Friday, March 30, 2007

Muscles and protein

Many body builders and weight lifters are overly concerned about what they eat and what food supplements they take. If you want to grow larger and stronger muscles, you should concentrate on lifting weights, but you can help muscles grow larger by understanding how what you eat affects how you recover from hard exercise. Just exercising will not make you strong and it will not help you to grow large muscles. If exercise made you strong, marathon runners would have the largest muscles. The only stimulus to make muscles larger and stronger is to stretch them while they contract. When you lift a heavy weight, your muscles start to stretch before they start to contract. This tears the muscle and causes soreness on the next day and beyond. If you rest and let the muscle heal, it will be stronger than before you stretched it lifting weights.

This training principle of stress-and-recover is so strong that you can enlarge a muscle by lifting weights even if you are fasting, losing weight and all your other muscles are getting smaller. In one study, obese, un-athletic women were instructed to restrict food and lift weights. They averaged a weight loss of more than 35 pounds in three months and gained a lot of muscle.

Training for sports is done by taking a hard workout and then having sore muscles on the next day. Then you take easy workouts or you take off until the muscle soreness disappears. You improve by taking hard workouts and your muscles grow and heal while you recover on your easy days. Of course, if you could recover faster from a hard workout, you could do more work and be a better athlete. Scientists have known for years that you recover faster by eating carbohydrates immediately after you finish your hard workout. New studies show that eating extra protein on the day that you take hard workouts helps you recover even faster. Eating extra protein reduces muscle damage during hard exercise (3). Eating carbohydrates along with a protein building block called leucine helps you to recover even faster.

Chronic muscle fatigue in athletes is associated with low blood levels of amino acids, the building blocks of proteins. The sooner you eat protein after you finish your hard workout, the quicker you will recover. The benefits of eating protein soon after you lift weights does not apply just to elite athletes. A study from the University of Arkansas shows that eating meat helps older people grow large muscles when they also lift weights. Muscles are made primarily from protein building blocks called amino acids. Muscles heal from a hard workout when amino acids and other nutrients travel from your bloodstream into the muscles. Eating food, particularly protein, immediately after you finish your workout helps muscles heal faster. This study shows that men between the ages of 51 and 69 recover faster and grow larger muscles when they include meat than when they eat only dairy, fruits, vegetable, whole grains, beans, seeds and nuts. Journal references for this article

Thursday, March 29, 2007

Fructose is Not Better than Other Sugars

Fructose is processed differently in the body than the far more common sugar, glucose. Glucose causes the pancreas to release insulin which drives sugar from the bloodstream into cells. Glucose causes fat cells to release leptin that makes you feel full so you eat less; it also prevents the stomach from releasing ghrelin that makes you hungry. On the other hand, fructose does not cause fat cells to release leptin and does not suppress ghrelin. This means that fructose increases hunger to make you eat more. Furthermore, the liver converts fructose far more readily to a fat called triglyceride, than it does with glucose. High triglyceride levels raise blood levels of the bad LDL cholesterol and lower blood levels of the good HDL cholesterol, which increases heart attack risk.

Large amounts of fructose appear to cause insulin resistance, impair glucose tolerance, produce high levels of insulin, raise triglycerides, and cause high blood pressure in animals. Not all of these studies have been replicated in humans, but there is every reason to believe that large amounts of fructose will have the same adverse effects. High-fructose corn syrup is found in almost all non-diet soft drinks and fruit beverages, and in a wide variety of processed foods. However, high-fructose corn syrup is no more significant as a dietary source of fructose than ordinary table sugar. It is only high in fructose compared to ordinary corn syrup.

Several recent studies show that drinking large amounts of soft drinks is associated with increased risk for obesity and that the extra gain in weight is not due just to the calories in the soft drinks. Calories consumed in beverages do not fill you up the way calories in solid foods do. High fructose corn syrup is the leading sweetener in the United States today, with 4.5 billion dollars worth sold each year. High-fructose corn syrup first appeared in the American market in 1966, and now the average American takes in 62.6 pounds per year. Check the list of ingredients in the foods you buy.

Wednesday, March 28, 2007

Swollen feet and ankles

Your leg muscles function as a second heart to pump fluid from your legs to your heart. When your leg muscles relax, the veins near them fill up with blood. When your leg muscles contract, they compress the veins and squeeze blood up toward your heart.

When you stand still, your heart has to work very hard to pump blood against gravity from your feet to your heart. When your feet are above your heart, gravity works with you to help blood and fluid return to the heart. Eight hours of standing or sitting causes your feet to swell up to more than 110 percent of their size. This can make your shoes feel tight and your feet hurt.

The best way to prevent swelling is to elevate your feet. The next best way is to move your feet and toes frequently while you are sitting or standing. This can reduce swelling by more than 50 percent and will usually prevent the pain that it causes. If your feet still swell, check with your doctor. You may have a more serious cause, or you may need diuretics or compression stockings.

Tuesday, March 27, 2007

Back Pain? Choose the Right Exercise

Runners who develop back pain often ask me if they can continue running.
People with back pain need to exercise as much as everyone else, but they should not do any exercise that causes pain. The bones of your spine are located one on top of the other, separated by pads called discs. Bones are much harder than discs, so when spinal bones are compressed and move closer together, they can flatten the discs like pancakes. Since the discs are then shorter, they have to go somewhere else, so they widen and press on the nerves near them, causing pain. This is called a herniated disc. Anything that presses the bones closer together squashes the disc further and usually makes it hurt more. During running, the force of the foot striking the ground is transmitted up the leg to the back, which can compress the discs and cause pain.

The best sports for people with back pain are those that do not hurt when you do them. Riding a bicycle, walking slowly and swimming do not exert a jarring force on the discs to compress them, so these exercises are recommended for people with back pain as long they don’t hurt while they exercise. Doctors often recommend special exercises to flatten the lower back, strengthen the belly muscles and stretch the lower back muscles. The key to exercising when you have a compressed disc is to stop exercising when you feel pain. You may need to try several different activities to find the right one for you. Treatment of back pain

Monday, March 26, 2007

Why the DASH diet lowers blood pressure

Scientists at the National Institutes of Health have shown why the DASH diet lowers high blood pressure to normal in more than 80 percent of people with high blood pressure. On the DASH diet you eat lots of leafy green vegetables that are rich sources of nitrites, common salts that your bloodstream, can be converted to nitric oxide which opens blood vessels.

This means that nitrites could be a new treatment for high blood pressure, heart attacks, sickle cell disease, and blocked arteries leading the heart, brain and legs. Hemoglobin is the red pigment in red blood cells that carries oxygen in your bloodstream. When hemoglobin releases oxygen, it converts nitrites to nitric oxide, to widen blood vessels. Blood nitrite levels are low in patients with high blood pressure.

However, at high concentrations nitrites are toxic, so you must take limited amounts. Leafy greens are rich sources of safe amounts of nitrites. The nitrites go into the bloodstream, where exposure to oxygen converts nitrites to nitrous oxide which dilates arteries and lowers high blood pressure. Hypertensives should also eat lots of other plants for the same reason and cut back on meat and chicken, that are rich sources of sodium that can raise high blood pressure.

The modified DASH diet I recommend will also lower cholesterol and help you lose excess weight; it is the most effective diet for preventing or controlling diabetes. Journal reference for this report

Saturday, March 24, 2007

Blood Pressure Drugs Can Interfere with Exercise

The beta blocker drugs used to treat blood pressure and heart problems can markedly impair your ability to exercise, according to a study from Switzerland. How hard you can exercise is limited by the ability of your heart to pump blood from your lungs to your exercising muscles. Beta blockers markedly reduce blood flow and oxygen supply to muscles. Beta blocker brand names include Toprol, Inderal, Blocadron, Coreg, Inopran, Levatol, Pindolol, Sectral, Tenormin, Timolol Trandate, Zebeta and Bisoprol.

Beta blockers are prescribed to treat people who have had heart attacks, heart pain, heart failure, rapid heart beat and atrial fibrillation. However, even though many physicians prescribe beta blockers to treat high blood pressure, there is no data show that they prevent heart attacks in healthy people. If beta blockers interfere with your ability to exercise, ask your doctor if you can take other types of medications such ace inhibitors, angiotensin receptor blockers or calcium channel blockers. Better yet, control your blood pressure with diet. More information on blood pressure drugs; Journal reference for this article.

Friday, March 23, 2007

How to Jump Higher

When former NBA player Kent Benson arrived at the University of Indiana he could jump only nine inches off the ground. That's an embarrassing jump for a seven-foot All- American. One year later, he was able to jump three times that high because he had a good coach.

How high you can jump is determined by the force that you can exert when you contract your leg muscles against gravity. so strengthening your muscles will help you to jump higher. However, you must exercise your muscles against resistance in the same way that you use them when you jump. You can bend your knees and hips and straighten them by performing leg presses up while lying on your back, sideways while sitting in a chair, or down against the ground when you squat in the upright position.

Basketball players who want to be able to jump higher should set up a schedule of weight training moderately on Monday, easy on Wednesday and hard on Friday. On days when your muscles feel sore or tight, skip your weight lifting workout. How to run faster

Wednesday, March 21, 2007

High cholesterol lowers testosterone

Men with high cholesterol or high blood pressure have lower blood levels of the male hormone, testosterone, than men with normal blood pressure.

How can this be? The male hormone, testosterone, was thought to raise cholesterol and increase risk for heart attacks. But this applied only to the methyl testosterone taken by some athletes, not the testosterone produced by the body.

Having high cholesterol, pre-diabetes or high blood pressure causes hardening of the arteries, which decreases blood flow to the testicles to damage the testicles and lower testosterone. High blood pressure and high cholesterol lower testosterone, so men with low testosterone are at increased risk for heart attacks. That means that every impotent man should have blood tests for cholesterol and diabetes, the two leading causes of heart attacks. The tests your doctor should order include HBA1C, lipid panel, C-Reactive Protein (CRP), homocysteine, Lp(a), prolactin and testosterone. By the time a man has low levels of testosterone, he may already have significant arteriosclerosis. Journal reference for this report More on lowering cholesterol and high blood pressure

Sunday, March 18, 2007

Who is Pre-Diabetic?

You can tell if you are at high risk for diabetes if you store fat primarily in your belly. Pinch your belly; if you can pinch an inch, you are at increased risk and should get a blood test called HBA1C. Having high blood levels of triglycerides and low levels of the good HDL cholesterol that helps prevent heart attacks also increases your risk for diabetes. When you eat sugar or flour, your blood sugar rises too high. This causes your pancreas to release insulin that converts sugar to triglycerides, which are poured into your bloodstream. Then the good HDL cholesterol tries to remove triglycerides by carrying them back into the liver, so having high blood levels of triglycerides and low blood levels of the good HDL cholesterol are both individual risk factors for diabetes.

High blood levels of insulin constrict arteries to raise blood pressure, so many people who have high blood pressure are also prediabetic. High insulin levels also constrict the arteries leading to your heart to cause heart attacks directly. People with insulin resistance have an increase in small, dense, low-density lipoprotein (LDL) cholesterol, which is more likely to cause heart attacks than the large, buoyant regular LDL cholesterol. High levels of insulin also cause clotting to increase your risk for heart attacks. You can help to prevent diabetes and heart attacks by avoiding sugar and flour, exercising and eating lots of vegetables.

Many people discover that they are diabetic only after they have had a heart attack. Researchers in one study recorded blood sugar levels in men who had had heart attacks and then did sugar tolerance tests at discharge and three months later. They found that 40 percent had impaired sugar tolerance tests three months later. This suggests that 40 percent of people who have heart attacks are diabetic, even though they may not know it. The authors recommend that all people with heart attacks be tested for diabetes. Journal references for this article; More on treatment of insulin resistance

Thursday, March 15, 2007

How to Interpret your Cholesterol Numbers

Doctors no longer predict your chances of suffering a heart attack by how high your total cholesterol is. The current guidelines recommend that everyone should have a blood level of the bad LDL cholesterol below 100. If you live in Canada, divide the American number by 40. That means that Canadians must have their bad LDL cholestrol levels below 2.5. If you have had a heart attack, you should try to get your bad LDL cholesterol below 70 (Canadian value below 1.75).

You can remember that HDL is the good cholesterol by thinking "H is for healthy"; and that LDL cholesterol is bad because "L is for lousy". The good HDL cholesterol carries cholesterol from your bloodstream to your liver where it can be removed from your body. The bad LDL cholesterol carries cholesterol to your arteries where it forms plaques. To some degree, your good HDL cholesterol protects you from the bad LDL cholesterol, so having a high level of the good HDL helps to protect you from having a heart attack from high levels of the bad LDL. However, this is sometimes not true. Some people with very high blood levels of the good HDL cholesterol still get heart attacks. Hence the new guidelines based purely on blood levels of the bad LDL cholesterol.

A heart-healthy diet can lower cholesterol levels in most people. You can lower your LDL cholesterol by restricting your intake of saturated and partially hydrogenated fats, refined carbohydrates and calories. The diet for lowering cholesterol is the same as the diet to control high blood pressure; see my modified DASH diet. If you are willing to make these lifestyle changes you may be one of the 80 percent who can control cholesterol and blood pressure without drugs.

Tuesday, March 13, 2007

Colon Cleansers Can Block Nutrient Absorption

Regular use of colon cleansers or laxatives can harm you by blocking the absorption of nutrients from your colon into your bloodstream. There are two absorption systems in the digestive tract. First the food that you eat passes from your stomach to your upper intestines, where secretions from your stomach, liver, intestines and pancreas break down carbohydrates, fats and proteins into their building blocks. Only these building blocks -- basic sugars, amino acids, fatty acids and glycerol -- are absorbed from your intestines into your bloodstream. The food that is not broken down cannot be absorbed so it passes to your colon.

Bacteria in your colon convert undigested starches into short chain fatty acids that heal ulcers, prevent colon cancer and other cancers, reduce the pain of arthritis, prevent the arterial damage of arteriosclerosis, lower cholesterol, and even lower high blood pressure. Colon cleansers or laxatives reduce the absorption of these beneficial short chain fatty acids. Promoters who recommend these products claim that they remove old stool that gets stuck and rots in your colon, but this is ridiculous. Undigested waste products stick together by a physical process called surface tension, so they cannot pass by older stool. More on treatment of constipation

Monday, March 12, 2007

Salt Not the Major Cause of Blood Pressure Rising with Age

Blood pressure often rises with aging. Contrary to what many doctors think, salt, obesity and alcohol have little to do with this rise.

High blood pressure is associated with heart attacks, strokes, aging and death. Recent research shows that high blood pressure associated with aging is probably caused by damage to the arteries leading to the kidneys. Obesity, excess salt and alcohol cause reversible high blood pressure. Taking a large amount of salt can cause your body to retain fluid, enlarge blood volume and raise blood pressure temporarily, but blood pressure returns to normal soon afterwards. For most people, taking in a lot of salt does not raise blood pressure. Drinking alcohol raises blood pressure only for a short time. Obesity is associated with a sustained high blood pressure at any age, and is usually reversible with weight loss.

Recent research show that damaged kidney arteries, called intimal fibroplasia, are the most likely cause of high blood pressure and that prevention of high blood pressure with aging includes preventing kidney arterial damage by eating plenty of fruits, vegetables, whole grains, beans and nuts, reducing your intake of processed foods and dairy products, exercising and avoiding overweight. More on the DASH diet to lower blood pressure

Sunday, March 11, 2007

Food Combining Theories Should be Ignored

Books and programs on food combining have been on and off the best-seller lists for years. They should be in the fiction section. The authors claim that eating protein and carbohydrates, or fat and carbohydrates together causes problems because they require different enzymes for digestion, and either acid or alkaline conditions. They give you elaborate lists of foods that you can or cannot eat at the same meal. If any of this were true, the human race would be extinct. Few foods are "pure" protein, carbohydrate or fat. Your digestive system has evolved to deal with mixed foods, and the enzymes secreted by your pancreas can digest them all in any combination.

Your stomach is strongly acidic, no matter what food you eat. Stomach acid is much stronger than lemon juice, tomatoes or any other acid food. Nothing you eat escapes this acid "soup" while it is in your stomach, so it makes no difference whether you combine acid and alkaline foods.

These authors tell you that the undigested food will ferment and putrify, causing you to accumulate toxins in your intestines. This just doesn't happen. Your intestines do a very efficient job of breaking down carbohydrates, fats and proteins into their building blocks, which are then absorbed into your bloodstream. As long as you are not constantly constipated, your colon does an excellent job of removing the waste products of digestion. If you have a problem with constipation, the answer lies not which foods you combine, but in adding fiber and water to your diet.

They even claim that the undigested food makes you fat, which is impossible. To be stored as fat, a food must be broken down into its building blocks and pass from the intestines into the bloodstream. Any undigested food would be excreted, making you thinner, not fatter.

People who lose weight following these nonsensical rules do so simply because they are forced to limit their food choices and therefore consume fewer calories.

Do not confuse these ridiculous diets with serious "combination" recommendations that are made in two special situations:

Diabetics and others who are concerned about sharp rises in blood sugar are advised to eat fruits and root vegetables only in combination with other foods. Fruits and root vegetables contain lots of sugar or quickly digested starches which can cause blood sugar to rise after eating. However, a healthy diet does not eliminate these foods because they also contain lots of vitamins, minerals and other phytochemicals that your body uses to keep you healthy and prevent diseases. When you eat these foods WITH other foods, particularly proteins or fats, they are digested more slowly. Diabetics should include a variety of fruits and root vegetables in their diet, but eat them with meals, not alone.

Strict Vegetarians who eat no animal products are often advised to COMBINE beans and grains so they will get complete proteins. This is true, but you do not need to eat the foods together at the same meal. The proteins found in meat and dairy products contain all nine essential amino acids (the ones your body needs and cannot make), and so they are called complete proteins. Most plant sources of protein, such as beans and grains, contain only two to seven of the essential amino acids, so you must eat a variety of these foods to assure that you get them all. However, you can do this over the course of the day or week. Amino acids circulate constantly in your bloodstream and are used as needed. You do not need to eat the foods simultaneously to supply your body with the different amino acids you need.

Saturday, March 10, 2007

Fatigue Causes Inefficient Form

Most experienced runners can tell when other runners are in shape just by watching them run. They look for efficiency, a measure of how much energy is lost by wasteful movements during running. You run with your legs and all of your other movements are used just to balance your body. The main reason you don’t fall when you are walking or running is that your brain constructs a "center of gravity", a point around which all movements on one side are balanced by equal movements on the other side. For example, when your right leg goes forward, your left arm goes forward and your right arm goes backward. You do this without thinking and your movements are automatically calculated in your brain.

A study from The Hospital of Laval in France shows that even the best runners lose their efficiency when they become fatigued (Journal of Sports Medicine and Physical Fitness, June 2006). Experienced runners have consistent stride length and form. This study shows that with fatigue, their stride length decreases and, more importantly, they start to lose form by adding a significant amount of side-to-side movement that wastes energy and does not drive them forward.

Running slowly does not teach your brain how to balance your body when you run fast. Good form comes from practicing running very fast in training. People who run slowly all the time usually have poor running form. They waste movements that do not help them move forward. For example, their feet often move to the side after they raise their feet from the ground. Their arms do not move loosely and comfortably to balance their bodies. They may run with toes pointed outward, which is a sign of weak shin muscles. If you want to improve your running form, run faster a few times every week. More

Thursday, March 08, 2007

Popular Diets Compared: Keeping Weight Off is Hardest

A major study comparing four popular diets tells the sad story that even when they are paid to eat less, people lose no more than 10 pounds in a year (JAMA, March 6, 2007.) Even sadder is the news that most of them will regain the weight as soon as they go off their diet.

At some time in their lives, most North Americans have lost more than ten percent of their weight and many have kept it off for at least one year. However, almost all regain the weight they lose, and frequently add even more pounds in the process. It is extremely uncommon for a person to lose more than 20 pounds and keep it off for the rest of his or her life.

If you want to lose weight and keep it off, you have to make major, permanent lifestyle changes. Start an exercise program that involves others; you are more likely to do it for the rest of your life if your exercise is a social activity. Join a running group or bicycle club, or participate in an exercise class such as aerobic dancing. In addition to a regular exercise program, you need to change your kitchen forever. Avoid stocking foods that raise insulin to high levels, which means avoiding all refined carbohydrates: foods made with flour, white rice or milled corn, and all added sugars. Limit concentrated sources of calories such as meat, dairy products (except skim) and added fats such as oils or butter. Most of your food should be whole grains, beans and other seeds, vegetables and fruits. This is a lifelong way of eating, not a short-term diet. More

Wednesday, March 07, 2007

Osteoporosis Linked to Vitamin D Deficiency

Vitamin D deficiency is being recognized as a growing problem in people who are at risk for osteoporosis. According to the National Osteoporosis Foundation, over 60 million Americans, 41 million of them women, will have either osteoporosis or low bone mass by the year 2020. Vitamin D deficiency also appears to be linked to certain cancers, periodontal disease, diabetes, rheumatoid arthritis and osteoarthritis (Nutrition Action, November 2007).

If you take calcium supplements, you should probably also take vitamin D, unless you are getting plenty of sunshine. Calcium uses up vitamin D, so if you are taking calcium in pills you should probably also take a vitamin D supplement. If you are not sure that you are getting enough vitamin D from sunlight or food, ask your doctor to do a blood test to check your vitamin D level. More

Monday, March 05, 2007

Diabetics Should Avoid Coffee

A survey reported in JAMA (July 6, 2005) showed that drinking coffee reduces risk for developing type II diabetes, but two other studies suggest that once you have diabetes, drinking coffee may be unwise. Canadian researchers writing in Diabetes Care (March 2005) showed that caffeine significantly reduced insulin sensitivity. In the July 2005 issue of the same journal, scientists from Duke University Medical Center reported that drinking coffee could upset a diabetic’s ability to metabolize sugar.

Blood sugar levels are supposed to rise after you eat. To keep your blood sugar levels from rising too high, your pancreas releases insulin. The researchers found that taking caffeine causes blood sugar and insulin levels to rise even higher after meals. If your blood sugar rises too high, sugar sticks to cells. Once sugar is stuck on a cell membrane, it cannot be released and is converted to a poison called sorbitol which destroys that cell. High levels of insulin constrict arteries to cause heart attacks and act directly on the brain to make you hungry, on your liver to make more fat, and on the fat cells in your belly to pick up that fat. If these studies are confirmed, diabetics will be advised to restrict coffee as well as those foods that cause the highest rise in blood sugar after meals. See my report on insulin resistance

Thursday, March 01, 2007

Cholesterol in Foods Less Significant Than Total Calories

Your blood cholesterol level is influenced far more by how many calories and how much saturated and partially hydrogenated fat you eat, than by how much cholesterol is in your food. Cholesterol is found only in foods from animals, such as meat, fish, chicken, dairy products and eggs. It is not found in plants. More than 80 percent of the cholesterol in your body is made by your liver. Less than 20 percent comes from the food that you eat. When you eat more cholesterol, your liver makes less.

Your liver makes cholesterol from saturated fats, which are found in most foods but are concentrated in meat, poultry and whole-milk dairy products. The saturated fat is broken down by your liver into acetone units. If you are not taking in too many calories, your liver uses the acetone units for energy, but if you are taking in more calories than your body needs, your liver uses these same acetone units to manufacture cholesterol. That explains why eating two eggs a day does not raise blood cholesterol levels in the average American. They are already taking in so much cholesterol from meat, fish and chicken and diary products, that when they take in more, they absorb less.

The average North American takes in 350 mg per day of cholesterol. If he takes in 26 mg per day, he absorbs 41 percent. When he takes in 188 mg cholesterol per day, he absorbs only 36 percent, and when he takes in 421 mg per day (the equivalent of two eggs), he absorbs only 25 percent. Some people absorb more than five times as much as other people at the same intake. So you lower blood cholesterol levels far more effectively by eating less food, less saturated fat and less partially hydrogenated fats than by avoiding foods that contain cholesterol. More