You might like things hot and steamy—but your swimmers don't. That post-gym trip to the sauna may be frying your sperm, finds new research in the journal Human Reproduction.
Men who spent 15 minutes in a sauna twice a week for 3 months saw an immediate drop in their sperm count after every sauna session, and levels didn't return to normal until after 6 months.
In order to produce healthy sperm, your testicles need to be kept at a temperature that’s about 2 degrees less than your core temp (98.6 degrees Fahrenheit), which is why they hang down away from your body. But any conditions that chronically increase their temperature have a negative effect on sperm production, says study author Andrea Garolla, M.D., of the University of Padova in Italy.
While sauna time didn't affect men's sperm long-term, the researcher still advise against it—along with prolonged exposure to other heat sources that could fry your fluids, like a hot tub or even your laptop. Meanwhile, here's a tip to strengthen your swimmers: Eating just 75 grams of walnuts a day—roughly a handful—can improve the quality of your semen, according to a 2012 report in Biology of Reproduction.
Clear your head before happy hour. Stress kills men’s self-control—and could make you drink more, suggests a new study from the Netherlands.
Scientists asked two groups of men and women to perform a task before drinking alcohol. One was a brain-buster meant to tax the subjects’ minds, mimicking a tough day at work. Guys who took that test not only guzzled more booze than men who performed the easier exercise, they drank four times more than women who completed the hard task.
Why? Self-control is like a glass of water, says study author Roy Otten, Ph.D. Challenging work projects drain your glass throughout the day, so when 5 p.m. rolls around, chances are that it’s pretty empty. And that lack of self-control makes your other glasses empty quicker—and more frequently—at the bar.
Women don’t have the same problem because their metabolisms work differently, Otten says. Ladies may naturally go into awareness mode when their self-control supply is depleted, so they drink less.
So how can you leave happy hour without seeing double? In a second experiment, researchers asked half the participants to track how many drinks they knocked back. Guys who kept tabs drank significantly less than those who didn’t. Otten says being more aware of your choices, even when you’re low on self-control, makes you evaluate those choices more closely.
Another tip: Avoid opening a tab, leave your credit card in the car, and walk into the bar with $20 in your pocket. Once the cash is gone, it’s time to go.
Give your pearly whites a workout to avoid the dentist. Food that’s tough to chomp on could strengthen your teeth, according to a new German study.
In fact, a lack of tooth wear (caused by eating soft foods too often) could actually deteriorate your teeth’s enamel, the researchers say.
According to the scientists, when you munch on foods that require a bit more work, you’re actually minimizing the load on your teeth. Tougher grub works like sandpaper, smoothing out the ridges of each tooth. The reason: Worn surfaces are flatter, so the chewing force is distributed more evenly, meaning it doesn't directly irritate the cusps, says lead study author Stefano Benazzi, Ph.D.
But not every tough-textured food is good for your teeth. Here’s a guide of what’s worth chewing—and where to be careful.
The verdict: Go for it. Eating carrots, celery, and even lettuce gives your teeth a chance to grind without the danger of splitting a molar. Unlike harder nuts, chewing on these fibrous textures provides resistance, but in a gentler way, says George C. Williams, D.D.S., associate professor at the University of Maryland School of Dentistry.
The verdict: Go for it. According to the American Dental Association, the phosphorus in red meat helps protect tooth enamel and bone. Unless you channel a hungry caveman at the dinner table, each slice of your sirloin deserves a good chew. “When you’re opening and closing your mouth, your teeth and gums are getting exercise,” says Dr. Williams. “If you don’t eat challenging foods your mouth won’t be strong.”
The verdict: Chew with caution. This relatively healthy snack can be devastating to enamel because you’re subjecting your teeth to sticky sugar. Plus, the bacteria responsible for breaking down the sugar emit an acidic byproduct that causes decay. “Post-snack, try to rinse with Listerine to reduce the amount of bacteria in your mouth,” Dr. Williams says. “At the very least, swish with water.”
The verdict: Chew with caution. Enamel may be the hardest substance in the body, but ironically it’s quite brittle. Coincidentally, your tooth enamel has similar structure to an ice cube. When you drop the ice on the floor, it might not crack, but it will acquire micro fractures. “Chewing something very hard, such as an almond, can eventually turn these fissures into problems that can lead to a root canal,” adds Williams.
thick rice noodles, BBQ pork, Asian pork sausages, mixed fresh vegetables in chilli sauce and oyster sauce