Tuesday, February 28, 2006

I read that microwaving broccoli destroyed all of its antioxidants. Should I stop using my microwave oven?

No. The researchers in this study cooked the broccoli in 2/3 cup of water for 5 minutes at full power (Journal of Science in Food and Agriculture, November 2003). Antioxidants were destroyed by the long cooking in water at a high temperature, not by microwaves. The study authors noted that it’s the length of time vegetables are exposed to hot water that determines the amount of water-soluble nutrients lost, whether the cooking is done in a microwave oven, steamer, pot or pressure cooker. Unfortunately, newspaper reporters misinterpreted the study and scared many people away from their microwave ovens. If you follow the standard instructions for microwaving vegetables, using just a tablespoon or two of water for a short time, the effect is similar to steaming and antioxidant loss will be minimal.

Monday, February 27, 2006

Are the low-carbohydrate diets the most healthful way to lose weight?

Some people increase their risk for heart attacks, cancers and other diseases by markedly restricting all carbohydrates because they think that all carbohydrates are harmful. Restricting good carbohydrates deprives a person of necessary nutrients that increase their susceptibility to disease. Bad carbohydrates are ones that cause an immediate high rise in blood sugar levels. Good carbohydrates do not do this. A recent report explains the difference (Current Atherosclerosis Reports, November 2005). Good carbohydrates are the ones found in nature and usually do not cause a high rise in blood sugar levels. Bad carbohydrates pass immediately from the stomach into the intestines and cause a high rise in blood sugar.

Whole grains have a thick fiber coating that releases starches and sugars very slowly so blood sugar levels do not rise too high. However, grinding a whole grain to form flour destroys the seed coat and allows the blood sugar rapidly to enter the intestines where it is absorbed almost immediately to cause a high rise in blood sugar. When you eat an orange, the solid particles go into your stomach, where the pyloric sphincter closes and prevents all solid particles from entering the intestines until they are broken down into a soup that is then allowed to pass. However, liquid orange juice passes directly into the intestine where it is absorbed immediately. For most healthy people and most diabetics, it is perfectly healthful to eat large amounts of the good carbohydrates: fruits, vegetables, whole grains, beans, seeds and nuts. The carbohydrates to limit or avoid are foods made with flour, fruit juices, sugared soft drinks, and foods that contain added sugars. Read Why Whole Grains are Better than Any Flour
and my recommended diet.

Saturday, February 25, 2006

Does drinking alcohol increase my risk for osteoporosis?

The person most likely to suffer from osteoporosis has pale skin, is very thin and drinks a lot of alcohol. Pale people often do not get enough sunlight to meet their needs for the bone-strengthening vitamin D; skinny people often miss essential nutrients necessary for bone health; and heavy drinking inhibits new bone from forming (Alcoholism: Clinical & Experimental Research, December, 2005).

Bones are always remodeling. Certain cells called osteoblasts continuously bring calcium into bones, while osteoclasts continuously take calcium out of bones. However, heavy drinking inhibits osteoblasts from forming new bone. So far, most studies show that people can take up to two drinks a day without harming their health. A drink is five ounces of wine, 12 ounces of beer, or two thirds of a shot glass of hard alcohol. However, exceeding that amount can hasten the onset of osteoporosis, in which the slightest trauma can break bones and they will heal much more slowly than normal.

More on osteoporosis

Thursday, February 23, 2006

How can a couple exercise together when one is much stronger?

Many couples don't exercise together because one partner is much more fit than the other. Riding a tandem bicycle is a great equalizer. The amount of work you do on a bicycle depends on how hard you push on the pedals. Pushing twice a hard on the pedals takes twice the work, so a world-class bicycle racer can ride with a novice and still get a good workout. Even a beginner will be able to keep up with the spinning pedals, no matter how fast they go. The less-fit partner just applies little or no pressure so he or she will not get tired. No matter how hard one partner tries to leave the other, you will always be together.

You can go faster together than the faster person can go alone. The more experienced rider sits in the front seat. If both are equally good riders, the taller one usually sits in front. The person who sits in the back copies the motions of the person in the front. At first it may seem strange not to have any control over steering, shifting or braking, but the you have the big advantage of being able to exercise only as hard as you like while enjoying the scenery.

Tuesday, February 21, 2006

How long should I rest between intervals?

To become stronger and faster, athletes use a technique called interval training, in which they exercise very intensely, rest and then alternate intense bursts of exercise and rest until their muscles start to feel heavy. You can apply this principle to your own exercise program, but the rest period between intervals is not the same for every sport.

Rest periods are different for runners and weightlifters. Runners run intervals as fast as they can and recover enough to run the same fast pace several times. Research shows that runners need very short recoveries between intervals, usually only about 30 seconds. So a runner may run a quarter mile 12 times, averaging 1 minute, with a 110-yard slow jog between each. However, weight lifters need much longer recoveries between hard sets, at least two and a half minutes.

Runners become short of breath and feel a burning in their muscles when lactic acid starts to accumulate in muscles. It takes only a few seconds for a trained athlete to recover from hard running and clear lactic acid, so runners usually need short 30 second recoveries between each hard run. On the other hand, weight lifters feel a burning caused by a tearing of the muscle fibers and it can take a much longer time for their pain to disappear so they can lift very heavy weights again.

How to become very strong

Saturday, February 18, 2006

How do the osteoporosis drugs such as Fosamax work?

Your bones change all the time. Every day, certain bone cells called osteoblasts bring calcium into bones to make them stronger. Other cells called osteoclasts carry calcium out of bone which makes them weaker. Your bones are strongest when you are 20 years old. As you age, the osteoclasts do more work than the osteoblasts, so most people spend their entire lifetimes losing calcium from bones.

Some people get osteoporosis so badly that they break their bones with slight trauma and can die from the complications. You are at increased risk for osteoporosis if you are thin, have blond hair or blue eyes, drink more than two drinks a day, smoke, do not exercise, eat huge amounts of meat, or are a woman who goes into menopause before age 52.

You can help to prevent or treat osteoporosis by lifting heavy weights, which increases the effect of osteoblasts strengthening bones. Bisphosphonates such as Fosamax block osteoclasts from taking calcium out of bones, while they leave osteoblasts alone, for a net gain of calcium taken in bones. The first large, long-term study of Fosamax, published in the New England Journal of Medicine (March 11, 2004) showed continuing bone-strengthening benefits after ten years with no significant side effects.

Wednesday, February 15, 2006

Does exercise when you're young help you as an adult?

Many research papers show that middle-aged and older women who are physically active are far less likely to suffer from heart attacks, the leading cause of death in women in America today. However, there has been very little research on the effects of physical activity during young adulthood on exercise patterns during middle and later age, and whether they influence heart attack risk in later life. Many years ago, researchers at Harvard Medical School recruited nearly 40,000 healthy female professionals, older than 45 years, for the Women's Health Study. Findings from this ongoing study show that women who exercise when they are younger are far more likely to exercise when they are older and are far less likely to die of heart attacks (Medicine & Science in Sports & Exercise, August 2005).

Women who exercised 12 months a year during high school years were more than twice as likely to exercise when they became middle aged and were also almost half as likely to suffer a heart attack as women who did not exercise in later life. So if you have young daughters, encourage them to start an exercise program that they can keep the rest of their lives. If you are a middle-aged woman and are not exercising regularly, get started now. It’s never to late; even 90-year-old women who begin a supervised exercise program can see dramatic strength gains in as little as six weeks.

How to start an exercise program

Tuesday, February 14, 2006

Are drugs necessary to lower cholesterol?

Many people can lower cholesterol with diet changes alone. A study in the Journal of the American Medical Association (July 23, 2003) shows that a combination of cholesterol-lowering foods is as effective as statin drugs in lowering both blood cholesterol and C-reactive protein. The subjects who were fed a diet that included plant sterol margarine, soybeans, almonds, psyllium fiber, barley, oats, eggplant, okra and many other vegetables had the bad LDL cholesterol levels drop by 29 percent compared to 31 percent in the statin drug group.

A cholesterol-lowering diet appears to be completely safe, while statin drugs can cause muscle pain. Athletes and serious exercisers train by taking a hard workout that makes their sore on the next day, take easy workouts until their muscles feel fresh again and then take another hard workout. Statin drugs make it difficult to maintain a good training program because they can delay recovery.

Here's the diet I recommend for lowering cholesterol AND blood pressure

Monday, February 13, 2006

Does the warning about belly fat and heart attack risk apply to all ethnic groups?

Yes; a study reported in the November 5, 2005 issue of Lancet covered people from 52 countries and confirmed that storing fat primarily in your belly markedly increases chances of suffering a heart attack in all groups. Some regions and ethnic groups appear to be more disposed to this pattern of fat distribution and their heart attack rate is correspondingly higher. When you store fat primarily in your belly, you also store it in your liver. After insulin does its job of driving sugar from the bloodstream into your cells, it is supposed to be removed by your liver. Having a lot of fat in your liver prevents your liver from removing insulin, causing blood levels of insulin to rise too high. Insulin constricts arteries to cause heart attacks. It also acts on your brain to make you hungry so you eat more. It acts on your liver to manufacture more fat and it causes fat to be deposited in the fat cells in your belly.

Storing fat on your hips, or in both your belly and your hips, does not increase risk for suffering heart attacks. The researchers conclude that larger hips are often associated with greater muscle mass, and strong muscles help to protect you from heart attacks.

Apples and Pears (belly-fat vs hip-fat)

Sunday, February 12, 2006

Are beta blockers the best drugs for lowering blood pressure?

Beta blockers are among the most-prescribed drugs to treat high blood pressure, but a study from Sweden shows that they can increase risk for strokes (Lancet, October 29, 2005.)

Brand names of the beta blockers include Toprol, Inderal, Blocadron, Coreg, Inopran, Levatol, Pindolol, Sectral, Tenormin, Timolol Trandate, Zebeta and Bisoprol. Studies show that they are the drugs of choice 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 in their patients who have not had heart attacks, no data show that they prevent heart attacks in healthy people. This is the second major study to show that beta blockers do not prevent first heart attacks and may even increase a person’s risk for stroke. Besides, they often make a person so tired that he has difficulty exercising.

More on blood pressure drugs
Lowering blood pressure with diet

Saturday, February 11, 2006

I'm trying to eat a healthful diet, but I get huge amounts of gas. What can I do?

You're not alone if you suffer gas when you eat dairy products, vegetables, beans, nuts, seeds, grains or cereals. The gas is caused by bacteria in your gut fermenting sugars.

Carbohydrates are made of sugars either alone or in combinations. They can be the single sugars, glucose and fructose, found in fruit; the double sugar, lactose, found in dairy products; thousands of sugars bound together called starch; or millions of sugars bound together called fiber. Before any carbohydrate can be absorbed from your intestines into your bloodstream, it must be broken down into single sugars. If it cannot be broken down into single sugars, it cannot be absorbed and it passes into the lower intestinal tract where bacteria ferment it to cause gas.

Half of the world's population develops cramping after drinking milk because they lack the intestinal enzyme that is necessary to break down the double sugar in milk called lactose. These people can purchase the missing enzyme, called lactase (in products such as Lactaid or milk that has lactase added), and drink milk without discomfort. Or they can avoid dairy products.

All humans will have intestinal gas after they eat significant quantities of many whole grains, beans or other seeds. These foods contain triple, quadruple and quintuple sugars and no human has the enzymes necessary to break them down. You can de-gas beans by soaking before you cook them, or you can use alpha-galactosidase products such as Bean-O, which contain an enzyme that splits these complex sugars.

When you change your diet, you build up colonies of the friendly bacteria gradually and the problem becomes less severe. If you are not constipated, a moderate amount of gas is not uncomfortable and is perfectly normal. However, some people still get unreasonable amounts of gas, even after several weeks of adjustment to the new diet. These people may be helped by taking Cipro 500 mg twice a day and metronidazole 250 mg four times a day for one week. Check with your doctor.

Friday, February 10, 2006

When is muscle soreness good?

If you are a regular exerciser and on the day after a harder workout, you never feel soreness in your muscles, you will not improve your fitness level as much as you could. Take a tip from competitive athletes who train by taking a hard workout, feeling sore on the next day and then take easy workouts until the soreness goes away in a day or two.

The good soreness that makes you stronger is called DOMS (Delayed Onset Muscle Soreness) and is caused by microscopic tears in your muscle fibers. It is not caused by lactic acid buildup. When muscles are damaged, they produce healing prostaglandins that cause muscles to become bigger and stronger than before they were exercised vigorously. Researchers have shown that DOMS heals faster when you do nothing, but if you take off every time your muscles feel sore, you will never become an athlete and you will not reach a high level of fitness. When you exert very slight pressure on your muscles when you have DOMS, you cause muscle fibers to become more fibrous and they will become stronger so they can withstand greater stress during your harder workouts. Never try to put a lot of pressure on your muscles when they feel sore. That will markedly increase your chances of injuring yourself.

It is relatively easy to tell the difference between DOMS and an impending injury. DOMS is usually symmetrical, involving muscles equally on both sides of your body. An injury is more likely to cause pain that is only on one side. DOMS does not feel worse as you exercise at light intensity. An injury worsens with continued use of the injured part. Stop exercising when you have an injury.

When your muscles feel sore from exercising, take the day off or exercise with very light resistance, such as running or cycling very slowly, or lifting extremely light weights. Try stretching gently to help restore flexibility. Deep massage may help you to heal faster and toughen your muscles.

Thursday, February 09, 2006

How can I make my exercise bike more comfortable?

Gabe Mirkin, M.D.


I can think of two solutions. Switch to a recumbent stationary bike, or do short, intense workouts where you alternate between sitting and standing. When you ride a conventional stationary bicycle, you sit on a narrow bicycle seat because your legs have to reach around the seat down to the pedals. The pudendal nerve in your pelvis can be pinched by the seat to cause numbness and pain in your crotch and genitals. When you sit on a recumbent bicycle that has the pedals at the same height as your pelvis, your legs are not separated by the seat so you don't need a narrow bicycle seat. You sit on a seat shaped like a regular chair which is contoured to fit your back and is very comfortable. Anyone who can sit in a chair can use a recumbent stationary bike, so even elderly people with poor coordination and weak muscles can get the benefits of exercise.

My current favorite workout bike is a "spinning" bike, the same kind used for classes in many gyms. It’s an upright bike with a standard narrow seat, but you don’t get sore because you never sit for long. In a "spinning" workout you cycle as fast and as hard as you can for brief periods, changing positions and resistance frequently. The bike has a very heavy wheel that moves smoothly and adjusts easily. In spinning classes, you have an upbeat instructor, music and other cyclists to keep you motivated, but you can do the same workout on your own. Used, reconditioned spinning bikes are available at reasonable prices if you decide you’d like to have one at home.

More on Spinning Classes

Wednesday, February 08, 2006

Why would pigeon toes make you run faster?

Most football coaches can pick their halfbacks just by watching them walk. The fastest runners are often flat footed, pigeon toed, and bow legged. When you run, you land on the outside bottom part of your foot and roll toward the inside. Most flat feet appear flat because the ankles roll in excessively causing the arches to touch the ground. Excessive rolling in causes feet to hit the ground with greater force to drive you forward faster.

Pigeon toes require very strong medial shin muscles to point your feet inward and shin muscles raise you up on your toes as you step off to the other foot. People with bowed legs have knees that whip inward as they step off from one foot to the other, which drives them forward with greater force and helps them to run faster. A football coach can often pick his halfbacks by looking for students with flat feet, pigeon toes, and bow legs.

Tuesday, February 07, 2006

Do lifestyle choices affect cancer risk?

One in three of the seven million cancer death worldwide is caused by nine potentially modifiable risk factors, according to a study from Harvard Medical School (Lancet, November 19, 2005.) Being overweight causes your full fat cells to release chemicals that cause inflammation that can lead to cancer. Lack of fruit and vegetables deprives you of antioxidants that prevent cancer. Lack of exercise increases inflammation that causes cancer by the same mechanism as full fat cells . Smoking exposes you to nicotine that causes blood vessels to grow and nourish cancer cells. Excess alcohol dehydrates cells, which can cause cancer. Unprotected sex exposes you to cancer-causing viruses. Urban air pollution and indoor smoke from solid fuels expose you to carcinogens in the air, and contaminated injections expose you to viruses and other agents that cause cancer. You can improve your odds against cancer by avoiding overweight, eating lots of fruits and vegetables, exercising, avoiding smoking and alcohol, practicing safe sex, and avoiding indoor and outdoor air pollution whenever possible. Avoid injections unless they are necessary for health.

Sunday, February 05, 2006

I read an article that said bicycling weakens bones. Can this be true?

One widely reported study showed that bicycle riders have bones that are less dense than people who don’t exercise at all. A science writer for a major newspaper made the ridiculous recommendation that bicycle riders should therefore lift weights to strengthen their bones, or change sports. Bone density tests do not necessarily measure bone strength. Birds have unbelievably thin bones that are extremely strong, and are far more resistant to fractures than many mammals that have much denser bones.

There is no evidence that bicycle riders or racers are at increased risk for bone fractures. Racers crash all the time. Lance Armstrong spends as much time on a bike as anyone, and he has had several high impact crashes. If he had weak bones, he would be in a wheelchair, and not be the greatest bicycle racer in the world.

Friday, February 03, 2006

Is Helicobacter the only bacteria that causes stomach ulcers?

Barry Marshall won the 2005 Nobel Price in Medicine for proving that stomach ulcers are caused by bacteria called Helicobacter pylori. Several papers have shown that a type of stomach cancer called MALT is caused by the same bacteria that causes stomach ulcers and that many cases of MALT stomach cancers can be cured by taking antibiotics to kill Helicobacter. An exciting report from Austria shows that antibiotics can cure the stomach cancer even though it is not caused by Helicobacter (Gut, November 18, 2005.)

So far, researchers have shown that more than 25 different bacteria can cause stomach ulcers, and doctors do not have the ability to test for all of these bacteria. Doctors cured this case of stomach cancer with metronidazole, clarithromycin and an antacid. I believe that anyone with symptoms of stomach distress should be given a trial with the triple therapy used to treat Helicobacter, even if the tests for Helicobacter are negative.

If you have any symptoms of stomach distress (belching, burning), check with your doctor.

Thursday, February 02, 2006

Why is it worse to have a fat stomach than fat hips?

A study from Queen’s University in Canada confirms that storing fat primarily in your belly, rather than your hips, increases your chances of suffering heart attacks and diabetes (American Journal of Clinical Nutrition, March 2004). When you take in more calories than your body needs, your liver turns them into fat. People who store fat primarily in their bellies are called "apples," while those who store fat primarily in their hips are called "pears." Fat cells in your belly are different from those in your hips. The blood that flows from belly fat goes directly to your liver, whereas the blood that flows from your hips goes into your general circulation. The livers of those who store fat in their bellies are blocked from removing insulin by the extra fat and therefore do not remove insulin from the bloodstream as effectively as the livers of those who store fat in their hips and have less fat in their livers. So "apples" have higher blood insulin and sugar levels.

You need insulin to drive sugar from your bloodstream into your cells, but insulin is also a harmful hormone because it lowers blood levels of the good HDL cholesterol that prevents heart attacks and raises blood levels of the bad triglycerides that cause heart attacks. Being shaped like an apple and having a beer belly increases your risk for a heart attack and diabetes. People who store fat primarily in their hips and are shaped like pears are less likely to have heart attacks.

Wednesday, February 01, 2006

Should I exercise during air pollution alerts?

It's healthful to exercise and harmful to breathe polluted air. Many people wonder if they will do more harm than good by exercising on days when the air is heavily polluted. The worst time for pollution is when clouds cover the sky and automobiles fill the roads. Automobile exhaust fumes are the principal source of air pollution in most cities, and overlying clouds increase pollution. Usually the sun’s rays heat the ground to warm air closest to the ground. Hot air rises, taking large amounts of pollutants skyward. On air inversion days, the clouds prevent the sun's rays from getting through to the ground, so the air near the ground is not heated, remains colder and doesn't rise, causing the air with its pollutants to remain close to the ground.

Air pollutants such as carbon monoxide, ozone, carbon dioxide, and sulfur dioxide can damage your lungs. When you exercise, you breathe more deeply and more frequently so that you breathe in more pollutants. However, you don't retain more pollution. Bicycle riders in rush hour downtown Washington traffic breathe in more carbon monoxide than car riders do, but have lower blood levels of carbon monoxide. So keep exercising, but if possible, try to avoid heavily trafficked streets, and exercise before the heavy morning traffic peak or at least two hours after the evening rush hour ends.