Sleep deprivation associated with food desire and food purchasing

Sleep deprivation significantly decreases activity in appetitive evaluation regions within the human brain and increases food purchasing the next day.

Sleep deprivation has been shown to reduce activity in appetitive evaluation regions within the human frontal cortex and insular cortex during food desirability choices. Functional magnetic resonance imaging (fMRI) was used to scan the brain of 23 healthy volunteers following both a normal night's sleep and a sleepless night. Activity in the frontal lobe, the region responsible for complex decision making, was impaired in the sleep-deprived brain while increased activity was observed in deeper brain centers which respond to rewards. Participants desired more high-calorie foods when they were sleep deprived. The findings suggest a brain mechanism by which sleep deprivation may influence the development of obesity.

Acute sleep deprivation has also been reported to increase food purchasing the following day. Sleep deprivation was associated with an increase in plasma ghrelin concentrations, a hormone responsible for increasing hunger, in 14 healthy volunteers. Sleep deprived individuals purchased significantly more calories and grams of food than they did after one night of sleep. The study suggests that acute sleep loss may influence food purchasing behavior.

Intelligent Eating Eggs: Science, Fiction, Or Yolklore?

It has previously been reported that omega-3 fatty acids lower the risk of cardiovascular disease, reduce triglyceride levels and lower blood pressure as well as delay the onset of dementia.

The effects of dietary intervention using eggs enriched with omega-3 fatty acids on plasma lipid concentrations, blood pressure and memory recall were determined in 8 healthy adult male and female participants.

Volunteers consumed three standard eggs per day in addition to their normal diet for the first 7 day test period followed by a 7 day washout period. The same group of volunteers then consumed three omega-3 eggs per day in addition to their normal diet for a further 7 day test period. Measurements were taken at baseline and periodically up to 11 days following commencement of each dietary regime.

Results analysis determined that mean plasma total cholesterol and LDL-cholesterol concentration was significantly increased by consumption of standard eggs (P<0.05) but significantly reduced (P<0.05) by consumption of omega-3 enriched eggs. Mean HDL-cholesterol concentration was unchanged by standard eggs but decreased significantly (P<0.05) by omega-3 eggs. No significant effect on plasma triglycerides was observed with consumption of either type of egg.

Both systolic and diastolic pressure was unchanged by intervention with either egg regime. There was a slight increase in memory recall test scores following consumption of both standard and omega-3 eggs. The increase however, was not statistically significant (P>0.05).

Inclusion of dietary omega-3 eggs may offer some health benefits, however the decrease in HDL cholesterol observed suggests the effects may also be detrimental to health.

Introducing disease-blocking bacteria into mosquitoes

A new technique of introducing a disease-blocking bacteria into mosquitoes has been announced.

Diseases such as dengue fever, yellow fever and malaria, all spread by mosquitoes, may be prevented by the introduction of the disease-blocking bacteria Wolbachia, into the mosquito.

When mosquitoes are infected with the strain of bacteria called wMelPop, they are unable to transmit viruses such as dengue fever which currently has no vaccination and is responsible for up to 40 000 deaths each year. It is difficult however, for the bacteria to spread among the mosquito population as it significantly reduces the ability of the mosquito to lay viable eggs. A suggested method to speed up the transmission of the bacteria involves introducing an insecticide resistance gene alongside Wolbachia into the mosquito. As insecticides are common in malaria and dengue-prone areas, this approach would allow survival of only Wolbachia infected mosquitoes and therefore prevent the transmission of viruses to humans.

This could be a major step forward in the disease control programme with a reduced rate of spread due to less infected mosquitoes.

Potential treatment for vitiligo skin disorder

There is now new hope for an effective treatment for the skin disorder vitiligo. 

Vitiligo is an autoimmune disorder defined by the destruction of melanocytes, the pigment cells responsible for giving skin its colour, which causes the progressive depigmentation of the skin associated with the disease. The current treatment options remain ineffective and provide little efficacy. The emergence of a new modified protein however, has given hope to the 1 in 200 people worldwide affected by the condition.

Researchers at the Loyola University Chicago Stritch School of Medicine have developed a modified protein which reverses the skin disorder in mice, with similar results in human skin tissue samples.

The protein HSP70i (inducible heat shock protein 70) has been previously shown to influence the autoimmune response in vitiligo. The protein, made of a number of amino acids, was altered by genetically modifying the amino acids which in turn replaces normal HSP70i and thereby reversing the autoimmune response. When applied to mice, the fur which was affected by vitiligo turned back to its normal colour. Similar effects were observed in human skin samples.

As none of the current treatment options, which include steroid creams and skin grafts  are successful in preventing vitiligo, this breakthrough research is a ray of hope for patients. A patent for the protein has been applied for, while researchers hope to enter the treatment option into human clinical trials.

Sleep loss can affect gene activity

It is well documented that individuals who do not get enough sleep are likely to experience a range of health problems. However, why this occurs at a molecular level has yet to be understood.

A study carried out by Möller-Levet et al at the University of Surrey investigated the affect of sleep on gene activity. When volunteers who were allowed just under 6 hours sleep per night were compared with those who slept for 8 or more hours each night, a change in activity of 711 of their genes were recorded. Among the genes affected were those linked with circadian rhythms, sleep homoeostasis, oxidative stress, and metabolism. It was concluded that lack of sleep can radically change the body's daily rhythms and may lead to health problems.

Dying stars may host planets with extra-terrestrial life

NASA/ESA Hubble Space Telescope image showing the glowing remains of a dying star 

with a white dwarf at its centre

A new theoretical study has led to evidence that life may be present in habitable, earth-like planets which form as a result of dying stars. Astronomers believe that scientists may be able to detect these life-forms with ease as soon as the next decade using NASA's James Webb Space Telescope which is set to be completed in 2018.

When a star such as the Sun dies, it loses its outer layers, leaving just a hot core called a white dwarf, also known as a degenerative dwarf. These gradually cool and despite their sizes being comparable to the size of the Earth, they can retain heat long enough to warm a nearby planet for billions of years. Since a white dwarf is much smaller and fainter than the Sun, a planet would have to be much closer in to be habitable with liquid water on its surface. Professor Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics (CfA) suggests that "In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs,". This is purely because detecting oxygen in the atmosphere (which, if found in large quantities, is indicative of the presence of plant life) is significantly easier as opposed to detecting oxygen levels in planets orbiting stars like our Sun. Professor Loeb estimates that observing 500 of the closest white dwarfs could lead to the discovery of at least one habitable planet, with conditions similar to that of Earth.

New national screening programme for bowel cancer in the UK

A new national screening programme for colorectal cancer will be available as a part of the National Cancer Screening Programmes in England following positive feedback from patients.

Bowel cancer is the third most common cancer in the UK with over 40 000 new cases reported in 2009 alone. This new screening programme, carried out by a flexible sigmoidoscopy, is a quick procedure which can aid early diagnosis and prevention of bowel cancer. 

Flexible sigmoidoscopy, otherwise known as the Flexi-scope, uses a small camera at the end of a flexible plastic tube to search for any any small growths or polyps. Any polyps found can be removed pain-free and with ease.

A study published in the Journal of Medical Screening reported that of the 1020 patients who had a flexible sigmoidoscopy, 98% said they were 'glad' they had the test and 97% would recommend it to a friend.

Unlike other screening programmes, this test has the potential to reduce bowel cancer from developing and for a quick 10 minute test, it would be considered more than worthwhile.