Q: Does laser hair removal work?
A: Yes. Lasers effectively remove hair, but multiple treatments are required for permanent loss. The process targets melanin-the dark pigment that gives colour to hair and skin. Melanin absorbs the laser energy, and the heat disables the 50 to 85 percent of nearby hair follicles in their active growth phase. The darker the hair, the more light absorbed, and the more zapped follicles. People with fair skin and dark hair get the best results.
Q: Does wearing briefs lower men’s sperm count?
A: No. For years, researchers have speculated that wearing briefs (which fit more snugly than airier boxers) overheats the scrotum, causing a dramatic drop in sperm count. But while several studies show that semen quality and fertility can be affected by excessive heat from, say, hot tubs, there is actually no evidence to suggest that wearing briefs will render men sterile.
Q: Is sugar addictive?
A: Maybe. Some studies have suggested that sweets and addictive drugs cause similar changes in the brain that can lead to dependence. Cocaine, for example, increases levels of dopamine, a brain chemical that seems to play a role in producing sensations of pleasure. A Princeton University study showed that laboratory rats allowed to binge on sugar water also produced large amounts of dopamine. When deprived of sugar, the rats developed withdrawal symptoms such as trembling. But more work is needed to understand whether the same happens in humans.