How exercise prevents diabetes: more than just weight control

A fascinating study from Maastricht University in the Netherlands shows that exercise helps to prevent and treat diabetes by increasing the number of enzymes that transport fat from fat cells to muscle cells where it can be used for energy by the muscles. Before insulin can do its job of removing sugar from the bloodstream and putting it into cells where it can be burned for energy, it must first attach on special hooks called insulin receptors on the surface of cells. Fat stored in cells internalizes receptors so insulin loses its attachment sites and is unable to its job. Exercise causes muscle cells to markedly increase their production of certain fat transported proteins that remove fat from fat and muscle cells. So less fat is available to block insulin receptors and blood sugar levels drop. Journal reference

Another study, from University of California at Berkeley, followed 36,000 male runners for almost a decade. Those who ran five or more miles per week were half as likely to develop diabetes as those who ran fewer than five miles per week (Diabetes Care, November 2007). Furthermore, researchers at the University of Western Australia showed that an eight-week exercise program markedly increased diabetics' ability to respond to insulin, even if they did not lose any fat. Journal reference

Anyone who wants to prevent diabetes should make exercise a priority. Because of the extremely high rate of heart disease in diabetics, all diabetics should have their hearts checked by a cardiologist. If they can pass a thalium stress test, they should be in some kind of supervised exercise program. More

Knee Cartilage Repair: Will it Work for You?

The ends of bones are soft, so they must be covered with a thick white gristle called cartilage. Once damaged, cartilage can never heal. When knee cartilage is damaged, the person spends the rest of his life losing more cartilage until it is completely gone and the knee hurts 24 hours a day.

If only a small area of the cartilage is damaged, it may be repaired with cartilage extracted from your own body. (If cartilage is taken from someone else, your immunity will try to kill it, but it doesn’t try to kill your own cartilage.) Your extracted cartilage is grown in special culture dishes and then injected into a hole in your own cartilage and secured in place. This procedure works very well if you have only a small piece of cartilage missing. The doctors just fill the hole. However, unless they can enclose the entire area for the donor site, the cartilage will not stay where it was put and will not be beneficial. That is why this procedure cannot be used to treat a cracked cartilage in the knee. Remember they have to cover the articular surface that meets the cartilage from the other side of a joint.

When all the cartilage in your knee is gone, the only effective treatment is to replace the whole knee. Knee replacements are now lasting for twelve to twenty years or more, and most remain pain-free.

If you have damaged cartilage in your knee, you should protect that knee for the rest of your life. Running, fast walking and jumping cause further damage, while pedaling and swimming usually do not. When the knee hurts all the time, your doctor will check to see how much cartilage is left. If it's gone, you probably need a knee replacement.