Monday, June 30, 2008

Changing Cancer Genes with Lifestyle

If you believe that cancer is genetic and there's nothing you can do to prevent it, take a look at the latest study from Dr. Dean Ornish. He reports that after just three months of a healthful diet and exercise, the genes associated with prostate cancer changed toward normal (Proceedings of the National Academy of Sciences, June 17, 2008).

The study involved 30 men with low-risk prostate cancer who had chosen not to undergo treatment unless their cancer got worse. The men followed a plant-based diet that avoided meat, saturated fat, and processed or refined foods; walked at least 30 minutes six days a week and at least an hour three days a week; and participated in a weekly support group. Each day they also did an hour of simple yoga-based techniques including stretching, breathing, meditation and imagery.

After just three months on Dr. Ornish's regimen, more than 500 genes associated with prostate cancer reverted toward normal. Cancer genes promote cell growth in a disorderly fashion. The researchers at University of California San Francisco (UCSF) showed that in these men, tumor-suppressing genes became more active and some of the cancer-causing genes switched off.

Many previous studies have shown that most cancers are caused by factors in the environment. Some people are genetically more susceptible to these factors. However, if they avoid the factors, they have an excellent chance of not suffering the cancers. We know that prostate cancer is more common in men who are overweight, diabetic, eat a lot of fat and meat, and/or do not exercise.

A leading theory is that each type of cancer is caused by many factors and the more of these susceptibility factors that involve you, the more likely you are to develop that specific cancer. For example, a woman cannot develop cervical cancer unless she is infected with the HPV virus. But more than 50 percent of American women are infected with this virus and fewer than one in 250 of those develop cervical cancer, so other factors must be involved. A woman with HPV who smokes has almost 20 times the chance of developing cervical cancer as one who has HPV and does not smoke. Other co-factors remain to be found.

Friday, June 20, 2008

Tip for Hot-Weather Competitors

If you compete in a sport during hot weather, you may be helped by this tip for recovering between events.

Researchers at Edith Cowan University in Australia showed that you can recover faster and compete at a higher level by soaking your legs in cold water (14 degrees C) for five minutes during rest periods between events (British Journal of Sports Medicine, June 2008). The cooling session dropped body temperature a half degree centigrade and the athletes were able to cycle faster with greater power output.

Tuesday, June 17, 2008

Vitamin D deficiency linked to many health problems

The hottest subject in medicine today is the amazing number of diseases associated with low vitamin D levels. People with low levels of vitamin D are at double the risk for blocked arteries in their legs, called peripheral artery disease (Arteriosclerosis, Thrombosis, and Vascular Biology, June 2008); markedly increased risk for heart attacks and strokes, angina, and heart failure (Circulation, January and April 2008; Archives of Internal Medicine, June 2008); increased rate of aging of their tissues (The American Journal of Clinical Nutrition, November 2007); cancers of the breast, lung and colon (American Journal of Clinical Nutrition, November 2007); diabetes (Epidemiology, May 20, 2008). Other recent articles show that Vitamin D helps pain control (Pain Medicine, April 2008); and vitamin D reduces the risk of falls (Archives of Internal Medicine, March 2008).

Next winter, ask your doctor to draw blood tests called vitamin D3 and D2. If your D3 level is below 40 ng/ml, you are at increased risk for a host of diseases. You can take pills containing D2 or D3. D2 is the plant pre-vitamin D that is so weak that it usually will not help raise your blood level. On the other hand, D3 is the animal pre-vitamin D that appears to be quite effective. Scientists do not agree on the optimum dose for people with blood levels of D3 below 40 ng/ml. It used to be 200 international units per day. Today, many doctors think that it should be at least 2000 international units. You can also meet your needs for vitamin D from sunlight by exposing a few inches of skin for 15 minutes every other day in the summer. However, during the winter in northern climates, the sun's rays come in at an angle and are therefore markedly reduced by the increased areas of atmosphere through which the sun's rays must pass. You can solve this problem with a tropical vacation.

I have found that tanning beds provide almost no vitamin D. Ultraviolet light is classified into UVA and UVB. UVB are the rays that cause skin cancer. They are also the rays that cause the skin to manufacture vitamin D. Since manufacturers of tanning bulbs are concerned about skin cancer, they reduce the percentage of UVB emitted from tanning lamps. This also markedly reduces the rays that provide vitamin D. More

Wednesday, June 11, 2008

Hip Fat can be Hardest to Lose

I'm not overweight; how can I lose the fat in my hips and thighs?First, realize that people who are shaped like pears live longer than those who are shaped like apples (storing fat primarily in their bellies). "Pears" are less likely to develop diabetes, heart attacks, strokes, and many types of cancers. As you have already found out, diets are of not of much value to people who are generically programmed to store fat in their hips. For a diet to get rid of your hip fat, you would have to be hungry all the time. Exercise will work, but you may need to exercise more than three hours a day to get rid of hip fat. However, you might not have time for a job or your family.

Have you noticed that most female athletes have large buttocks? People who store fat in the buttocks are often genetically programmed to be gifted athletes. If you can double or triple your workout schedule, you would lose fat. Try competing in cycling, running or weightlifting. The odds are that you will be very successful.

Monday, June 09, 2008

New Theory on Recovery from Workouts

The soreness that you feel 8 to 24 hours after an intense workout is caused by a tearing of the muscle fibers. The fastest way to get muscles to heal is to have your body produce lots of insulin and also provide a supply of protein to repair the damaged tissue. We have known for a long time that insulin drives sugar into cells for energy. Now we know that it also drives protein building blocks called amino acids into the muscle cells to help them heal faster. A study from New Zealand shows that protein loading immediately after exercise helps cyclists recover faster so they can ride harder for several days after an intense workout (Physiologie Appliquée, Nutrition et Métabolisme, February 2008).

On the surface of muscle cell membranes are little hooks called insulin receptors. Before insulin can do its job of driving sugar and protein into cells, it must first attach to these receptors. Hard exercise markedly increases insulin's ability to attach to insulin receptors and therefore makes insulin more effective. However, this increased response of insulin to exercise lasts only during exercise and for perhaps half an hour after exercise. An hour after you finish exercising, you have lost this added sensitivity of insulin receptors to insulin. So to help muscles recover faster, you need to take a carbohydrate source during a hard workout and immediately after you finish. Any source of carbohydrates will be broken down into simple sugars that call out insulin. Then, as soon as possible after your workout, you should eat any source of protein to supply the amino acids needed to heal damaged muscle tissue.

Entrepreneurs will probably use this information to promote various protein drinks and supplements, but you will get the same results with any sugared drink and any food or drink that contains protein. Soda and cheese or your favorite sports drink and shrimp or nuts will work just fine. More

Sunday, June 08, 2008

Low maximum heart rate signals fitness

No matter how hard I exercise, my heart rate never gets as high as my husband's. Should I be concerned? No; it may just mean that you are in very good shape. Researchers at Liverpool John Moores University in England showed that athletes have much lower maximum heart rates than sedentary people and that female athletes have lower maximum heart rates than male athletes (International Journal of Sports Medicine, February 2008).

Most exercisers should not even bother with heart rate calculations. Your training heart rate occurs when you exercise vigorously enough to make your body require more oxygen. You can tell when this happens because you will start to breathe deeper and faster, raising your shoulders with each breath. Once or twice a week, you should try to exercise intensely enough to increase your need for oxygen. If you feel uncomfortable, you should slow down. Non-athletes do not ever need to exercise so vigorously that they become severely short of breath. More

Tuesday, June 03, 2008

Salt restriction hinders exercisers

Most doctors recommend low salt diets because of the evidence that taking in too much salt can cause high blood pressure, a major risk factor for heart attacks and strokes. However, this may not be good advice for dedicated exercisers. If you exercise heavily and restrict salt, you will not replace the salt you lose through sweating, which can cause high blood pressure as well as fatigue, cramps and muscle pain. When the body is low in salt, the adrenal glands produce large amounts of aldosterone and the kidneys produce renin, which constricts arteries and can raise blood pressure.

Researchers at Albert Einstein College of Medicine showed that people on low-salt diets are actually more likely to suffer heart attacks than those on high salt diets (Journal of General Internal Medicine, June 2008). They analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III) of American adults. Dr. Hillel W. Cohen, lead author of the study, stated, "Our findings suggest that for the general adult population, higher sodium is very unlikely to be independently associated with higher risk of death from heart attacks."

Many years ago, when I was competing in marathon races, I decided to try a low-salt diet. I was surprised to find that my blood pressure rose from a normal 120/ 80 to as high as 160/80, and I suffered severe fatigue and frequent injuries. When I added salt back into my diet, my blood pressure went down to normal and I was able to train and compete again. This is why I recommend a relatively high-salt diet for exercisers. If you decide to increase your intake of salt, get a blood pressure cuff and check yourself for a month. If your blood pressure goes above 120/80, you may have added too much salt. Also, if you stop exercising because of an injury or for any other reason, be sure to cut out the extra salt to keep your blood pressure under control. More