Science Questions

Does milk affect stamina?

Does drinking too much milk, or calcium, reduce your physical endurance or stamina? Sheila via email

If you drink milk that isn't skimmed, it's got lots and lots of fat in it. Having lots of fat isn't good for you because of the calories, but also because it furs up your blood vessels. Milk is also very rich in calcium which, in people who are prone to stones, can deposit in the kidney and cause kidney stones. And the other side effect of milk that not many people know, is if you have irritation to the stomach lining and you're at risk of getting stomach ulcers, calcium is used as a co-signal by the wall of the stomach to produce acid. If you have calcium levels in the blood going up, you make more acid. Some people think when they have a dodgy stomach that drinking milk will settle it. When you first do that your stomach feels happier because you've given the acid something to eat other than the wall of your stomach. But then the calcium is absorbed and goes into the blood stream and increases the amount of acid your stomach makes, causing a vicious cycle.

January 2007