How many times will you see your parents before they die?

It's a question many people don't want to face. Logically, we know our moms and dads will die someday. Yet the idea that they will be gone one day is easy to ignore. "See Your Folks" is a disturbing yet enlightening website that puts this question front and center. By answering a few simple questions, it can predict how many more times you might see your parents before they die.

"We're so busy growing up we sometimes forget that they are also growing old," the site says.

The predictions are not random and have no elements of mysticism. They simply draw on life expectancy data from the World Health Organization. By answering four basic questions — "Where do your parents live?" "How old is your mum? "How old is your dad?" "On average how many times do you see your parents a year?" — the site will estimate the number of times you'll see your parents before they are likely to die.

It took mere seconds to learn that I will probably see my parents, who are in their 60s and live in New Jersey, 138 more times. (And given our current rate of visits, my younger sister and I will see each other 1,225 more times before I die.)

What to do with this information? Well, for some of us it will inspire a weepy call to our parents and a plan for more frequent visits home.

For others, the exercise may be little more than a gentle reminder that mortality is not an abstract idea. Acknowledging its inevitability can help us "make the most of our lives," say the site's creators — whether or not that involves seeing our parents more often. "The right kind of reminders can help us to focus on what matters, and perhaps make us better people."

Maggie Fazeli Fard • Washington post

spending time in great outdoors may reset our internal clocks

Our internal clocks are drifting out of sync, and indoor lighting may be to blame. A new study suggests that just a few days in the great outdoors puts us back in tune with the solar cycle, and reconnecting with the sun could make us less drowsy.

Electricity has given us the freedom to choose our bedtimes; staying up after dark is as easy as flipping a light switch. But we pay a price for this luxury, says integrative physiologist Kenneth Wright, of the University of Colorado, who led the new study. People with later bedtimes and wake times are exposed to more artificial light and less sunlight, he says, which means their bodies aren't getting the natural cues humans once relied on.

To understand how falling out of sync with the sun changes our body's internal clock — or circadian rhythm — sleep researchers look to the timekeeping mechanisms in the brain, particularly how we regulate the hormone melatonin. Released about two hours before sleep, melatonin makes us feel drowsy as we wind down for rest, Wright says. It then decreases as we become alert in the morning. The mechanisms driving our clock are complex and hard to measure, but the daily spike and drop in melatonin are like its chimes. "Melatonin tells us what time it is in the body," Wright says.

And when we keep strange schedules, our melatonin goes haywire. Turning lights on at night can delay melatonin release and shift the timing of our internal clock, says sleep physiologist Derk-Jan Dijk, of the University of Surrey in England, who was not involved in the work. But it wasn't clear just what would happen in modern, electricity-adapted humans if all artificial light were suddenly taken away. "This is the first time that somebody has done the obvious but important experiment," he says.

"When we expose ourselves to only natural light, we are in sync with that light-dark cycle quite strongly," Wright says.

The natural night owls in his study saw an especially dramatic shift in their melatonin cycle and became more similar to the early birds. The team suggests that artificial light had been exerting a particularly strong influence on the internal clocks of the night owls. The subjects weren't asked to report whether they felt less drowsy after the change in lighting.

Because we're not going to abandon our electrified existence anytime soon, Wright says that certain habits can counteract our estrangement from the sun. He recommends letting plenty of light into your room in the morning, exposing yourself to more natural light throughout the day, and dimming the lighting in your home a couple hours before bed.

sciencenow

even moderate levels of Sugar may be toxic to health, sex life

Sugar, even at moderate levels, could be toxic to your health — or at least to your sex life.

Scientists at the University of Utah looked at how sugar affected mice and found that the mouse equivalent of just three sugary sodas a day had significant negative effects on life span and competition for mates. "That's three sodas if the rest of your diet is pristine and sugar-free," said lead author and biologist James S. Ruff. "And those are 12-ounce sodas, not double Big Gulps."

Sugar-fed females died twice as quickly as control mice, which were fed the same number of calories. And sugar-fed males had trouble competing against the control males for mates. The study was published online by the journal Nature Communications.

For the rodents on the sweetened diet, sugar accounted for 25 percent of their total calorie intake. Up to a quarter of Americans consume that proportion of sugar as part of their diets. Previous studies that found harmful effects of sugar consumption tended to use unusually high amounts.

Potts and his team found that the sugar-fed rodents, which didn't appear less healthy than the control animals, were "physiologically worse at doing things they need to do on a daily basis."

Sugar-fed females — but not males — died off sooner than their healthier counterparts, possibly from being too worn out to handle the burdens of reproduction. For the sugar-fed males, meanwhile, reproductive efforts were hindered by their inability to hold down territory. A male mouse will typically control a designated area, defending it fiercely from short, intrusive forays by other males. A weakened male mouse will lose territory, along with female attention.

Washington post