Could laughter be the newest weight loss fad? Investigators at the Vanderbilt University Medical Center in Nashville say that laughing for 10 to 15 minutes each day can burn 10 to 40 calories, depending on a person’s body weight. Long considered “the best medicine,” laughter raises the body’s metabolic rate by 20 percent, producing energy and burning calories. The investigators believe that their research, which monitored the energy expended by students watching television comedy clips in a metabolic chamber, is the first to measure how much energy is created by laughter. Researchers estimate that people who consistently laugh for 10 to 15 minutes per day would lose 4.4 lb each year.

Experts agree that self-medicating to fight chronic insomnia is a bad idea. According to an independent panel convened by the National Institutes of Health, chronic insomnia has become a major health problem among adults. Almost one third of adults have trouble sleeping, and 10 percent have daytime symptoms that indicate true insomnia. Although scientists still don’t know much about what causes insomnia or how to treat it, most agree that treatments not approved for the problem can do more harm than good. They say that people who regularly self-medicate with alcohol or sedating antihistamines are disrupting their regular sleep patterns and can feel even worse when they wake up. Research indicates that techniques of cognitive and behavior therapy are the most effective means of dealing with insomnia.

Can a raisin a day keep the dentist away? Researchers at the University of Illinois at Chicago College of Dentistry recently found that raisins contain chemicals that can help prevent cavities and gum disease. Although raisins may seem like a sugary treat, their sweet taste and sticky texture are misleading. Raisins contain five compounds called phytochemicals, which are antioxidants found in plants. These phytochemicals have been shown to fight oral bacteria. The researchers noted that one particular phytochemical, oleanolic acid, slowed the growth of bacteria and stopped it from sticking to the surface of teeth, which can help protect mouths from cavities, plaque, and periodontal disease.

Children with pulmonary hypertension may benefit from taking an impotence drug, according to early results of a small study published in Circulation. Sildenafil (Viagra) was given to 14 children with pulmonary hypertension. Children with pulmonary hypertension usually die within one year if untreated; even with treatment, few live more than five years past diagnosis. After one year of treatment with various dosages of sildenafil, resistance in the pulmonary arteries dropped by about 20 percent and the average distance the children were able to walk in six minutes increased by 508 feet. Researchers say the advantages of using sildenafil are that it’s easy to take and has few side effects.

In the battle of love versus sex, is there a clear winner? According to a study published in the Journal of Neurophysiology, love is the stronger emotion. Using a functional magnetic resonance imaging system, investigators examined the brain patterns of couples who had recently fallen in love. The couples were monitored while they filled out questionnaires. The results showed that romantic love has more power than sex over the human mind. Scientists also found that sex and romance are linked to two entirely separate brain systems. Romance originates in parts of the brain that are rich in dopamine and that are involved in the motivation for rewards. This may explain why up to 40 percent of people rejected in love fall into a clinical depression. The study also may help to unravel some of the physiology behind stalking behavior.