The Science of Appetite

Want to lose weight but can’t stop eating? There’s a reason for that.

Why teenagers really do need an extra hour in bed

The biology of human sleep timing, like that of other mammals, changes as we age. This has been shown in many studies. As puberty begins, bedtimes and waking times get later. This trend continues until 19.5 years in women and 21 in men. Then it reverses. At 55 we wake at about the time we woke prior to puberty. On average this is two hours earlier than adolescents. This means that for a teenager, a 7 am alarm call is the equivalent of a 5 am start for a person in their 50s.

Precisely why this is so is unclear but the shifts correlate with hormonal changes at puberty and the decline in those hormones as we age.

However, biology is only part of the problem. Additional factors include a more relaxed attitude to bedtimes by parents, a general disregard for the importance of sleep, and access to TVs, DVDs, PCs, gaming devices, cellphones and so on, all of which promote alertness and eat into time available for sleep.

The amount of sleep teenagers get varies between countries, geographic region and social class, but all studies show they are going to bed later and not getting as much sleep as they need because of early school starts.

Sleep is not a luxury or an indulgence but a fundamental biological need, enhancing creativity, productivity, mood and the ability to interact with others. Learn more here.

Not white noise, white smell

If you play sounds of many different frequencies at the same time, they combine to produce neutral “white noise.” Similarly, if you combine all the colours of the rainbow together it forms “white light”.

Neuroscientists say they have created an analogous generic scent by blending odors. Such “olfactory white” might rarely, if ever, be found in nature, but it could prove useful in research, other scientists say.

Using just a few hundred types of biochemical receptors, each of which respond to just a few odorants, the human nose can distinguish thousands of different odors. Yet humans can’t easily identify the individual components of a mixture, even when they can identify the odors alone. When various blends made up of a large number of odors all begin to smell the same—even when the blends share no common components.

Illustration of nose

Researchers have found that white noise is a useful stimulus in experiments to probe auditory responses and scientists probing the human sense of smell might find similar uses for olfactory white. Learn more here.

The Scientific Power of Naps

Want an excuse to sleep on the job? Take these scientific tips on “Power-Naps” to get the most energy out of your day, while remaining productive and non-reliant of caffeine. If done properly, naps can change your life!

Why else do we sneeze?

Sure, they blast out germs and other unwanted intruders, but sneezes have another, just discovered purpose, a new study says.

When we breathe in foreign particles, sensors in our noses and sinuses detect the objects. The sensors signal the cilia—tiny, hairlike paddles that line our nostrils and sinuses—to move to expel the irritants.

This process is always idling at first gear with the cilia ready to spring into action when needed.

The study found that the burst of air produced by a sneeze not only clears nasal passages but also triggers the cilia sensors to kick the paddles into high gear for an extended period—about a couple minutes.

In that sense, a sneeze works by resetting the system—like Control-Alt-Delete on a PC.

The study highlights what an underestimated organ the nose is, especially in terms of keeping us healthy. Learn more here.

Happy Valentine’s Day

We call it love. But the most exhilarating of all human emotions is probably nature’s beautiful way of keeping the human species alive and reproducing. That’s right, it can all be explained by science!

Psychologists have shown it takes between 90 seconds and 4 minutes to decide if you like someone. And research has shown this has little to do with what is said, rather:

• 55% is through body language
• 38% is the tone and speed of their voice
• Only 7% is through what they say

Next comes love and the 3 stages of love are lust, attraction and attachment.

Stage 1: Lust

This is the first stage of love and is driven by the sex hormonestestosterone and oestrogen – in both men and women.

Stage 2: Attraction

This is the amazing time when you are truly love-struck and can think of little else. Scientists think that three main neurotransmitters are involved in this stage; adrenaline, dopamine and serotonin. For example, adrenaline has the charming effect that when you unexpectedly bump into your new love, you start to sweat, your heart races and your mouth goes dry.

Stage 3: Attachment

Attachment is the bond that keeps couples together long enough for them to have and raise children. Scientists think there might be two major hormones involved in this feeling of attachment; oxytocin and vasopressin.

So there you go, it’s all about hormones and neurotransmitters.

But finally, if you are wondering how to fall in love, it’s simple just:

• Find a complete stranger.
• Reveal to each other intimate details about your lives for half an hour.
• Then, stare deeply into each other’s eyes without talking for four minutes.

A psychologist asked some subjects to carry out the above 3 steps and found that many of his couples felt deeply attracted after the 34 minute experiment. Two of his subjects later got married! Read lots more here or here and watch a video here.

Oh, and Happy Valentine’s Day!

Eat this

Fuelling your body is easy. Just load your plate with foods that are proven to make you stronger and healthier, eat, and repeat. Repeating this spartan meal will help you outperform and ultimately outlive others.

1. Eating whole grains has been associated with lower risk of heart disease and diabetes.
2. Salmon’s omega-3 fatty acids work to build the brain’s cell membranes, lower blood pressure, and improve circulatory function.
3. Berries are a tasty vitamin-delivery system, providing A, C, and E, along with folate, which is important for cellular metabolism and renewal. Cantaloupe contains potassium, which is crucial in keeping the heart, muscles, nerves, and digestive system working.
4. Vegetables lower blood pressure, slash heart disease risk, and help ward off stroke and cancer.
5. A glass of water before dinner will help you eat less, and drinking enough water overall aids digestion, gets nutrients efficiently to your body’s cells, and protects your organs and tissues.

Learn more here.

Using Marijuana Makes You Dumber

Marijuana is the world’s most widely used illicit drug. But smoke too many joints too soon, and you might lose IQ points: A new study suggests extensive marijuana use starting as a teenager could lead to cognitive decline.

In a study of 1,037 New Zealanders followed from birth to age 38, people who began using marijuana as adolescents and used it extensively for years saw their IQs drop by about eight points. What’s more, among adolescent-onset users, quitting the drug did not reverse the mental deficits.

Marijuana is not harmless, and particularly not for adolescents. To get a sense of how significant a decline of eight IQ points is, consider this: Having an average IQ of 100 puts you in the 50th percentile for intelligence, whereas an IQ of 92 slides you down to the 29th percentile. Learn more here, here or here.

Why We Sunburn

For the first time, science has illuminated why our skin reddens and stings when we get too much sunshine.

Though sunburn is a common experience for human beings, there’s surprisingly little information on how energy in sunlight is detected in the body as a source of danger.

Now scientists have identified the chemical culprit that triggers our skin’s warning signs. A type of RNA, they found, breaks into pieces within a dead cell done in by ultraviolet sunlight.

Next, so-called receptor molecules in neighboring cells detects the damaged RNA and “tell” the body to inflame the healthy skin around the dead cell—and voilà: sunburn. Learn more here.

Sleep to stay thin and be happy

Scientists have repeatedly shown that there’s a link between sleep deprivation and obesity. When you cut back on sleep, your body produces less leptin, a hormone that helps regulate appetite and metabolism, and more ghrelin, a hormone that stimulates hunger. Scientists studied how sleep affects activity in the brain’s frontal lobe, which controls behavior, and found that lack of sleep impairs our capacity to evaluate which foods are best for us.

But weight control isn’t the only reason to get a full night’s rest. Researchers have consistently found that getting enough sleep is correlated with feeling happier. A study determined that earning $60,000 more a year has less effect on daily happiness than getting just one additional hour of sleep each night. Learn more here.