All kinds of names have been given to this condition, including widows’ stoop and brittle bones. It is, in fact, the loss of bone mass – essentially calcium – leading to more fragile bones. It is a very serious disease and accounts for more deaths – mostly from fractured hips – than cancers of the cervix, breast and uterus combined (76).
Meat is not a source of calcium so the amount taken in by vegetarians tends to be similar or greater than in meat eaters. The slogan ‘drink more milk’ in order to avoid osteoporosis has almost certainly got more to do with marketing than good dietary advice because preventing osteoporosis isn’t that simple. Milk contains protein and the more protein you consume – animal protein – the more your body loses calcium.
Animal protein produces an acid overload which the body tries to neutralise by calling on its calcium stores in the bones, which are then urinated out of the body. (Not surprisingly, vegans urinate less calcium than meat eaters.) The process happens through a complex series of reactions involving the body’s hormonal balance, which is why osteoporosis is often associated with post-menopausal women when the hormonal balance is readjusted.
The ideal scenario for calcium consumption is to have a good intake and minimal loss – although no one is quite sure what the ideal intake should be. On the intake side, calcium is found in most green leafy vegetables (the darker the better) and the amount available from these sources is equal to or better than milk (77, 78, 79, 80).
Nuts (especially almonds) and seeds (especially sesame seeds) as well as pulses of all types such as beans, lentils and soya are also good sources. Of course, these vegetable sources also provide other important minerals, antioxidants and complex carbohydrates.
Unfortunately, most medical advice concentrates only on the intake side of the equation and ignores the reasons for calcium loss. These include salt, caffeine, tobacco, lack of exercise and maybe alcohol as well as animal protein. Professor T. Colin Campbell, of the China Health Study, says: “Osteoporosis tends to occur in countries where calcium intake is highest and most of it comes from protein-rich dairy foods” (81). However, sufficient calcium can be obtained from vegetables (82).
A trace element called boron plays an important part in helping to prevent calcium loss. When a group of menopausal women included it in their diet, calcium losses were cut by 40 per cent (83). The natural sources of boron are not dairy products but apples, pears, grapes, nuts, leafy vegetables and legumes.
Again it’s not surprising that vegans have lower rates of hip fracture than meat eaters, despite having lower intakes of calcium (84). This clearly makes the point that to concentrate only on intakes of calcium is just half the picture. It is like dealing with haemorrhaging by giving a blood transfusion but without stopping the source of the bleeding.