Last week I spoke about how milk is not the healthiest option for us in our diet. Especially considering the amount of processing that it goes through before hitting the shop shelf, it really is a poor choice of food. These comments lead to a few questions from some readers about calcium. Milk is supposed to be our best source of calcium, so where do we as runners, get our bone strength from? Our legs are pounding the pavement for so many miles a week, so the last thing you want is weak bones.
I had considered including this in last weeks blog, but thought it deserved its own post as it needs more than a paragraph to get the facts across.
We are all told to have milk for its high calcium levels, but really when you think about it, with the amount of milk drunk throughout the world, why is osteoporosis even an issue today? If the milk we buy from the supermarkets was such a great source of calcium, we would all have bones to rival Wolverines from X Men! Sorry, the inner nerd snuck out of me for a second… Unfortunately, the dairy industry has been at the forefront of this promotion to sell milk as the cure for osteoporosis. Somehow I think they may have a vested interest in this other than people’s health.
The fact is, that in the US, 1 in every 4 (or 25%) of US women will develop the disease by the age of 65. The amount of bone loss to count as osteoporosis is in excess of 50%. Now don’t get me wrong, I’m not saying the whole medical industry is wrong and calcium does not play a role in bone health/strength, it most certainly does. What I am saying is that increasing your calcium intake is not necessarily the answer.
A while ago I spoke about an alkaline diet and the positive effects it can have on many aspects of your health with bone health being one of these aspects. You see, when our body is in a state of acidosis, or over acidity, we use calcium stores to help bring our bodies back to balance, or homeostasis.
“Calcium in the form of phosphates and carbonates represents a large reservoir of base in our body. In response to an acid load such as the modern diet these salts are released into the systemic circulation to bring about pH homeostasis.”
L. Frassetto, R. C. Morris, Jr. R.C. Jr., D. E. Sellmeyer, K.Todd, and A. Sebastian, “Diet, evolution and aging—the pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet,” European Journal of Nutrition, vol. 40, no. 5, pp. 200–213, 2001
If you want to learn more about an alkaline diet, you can read my post on that topic here.
Supplementation of calcium is not always the answer either. There are some nations that get very low levels of calcium, but have very low levels of osteoporosis. What is most important is the usability, or bioavailability, of the calcium and there are a number of factors to take into account here. The calcium in store bought milk has been damaged in the pasteurization process and the vitamin D which aids in the digestion of calcium has also been damaged, meaning its bioavailability is very low.
Another factor is that our bodies hate high doses of anything in one shot. Minerals like calcium are no different. Dark leafy green vegetables have smaller amounts of calcium in them compared to milk, but it is very easily absorbed (high bioavailability) and are also very alkalizing, meaning less demand on our calcium stores.
Protein rich foods are quite acidic, meaning they create a very acidic environment in the body and lead to excess leaching of calcium.
“Excess dietary protein with high acid renal load may decrease bone density if not buffered by ingestion of supplements or foods that are alkali rich.”
U. S. Barzel and L. K. Massey, “Excess dietary protein may can adversely affect bone,” Journal of Nutrition, vol. 128, no. 6, pp. 1051–1053, 1998.
Now I know we need a source of protein to recover from our workouts, that’s a no brainer. But the quantities that people take are sometimes over inflated. Most people can get away with as little as 1 – 1.2 grams of protein per day per Kg of body weight. So a 70 Kg person needs roughly 70 – 84 grams of protein per day. A 50 gram egg has roughly 6 grams of protein depending on the quality of the egg.
Last but not least is exercise. Make sure you get plenty of it. I know I am preaching to the converted here, but our body is great at making adaptions to any stresses you place upon it. We lift heavy weights, our muscles get stronger, we run long distances, our endurance improves. But what also happens is the stress exercise puts on our bones, causes them to strengthen, or become denser, the opposite to osteoporosis.
So to sum it all up,
- Eat a mostly alkaline diet,
- Exercise regularly (load bearing and cardio),
- Get plenty of vitamin D with the best source being from the sun,
- Start young as once you have low bone density, it’s very hard to rectify,
- Avoid milk as it is actually very acidic, although raw milk is OK occasionally
- Don’t take any of those calcium supplements, they will only make you broke! (Low bioavailability)