Can you tell me anything about organic wines? I usually seek out organic produce, but have only recently learned that organic wines are available. Do they contain sulfites?

A previous survey of European and other wines, performed in 2008 by Pesticide Action Network UK, came up with results that align with those seen in the French study. I haven't seen any similar studies of wines produced in the U.S.

I discussed the way grapes are grown with Véronique Raskin, founder and president of The Organic Wine Company, headquartered in San Francisco, Calif. In 1972, her grandfather, Pierre Fabre, a retired physician, began to grow organic grapes on the family's 200 year-old vineyard, La Bousquette, in France's Languedoc region. Ms. Raskin began importing organic wines from her family's vineyard in France in 1979. Ms. Raskin notes that "people eat organic but haven't expanded their thinking to drinking organic" and are not aware that "the grapes used to make most wines are conventionally grown and that grapes are one of the most heavily sprayed crops."

In the United States, finding true organic wines can be a bit tricky. The National Organic Program, administered by the U.S. Department of Agriculture, holds that wine cannot be labeled "organic" if it contains sulfites, chemicals found naturally in grapes and also added in very small quantities to most wines to inhibit the yeasts and bacteria from grape skins that can proliferate and ruin the taste of wine. You can find wines labeled organic and sulfite-free, but if you're a wine enthusiast, I'm told you probably won't like them very much.

If you want to try wine made from organically grown grapes, advises Ms. Raskin, "check the label for the words 'made from 100% certified organically grown grapes.' If it doesn't say that on the label, don't buy it." These wines do contain sulfites in very small amounts, up to about 100 parts per million, but that shouldn't concern you unless you have asthma. Sulfites can cause constriction of the airways and precipitate an asthma attack. In 1986, the FDA banned the use of sulfites as spray-on preservatives for fresh fruits and vegetables (as used in salad bars) in response to 13 deaths and many illnesses linked to them, mostly in asthmatics. Sulfites are still used in some foods, such as dried fruit, as well as wine.

Incidentally, vegan wines are also available. These are made without filtering the wine through certain animal-derived "fining agents" to remove yeast, cloudiness, protein and other unwanted particles. Animal derived fining agents include casein (milk protein) egg albumen, fish oil, isinglass (gelatin from fish bladder membranes), and other substances. Vegan alternatives include carbon, bentonite clay, limestone, and kaolin clay.

I enjoy an occasional glass of wine and mostly drink organic vintages. I have found excellent ones from France, Chile, Argentina, and the U.S.

Andrew Weil, M.D.

What is your view of stretching before exercising? I've heard people say it is essential, while others say it is unnecessary and possibly harmful. If you don't stretch before a workout, how should you warm up?

One of the latest reports of the effect of static stretching (defined as stretching in which the muscle's elongated position is held steadily, rather than intermittently) comes from the University of Zagreb. It focused on how static stretching affects athletic performance. The Croatian researchers examined data from 104 earlier studies that explored this issue and calculated that static stretches reduce strength in the target muscles by almost 5.5 percent, with even greater impact if stretches are held for 90 seconds or more. Stretching for shorter periods of time may diminish this negative effect but doesn't eliminate it, the researchers concluded. The analysis, published in the March 2013 issue of Scandinavian Journal of Medicine and Science in Sports, also showed that stretching reduces a muscle's ability to produce force by about two percent.

A second new study, from Stephen F. Austin State University in Texas and published inthe Journal of Strength and Conditioning Research, found that after passive, static stretching, young men described as "moderately trained" were 8.36 percent less able to perform a single squat holding barbells than they had been earlier after warming up on resistance machines and with free weights. Incidentally, the researcher who conducted this study reported other results in the December, 2010, of the same journal showing that static stretching before playing golf worsened the game of test subjects, leading to significant decreases in clubhead speed, distance, accuracy and consistent ball contact.

No one knows exactly why stretching should have a negative effect on exercise. The authors of both reports suspect that the problem is the loosening effect of stretching on muscles and tendons, reducing their ability to store energy and spring into action.

Instead of stretching, the best way to warm up is to do a slower version of the exercise you're about to perform: if you run, walk, then jog to warm up. If you plan to walk, start off slowly. And if you're doing strength-training exercises, start off with lighter weights, using slow, deliberate form with enough repetitions to get used to each movement.

Stretching does have a role in fitness - it improves flexibility, lengthens muscle tissue, improves posture and body awareness and helps neutralize stress. For best results, stretch after your workout when your muscles are warm and most elastic.

Andrew Weil, M.D.

I read about a procedure called hot chemotherapy that is effective against certain abdominal cancers. Apparently it doesn’t have the same side effects as regular chemotherapy. Is this for real?

Hot chemotherapy can also use much stronger doses of chemotherapy agents, because they mostly stay in the abdominal cavity. The drugs are heated to about 108 degrees and then are pumped into the abdominal cavity and circulated there for 90 minutes. During that time, they're also pumped back through the heating apparatus to make sure they stay hot. While this is going on, the patient's abdomen is rocked gently back and forth to ensure that the drugs are dispersed as widely as possible. (This part has been described as "shake and bake.") The whole procedure can take up to 10 hours until the drugs are pumped out. Given by this method, chemotherapy doesn't have the same side effects as it does when given intravenously to the whole body: your hair won't fall out and you may not suffer other unpleasant symptoms. But hot chemotherapy is a grueling, high-risk treatment; it can lead to serious infection, for example.

I discussed your question with Donald Abrams, M.D., chief of Hematology-Oncology at San Francisco General Hospital and a Professor of Clinical Medicine at the University of California, San Francisco. Dr. Abrams tells me that he is not a big believer in "topical" treatment of internal malignancies but noted that intraperitoneal chemotherapy is used to treat ovarian cancer based on some findings from clinical trials. He added that he would like to see more data on hot chemotherapy.

Only one randomized trial of HIPEC has been conducted, in 2003 in the Netherlands. It concluded that HIPEC improved patients' survival rate from the 12.6 months achieved with regular (intravenous) chemotherapy to 22.3 months. However, 8 percent of the patients treated with HIPEC died from the procedure itself. Additional clinical trials are in progress.

At present, the procedure is available only to certain patients, including those with pseudomyxoma peritonei, a rare disease characterized by a buildup of mucus in the peritoneal cavity; cancer of the appendix; abdominal mesothelioma, and colorectal cancer.

An article on HIPEC published in 2011 IN the New York Times quoted physicians' estimates of the cost of surgery plus HIPEC (including hospitalization) from $20,000 to more than $100,000. Medicare and insurers usually pay for the surgery, but the heated chemo may not be covered unless it is described (and billed) merely as "chemotherapy," according to the Times.

Like Dr. Abrams, I would like to see more data.

Andrew Weil, M.D.

What are some possible treatments for exercise-induced asthma?

Exercise can trigger asthma symptoms. This is true even in people who don't otherwise suffer from the condition, and physical activity can induce symptoms in up to 80 percent of those who do have asthma. Coughing, wheezing, shortness of breath, or tightness in the chest usually come on after exercise, although these symptoms can also occur soon after you begin to work out. Fortunately, you can help address problems with exercise by taking some simple pharmaceutical precautions to prevent or minimize symptoms. Here's a rundown of your medication options provided by my colleague, John Mark, M.D., a pediatric pulmonary specialist at Stanford University medical Center who treats asthma in both adults and children:

• Albuterol: A short-acting bronchodilator that's inhaled 15 to 20 minutes prior to exercise and that protects against symptoms for about four to six hours.
• Salmeterol and Formoterol: These long-acting bronchodilators are effective in protecting against exercise induced asthma if taken 30 minutes or so before exercising. However, formoterol has a quicker onset. Both of these bronchodilators carry an FDA "black box" warning that they may increase the risk of asthma-related death. Neither one should be used as the only therapy for asthma, Dr. Mark said.
• Montelukast (Singulair): A drug that blocks the action of leukotrienes in the lungs, resulting in less constriction of bronchial tissue and less inflammation. Leukotrienes are one of several classes of chemical messengers produced in the body that can trigger bronchial constriction and inflammation. Montelukast is available in pill form and is taken the night before you exercise.
• Cromolyn (Intal): An anti-inflammatory drug inhaled 15 to 20 minutes before exercising that prevents the release of histamines and leukotrienes. It's most useful in asthma when an allergic component is present.

In addition to medication, the following natural approaches can help you prevent or minimize symptoms:

• Warm up very slowly to the point where you almost feel the "tightness" associated with exercise-induced asthma. Then stop and stretch or, if you're exercising vigorously, slow down. By taking this break, you often can block the development of asthmatic symptoms. You can then go back to your normal pace. This may take some getting used to, but can possibly eliminate the need for medication.
• Try breath work. The most effective approaches are pranayama techniques (breath control exercises taught in some yoga classes). You can do these after the initial warm-up when symptoms are almost felt. For beginners, start with "The Relaxing Breath," a technique which I also describe in my books.
• Find a form of physical activity that minimizes your exercise-induced symptoms. Sports or activities that have intermittent rest periods (such as tennis, softball, and golf) can allow you to regain control of your breathing. Swimming may be better than running outdoors in cold weather, but no type of exercise is off-limits with proper treatment. In fact, some of the world's top athletes have exercise-induced asthma, and they're still able to compete successfully in Olympic-level events.

Andrew Weil, M.D.

I was stunned to hear that Angelina Jolie had a double mastectomy to prevent breast cancer. What do you think of her choice? Are there any other options for women who have one of these bad genes?

Normally, BRCA1 and another gene, BRCA2, act as tumor suppressors. Harmful mutations make them incapable of performing this important function and thus place women at very high risk of breast (and ovarian) cancer. Having a history of breast cancer in the family doesn't necessarily mean that you have mutations in these genes, but the National Cancer Institute estimates that ; inherited BRCA1 and BRCA2 mutations account for 5 to 10 percent of breast cancers and 10 to 15 percent of ovarian cancers among white women in the United States. According to the American Cancer Society "in the United States, BRCA mutations are more common in Jewish women of Ashkenazi (Eastern Europe) origin than in other racial and ethnic groups, but they can occur in any racial or ethnic group." You are more likely to have this mutation if you have many close relatives who have had breast cancer.

Once she knew her test results, Ms. Jolie decided to "be proactive and to minimize the risk as much as I could." She opted for preventive surgery. "I started with the breasts, as my risk of breast cancer is higher than my risk of ovarian cancer, and the surgery is more complex," she wrote. She had three consecutive operations. The first, called "nipple delay," checks the breast ducts behind the nipple for cancer and is designed to spare the nipple and surrounding areola. Next, working through incisions in the breast, surgeons remove all the breast tissue but save the skin. In a third procedure, her breasts were reconstructed with implants. This three-stage process began on February 2 and ended on April 27. Ms. Jolie wrote that her children can see her small scars "and that's it."

If you think your family history suggests that you might be at risk, your first step should be genetic counseling with a qualified expert who can help you decide whether testing really is necessary. If the test proves positive, he or she can explain your options. ;(In many cases, results of the tests are unclear.) If a mutation in BRCA1 or BRCA2 is confirmed, you then have to decide what to do. Keep in mind that not everyone with a mutation in these genes will develop cancer, and a woman's personal risk will vary based on other factors. A prophylactic double mastectomy with breast reconstruction was Angelina Jolie's choice based on her personal risk. Another possibility is taking tamoxifen, an estrogen-blocking drug. A woman can also volunteer to take part in a clinical trial on breast cancer prevention. Or she can opt for careful medical monitoring in an effort to catch breast cancer early if it occurs, then treat it.

Angelina Jolie was at high risk for breast cancer. And she has six young children. She made the decision that she felt was right for her.

Andrew Weil, M.D.

How often are you supposed to replace running shoes or athletic shoes you use for walking? I've heard everything from three months to 500 miles. Is there a definitive answer to this question?

Here's a brief summary of what the ACSM suggests evaluating when you're buying running shoes: make sure that you have plenty of room at the widest part of your feet and that the shoes aren't too tight but not so loose that your feet slide around in them. Your heel should fit snugly into the rear of the shoe.

Once you start wearing the new shoes, the ACSM advises that it can take between 60-70 miles, to break them in. Eventually, however, you'll have to replace them. According to the ACSM, the rule of thumb is between 400 and 500 miles of running; so you'll have to keep track. That's a more objective way of calculating when to replace shoes than an arbitrary time limit on their lifespan or visible wear and tear on the tread, midsole and outer soles, which may not show up for many more miles.

Surprisingly, with so many people running and so many injuries from improper footwear, there have been no clinical trials to give us scientific information on how long you can continue to use a pair of running shoes without risking damage. (An article on this subject in the New York Times on February 18, 2013, reported that a Danish researcher is looking for funding for a 15-month study with 600 runners to learn how long you can use shoes without developing physical trauma related to such issues as support and cushioning.)

As a rule, your running shoes will last longer if you run on soft surfaces rather than concrete. Other factors to consider are your weight, your running style and how cushioned or lightweight your shoes are. Certainly, don't let your shoes fall apart. Bear in mind that worn shoes can worsen an existing foot problem and put you at increased risk of injury.

Andrew Weil, M.D.

I've been a smoker for many years but recently quit. Is there anything I can do to prevent paying the price for smoking for so many years and to avoid weight gain?

Published in the January 24, 2013 issue of the New England Journal of Medicine, ;the study was based on examinations of the health records of 16,000 people in the United States who had died but had reported smoking earlier in life. It compared them with the records of people with comparable histories who never smoked. The researchers found that individuals who never smoked were about twice as likely to live to age 80 as smokers. But the big surprises came when the investigators analyzed the lifespans of smokers who quit. They found that those who gave up cigarettes between the ages of 35 and 44 gained back about nine of the 10 years they would have lost if they continued smoking. Smokers who quit between ages 45 and 54 got back six years and those who quit between 55 and 64 regained four.

In terms of health concerns, the study showed that the former smokers retained a risk of lung cancer, but that it was much smaller than it would have been if they had continued to smoke. The added risk of heart attack from smoking disappeared over time after smokers quit.

Another study, in Germany, followed 8,807 men and women between the ages of 50 and 74 for up to 10 years and found that those who quit smoking, even after age 50, saw a 40 percent reduction in the risk of heart attack and stroke within five years. It also showed that smokers have more than twice the risk of cardiovascular diseases as nonsmokers and are affected at a much younger age. For example, a 60-year-old smoker has the same risk of a heart attack as a 79-year-old nonsmoker and the same risk of stroke as a 69-year-old nonsmoker.

If you're concerned that giving up smoking might lead to weight gain, emphasize fruits and vegetables as well as whole grains and healthy sources of protein in your diet. Avoid foods made with flour and added sugar as much as possible. You can also combat weight gain by drinking at least eight glasses of water a day and by regularly practicing a relaxation technique such as deep breathing, yoga, or visualization. If you haven't been exercising, try to fit 30 minutes of walking into your daily schedule at least five times a week. If you already exercise regularly, add an extra half-hour to your weekly total. Exercise not only burns calories to minimize weight gain, but it will also help reduce any stress you're feeling as a result of not smoking.

Andrew Weil, M.D.

Can you tell me if there’s a way to control or stop belching? I’m so embarrassed when an uncontrollable belch escapes me when I’m with other people, particularly at a business-related meal.

Unfortunately, our culture (and most others), frown on audible belching or burping (except from babies who have to be encouraged to burp up air swallowed while being fed). ;I looked around the Internet to see which cultures regard belching or burping as a sign of appreciation or enjoyment of a meal, but in spite of commonly held beliefs about European customs, I didn't come up with anything I would regard as definitive. ;Similarly, when I checked etiquette sites to see if I could find an accepted way to mask belches, I found no advice at all. But you can be assured that we all swallow air and that we all belch occasionally, often audibly. (During my web surfing, I came across the site of the World Burping Federation, which seeks to remove the associated stigma and holds an annual contest for the world's longest burp. The titleholder when I accessed the site was a New York pizza chef, whose "powerful and highly controlled" burp lasted for 18.1 seconds. But Guinness World Records lists an Italian as the source of history's longest burp: l minute 13 seconds, a record set in June 2009.)

Here are some suggestions to help you cut back on belching:

• Get used to eating and drinking slowly so that you'll swallow less air.
• Avoid carbonated drinks and beer, which release carbon dioxide gas that can lead to belching.
• Don't chew gum or suck hard candy.
• Don't smoke. In addition to all the adverse health consequences it presents, smoking promotes swallowing air.
• If you wear dentures, make sure they fit properly. If not, they may cause you to swallow air.
• Don't drink through a straw.
• Treat heartburn with over-the-counter antacids. If they don't help, see your doctor. You may have GERD.

Andrew Weil, M.D.

I was alarmed to read about a new study showing that Ginkgo biloba causes cancer. What do you recommend for those of us who have been taking supplements of it? I haven't taken any since I read about the study.

The study you mention comes from the U.S. government's National Toxicology Program (NTP), which evaluates chemicals of concern to the public. It was asked to evaluate ginkgo extract by the National Cancer Institute. After two years of study, the NTP concluded that the extract causes liver cancer in mice and that there was "some evidence" that it causes thyroid cancer in rats.

While that certainly sounds scary, it isn't the whole story. I checked with Mark Blumenthal, executive director of the American Botanical Council (ABC), a highly reputable nonprofit research and education group that provides the public with scientifically based information about herbs. I learned that in a letter to the NTP, the ABC took issue with the Shanghai-manufactured ginkgo extract used in the study, noting that it doesn't meet "botanical and chemical standards for quality as set forth in various official pharmacopeias and does not conform to the well-established chemical profiles, quality, and purity of the leading, clinically tested ginkgo extracts." This means that while the NTP results may be true for the non-standardized ginkgo extract it tested, we can't assume that they apply to the standardized ginkgo extracts used in the many clinical trials that have shown them to be safe and beneficial.

The ABC also noted that the dosage of ginkgo used in the studies was 55 to 108 times higher than those in supplements normally taken by consumers.

Bill J. Gurley, Ph.D., professor of pharmaceutical sciences in the College of Pharmacy at the University of Arkansas School for Medical Sciences, Little Rock, also weighed in on the NTP results. He noted that "almost anything will create cancer in rats and mice when fed to them at high doses for two years. All toxicologists and pharmacologists are aware of the susceptibility of certain strains of rodents used for research purposes to develop various forms of cancer and other diseases when subjected to various substances."

Ginkgo was added to some popular brands of energy drinks prior to the U.S. Food and Drug Administration notifying manufacturers that the herb has not been approved for use in food and beverages. In a news release, the Washington-based Center for Science in the Public Interest (CSPI) noted that the FDA has sent warning letters to several drink companies, including Rockstar, stating that ginkgo is not generally recognized as safe for use in food, though it is legally sold as an herbal supplement. Ginkgo also had been added to some herbal teas.I recommend checking the ingredients of these products to see if the source of the herb is listed.

Andrew Weil, M.D.

I just heard that parents are now supposed to suck babies’ pacifiers to clean them. This sounds really unhygienic to me. Wouldn’t the parents be passing on their germs?

While the study didn't prove that exposure to parental saliva was responsible for the lower rate of allergies, the findings conform to the "hygiene hypothesis," which holds that children who grow up in less sanitary environments are less likely to develop allergies and asthma than youngsters raised in cleaner, more protected ones. The idea is that the developing immune systems of less privileged kids are exposed to more germs from an early age and become stronger as a result.

The Swedish study found that a majority of the parents whose babies used pacifiers said that they cleaned the pacifiers by rinsing them off with tap water or boiling them. But the parents of 65 of the children reported also "cleaning" pacifiers by putting them in their own mouths and briefly sucking. Not only were the children of these parents less likely to have eczema at 18 months than youngsters whose parents did not use their own mouths to clean the pacifiers, they were also 37 percent less likely to test positive for sensitivity to common allergens such as birch and timothy grass pollen, dander of cat, dog and horse; mold, dust mites, milk, egg, soy, fish, wheat, and peanut.

Babies in this study who had the lowest incidence of eczema at 18 months were those who were delivered vaginally and whose parents "cleaned" their pacifiers by sucking. The highest prevalence of eczema occurred among the babies delivered by Caesarean sections whose parents cleaned pacifiers by rinsing or boiling. A Canadian study published in February, 2013, found that babies born by C-section lack a specific group of bacteria found in babies born via vaginal delivery (even if breastfed). And babies who were formula-fed had a different bacterial makeup than babies who were exclusively or partially breastfed. We don't know yet how - or if - these differences affect long-term health, but based on the Swedish findings, parents who suck their babies' pacifiers clean may be on to something.

Andrew Weil, M.D.