Category Archives: WHY CORNER

Why Some Diets Work Better for Some People than Others


Ever notice some people seem to eat anything they want and never gain a pound, while others seem to gain weight just by looking at fattening foods? You may be seeing things correctly after all. According to research this may have a biological cause. Using fruit flies, researchers have found that genes interacting with diet, rather than diet alone, are the main cause of variation in metabolic traits, such as body weight. This helps explain why some diets work better for some people than ot…hers, and suggests that future diets should be tailored to an individual’s genes rather than to physical appearance.

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“There is no one-size-fits all solution to the diseases of obesity and type-2 diabetes,” said Laura K. Reed, the lead investigator in the work. “Each person has a unique set of genetic and environmental factors contributing to his or her metabolic health, and as a society, we should stop looking for a panacea and start accepting that this is a complex problem that may have a different solution for each individual.”

To make this discovery, the scientists studied 146 different genetic lines of fruit flies that were fed four different diets (nutritionally balanced, low calorie, high sugar, and high fat). Researchers then measured a variety of metabolic traits, including body weight, in each group. Flies in some of the genetic lines were highly sensitive to their diets, as reflected by changes in body weight, while flies of other lines showed no change in weight across diets. The scientists were able to ascertain what portion of the total variation in the metabolic traits was determined by genetics alone, by diet alone, or by the interaction between genotype and diet. Results showed that diet alone made a small contribution to the total variation, while genotype and genotype interactions with diet made very large contributions. This study strongly suggests that some individuals can achieve benefits from altering their dietary habits, while the same changes for others will have virtually no effect.

“The summer beach season often serves as a ‘gut check’ for many in terms of their weight,” said Mark Johnston, Editor-in-Chief of the journal Genetics. “This research explains why the one-size-fits-all approach offered by many diet programs can have dramatically different effects for people who try them.”

: Elements4Health


Why We Never Forget How to Ride a Bicycle

Ever wondered why we don’t forget how to ride a bike? Well, researchers from the University of Aberdeen claim to have found an answer to the  question.
Lead researcher Dr Peer Wulff has discovered a key nerve cell in the cerebellum section of the brain that controls skills such as riding a bicycle, skiing, or even eating with chopsticks, reports the Daily Express.

This nerve cell monitors electrical signals that leave the cerebellum and transform them for storage in other parts of the brain.

The “gatekeeper” cell helps brain to remember newly learnt coordination skills.

The researchers hope that the new discovery could pave way for creating artificial devices to mimic normal brain functions and benefit those who have suffered brain disorders.

Source: The Times Of India

Why Painkillers Relieve Men Faster

Does popping a painkiller provide faster relief to you than your wife?

Thank the middle section of your brain.

Scientists at Georgia State Universitys Neuroscience Institute and Center for Behavioral Neuroscience have for the first time identified the most likely reason why analgesic drug treatment is usually less potent in females than males.

“Opioid-based narcotics such as morphine are the most widely prescribed therapeutic agents for the alleviation of persistent pain. However, it is becoming increasingly clear that morphine is significantly less potent in women compared with men. Until now, the mechanism driving the phenomenon was unknown,” said Anne Murphy, who conducted the research with Dayna Loyd.

Scientists through animal studies have shown that the previously reported differences in morphine’s ability to block pain in male versus female rats are most likely due to sex differences in mu-opioid receptor expression in a region of the brain called the periaqueductal gray area (PAG).

Located in the midbrain area, the PAG plays a major role in the modulation of pain by housing a large population of mu-opioid receptor expressing neurons. Morphine and similar drugs bind to these mu-opioid receptors and ultimately tell the brain to stop responding to pain signals to the nerve cells resulting in the reduced sensation of pain.

The findings have been reported in the December issue of `The Journal of Neuroscience‘.

Scientists say the discovery is a major step toward finding more effective treatments for females suffering from persistent pain.

Reacting to the study, Dr Madhuri Bihari, head of department of neurology at AIIMS said: “There is a difference in reaction of analgesic drugs on male and female bodies even though it is slight. Pain reduces slightly more in men than women after popping a painkiller.”

“It was believed that it’s because of the faster metabolic rate among women. This study is, therefore, significant. How much it will help clinically is yet to be understood,” Dr Bihari said.

Using a series of anatomical and behavioural tests, Murphy and Loyd were able to determine that male rats have a significantly higher level of mu-opioid receptors in the PAG region of the brain compared with females.

This higher level of receptors is what makes morphine more potent in males because less drug is required to activate enough receptors to reduce the experience of pain.

Interestingly, when they used a plant-derived toxin to remove the mu-opioid receptor from the PAG, morphine no longer worked, suggesting that this brain region is required for opiate-mediated pain relief.

Additional tests also found females reacted differently to morphine depending on the stage of their estrous cycle.

Analgesic drug market in India has swelled over the years. Painkiller drug Voveran had emerged as the top brand in the domestic pharmaceutical market with the largest sales for the first seven months of 2007

Sources: The Times Of India

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Why Do Ants Work 24/7?

You think they are working 24 hours a day because you see them working at every wakeful hour. And all the workers look the same. But no one knows whether ants “sleep”. They don’t have eyelids, so they can’t close their eyes. But they do have periods of rest, where the brain and biological functions slow down and they stop moving. Though not well documented and possibly varying from species to species, it is generally accepted that most ants have periods of dormancy akin to sleep.

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As workers, ants have to respond to the colony needs. Ants seen foraging for food work from sunrise to sunset. Others inside the colony do other chores like tending to the queen and raising the larvae. The whole colony does not ‘sleep’ at the same time. They have “shifts” — one ant takes up the responsibilities, relieving another which can then tend to its own needs like sleep and feeding itself. Once inside for the night, ants reduce their activities. They fall in a sleep-like idleness with reduced biological functions. Each ant rests (a way of preserving resources) when necessary and “wakes up” when the colony needs it again, but the ants need time to get to normal functioning, resulting in a sluggish movement.

Sources: The Telegraph (Kolkata, India)

Why Large Amounts of Fruit May Not Be Healthy

fruit The editorial linked below appeared in the American Journal of Clinical Nutrition. It traces the rise in fructose consumption, and the rise in chronic diseases that have come in its wake.Fructose is a simple sugar found in honey, fruit, table sugar, and high-fructose corn syrup (HFCS). Because of the increase in the consumption of these sweeteners, fructose intake worldwide has quadrupled since the early 1900s.


Over the past three decades, there has been an even greater acceleration in consumption, in part because of the introduction of HFCS. The increase in fructose consumption parallels the rise in obesity, diabetes, hypertension, and kidney disease.

Studies in animals have shown that fructose can induce insulin resistance, elevated triglycerides, abdominal obesity, elevated blood pressure, inflammation, oxidative stress, endothelial dysfunction, microvascular disease, hyperuricemia, glomerular hypertension and renal injury, and fatty liver. The consumption of large amounts of dietary fructose also can rapidly induce insulin resistance.

Snoring Good for the Elderly

If you think that snoring is bad for your health, think again, for a study has suggested that the nocturnal snorts, whistles and wheezes can give you a long and healthy life, particularly if you are elderly.


Researchers in Israel have carried out the study and found that people aged over 65 years who suffer from a snoring -related condition, called sleep apnoea, tend to live longer than those who do not snore.

According to the researchers, this is because short bursts of hypoxia — interrupted breathing — actually have a protective effect on the elderly people by conditioning their cardiovascular system to cope with lack of oxygen.

This means that when oxygen supplies are cut off, as in a heart attack or stroke, the body is better able to cope, they said.

But the study has found that the effects of sleep apnoea do not have the same effect in younger people — in fact, middle-aged men in particular are at a higher risk of heart disease, the Daily Mail paper reported.

The researchers at Technion Institute have based their findings on an analysis of more than 600 elderly people over a period of four years — they found fewer heart-related deaths than in a control group of ‘healthy’ volunteers.

The findings of the study have been presented at a meeting of the European Association for Sleep Research in Glasgow.

Sources: The Times Of India

Why Do Leaves Fall Off Trees?

Ever wondered why leaves fall off trees in fall? Well, the secret actually lies in cellular mechanism, says a new study.

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Researchers have found that trees use an elaborate cellular mechanism to part company from their leaves, which act as “solar cells” in the summer but become superfluous in the darker winter months.

According to them, at the base of each leaf is a special layer called the abscission zone. When the time comes in autumn to shed a leaf, cells in this layer begin to swell, slowing the transport of nutrients between the tree and leaf.

And, once the abscission zone has been blocked, a tear line forms and moves downwards, until eventually the leaf is blown away or falls off – a protective layer seals the wound thereby preventing water evaporating and bugs getting in, ‘The Daily Telegraph‘ reported.

In fact, the discovery into how trees take on their winter aspect follows a study explaining the bright colours of autumn foliage.

And, in their new study, the researchers at Missouri University has revealed that the genetic pathway that controls abscission in the plant species Arabidopsis thaliana, a little weed that’s the favourite experimental subject of scientists.

According to them, a pathway of genes is involved in the process of abscission in Arabidopsis using a combination of molecular genetics and imagine techniques.

“Several different genes are involved in the process. Instead of looking at individual genes or proteins, we looked at an entire network at once to see how the difference genes work together in abscission,” lead researcher Prof John Walker was quoted as saying.

Sources: The findings are published in the ‘Proceedings of the National Academy of Sciences‘ journal.

Why do White Spots Appear on our Nails?


Small semi-circular white spots may be found on the fingernails or toenails.


These spots — called “leukonychia” — are a common occurrence, especially in children. More often than not, they simply are a sign of mild trauma to the nail. They may result from some past injury — like getting banged, stuck in a door or exercising in poorly fitting shoes — to the matrix (base) of the nail. The matrix is the part under the visi ble nail where the nail cells and the nail itself are produced. By the time the spots show up (about six weeks after the injury), you would have probably forgotten all about it.

According to some doctors, the appearance of the spots could also mean you have zinc deficiency. Others believe they are an indicator of calcium deficiency.

The spots can also be a sign of an allergic reaction to nail polish or nail hardeners and, sometimes, are a symptom of a mild infection.

Whatever the cause, they are temporary and will grow out as your nails grow. Never try to buff them off as this can lead to brittle nails. There’s no way to erase the spots.

Sources: The Telegraph (Kolkata, India)


Why Does the Skin Tan?

Go to any beach and you are sure to find sun worshipers baking their bodies in the sun, totally oblivious to the fact that the sunburns they acquire may develop into skin cancers 10 to 20 years later. In most parts of the world, tanning is considered to be the “in” thing, as opposed to the earlier times when pale skin was preferred. It was thought that the paler one’s skin the higher was the class, and men and women went to great (and sometimes unhealthy) lengths to be pale.

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Tans are natural shields against the sun’s ultraviolet (UV) radiation, which can damage skin tissue by causing sunburns as well as cancer in the long run.

Exposure to UV rays causes certain skin cells to produce the pigment melanin, which darkens through oxidation. Over exposure causes those cells to migrate closer to the skin’s surface and produce more melanin, further darkening the skin into a suntan. It’s no wonder then our bodies are equipped to produce melanin.

Melanin absorbs UV radiation and defends against further penetration of skin tissue. In other animals it proves diversely useful. It absorbs heat, an essential for cold-blooded creatures. It colours bird feathers, fish scales and squid ink, and helps to conceal nocturnal animals. Melanin even absorbs scattered light inside the eye to sharpen vision.

But it appears that only humans will risk their skins for a little extra skin pigment!

Sources: The Telegraph (Kolkata, India)

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Why is a Dog’s Nose Black and Wet?


Most dogs have black noses, not all. The noses of Vizslas and Weimaraners, for example, are closer to their coat colours. And it’s not unusual for puppies to start out with pink noses that darken as they mature.

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In all likelihood, dogs have developed black noses as a protection against sunburn. While the rest of the animal’s body is protected by fur, the noses are exposed to the sun’s rays. Pink-nosed dogs and breeds that are hairless or have very thin hair on their ears need to be protected with sunscreen when they go outdoors, or they risk the same sort of cancers and burns that humans do.

The canine nose — or nasal planum — is normally cool and moist, but not always wet. It has no sweat glands. The mucus lining causes the moisture. The evaporation of moisture from the nose helps to cool the dog. This moisture also makes the dog more sensitive to odours. Generally a happy dog continually licks his nose. When the dog isn’t feeling well, he tends not to lick his nose. And this makes the nose dry. But this is not a direct correlation. The brachycephalic breeds (bulldogs, Bostons, pugs, etc.) have noses set so high on their muzzles that they can’t reach them with their tongues and thus the noses tend to become cracked and dry on the top.

Sources: The Telegraph (Kolkata, India)