Monday, April 28, 2008

Get Your Vitamins From Food, Not Pills

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

Wednesday, April 23, 2008

Will Organic Foods Make You More Healthy?

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.

Tuesday, April 22, 2008

How Exercise Prevents Diabetes AND Preserves Your Brain

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

Monday, April 21, 2008

Vitamin C Won't Help You Exercise Longer

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.

Wednesday, April 16, 2008

Microwaving Does Not Harm Foods

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

Monday, April 14, 2008

Vitamin D and Muslce Pain - Special Report

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

Saturday, April 12, 2008

Branched Chain Amino Acids

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.

Friday, April 11, 2008

Eggs Do Not Raise Cholesterol

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

Wednesday, April 02, 2008

Men Underestimate their Waist Sizes

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