A novel form of vitamin B3 found in milk in small quantities produces remarkable health benefits in mice when high doses are administered, a new study has shown.

The findings revealed that high doses of the vitamin precursor, nicotinamide riboside (NR) - a cousin of niacin - prevent obesity in mice that are fed a fatty diet, and also increase muscle performance, improve energy expenditure and prevent diabetes development, all without side effects.

Researchers at Weill Cornell Medical College and the Polytechnic School in Lausanne, Switzerland conducted the study.

The Swiss researchers, led by Dr. Johan Auwerx, performed the mouse experiments, while the ability to give the animals sufficient doses of NR was made possible by Weill Cornell Medical College researchers, who played key roles in uncovering the biological story of NR.

"This study is very important. It shows that in animals, the use of NR offers the health benefits of a low-calorie diet and exercise - without doing either one," said Dr. Anthony Sauve, associate professor of Pharmacology at Weill Cornell Medical College.

Dr. Sauve is the pharmacologist and organic chemist who has invented a simple method for efficiently synthesizing NR in large scale. He was first to show that NR increases nicotinamide adenine dinucleotide (NAD) levels in mammalian cells. NAD is a central player in energy metabolism. He has pioneered research into the compound, and he is a leader in investigating how NAD can signal adaptation in cells and in physiology.

"The research also suggests that the effects of NR could be even broader," Dr. Sauve stated.

"The bottom line is that NR improves the function of mitochondria, the cell's energy factories. Mitochondrial decline is the hallmark of many diseases associated with aging, such as cancer and neurodegeneration, and NR supplementation boosts mitochondrial functioning," he explained.

The Swiss researchers call NR a "hidden vitamin" that is believed to also be present in many other foods, although levels are low and difficult to measure. Nevertheless, the effects of NR on metabolism "are nothing short of astonishing."

While the new study demonstrates that high doses of NR can largely prevent the negative health consequences of a poor diet in mice, Dr. Sauve stresses that the effects of high doses of the vitamin in humans have not been evaluated.

"It is important to keep in mind that the amount of NR in milk and other foods appears to be small. We don't know what effects NR would have in humans at relatively high doses," he said.

"Still, we have very encouraging evidence of benefits of NR and NAD augmentation in general from this animal study - and much more work to do," he added.

The finding was recently reported in the June 2012 issue of the journal, Cell Metabolism. (ANI)

There's no shortage of reasons that many Americans don't get enough sleep: stress, obesity, late-night shifts on the job, to name just a few. Now new research suggests another factor to consider as well their race or ethnicity.

In two presentations at the annual meeting of the Associated Professional Sleep Societies in Boston, scientists report that the amount and quality of sleep people get each night vary across racial and ethnic lines. In one study, researchers found that blacks and Asians don't sleep as much as whites do, while another study showed that foreign-born Americans are less likely to report having sleep problems than those born in the U.S.

A better understanding of these discrepancies could help researchers improve the sleep habits of particular groups a potential public-health boon, considering that inadequate sleep is increasingly associated with greater risks of chronic conditions like heart disease, diabetes, obesity and certain cancers.

For the first study, led by Mercedes Carnethon, an associate professor of preventive medicine at Northwestern University, researchers randomly selected 439 Chicago-area adults from the phone book to participate. The volunteers, aged 35 to 64, were of white, black, Hispanic or Asian descent. Researchers screened the participants for sleep disorders like sleep apnea, and then asked them to wear a wrist monitor that detected their movements and determined how much time they spent sleeping over a period of seven days. The participants also self-reported the amount and quality of sleep they got each night.

Overall, the researchers found, blacks, Hispanics and Asians slept less than whites. Blacks got 6.8 hours of sleep a night on average, compared with 6.9 hours for Hispanics and Asians, and 7.4 hours a night for whites. The differences in sleep times persisted even after the researchers adjusted for other factors known to interfere with sleep, such as weight, diabetes status, high blood pressure and other heart disease risk factors. The study authors also accounted for socioeconomic factors like low education and low income, both of which can increase stress and disrupt sleep.

Interestingly, despite the fact that every racial group got less sleep than whites, only blacks reported suffering poor sleep quality and only Asians reported significant levels of daytime sleepiness. The latter finding was particularly surprising, since Asians tended to have lower body mass indexes and higher or equal education levels as whites, but still showed shorter and poorer sleep. "It's one of our more compelling and interesting findings, and one we intend to explore in depth further," says Carnethon, who notes that there's very little data on the sleep habits of Asians.

The authors surmise that the majority of the differences in sleep patterns between races can be chalked up to environmental or even geographical factors rather than genes or physical characteristics like variations in facial structure that could interfere with breathing and sleep. For example, Carnethon notes that Chicago is a relatively segregated city, and blacks and Hispanics tend to live in areas with higher pollution, more mass transit noise and higher crimes rates than predominantly white neighborhoods, which can lead to stress and disturbed sleeping. "I think social factors are more likely to account for the race and ethnic differences we observed," she says.

In the other paper, presented by Dr. Abhishek Pandey of SUNY Downstate Medical Center, scientists compared nightly sleep duration between foreign-born Americans and those who were born in the U.S. Based on phone survey data collected on 434,849 participants in the National Health Interview Survey in 2004-10, the researchers found that U.S.-born residents were more likely to report longer sleep more than eight hours a night on average while African-born Americans reported the least, less than six hours a night. Indian-born Americans fell in between, getting six to eight hours of sleep on average per night. The differences held even after the researchers adjusted for factors that can affect sleep duration, such as weight, age, and health risk behaviors such as smoking and drinking alcohol.

But despite their shorter sleep, foreign-born Americans were 20% less likely to report getting insufficient sleep than their native-born counterparts. While the study wasn't designed to determine why a person's country of birth might have such a strong effect on their sleep patterns, Pandey says that cultural beliefs and attitudes about sleep may influence how people view the importance of getting enough nightly slumber. In a previous study of Afro-Caribbean men in Brooklyn, for example, Pandey says that about 60% reported short sleep, but weren't aware of the health effects of sleep deprivation.

Taken together, the findings suggest that when it comes to sleep, a individual's racial or ethnic heritage may not only help explain his or her sleep patterns, but also encourage certain groups to sleep longer by addressing culturally based misperceptions about healthy sleep. In the U.S., racial ancestry has a lot to do with how we live our lives whether we're awake or asleep.

According to World Health Organisation experts the answer is a resounding 'Yes'.

Diesel engine exhaust fumes can cause cancer and belong in the same potentially dangerous category as asbestos, arsenic and mustard gas, said WHO experts.

France-based International Agency for Research on Cancer (IARC), part of the WHO, reclassified diesel exhausts from its group 2A of probable carcinogens to its group 1 of substances that have definite links to cancer. The experts claimed their decision was unanimous and based on compelling scientific evidence. They urged people across the world to reduce exposure to diesel fumes as much as possible.

"The (expert) working group found that diesel exhaust is a cause of lung cancer and also noted a positive association with an increased risk of bladder cancer," it said in a statement.

The decision to reclassify diesel wasn't taken lightly and is the result of a week-long meeting of experts who analysed the latest scientific evidence on the carcinogenic potential of diesel and gasoline exhausts. It puts diesel fumes in the same risk category as noxious substances such as asbestos, arsenic, mustard gas, alcohol and tobacco.

Christopher Portier, chairman of the IARC working group, said the group's conclusion "was unanimous, that diesel engine exhaust causes lung cancer in humans". "Given the additional health impacts from diesel particulates, exposure to this mixture of chemicals should be reduced worldwide," he said in a statement.

These findings are ever more relevant in India where the petrol prices are skyrocketing compared to diesel and most auto-manufacturers come out with diesel versions of cars. Outside of Europe and India, diesel engines are almost entirely confined to commercial vehicles. German carmakers are trying to raise awareness for diesels in the United States, where the long distances travelled on highways suit diesel engines.

IARC noted that large populations all over the world are exposed to diesel exhaust in everyday life, whether through their jobs or in ambient air. "People are exposed not only to motor vehicle exhausts but also to exhausts from other diesel engines (such as diesel trains and ships) and from power generators," it said. IARC's director Christopher Wild said that against this background, Tuesday's conclusion "sends a strong signal that public health action is warranted".

"This emphasis is needed globally, including among the more vulnerable populations in developing countries where new technology and protective measures may otherwise take many years to be adopted," he said in a statement.

For the last two decades diesel engine exhaust was classified as possibly carcinogenic to humans 0 group 2A but an IARC advisory group has constantly recommended diesel's status be re-evaluated since 1998.

The global auto industry, on the other hand, had argued diesel fumes should be given a less high-risk rating to reflect tighter emissions standards.

Reacting to the decision, Allen Schaeffer, executive director of the Washington-based Diesel Technology Forum said diesel engine and equipment makers, fuel refiners and emissions control technology makers have invested billions of dollars in research into technologies and strategies to reduce emissions.

"New technology diesel engines, which use ultra-low sulphur diesel fuel, advanced engines and emissions control systems, are near zero emissions for nitrogen oxides, hydrocarbons and particulate matter," he said in a statement. A spokeswoman for the European Automobile Manufacturers' Association said she was surprised by the move and the industry would "have to study the findings in all their details". "These technologies have been developed to address precisely these concerns," Sigrid de Vries told Reuters. "The latest diesel technology is really very clean."

After the IARC report was issued, General Motors Co, said in a statement: "We will continue with our plans to introduce new fuel saving technologies and engines that run on alternate fuels, including diesel."

GM said diesel engines being made today have lower sulphur content and emit much less particulate matter than engines from a few years ago.

However, experts feel the findings will have little impact on auto-companies and won't force them to change plans their plans for expanding diesel fuel automobiles in the United States. About 5.5 percent of new autos, including light-duty pickup trucks, sold in the United States run on diesel, said Baum, and he said that figure is expected to rise to 8 or 9 percent by 2015. IARC said it had considered recent advances in technology which had cut levels of particulates and chemicals in exhaust fumes, particularly in developed economies, but said it was not yet clear how these might translate into health effects.

"Research into this question is needed," it said. "In addition, existing fuels and vehicles without these modifications will take many years to be replaced, particularly in less developed countries, where regulatory measures are currently also less stringent." IARC also said gasoline exhaust fumes should be classified as "probably carcinogenic to humans", a finding that was unchanged from its previous assessment in 1989.

US researchers have found a way to calm the fears of anxious mice with the help of a drug that alters their brain chemistry.

They have also found that human genetic differences related to the same brain chemistry influence the capacity of people to deal with fear and stress.

The research team claims that it's an advance in understanding the brain's fear circuitry and may hold particular promise for people at risk for anxiety disorders, including those who are suffering post-traumatic stress disorder (PTSD).

"What is most compelling is our ability to translate first from mice to human neurobiology and then all the way out to human behavior," Ahmad Hariri, a neurobiologist at the Duke Institute for Genome Sciences and Policy, said.

"That kind of translation is going to define the future of psychiatry and neuroscience."

The common thread in their studies is a gene, which encodes the enzyme called fatty acid amide hydrolase, or FAAH.

This enzyme breaks down a natural 'endocannabinoid' chemical in the brain that acts in basically the same way that Cannabis, aka marijuana, does.

Earlier studies had suggested that blocking the FAAH enzyme could decrease fear and anxiety by increasing 'endocannabinoid's.

In 2009, Hariri's lab found that a common variant in the human FAAH gene leads to decreased enzyme function with influence on the brain's circuitry for processing fear and anxiety.

In the new study, Andrew Holmes' group at the National Institute on Alcoholism and Alcohol Abuse tested the effects of a drug that blocks FAAH activity in fear-prone mice that had were trained to be fearful through experiences in which they were delivered foot shocks.

Tests for the ability of those mice to overcome their bad experiences found that the drug allowed a faster recovery from fear thanks to higher brain 'endocannabinoid' levels.

More particularly, the researchers showed that the drug effects traced to the amygdala, a small area of the brain that serves as a critical hub for fear processing and learning.

To test for the human relevance of the findings, Hariri's group went back to the genetic variant they had studied before in a group of middle-aged adults.

They showed the study participants a series of photographes , depicting threatening faces while they monitored the activity of their amygdalas using functional magnetic resonance imaging (fMRI) scans. They then looked for how the genetic variant had affected this activity.

While the activity of the amygdala in all participants went down over repeated exposures to the pictures, people who carried the version of the FAAH gene associated with lower enzyme function and higher 'endocannabinoid' levels showed a greater decrease in activity.

Hariri revealed that those people might be better able to control and regulate their fear response.

Further confirmation came from an analysis that is led by Duke's Avshalom Caspi and Terrie Moffitt of 1,000 individuals in the Dunedin Study, who have been under careful observation since their birth in 1970s in New Zealand.

Consistent with the mouse and brain imaging studies, the New Zealanders who carried the lower-expressing version of the FAAH gene were found more likely to keep their cool under stress.

"This study in mice reveals how a drug that boosts one of the brain's naturally occurring endocannaboids enables fear extinction, a process that forms the basis of exposure therapy for PTSD," Holmes said.

"It also shows how human gene variation in the same chemical pathways modulates the amygdala's processing of threats and predicts how well people cope with stress," he added.

Past a certain age, blowing out the birthday candles can bring more dread than cheer.

But the passing of another year may be the least of our problems, according to scientists who found we are statistically more likely to die on our birthday than any other day.

From a study of more than two million people, researchers say the 'birthday blues' bring a rise in deaths from heart attacks, strokes, falls, suicides and even cancer.

On average, people over the age of 60 were 14 per cent more likely to die on their birthdays.
The findings from a study over a 40-year period in Switzerland back up the idea that 'birthday stress' has a major effect on our lifespan.

Most of the rise was accounted for by heart attacks, which rose 18.6 per cent on birthdays and were significantly higher for men and women.
Levels of strokes were up 21.5 per cent mostly in women and there was a surprisingly large increase in cancer deaths in both sexes of 10.5 per cent.

Dr Vladeta Ajdacic-Gross, a senior researcher in psychiatry at the University of Zurich, said: 'Birthdays end lethally more frequently than might be expected.'

He added that elderly people may feel particularly exposed to stress on birthdays.

The risk of birthday death rose as people got older.

This is backed up by other data on hospital admission taken in Canada showing that strokes were more likely to occur on birthdays than other days, especially among patients with a history of high blood pressure.

There was no significant increase in birthday deaths for the under-60s in the official mortality records from between 1969 and 2008.

A significant rise in suicides and accidental deaths for the over-60s on birthdays was found only in men.

There was a 34.9 per cent rise in suicides, 28.5 per cent rise in accidental deaths not related to cars, and a 44 per cent rise in deaths from falls on birthdays, with the risk increasing for about four days before the big day.

It was previously thought that people would be more likely to die in the days after their birthday as the thought of reaching the milestone would help them cling on for longer.

But the researchers said this theory was disproved by their findings, and they support the 'anniversary reaction' theory also known as the birthday blues.

Dr Lewis Halsey, a senior lecturer in environmental physiology at the University of Roehampton, said: 'One interesting finding is that more suicides happen on birthdays, though only in men.

'The authors suggest that this increase could be related to them drinking more alcohol on birthdays.

'But perhaps men are more likely to make a statement about their unhappiness when they think people will be taking more notice of them.

'Or perhaps women feel that it is unfair on others who might be celebrating with them to put them through dealing with suicide.'

Ingrid Bergman died of breast cancer on her 67th birthday in 1982.

William Shakespeare is also reported to have died on his 52nd birthday in 1616 of unknown causes.

The study is published in the journal Annals of Epidemiology.