Q: I heard that there is a new cure for nail biting. I'm told it comes from Europe. Do you know anything about it? Does it work?
A: Nail biting is a nervous habit and one of the most common symptoms of stress, especially among teenagers. I've read that about 45 percent of adolescents bite their nails. Most eventually stop of their own accord, but there are plenty of adults who haven't been able to break the habit. In some instances, nail biting has been linked to obsessive-compulsive disorder and is now considered one of a category of disorders known as body-focused repetitive behaviors.
While the habit can be embarrassing, and thus a source of anxiety as well as a response to it, there's not a lot of scientific research on the subject. However, a study from Britain, published in the May 2007 issue of Behaviour Research and Therapy, found, not surprisingly, that young people most frequently bite their nails when they're frustrated or bored.
People are also reading…
I don't know of any sure cures for nail biting, but you may have heard about a treatment from the Netherlands, which got a lot of media attention in the fall of 2007. The method was devised by a businessman, not a doctor or psychologist, and involves the use of a tooth guard that makes it impossible to bite the nails. The device is molded to fit either the upper or lower teeth and is said to be barely visible. It can be removed for eating. The developer of this latest "cure" contends that it works by frustrating the impulse to bite your nails. After four weeks, he says, the problem is permanently solved. So far, we have only his word for it — I've seen no studies demonstrating that the method actually works.
The same goes for some of the other treatments available, such as painting nasty-tasting stuff on your nails, a form of aversion therapy. Another approach involves putting a rubber band on your wrist — not tight enough to stop circulation but not loose enough to fall off. The idea is to snap the rubber band hard enough to make it sting the second you start the movement that leads to biting your nails, such as running your thumb along the edges of your nails to decide which one to bite.
My recommendation would be to try hypnotherapy as well as relaxation techniques — such as breathing exercises, biofeedback or yoga, for example — to reduce underlying stress.
Q: What can you tell me about MonaVie, a blend of antioxidant juices? One blend is just juices, and the other also contains glucosamine. Is this a safe product to use for adults and for children?
A: MonaVie is a product that contains açaí (pronounced a-SAH'ee) berries plus other fruits, but its promoters base their health claims for it on açaí berries, which reportedly provide 10 times the antioxidants found in red grapes and 10 to 30 times those in red wine.
Native people in Brazil have traditionally used açaí berries to treat digestive disorders and skin conditions, said University of Florida researcher Stephen Talcott, who has been investigating the berry. He and his colleagues have published findings from laboratory studies showing that açaí extracts caused leukemia cells to self-destruct. While Talcott cautioned that the study doesn't show that açaí could treat leukemia in humans, he noted that compounds that show good activity against cancer cells in cell cultures are likely to have beneficial effects in the body. I don't agree. It's a long way from test-tube results to safe and effective treatments for cancer in humans.
There are no reliable studies on any commercially available products containing açaí. (One posted on a Web site promoting MonaVie contains a disclaimer that it involved only a small number of healthy adults and would have to be repeated in a larger group before results could be generalized to the population at large.)
MonaVie is an expensive way to get your antioxidants — it sells for about $40 for a 25.3-ounce bottle. That works out to $4 to $6 per day if you use it as directed. While it's probably safe, I recommend sticking closer to home for your protective phytonutrients. Opt for organically grown blueberries, which are more available, much less expensive and give you fiber as well as plenty of antioxidant activity. And don't forget black raspberries and pomegranates, both of which have health benefits for which there is good scientific evidence.
As for the glucosamine in some MonaVie products, there are less expensive ways to get that, too. If you have osteo-arthritis, I think glucosamine is worth trying, and it may help restore damaged cartilage in joints. But buy a good brand of it and use the recommended dosage for a trial period — two months, say — to see if it helps. If you do not have osteoarthritis, you do not need glucosamine, nor do children need it.
I also object to MonaVie because it's sold via a mix of multilevel marketing and direct-from-distributor sales. I'm sorry, but I'm prejudiced against multilevel marketing of any kind.
Note: Today's Dr. Weil column is his final one. The syndicate that distributes it, Universal Press Syndicate, has discontinued the column.