Nutrim, which is relatively high in beta-glucans, is said to be more effective than oatmeal or oat bran cereals for lowering cholesterol. True, or just marketing hype?

The type of soluble fiber Nutrim provides is beta-glucan, in this case derived from oats and barley. While beta-glucan can help lower cholesterol when it is part of a low-fat diet, its effect is quite modest compared to that of red rice yeast extracts. Red rice yeast (Monascus purpureus) is a source of naturally occurring statins, the same class of compounds used in prescription drugs to lower and control cholesterol. Because red rice yeast extract delivers a mix of those substances rather than a single molecule, it is much less likely to cause the side effects that often occur with the pharmaceutical versions.

If you take red rice yeast extracts, be sure to have your cholesterol and triglyceride levels monitored periodically by your physician so that your dosage can be adjusted if necessary. The same would be true if you were taking statins. Because these drugs inhibit the body's natural synthesis of coenzyme Q10 (CoQ10), which is needed for optimum heart health and general health, be sure to take 90 - 120 mg of CoQ10 every day - whether you take red rice yeast extract or a pharmaceutical statin.

Here are my other recommendations to help keep cholesterol under control:

• Follow my anti-inflammatory diet.
• Be sure to get at least 30 minutes a day of aerobic exercise.
• Keep your saturated fat intake low: no more than five percent of daily caloric intake.
• Increase omega-3 fatty acids. Take 2-3 grams a day of fish oil.
• Minimize consumption of quick-digesting (high glycemic load) carbohydrates.
• Increase consumption of soluble fiber, such as oat bran.
• Eat garlic, hot red pepper (chili), and shiitake mushrooms frequently.
• Drink green tea regularly.

Andrew Weil, M.D.

I am a 20 year old female, physically active, and at a healthy weight. I have never menstruated and have been found to have extremely low estrogen levels. I have been on Premarin for 3 or 4 months now and am concerned about future health risks associated with taking it long term. Is there a safer alternative?

There are many reasons for primary amenorrhea including hormonal problems involving the pituitary gland or the hypothalamus, both of which set in motion the other hormones that regulate the menstrual cycle. Thyroid problems can also be to blame, and in some cases, birth defects, genetic anomalies, or underlying systemic diseases are at fault. Obesity and malnutrition can also cause primary amenorrhea, but none of these problems seems relevant in your case since you say that you're otherwise healthy and of normal weight.

Your wisest course at this point would be to consult an endocrinologist with a special interest in amenorrhea. You need a thorough gynecological and endocrinological workup to determine why you haven't begun menstruating. What you're experiencing isn't normal, and I'm not sure that replacing low estrogen by taking Premarin is the best course to follow. Once the cause of amenorrhea is identified, treatment can be targeted to the problem and usually is successful.

Andrew Weil, M.D.

My son, age three, has been diagnosed with alpha-1 antitrypsin deficiency. His liver enzymes are elevated, but he is in good health. I am very interested in milk thistle for liver support, but his specialist does not agree. Is milk thistle safe for children as a long term supplement?

According to the American Liver Foundation, many people who inherit an AAT deficiency never develop any of the associated lung and liver diseases. The disorder can be diagnosed with a blood test (if one family member is deficient, others should be tested). Those affected individuals who have a related lung or liver disease require ongoing medical care.

The most important thing anyone with this deficiency can do to protect the lungs is to avoid smoking, secondhand smoke, and exposure to dust, fumes or other airborne toxins. At home and at work, avoid flower and tree pollen, ash, paint fumes and fumes from cleaning products. There is no cure for AAT. Treatment emphasizes good nutrition to ensure that the liver and the rest of the body have essential nutrients.

I see no reason why your son shouldn't be able to take milk thistle (Silybum marianum), an herbal preparation. I checked with Tieraona Low Dog, M.D., director of The Fellowship at the Arizona Center for Integrative Medicine and an expert in botanical medicine. She agreed that it is safe for your son to take milk thistle on a long-term basis, although she said that she didn't know if it would be effective given his AAT deficiency. The correct dosage for children is 5-10 mg per kilogram of body weight per day.

Make sure that your son sees his physician as scheduled so that any complications of AAT deficiency can be detected early and treated promptly.

Andrew Weil, M.D.

My son, a 29-year-old hemophiliac, will be undergoing treatment for hepatitis C with interferon and ribavirin. What can he do or take to ease the debilitating side effects? 

I discussed your question with Qingcai Zhang, MD, a Chinese physician and hepatitis expert who practices in New York City. He noted that the body's immune system naturally produces interferon, which helps fight off infections, especially viral infections. It also has anti-inflammatory, anti-fibrosis, and anti-cancer effects and is a key component of the body's healing system. An interferon deficiency is one of the factors that results in hepatitis C infections becoming chronic. The combination of interferon and the antiviral drug ribavirin is, so far, the only tool conventional medicine has to eradicate the hepatitis virus, Dr. Zhang said.

However, he acknowledged that this treatment is not easy to tolerate because of strong side effects, which include flu-like symptoms, depression, low blood cell counts, and in some cases, auto-immunity. Worse, treatment does not always achieve the desired goal: after 48 weeks of treatment the serum viral load should be undetectable and remain undetectable six months later. The combination of toxicity and less-than-great efficacy make it difficult for many patients to attempt or complete this treatment.

Dr. Zhang has found that some of the side effects can be mitigated by taking liver protective supplements along with the drugs. He regularly uses schizandra (Schisandra chinensis), the fruit of a Chinese plant; glycyrrhizin (a licorice derivative) and silymarin (milk thistle). He also recommends vitamin B-complex, which may help support the liver's detoxification pathways. Folic acid and vitamin B12 may protect against ribavirin-induced anemia, which occurs in about 10 percent of patients. Dr. Zhang also noted that vitamin K deficiency is associated with liver disease. Because that impairs blood clotting, he advises that hemophiliac patients undergoing ribavirin treatment also take a vitamin K supplement.

Andrew Weil, M.D.

Have your views on fluoridation changed given new findings about osteosarcoma in dogs and studies linking fluoride to bone cancer in young boys?

I have always maintained, however, that fluoride isn't risk-free. Excessive amounts can create chalky white, irregular patches on the surface of teeth, causing the enamel to appear mottled. In very large amounts, fluoride is toxic. It can cause gastrointestinal problems and, rarely, death. Signs of fluoride overdose include excessive salivation, tremors, weakness, convulsion and a soapy or salty taste in the mouth. While high amounts of fluoride over several years can cause brittle bones, this is extremely rare.

As far as bone cancer is concerned, every year about 400 children and adolescents (boys and girls) in the U.S. are diagnosed with osteosarcoma, a rare disease. In 2006, Harvard researchers reported an association between fluoride in drinking water and the incidence of osteosarcoma in boys (not girls). A preliminary analysis of a second set of cases doesn't appear to support the earlier observed connection between fluoride in drinking water and osteosarcoma in young boys, according to the U.S. Centers for Disease Control and Prevention.

Furthermore, the CDC concluded that analysis and reviews of earlier studies of water fluoridation and osteosarcoma don't support an association between the two. This case isn't closed - more research is in progress, but so far, we have no hard evidence demonstrating that fluoride causes or promotes bone cancer.

As far as dogs are concerned, a study by the Environmental Working Group (EWG), a Washington, D.C.-based consumer protection organization, found that eight major national brands of dog and puppy food contained fluoride in amounts between 1.6 and 2.5 times higher than the Environmental Protection Agency's maximum legal dose in drinking water and higher than amounts associated with bone cancer in young boys in the study mentioned above. All eight brands contained bone meal and animal byproducts, which is probably where the fluoride came from.

According to the EWG data, some 8,000 dogs in the United States are diagnosed with osteosarcoma each year compared to only 900 human cases (500 adult cases in addition to the 400 children). However, we simply don't know whether the fluoride in dog food or drinking water accounts for the osteosarcoma some animals develop. If you're concerned about any potential risk to your pets, avoid buying dog food containing animal byproducts. Regardless of the osteosarcoma risk, I strongly recommend this for the health of your pets in general. When choosing food for my own dogs I stay away from anything containing animal byproducts, rendered or recycled meats, poultry or fats. Avoid animal based "meals" (for example, "chicken meal") and look for quality meat or fish protein as first ingredients.

Andrew Weil, M.D.

Does apple cider vinegar truly aid in weight loss? How does it work?

The apple cider vinegar diet has been around for decades - at least! Some proponents claim the ancient Egyptians used apple cider vinegar for weight loss. I'm sure it didn't work any better then than it does now, despite the rave reviews and anecdotal evidence cited by the folks who want to sell you the vinegar or products containing it.

The only research I've seen suggesting that vinegar may help reduce fat was a study published in the July 8, 2009, issue of the Journal of Agricultural and Food Chemistry. Japanese researchersreported that they had put laboratory mice on a high-fat diet and fed them acetic acid, the main component of vinegar. Another group of mice on the same high-fat diet received water, not acetic acid. Both groups of mice gained weight but those on the vinegar "diet" put on up to 10 percent less body fat than the others. The researchers said that the acetic acid may turn on genes for fatty acid oxidation enzymes. Theoretically, this would result in the production of proteins that can break down fats and therefore suppress body fat accumulation. Additional research will be needed to confirm these results and determine if acetic acid can help humans slow weight gain.

As far as the apple cider vinegar diet is concerned, there is absolutely no scientific evidence showing that it can aid in weight loss or that it contains any magic ingredients that help you to shed pounds. Back in the 1970s when this diet took its place among the many weight loss fads and scams, proponents claimed that somehow a combination of apple cider, kelp, vitamin B-6, and lecithin fooled the body's metabolism into burning fat faster than it would normally.

These days the claims are a bit less grandiose - supposedly, all you need to do to lose weight is to take one, two, or three teaspoons of apple cider vinegar before every meal, starting with one teaspoon and then working up to two or three. The only advice you get with this "diet" is to eat moderate portions at meals, avoid snacking, and wait for the apple cider vinegar to reduce your hunger and food cravings. It won't do that, but like any acid, it can slow gastric emptying, blunting the effect of high-carb meals on blood sugar.

In addition to weight loss, apple cider vinegar has been promoted for relief of arthritic stiffness, and as a treatment for sore throats, acne and other skin problems, high blood pressure, headaches, dandruff, sunburn, and elevated cholesterol levels. Again, I have seen no good evidence to back up these claims.

Weight loss requires effort and commitment. The only formula you can depend on is learning and applying the principles of healthy eating and getting enough physical activity.

Andrew Weil, M.D.

How can vegans and vegetarians get enough omega-3s?

I recommend that anyone who eats no oily fish at least twice a week take an omega-3 fatty acid supplement. The best available of these is fish oil at a dose of 2 to 3 grams per day, but vegans and others whose diets don't include fish can substitute Neuromins DHA, a product which is extracted from carefully grown microalgae (vegans can break the gelatin capsule to get the oil). Taking 400 to 600 mg a day of Neuromins DHA and relying on dietary sources of ALA is probably the best vegan strategy for getting omega-3s. A daily handful of walnuts or one to two tablespoons of freshly ground flaxseed per day provide ALA. I hope we will soon see products made from algae that provide both EPA and DHA. I also recommend that vegans and vegetarians supplement with at least 10 micrograms (mcg) of vitamin B-12 daily or take 1,000 mcg once a week.

To get enough iron without eating meat, cook in iron pots and eat such iron- rich foods as blackstrap molasses, cocoa, and leafy greens. You can boost your absorption of iron-rich foods by eating foods high in vitamin C at the same meal. And since many animal-based foods that provide zinc are shunned, vegans and vegetarians should take 8 to 15 mg of supplemental zinc per day.

Andrew Weil, M.D.

I'm trying to follow your anti-inflammatory diet, but I'm allergic to soy. Is there a nutritional substitute?

Allergic reactions are mediated by the immune system and are marked by symptoms such as hives, runny nose, rashes, nausea, diarrhea and, most seriously, anaphylactic shock. Some 15 possible allergens in soy protein are capable of triggering these responses. Fortunately, soy allergy symptoms are typically mild.

You can be tested to confirm an allergy to soy with a skin-prick test or an IgE RAST blood test. If those tests are negative, your problem with soy foods is likely to be an intolerance or sensitivity. Randy Horwitz, M.D., Ph.D., medical director of the Arizona Center for Integrative Medicine at the University of Arizona, who specializes in immunology, notes that when food sensitivities are the problem, traditional allergy tests often yield negative results. He says that in his practice, he has not seen uniformly good results with IgG anti-food blood tests, applied kinesiology (muscle strength testing), or "live blood" microscopic analysis, all of which have been advocated by some practitioners as ways of determining food intolerances. I also don't recommend any of these tests to confirm or diagnose food sensitivities.

Dr. Horwitz and I agree that the only reliable approach to determining food intolerances or sensitivities is to eliminate suspect foods, then reintroduce them to see if they provoke reactions

If your problem with soy is an intolerance or sensitivity, you may be able to overcome it. After avoiding soy foods for a few months, try reintroducing them very gradually. Start with a teaspoon of soy milk every day and increase the amount very slowly over a month or so. If you do this, chances are good that you'll be able to develop tolerance to soy and expand the number of whole soy foods you can enjoy on my anti-inflammatory diet. Best of luck.

Andrew Weil, M.D.

What precautions should parents take for children who swim a lot, particularly those on swim teams? Is there a higher incidence of chlorine-related health problems among swimmers? Does sunblock prevent the skin from absorbing chlorine?

Chlorine used to disinfect swimming pools is widely recognized as a health hazard. New research suggests that children who swim frequently in chlorinated pools may have increased risks of developing allergies or asthma. Among adults exposure to chlorine in swimming pools has been linked with other health problems including bladder and rectal cancer and, possibly, an increased risk for coronary heart disease.

The latest on this comes from a study in Belgium, which found that teens who spent more than 1,000 hours swimming in chlorinated pools had more than eight times the risk of developing asthma or allergies, compared to kids who usually swam in pools using a copper-silver disinfecting method.

A total of 847 youngsters between 13 and 18 took part in the study - 114 of them mainly swam in pools disinfected with a copper-silver ion system. The number of kids who developed asthma increased in proportion to their exposure to chlorinated pools. Those who swam for 100 to 500 hours had almost twice the risk of developing asthma; while those who spent 500 to 1,000 hours had just over twice the risk; and asthma cases nearly quadrupled among those who spent more than 1,000 hours in chlorinated pools compared to teens who swam in non-chlorinated ones.

The Belgian researchers also found that the risks of hay fever and other allergies more than doubled with significant exposure to chlorinated pools. The study was published in the online issue of Pediatrics on Sept. 14, 2009.

Another Belgian study, published in 2003, showed that an irritant released when chlorinated water reacts with urine, sweat or other organic matter from swimmers increased the risk of asthma among children who regularly swam in public pools. This irritant, trichloramine, is believed to damage the cellular barrier that protects the lungs. Blood samples showed elevated trichloramine levels even among individuals who sat at the side of pools but didn't swim.

I've long believed that inhaling chlorine fumes that accumulate above and around pools is unhealthy. Chlorine is a strong oxidizing agent and irritant, harmful to eyes and skin, the respiratory passages and lungs.

To protect yourself in chlorinated pools, consider wearing a mask and snorkel to shield your eyes, and after swimming, leave the pool area and inhale fresh air to flush the gas out of your system. Shower quickly and thoroughly to wash the chlorine off your skin.

Sunblock won't protect against the effects of chlorine. Instead, lobby local officials and public pool managers to switch from chlorine to safer, more modern disinfection methods. I use a Sigma System silver-copper ion generator in my own pool. Chlorine-based disinfection of swimming pools is obsolete.

Andrew Weil, M.D.

I know you've written before about potential health risks from cell phone use. I recently heard a report that sounds truly alarming about the cancer risk as well as other dangers. Is there new evidence?

• An analysis of 25 earlier studies by two research groups showing a 50 to 90 percent increase in the risk of glioma, a usually malignant brain tumor on the side of the head favored for cell phone use in individuals who had used cell phones for more than 10 years, and a 60 percent increase in acoustic neuromas, benign but troublesome tumors of a cranial nerve among long-term cell phone users
• A 50 to 60 percent increased risk of salivary gland tumors among people who used cell phones frequently.
• A 10 to 20 percent increased risk of hospitalization for migraine and vertigo among long-term cell phone users.
• An 80 percent increased risk for emotional and hyperactivity problems among young children who use cell phones and whose mothers used cell phones during pregnancy.

All of this sounds very alarming - and it isn't good news - but it is important to keep some of these numbers in perspective. When speaking in terms of a percentage increase in risk, bear in mind that if, for example, one person out of 100 is normally at risk of a brain tumor, a 100 percent increase in risk means that 2 people out of 100 would be at risk. It does NOT mean that as a cell phone user, you have a 100 percent chance of developing a brain tumor.

The EWG report maintains that current U.S. government radiation standards are outdated. It noted that in 2008, the European Parliament passed a resolution urging member countries to develop lower radiation limits for cell phones; no such steps have been taken in the U.S. Here, particular concern is focused on the amount of radiation that could penetrate a child's softer, thinner skull (roughly twice the amount that could penetrate an adult skull) and that long-term cell phone use starting in childhood could pose even bigger risks than those already documented. Experts in the U.S. and Europe have advised limiting youngsters' cell phone use.

I noted that the EWG check list for safe cell phone use is similar the safety tips I've been recommending for some time:

• Save long conversations for conventional phones.
• In your car, use a cell phone that has a remote antenna outside the vehicle.
• Always use a headset and keep the phone itself away from your body.
• Find out how much radiofrequency energy your cell phone emits. (This measurement is called the Specific Absorption Rate or SAR; find the SAR for your cell phone. The SAR permitted in the United States is 1.6 watts per kilogram.) The EWG also has a tool that may be easier to use to check on your phone's emissions.

To eliminate the most immediate danger of cell phone use to yourself and others, don't talk or text while driving.

Andrew Weil, M.D.