone, estrogen, and growth hormone. Our body isn’t stupid. Feed it a low amount of protein, and it will channel any that it gets towards essential functions such as keeping essential organs alive at the neglect of your muscles, bones, and immune system. Lastly, it is also known that protein induces an increase in insulin-like growth factor, which promotes bone building.
Robert Heaney, whose team conducted the widely cited study showing a positive correlation between protein intake and urinary calcium loss, has taken it upon himself to revisit his original data in light of all of the evidence pouring forth from prospective studies showing that protein intake is actually beneficial for bone. In his editorial in the American Journal of Clinical Nutrition, he critiqued his own study, stating that the women in the study were in a metabolic ward receiving abnormally low amounts of calcium. He speculated that under such conditions, protein MAY have some negative effects. In addition, he blasted the twisting of the scientific evidence by special interest groups such as vegetarians to suit their political agendas.
The next topic in this discussion is vitamin D, which is essential to calcium absorption in the intestine. In fact, without vitamin D all of the calcium in the world wouldn’t be worth squat. Vitamin D may also have a role in the prevention of some cancers. The cheapest, easiest way to get vitamin D is sunlight, which produces vitamin D in your skin. Thus those of you who shy away from all sunlight, or who always use sunscreen, are doing your body more harm than good. Am I saying you should go out there for hours on end? NO! Of course not. You don’t want skin cancer. However, 10-15 minutes a day or more (depending on your skin type) is very healthy. Just don’t overdo it or go out around midday when the sun is at its hottest and you’ll be fine. Vitamin D is also found in milk, where it is added, and fatty fish and organ meats. However, all those of you drinking lots of skim milk with your nonfat cereals aren’t getting one iota of the vitamin D in the milk since it is a fat soluble vitamin which needs fat to be properly absorbed in the intestine. In addition, there is evidence that fat also increases calcium absorption.
The final factor I want to talk about and emphasize, as it is probably one of the most important ones, is weight-bearing exercise. Your body, being efficient, works on a “use it or lose it” mentality. If you sit around all day for 50 years, your body will realize, “Hey, I don’t need strong bones or muscles since I never use them! Why waste all this energy trying to maintain them. Let them go and I can go nap.” The result is weak muscles and bones, factors that make you more susceptible to fractures. Many people believe that walking is enough to protect you, but I disagree. Walking is a healthy exercise, but I don’t believe that the stress on your skeleton is enough to keep those bones strong. Instead, lifting weights or performing calisthenics such as deep knee bends should do the trick.
In conclusion, we have seen that to protect our bodies from getting osteoporosis, we should consume a diet which includes calcium, magnesium, potassium, protein, and which is low in sodium, as well as get some sunlight for vitamin D and perform weight-bearing exercises such as lifting weights or calisthenics. By following a hunter-gatherer type diet such as the TBK diet, you will get all of the above nutrients in natural healthy proportions. Furthermore, by following the TBK exercise program, you will build up those bones and muscles.
References
Hannan MT, Tucker KL, Dawson-Hughes B, Cupples LA, Felson DT, and Kiel DP. Effect of Dietary Protein on Bone Loss in Elderly Men and Women: The Framingham Osteoporosis Study. Journal of Bone and Mineral Research. 2000;15:2504-2512.
Heaney RP. Protein Intake and Bone Health: The Influence of Belief Systems on the Conduct of Nutritional Science. American Journal of Clinical Nutrition. 2001;73:5-6.
Munger RG, Cerhan JR, and Chiu BCH. Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women. American Journal of Clinical Nutrition. 1999;69:147-152.
New SA, Robins SP, Campbell MK, Martin JC, Garton MJ, Bolton-Smith C, Grubb DA, Lee SJ, and Reid DM. Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health? American Journal of Clinical Nutrition. 2000;71:142-151.
Promislow JHE, et al. Protein Consumption and Bone Mineral Density in the Elderly – The Rancho Bernardo Study. American Journal of Epidemiology. 2002;155:636-44.
Tucker KT, Hannan MT, Chen H, Cupples L, Wilson PWF, and Kiel DP. Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone density in elderly men and women. American Journal of Clinical Nutrition. 1999;69:727-36.
Weinster RL, and Krumdieck CL. Dairy foods and bone health: examination of the evidence. American Journal of Clinical Nutrition. 2000;72:681-9.
Wolf RL, et al. Factors Associated With Calcium Absorption Efficiency in Pre-and Perimenopausal Women. American Journal of Clinical Nutrition. 2000;72:466-71.