Dealing with doctors over your diabetes diet
Q: Can a reduced-carbohydrate / higher-protein plan lead to osteoporosis?
A: No, a low-carb diet reduces the risk of osteoporosis. In certain sections of the nutritional world, there seems to be a belief that if we eat animal protein this will cause our bones to lose calcium. This question is of particular interest in light of Palaeolithic diet research for two related reasons. The first is because estimates of the levels of animal protein in the hominid diet during at least the last 1.7 million years of human evolution (from the time of Homo erectus) are much higher than is considered 'healthy' in some sectors of the nutritional research community today. The second is because the fossil evidence shows that Palaeolithic humans had a higher bone mass that would have been more robust and fracture-resistant than modern Western human's bones.
When studies were done with people eating meat together with its fat, no calcium loss was detected, even over a long period of time.7 Other studies confirmed that meat eating does not adversely affect calcium balance 8 and that protein actually promotes stronger bones.9
For example, researchers at Tufts University in Boston studied the bone density of elderly men and women who were taking calcium and vitamin D and found that bone density improved most in the participants who ate the most protein, including animal proteins.10 The lead researcher, Dr Bess Dawson-Hughes, said: 'Excess protein intake should be bad for bone, but the results of the study suggest that concerns about protein intake are probably unfounded.' She admitted that the study and other published research 'go a long way toward refuting' concerns that animal protein is bad for bones.
A year later researchers at the Bone Metabolism Unit, Creighton University School of Medicine, Omaha, looked again at this question concluded that 'the results of the present study in postmenopausal elderly women suggest that a higher protein intake as a percentage of energy is associated with higher BMD [bone mass density] in the presence of an adequate calcium intake. . . Our results suggest that in the elderly, who are at the highest risk of osteoporosis, a higher protein intake is important for the maintenance of good bone health.' 11
Other evidence shows that men and women who ate the most animal protein had better bone mass compared to those who avoided it.12 The evidence also showed that vegan diets containing no foods from animal sources placed women at a greater risk for osteoporosis.13 My wife, Monica, is the only woman I know to have lived with this way of eating as long as I have. Just before her 67th birthday Monica had a bone scan as part of a clinical study. The results showed that her bones are as good as someone less than half her age.
The studies that purported to show that calcium loss from bone was greater in people who ate lots of protein were not conducted with real, whole foods but with isolated amino acids and fractionated protein powders. The reason why the amino acids and fat-free protein powders caused calcium loss while the fat meat diet did not, is because protein, calcium and other minerals require the presence of other nutrients such as the fat-soluble vitamins A and D before they can be used by the body. When protein is consumed without these other nutrients, it upsets the normal biochemistry of the body and mineral loss may be the result.14 True vitamin A and full-complex vitamin D are only found in animal fats. Furthermore, saturated fats that are present with meat are essential for proper calcium deposition in the bones.15
What the protein-causes-osteoporosis hypothesis really teaches us is avoid special 'low-carb' foods such as whey powder, soya protein isolates, high-protein smoothies and protein bars — and to eat meat in its natural state — with its fat.
Q: Does the plan in this book contain all the nutrients I need to protect my bones?
A: Yes. This eating plan is high in protein and calcium- and magnesium-rich foods like cheese, fish, green leafy vegetables and nuts.
There is just one caveat: Vitamin D is needed to metabolise calcium and there is very little Vitamin D in any foodstuffs. Our bodies make it from the action of sunlight on the skin. It is also made in other animals the same way. Vitamin D is a fat-soluble vitamin. It is found in the fat of animals that have been allowed to graze in sunshine, but you won't find any in plant foods. This is why the best foods are animal fats and full-fat dairy products — as long as animals that supply these have been kept outside. These days, that is not guaranteed, so it is also a good idea to get out in the sun often so that your body can make vitamin D naturally.