Fitness & Health with Dr. Gabe Mirkin

Changing Cancer Genes with Lifestyle

2008-06-30T19:35:00.001-04:00

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.

Tip for Hot-Weather Competitors

2008-06-20T20:19:00.002-04:00

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.

Vitamin D deficiency linked to many health problems

2008-06-17T11:03:00.001-04:00

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

Hip Fat can be Hardest to Lose

2008-06-11T13:42:00.000-04:00

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.

New Theory on Recovery from Workouts

2008-06-09T19:38:00.000-04:00

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

Low maximum heart rate signals fitness

2008-06-08T20:59:00.001-04:00

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

Salt restriction hinders exercisers

2008-06-03T18:38:00.000-04:00

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

Fewer Omega-6's May Reduce Cancer Risk

2008-05-27T20:22:00.000-04:00

Researchers at UCLA show that reducing intake of corn oils helps to prevent prostate cancer in mice (Cancer Research, April 15, 2008). Corn oil and other vegetable oils are extremely rich sources of omega-6 fatty acids.

Fats are classified by their chemical structure into omega-3s, omega-6s, and omega-9s. Omega-6s cause your body to produce prostaglandins that turn on your immunity to cause inflammation, while omega-3s turn down your immunity to reduce inflammation.

Your immunity is supposed to be good for you. When a germ enters your body, your immunity produces white blood cells and proteins called antibodies that attack and kill the germ. After that germ is gone, your immunity is supposed to stop making so many immune cells and proteins. If it remains active, your immunity attacks your own body to damage tissue and increase risk for heart attacks, certain cancers, and diabetes; it can also worsen existing diseases such as some types of dementia, asthma or psoriasis.

For more than 2 million years, humans have eaten diets that have a ratio of omega-6s to omega-3s of about two to one. However, over the last 100 years, humans have added extracted vegetable oils to other foods that they eat and increased the ratio to 12 to one and perhaps as high as 20 to one. This increase in the ratio of omega-6s to omega-3s is a cause of inflammation. The increase in omega-6's has come primarily from vegetable oils that are added to baked, fried and other prepared foods. Omega-3s oils are relatively unstable so they are not found in most prepared foods.

Good food sources of omega-3's include seafood and beans, whole grains, nuts and other seeds. We do not know if changing the ratio of omega-6s to omega-3s will help to prevent cancers in humans, but several studies show that they appear to both prevent and slow cancers in animals.
More on omega-3s and omega-6s

Breast Cancer Risk Lower with Exercise

2008-05-22T15:08:00.001-04:00

A recent study from Washington University School of Medicine in St. Louis shows that exercise starting during adolescence can protect girls from breast cancer (Journal of the National Cancer Institute, May 2008). Researchers tracked 65,000 nurses who answered questionnaires about exercise. Within six years, 550 were diagnosed with breast cancer before menopause. Those who exercised regularly as teens were 23 percent less likely to develop premenopausal breast cancer than their sedentary peers. Ages 12 to 22 appear to be the most important time to use exercise to help prevent breast cancer.

Higher estrogen levels increase risk of breast cancer. Exercise lowers estrogen by reducing body fat. Fat cells make estrogen, and after the menopause fat cells are the principal source of estrogen. Other factors that increase breast cancer risk are also related to higher estrogen levels: starting to menstruate at an early age, late onset of menopause, taking estrogen after menopause, and being overweight.

Kidney function improved by exercise

2008-05-21T18:31:00.002-04:00

We already know that exercise helps to prevent heart attacks, strokes, diabetes, obesity and certain cancers, and may extend life span. Now a report from Italy shows that exercise may also help to prevent kidney damage that occurs with aging (Clinical Journal of Sport Medicine, May 2008).

Doctors measure kidney function by calculating the ability of the kidneys to rid the body of a breakdown product of metabolism called creatinine. Regular exercisers have lower blood creatinine levels and also have kidneys that are better able to clear creatinine from the bloodstream as measured by a test called Glomerular Filtration Rate (GFR).

According to this study, professional bicycle racers have better kidney function than both sedentary people and recreational cyclists. This is very interesting because professional cyclists dehydrate themselves with almost every workout, in spite of the huge amount of fluid they consume. The researchers found that frequent dehydration accompanied by drinking large amounts of water did not cause kidney damage. This repeated stress on the kidneys may even explain why the professional cyclists had better kidney function than the less-active participants.
Newsletter

Ibuprofen reduces risk of Alzheimer's

2008-05-18T08:37:00.001-04:00

Researchers at Boston University School of Medicine followed 250,000 veterans over the age of 55 years and showed that taking ibuprofen for five years was associated with a 40 percent reduction in the development of Alzheimer's disease (Neurology, May 2008).

Alzheimer's disease is associated with the deposition of tangled webs of protein in the brain. Several previous studies show that ibuprofen reduces these protein deposits in the brains of animals. A leading theory on the cause of Alzheimer's disease is that a person's immunity attacks the brain to cause dementia. Ibuprofin reduces inflammation, the body's response to an overactive immunity. Another study in the same issue of Neurology showed people that with shorter arms and legs may be at a higher risk for developing dementia later in life. More on preventing dementia

Smoking Bans DO Reduce Teen Smoking

2008-05-15T21:12:00.001-04:00

Teenagers who live in cities or towns with strict smoking bans are 40 percent less likely to become regular smokers, according to a study published in the Archives of Pediatrics & Adolescent Medicine (May 2008). The study also reported that youths with smoking parents or friends are at high risk for smoking themselves, but strong smoking bans in restaurants reduce the chance that they will become smokers.

Massachusetts passed a workplace smoking ban that included restaurants in 2004. Since then, high school smoking rates in Massachusetts have dropped from 21percent of students in 2005 to 18 percent in 2007. At least 23 states, the District of Columbia and Puerto Rico now require most public places and workplaces, including restaurants and bars, to be smoke free.
Fitness and health newsletter

Progesterone helps to prevent uterine cancer

2008-05-14T08:58:00.001-04:00

They're supposed to prevent pregnancy, and they do, but intrauterine devices (IUDs) also reduce uterine cancer risk by more than 40 percent (Meeting of the American College of Obstetricians and Gynecologists, May 6, 2008).

An IUD is a small, T-shaped plastic device inserted into the uterus. Only two percent of women who use contraception in the United States choose an IUD, despite the proven safety and effectiveness of this long-term method. Worldwide, however, IUDs are the most widely used reversible contraceptive. Most IUD's prevent pregnancy by releasing small amounts of the hormone progesterone into the uterus. This is also why they help to prevent uterine cancer.

The ovaries of healthy women are supposed to produce two hormones: estrogen and progesterone. Many women lack progesterone and they are the women who are at increased risk for uterine cancer. Estrogen stimulates the uterus to grow, and progesterone stops the stimulation. If a woman has estrogen and no progesterone, her uterus is stimulated all the time, which can lead to uncontrolled growth which is cancer.

The woman most likely to get uterine cancer has high blood levels of insulin. Insulin acts directly on the ovaries to stop them from releasing eggs. Women who do not release eggs have no progesterone and therefore are at high risk for uterine cancer. A woman can find out if she has high insulin levels just by getting a blood test, called C peptide, that measures insulin production by the body. If it is above 3, her body makes too much insulin.

However, you can usually tell if a woman has too much insulin just by looking at her. Insulin causes a person to lay down fat primarily in the belly. Women with big bellies and small hips usually have high insulin levels and are also at high risk for diabetes. Most people who will develop diabetes usually stop responding to insulin. This causes the pancreas to release increasing amounts of insulin, until the pancreas eventually dies and then the person must take insulin.

If you are a woman who stores fat primarily in your belly, you should get blood tests called C peptideand HBA1C to see if you are already diabetic. You can also tell if you are pre-diabetic if your good HDL cholesterol is low, your triglycerides are high, or your liver shows excessive amounts of fat. Start a supervised exercise program, lose weight, and restrict refined carbohydrates. You may also want to see if your doctor advises using an IUD to help prevent uterine cancer.
More on Polycystic Ovary Syndrome (PCOS)

How Vitamin Pills May Affect Lifespan

2008-05-12T20:33:00.001-04:00

The issue of vitamin supplements is far from settled. Most doctors take multivitamins themselves and recommend them to their patients. However, I continue to believe that it is better to get vitamins in whole foods than in pills.

Most vitamins are parts of enzymes that start chemical reactions in your body. Each chemical reaction produces end products that are changed by further chemical reactions from other vitamins to other products that benefit your body. When you take a vitamin that has been isolated from the hundreds of other substances found in foods, that enzyme causes a chemical reaction that accumulates a disproportionate amount of its end products. If the substance that acts as an enzyme for the next chain of chemical reactions is not available, you can accumulate end products that may be harmful.

For example, people who take niacin to lower cholesterol show a marked elevation of homocysteine, a major risk factor for heart attacks. Homocysteine levels are raised by a deficiency of B12, folic acid and pyridoxine. When you eat your niacin in whole grains, all of those components are present, along with many others whose functions we may not yet understand.

The study I mentioned in the previous post is in Cochrane Database of Systematic Reviews More

Prevent Injuries: Background Before Peaking

2008-05-09T18:15:00.001-04:00

Injuries often occur when people start a new exercise program, change to a different sport, or return to exercise after a long break. In the enthusiasm to get started, it is easy to overstress muscles that have not been used before. That's why "background before peaking" is one of the most important principles of training. It takes several weeks or even months to build up strength and endurance for any new sport.

Competitive athletes in all sports use this principle. First they spend many months in background training, working out for long hours, mostly at low intensity, followed by a shorter period of peak training in which they do far less work, but at a much greater intensity. A few months before an important race, they reduce their workload but go as fast and hard as possible two or three times a week.

Start your new exercise program at very low intensity and low volume. Gradually increase your workload for several months before you try to run fast, lift heavy or exercise intensely. If you are just beginning to exercise, go at a relaxed pace until your muscles feel heavy and then stop. For the first several days or weeks you may be able to exercise only for a few minutes at a time. If your muscles feel sore the next day, take the day off. Increase the amount of time gradually until you can exercise 30 minutes a day at a relaxed pace and not feel sore. You may progress rapidly to the 30-minute goal, or it may take you two, four, six weeks or more. No matter how long it takes, don't get discouraged. Exercising too much or too hard, too soon will set you up for injuries. More

Weight Lifting Past Fatigue Does Not Strengthen Muscles More

2008-05-01T18:43:00.004-04:00

When you want to become very strong, you try to lift very heavy weights. Weight lifters have known for a long time that you don't pick up the heaviest weight you can move, raise it once and then quit for the day. They do their weightlifting in sets. For example, they lift and lower a weight in three sets of ten or one set of six.

If you exhaust your muscles by bench pressing a weight for three sets of ten, is there any benefit to try to do another set? Researchers from Australia showed that you gain nothing if you force extra lifts after your muscles are exhausted (Journal of Strength and Conditioning Research, August 2007). This study should serve as a warning particularly to young lifters. Plan your workouts. When your muscles are tired or sore, don't try to keep on lifting through the soreness. After a hard workout, go easy for as many days as it takes for your muscles to feel fresh again. More

Get Your Vitamins From Food, Not Pills

2008-04-28T08:06:00.001-04:00

One in three women and one in four men in the United States take vitamin pills. If you are among them, you may be doing more harm than good. In a wake up call to the multibillion dollar vitamin pill industry, a review of 67 randomized trials of vitamin pill effects on life and health has found that taking vitamin pills may shorten life (Cochrane Database of Systematic Reviews, Issue 1, 2008). Other studies have shown that taking vitamin pills may increase risk for cancers and heart attacks.

This review of 232,000 adults showed that those taking beta-carotene, vitamin A, C, and E and selenium gained no benefit over those who took placebos or no pills. "The findings show that, if anything, people in trial groups given beta-carotene, vitamin A and vitamin E showed increased rates of mortality. There was no indication that vitamin C and selenium may have positive or negative effects."

The study was originally set up to see if antioxidant vitamin pills and minerals prevent gastrointestinal cancers. It found no protection whatever. Instead, an increased death rate of 16 percent was seen in those taking vitamin A pills, seven percent with beta- carotene, and seven percent with vitamin E. No increased death rate was seen in those taking vitamin C or selenium. Free newsletter

Will Organic Foods Make You More Healthy?

2008-04-23T21:18:00.003-04:00

According to a report published by The Organic Center's State of Science Reviews(March 2008), organic foods are more nutritious than those grown conventionally. But since the average North American eats far more food than is necessary, it is doubtful that adding more nutrients to the diet will have much effect on health.

A review of 97 scientific papers shows that organic food has higher levels of eight of 11 nutrients studied, including greater concentrations of polyphenols and antioxidants. However, we don't know how much of these nutrients the body requires. With 35 percent of the population becoming diabetic, 91 percent developing high blood pressure, 78 percent having high cholesterol levels, and 40 percent dying of heart attacks and strokes, I think it is more important to focus on the lifestyle factors that cause these health problems: overeating; eating too much meat, saturated fat, partially hydrogenated fats and refined carbohydrates; not eating enough vegetables; exercising too little; drinking too much; and smoking. Enjoy organic products if they fit into your budget, but you harm yourself if the higher cost causes you to eat fewer fruits and vegetables.

How Exercise Prevents Diabetes AND Preserves Your Brain

2008-04-22T11:42:00.001-04:00

Several studies show that vigorous exercise can help to prevent and to treat diabetes. A recent study from the University of Missouri in Columbia helps to explain why (American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, April 2008).

The vast majority of people who have diabetes do not lack insulin. Their disease is caused by an inability to respond to insulin. Since their cells do not respond to insulin, blood sugar levels rise and damage their cells. By studying blood flowing to and from the hind legs of obese rats, researchers found that acute muscle contractions markedly increased the passage of sugar into skeletal muscles, and markedly increased the flow of electrons in mitochondria.

Muscle cells have anywhere from six to thousands of tiny inclusions called mitochondria. Mitochondria convert food to energy by shuffling electrons from the building blocks of food. Each movement of electrons supplies more energy. However, in converting food to energy, some electrons end up attached to oxygen to produce reactive oxygen species (ROS) that stick to your DNA and proteins to damage them, preventing insulin from doing its job of driving sugar into cells and shortening cell life. When a muscle contracts, it shunts electrons away from oxygen so that fewer reactive oxygen species are formed.

Furthermore, this same process protects brain function and helps to prevent strokes, Alzheimer's and Parkinson's diseases. A study from Semmelweis University in Budapest shows that the lowering of ROS levels with exercise helps to prevent loss of mental function (Applied Physiology, Nutrition and Metabolism, October 2007).

More than 80 percent of diabetics die of heart disease. If you are at high risk for diabetes or are already diabetic, check with your doctor and perhaps get a thallium stress test to check out the condition of your heart. If you pass the test, you should try to exercise as much as possible. More on insulin resistance

Vitamin C Won't Help You Exercise Longer

2008-04-21T13:02:00.000-04:00

Some exercisers take vitamin C because they think that it will help them recover faster and therefore become better athletes. However, a study from the University of Valencia in Spain shows that vitamin C pills can make an athlete tire earlier during long-term exercise. (Journal reference)

Every muscle cell has hundreds, and even thousands, of small inclusions called mitochondria that turn food into the force that drives muscles. They do this by shuffling electrons to produce energy. After the electrons are moved, they can end up stuck on oxygen molecules to produce poisons called oxidants that make muscles burn, and feel sore and tired. The human body produces antioxidants that help protect a person from cell damage from these oxidants. Large doses of vitamin C have been shown to block antioxidants, so giving large doses of vitamin C to either humans and animals before they exercise would make them tire earlier.

Microwaving Does Not Harm Foods

2008-04-16T17:50:00.001-04:00

A report from the nutrition department of Cornell University should convince you that microwaving food does not destroy its nutritional value. Dr. Gertrude Armbruster and her colleagues showed that fruits and vegetables lost the least vitamin C when microwaved, compared to other cooking methods. Vitamin C is a good indicator of the amount of nutrients lost because it is both water soluble and sensitive to heat (Newsweek, March 14, 2008).

Microwave ovens use electromagnetic waves that vibrate water molecules inside food to produce heat. Most nutrients in food are not destroyed by microwaving because they are not in the watery layer. An earlier study from Spain, widely reported in the news media, claimed that microwaving broccoli destroyed all of its antioxidants (Journal of Science in Food and Agriculture, November 2003). However, the researchers in this study cooked the broccoli in almost a cup of water for five minutes at full power. The antioxidants were destroyed by the long cooking in water at a high temperature, not by the microwaves. The length of time vegetables are exposed to hot water determines the amount of water-soluble nutrients lost, whether the cooking is done in a microwave oven, steamer, pot or pressure cooker. For nutrient- rich vegetables from your microwave, use very little water (no more than a tablespoon or two) and short cooking times.

Contrary to myths spread by a popular natural health newsletter, the radiation from microwaves is not harmful and has no effect whatever on food other than to heat it up. Once the food comes out of the oven, there are no lingering effects of the microwaves. If you are worried about chemical changes to the nutrients in your food, avoid broiling, grilling, frying or any other method that browns foods. The reason food cooked in a microwave oven is so bland is that the chemical changes caused by high surface temperatures don't happen. That's why most people use their microwave ovens to reheat food instead of for cooking. More

Vitamin D and Muslce Pain - Special Report

2008-04-14T19:13:00.000-04:00

Over the last few years I have reported on numerous studies linking vitamin D deficiency with various diseases: diabetes, heart attacks, at least 30 types of cancer, and autoimmune disease such as lupus and rheumatoid arthritis (a list of these reports appears below).

This winter I have had a series of baffling exercise- associated muscle injuries. My blood levels of vitamin D have been extremely low, even though I spend a lot of time outside riding my bike. I reviewed my diaries and found that wintertime injuries have been a lifelong pattern for me. I have not been able to find any strong evidence that lack of vitamin D causes muscle injuries. However, it is associated with muscle weakness, falling in older people, bone deformities and fractures.

People get most of their vitamin D from sunlight. The skin has an enormous capacity for vitamin D production and supplies the body with 80-100 percent of its vitamin D. However, a recent study showed that a high percentage of people in sunny Arizona are vitamin D deficient (American Journal of Clinical Nutrition, March 2008). How can this be? A clue to the problem is that a large percentage of the people who were deficient were African- American, Hispanic, elderly or overweight. We know that people who have dark skin need more vitamin D because dark skin blocks the sun's UVB rays that make vitamin D. Another study showed that almost 50 percent of African Americans in Boston had low vitamin D in March. We also know that obesity can cause vitamin D deficiency because body fat removes vitamin D from circulation. Furthermore, as people age, skin cannot synthesize vitamin D as efficiently and the kidneys are less able to convert vitamin D to its active hormone form.

An article from Australia showed that 15 out of 18 gymnasts in Australia suffered from vitamin D deficiency (Clinical Journal of Sport Medicine, March 2008). These athletes spend a lot of time training indoors. Even if you spend several hours a day outside in winter, you probably will not get enough sun to meet your vitamin D needs. At our latitude the sun's rays reach earth at an angle so they have to penetrate a thick layer of the earth's atmosphere and fewer rays get through. Also, when the weather is cold we cover most of our skin with clothing.

My personal plan and recommendations

While we wait for the scientific community to resolve whether lack of vitamin D causes cancers, heart attacks and so forth, or is just a marker for other risk factors such as lack of activity or excess weight, I think you should be aware of your own vitamin D status and take action if you are deficient.

If you seldom go outdoors, have dark skin, are over 50 or are overweight, I recommend that you ask your doctor to do blood tests for vitamin D3 and D2. D3 is made by your skin from ultraviolet light (UVB) or from the vitamin D you get in foods or supplements. D2 comes just from food or supplements. Your total blood level of vitamin D should be over 50. If it is below 50, you may need to take a tropical vacation, use a tanning bed or take vitamin D supplements. A safe dose appears to be 1000 IU per day during the winter.

Until summer arrives and my vitamin D levels return to normal, I have chosen to use a tanning salon. I am reluctant to take supplements because one study from Australia suggests that they may suppress the body's ability to synthesize vitamin D.

Tanning lamps emit both UVA and UVB. However, because UVB are the primary rays that cause skin cancer, most tanning beds are high in UVA which does not make vitamin D and low in UVB that makes vitamin D. Ask the tanning center about the amount of UVB in their lamps. Some have 70 percent UVA and 30 percent UVB, but some emit less than five percent UVB. If you use a tanning bed, start at very low exposure, preferably with less than five minutes on your first visit. You won't know if you have burnt yourself until that evening. Then add only two minutes per exposure and don't go every day. After a couple of weeks, you can repeat your blood test. Stop using tanning bed when your total level reaches 50. If it does not reach 50 in a month, you should stop the tanning bed and take vitamin D supplements.

I will report to you from time to time on the progress of my training program, injuries and vitamin D levels; and I will continue to survey the scientific literature for studies on the association between vitamin D and various health problems. My earlier reports on vitamin D

Branched Chain Amino Acids

2008-04-12T21:19:00.001-04:00

A study from Sacred Heart University in Fairfield, Connecticut showed that taking branched chain amino acids decreased the amount of muscle damage from exercise in untrained volunteers. Branched chain amino acids are protein building blocks that can be converted easily to sugar by your body. A likely explanation for the advantage shown in this study is that muscles become damaged when they run out of their stored sugar and start to burn protein in the muscles themselves for energy.
Journal reference

However, it makes no sense to spend a lot of money on these expensive protein supplements. You will get the same benefit from any food that contains protein. Eat some cheese, seafood, peanut butter, chicken, nuts or any other convenient source of protein when you exercise for more than an hour.

Eggs Do Not Raise Cholesterol

2008-04-11T08:34:00.000-04:00

For more than 50 years eggs have been called unhealthful because they are among the foods that contain the highest levels of cholesterol. However, in recent years eggs have been rehabilitated. This month, a team of researchers at Mahidol University in Bangkok showed that adding an egg a day to the diets of healthy people in Thailand raised the good HDL cholesterol that prevents heart attacks. It did not affect the bad LDL cholesterol or triglycerides (Journal of the Medical Association of Thailand, March 2008).

Adding as many as three eggs per day to your diet will not raise cholesterol. More than 80 percent of the cholesterol in your body is manufactured by your liver, and less than 20 percent comes from the food you eat. When you eat more cholesterol, your liver makes less. When you eat less cholesterol, your liver makes more. However, if you add eggs you must subtract another equal source of calories, because increasing caloric intake will raise cholesterol. So this is not an invitation to eat an unlimited amount of eggs. The study supports other research showing that eggs in moderation are not harmful, and that up to one egg a day may have specific health benefits. How to lower cholesterol

Men Underestimate their Waist Sizes

2008-04-02T08:22:00.000-04:00

Men report that their waist circumferences are an average of 3.1 inches slimmer than they actually are, according to a study from University of Leicester in England. They can die from this vanity. Storing fat in your belly is a major risk factor for diabetes that causes blindness, deafness, heart attacks, strokes, amputations and kidney disease.

Almost all men who have more than three inches of fat underneath the skin over their bellies are either diabetic or pre- diabetic. More than 80 percent of people diagnosed with type 2 diabetes are overweight at the time of their diagnosis. Since insulin causes fat to be deposited primarily in the belly, storing more than three inches of fat underneath your skin is a sign of high insulin levels. Almost all type 2 diabetics who still make insulin go through periods of extremely high insulin levels long before their insulin levels drop. The disease is usually caused by inability to respond to insulin, so blood levels of insulin just keep on rising as a person gains weight. If these men would accept the existence of their fat bellies, they might recognize that they are at risk for diabetes and change their lifestyles before they develop complications from a potentially fatal disease. More