Friday, October 30, 2009

Chronic Fatigue Syndrome - a new explanation

Sixty-seven percent of 101 patients diagnosed with Chronic Fatigue Syndrome (CFS) were found to be infected with a retrovirus called XMRV (Science, published online October 8, 2009). One hundred percent of those with CFS who subsequently developed lymphomas or leukemias were infected with the XMRV virus. If further studies confirm this finding, doctors will soon have a test to diagnose this horrible condition and possibly a vaccine to prevent it.

More than a million Americans are seriously ill with Chronic Fatigue Syndrome, also known as Myalgic encephalomyelitis. CFS symptoms include severe weakness, exhaustion after any activity, loss of memory, and chronic recurrent infections. Patients rarely recover.

The retrovirus XMRV was first found in humans in 2006, in prostate cancer cells. It has been shown to cause nerve damage, immune deficiency, lymphoma and leukemia in animals. Retroviruses do not have their own DNA; they use the DNA of the host cells they invade. Retroviruses include HIV that causes AIDS, and Human Lymphotropic Viruses that cause leukemia and lymphoma. Just as some people infected with HIV do not develop AIDS, not everyone infected with XMRV will develop CFS. XMRV has been found in 3.7 percent of healthy Americans tested, adding up to an estimated 10 million Americans carrying this virus.

Although not proven yet, there is every reason to believe that XMRV is spread by exposure to body fluids (saliva, blood, semen). Having an infection with one of these retroviruses impairs your immunity so that you are more likely to become infected when exposured to any other germ.

Sunday, October 25, 2009

The Potassium Deficiency Myth

Sports drink promoters have convinced many athletes that they need special drinks to replace potassium during exercise. A recent study of female soccer players confirms that this is a myth (International Journal of Sports Medicine, June 2009). When body levels of potassium are low, the kidneys and sweat glands conserve potassium so effectively that potassium deficiency rarely occurs.

Tiredness in healthy athletes can have many causes, but low potassium is not one of them. Many years ago, Dave Costill of Ball State University tried to create potassium deficiency in healthy national champion runners. He couldn't do it because potassium is found in all foods except refined sugar, and his athletes would not stay on a diet that consisted only of hard candy. Even with prolonged exercise in very hot weather, potassium needs can be met by eating virtually any food.

Potassium deficiency CAN be caused by certain drugs, such as diuretics or corticosteroids, or by severe diarrhea or repeated vomiting. One of the best female long-distance runners in the country came to me to find a cause for her sudden drop in performance. All tests I ordered were normal except for a low blood level of potassium. I knew that hard exercise does not cause potassium deficiency and that the most common cause of potassium deficiency is vomiting, but she repeatedly denied doing this. I then requested that she collect her urine for one day and the laboratory reported that it contained three times as much potassium as normal. This proved that she was bulemic. To control her weight, she was sticking her finger down her throat to makie herself throw up. After she was able to accept the diagnosis, she got help, stopped vomiting and went on to win several national long distance running titles.

With vomiting, you throw up the stomach's acid (hydrogen) and the blood becomes alkaline. This causes the kidneys to retain hydrogen and consequently lose huge amounts of potassium in the urine. In both athletes and non-athletes, the most common cause of low potassium blood levels and high potassium urine levels is vomiting.

Thursday, October 22, 2009

Metabolic Syndrome and Diabetes

As the standard of living in a country increases, so does the incidence of Metabolic Syndrome. Today, one of three North Americans will suffer premature death from the consequences of Metabolic Syndrome, which is caused too little activity and too much food (The Journal of Clinical Hypertension, September 2009). Warning signs include: abdominal obesity, high triglycerides, low good HDL cholesterol, overweight, high blood sugar and high HBA1C. (HBA1C is a blood test that measures sugar stuck on cells. An HBA1C greater than 5.7 shows that you have Metabolic Syndrome).

Metabolic Syndrome means that you are in the early stages of diabetes. If you store fat primarily in your belly, you probably have high blood insulin levels, a sign that your body cannot respond adequately to insulin. High insulin levels are caused by high blood sugar levels that cause blood sugar to stick to the surface of cell membranes. Once there, sugar can never get off. It is eventually converted to sorbitol which destroys the cell to cause all the side effects of diabetes. As long as your pancreas still makes insulin, you can reverse metabolic syndrome and diabetes. However, once your pancreas dies you cannot make insulin and your diabetes is not curable.

Read my recommendations on preventing diatetes, and for treating it if you have already been diagnosed. In summary:

• Exercise
• Don't be overweight
• Avoid refined carbohydrates except during exercise
• Make sure you have enough vitamin D
• Don't smoke
• Limit alcohol to no more than two drinks per day
• Eat a healthful diet with plenty of vegetables, beans, whole grains, nuts and other seeds.

Friday, October 16, 2009

Preventing Muscle Cramps

Most older textbooks explain that muscle cramps are caused by lack of water (dehydration) and lack of salt. However, studies on endurance athletes show that athletes who cramp do not have less body water or sodium than those who do not cramp (British Journal of Sports Medicine, June 2009). So the current explanation for muscle cramps in conditioned athletes is that prolonged, intense exercise damages muscles, which can cause sustained contractions or cramps.

Cramps may occur as a side effect of drugs used to treat high cholesterol, high blood pressure or diabetes. Oral contraceptives, various other drugs or alcohol can also cause muscle cramps. If you suffer from recurrent muscle cramps that cannot be explained, check with your doctor. Possible causes include pinched nerves, Parkinson's disease, hypothyroidism, diabetes, narrowed arteries, low blood mineral levels, or metabolic diseases that cause muscle damage. However, these diseases are rarely the cause of cramps in athletes.

Cramps can often be prevented by slowing down when a muscle starts to feel tight. However, athletes usually are not willing to do this during competition or hard training, so they will continue to suffer from occasional cramps and work them out as they occur. You can help to prevent cramps with a training program that includes both hard days and recovery days. We do this by cycling at 18-20 mph pace on Tuesdays, Thursdays and Saturdays and 10-12 mph pace on the other four days.

Saturday, October 10, 2009

New Rules for Sunscreens

If you use sunscreens, be sure to reapply them frequently. Many sunscreens contain the filters octylmethoxycinnamate, benzophenone-3 or octocrylene, which reflect ultra violet rays away from your skin to protect it only when they are on the surface of the skin. However, when these sunscreens are absorbed and the skin is not re-coated, they increase skin production of harmful oxidants that can cause skin aging and cancer (Free Radical Biology & Medicine, September 2009). Reapplying the sun screen so some remains on the skin's surface can prevent this damage.

• Before you go out in the sun, apply sunscreens to the areas with the most exposure to sunlight over your lifetime: the top of your ears, your face, the back of your neck, and your arms and hands. It is the cumulative exposure to UV light that increases skin cancer and aging.

• To meet your daily vitamin D requirements from sunlight, expose your legs or other areas of your body that have received little cumulative sun exposure over your lifetime. Take care to avoid sunburn.

• Reapply sunscreens every hour or two, particularly when you are swimming or sweating.

• Some sunscreens contain stronger UVA filters (avobenzone, mexoryl, titanium dioxide or zinc) that are less likely to be absorbed into the skin. You do not need to reapply these if they leave a visible white paste on your skin. Check the list of ingredients.

A comprehensive review of more than 1000 sunscreens was conducted by the Environmental Working Group in summer of 2009. Their findings, with brand name listings and recommendations, are available at http://www.ewg.org/cosmetics/report/sunscreen09/investigation/summary-of-findings

Saturday, October 03, 2009

Large Thighs are Good

Large thighs appear to confer health benefits, not risks. A study reported this month shows that people who have small thigh muscles, independent of how much fat they have in their bellies, are at increased risk for premature death, particularly from heart attacks (British Medical Journal, September 2009). 2800 men and women aged 35 to 65 had their thighs measured and were followed for ten years. Those whose thigh circumference was below 24 inches (60 cm) were at increased risk for death from heart attacks.

Other studies show that having very low body fat is also associated with early death, as are being overfat or storing fat primarily in the belly. If you store most of your fat in your belly and have very small thighs or buttocks, you are probably already diabetic or prediabetic and at significant risk for a heart attack.
Another interesting study on benefits of thigh fat
Why belly fat is risky

Thursday, October 01, 2009

CRP Better Predictor of Heart Attacks than Cholesterol

Blood tests for cholesterol and C-reactive protein (CRP) both help to measure heart attack risk, but CRP may be more important. CRP measures inflammation which indicates an overactive immunity, while cholesterol measures a type of fat in your blood. Having a high CRP blood test increases your risk of suffering a heart attack or stroke by twice as much as having a high cholesterol (New England Journal of Medicine, November 2002). Everything that activates your immunity can increase risk for heart attacks and everything that damages your body turns on your immunity. Inflammation is part of the immune reaction that protects you from infection. It causes redness, pain and swelling, and can damage the inner lining of arteries or break off clots from arteries to block the flow of blood which can cause strokes and heart attacks.

If you have a high CRP, try to correct the known causes: any type of infection such as chronic gum disease, high blood pressure, alcohol use, smoking, low levels of physical activity, chronic fatigue, eating a high protein/high meat diet, or having elevated triglycerides, insulin resistance or diabetes. People with sleep disturbances, depression, or any of the "auto-immune" diseases such as rheumatiod arthritis or psoriasis are also likely to have a high CRP and are at increased risk for heart attacks. More