Australasian Science: Australia's authority on science since 1938


By Stephen Luntz

Blackcurrants improve alertness, chocolate makes you calm, climate change shrinks waves, and more.

Blackcurrants Improve Alertness

Blackcurrant extract enriched in anthocyanins improves alertness and reduces mental fatigue, according to a double-blind trial by New Zealand’s Plant and Food Research.

Participants drank either the extract or a placebo and then completed a tiring computerised assessment. Those on the extract worked more accurately, and reported feeling more alert and less mentally fatigued afterwards.

“We know there are compounds in dark berry fruits, like blackcurrants, that have real effects on people’s health and well-being,” said study leader Dr Arjan Scheepens. “Our next stage is to identify exactly which compounds are creating this effect, and use this knowledge to develop new whole and processed foods or ingredients that deliver optimised performance.”

Chocolate Makes You Calm

Swinburne University PhD student Matthew Pase has proven what chocoholics already knew – dark chocolate keeps you calm.

“Anecdotally, chocolate is often linked to mood enhancement,” said Pase. “This clinical trial is perhaps the first to scientifically demonstrate the positive effects of cocoa polyphenols on mood.”

Pase had 72 people drink a chocolate mix containing either 0 mg, 250 mg or 500 mg of cocoa polyphenols in a double-blind trial once per day for 30 days.

Those who had drunk the high polyphenol drink reported greater calmness and contentment, but did not show any signs of improved performance on cognitive tests. Pase reported in the Journal of Psychopharmacology that no significant effects were demonstrated from the medium dosage.

The study was funded by chocolate manufacturer Barry Callebaut, which has recently released a high polyphenol chocolate line it wishes to brand as healthy.

Emu in the Guts

Emu oil’s use by indigenous people as a treatment for skin wounds represents only one of its benefits, according to University of Adelaide researchers.

Ms Suzanne Mashtoub Abimosleh, a physiology PhD student, found that emu oil stimulates the growth of intestinal crypts, which produce the villi the gut uses to absorb food.

“Disorders of the gastrointestinal tract, such as the inflammatory bowel diseases and chemotherapy-induced mucositis, are associated with malabsorption of food together with inflammation and ulceration of the bowel lining (mucosa),” Abimosleh said. Roughly half of chemotherapy patients experience mucositis. “There are no effective treatment options,” Abimosleh added.

“Longer crypts and villi mean a healthier bowel that can better absorb food,” said Prof Gordon Howarth of the School of Animal and Veterinary Sciences. The team is keen to undertake clinical trials of emu oil for bowel conditions, particularly to identify appropriate dosage.

Swine Pneumonia Tackled

New South Wales scientists believe they are on the trail of a better vaccine against the Mycoplasma hypopneumoniae bacterium, which causes pneumonia in pigs.

While swine pneumonia, unlike swine flu, is not a threat to human health, the Australian pig industry loses $20 million per year as a result. Current vaccines are expensive and unreliable.

Open Biology published the results of a genome-wide proteomics analysis that found the proteins on the bacterium’s surface used to colonise hosts. These make promising vaccine targets.

“Based on these findings, we are now in a position to design vaccination trials that include this protein as a component in a vaccine cocktail against one of the most troublesome diseases afflicting swine production. Our strategy offers a completely new approach to the identification of vaccine antigens,” says Prof Steve Djordjevic of the University of Technology, Sydney.

Mouse Atlas

The most detailed atlas of the mouse brain ever produced has been released by the University of Queensland’s Centre for Advanced Imaging.

“The mouse is now the most widely used animal model for neuroscience research, and magnetic resonance imaging (MRI) is fundamental to investigating changes in the brain,” said Dr Jeremy Ullman. “Our atlas is already much in demand internationally because it allows researchers to use MRI to automatically map brain structures.”

Prof David Reutens, in whose lab the research was done, said: “In making these world-first maps, we had the advantage of using the most powerful MRI scanners in the Southern Hemisphere”.

The atlas’ arrival was announced in NeuroImage, and should allow mouse researchers to target genes responsible for diseases such as Parkinson’s and Alzheimer’s.

Climate Change Shrinks Waves

Global warming may have found a whole new set of opponents, with modelling suggesting that many surfers are set to lose out.

A comparison of five different wave modelling programs found that 25% of the world’s oceans are set to experience smaller waves as a result of changing atmospheric circulation patterns, while only 7% will see wave heights increase. Most of the higher waves will be in the Southern Ocean.

Lead author of the Nature Climate Change study, Dr Mark Hemer, said: “Waves are dominant drivers of coastal change in these sandy environments, and variability and change in the characteristics of surface ocean waves (sea and swell) can far exceed the influences of sea-level rise in such environments.

“If we wish to understand how our coasts might respond to future changes in climate then we need to try and understand how waves might respond to the projected changes in global atmospheric circulation seen as shifts in storm frequency, storm intensity and storm tracks.”

Parents Vulnerable to Junk Advertising

Parents can no longer get away with blaming their children’s pestering for feeding them junk food, as it turns out they are equally vulnerable to the appeal of advertising for unhealthy food.

Prof Simone Pettigrew of the University of Western Australia’s Health Promotion Evaluation Unit tested advertisements for high calorie, low nutrient foods on 1000 parents and their children aged 8–14.

For all their supposed scepticism parents were just as likely as children to evaluate products more favourably, express a desire to consume the product and think they could eat them frequently without harm after seeing an advertisement just once.

“Adults are thought to have greater immunity to advertising effects relative to children due to their greater cognitive processing abilities,” says Pettigrew. She says her evidence suggests regulations may need to consider the effects of overexposure in parents as well as children.

Vitamin C No Gout Cure

Vitamin C lowers uric acid, the cause of gout, in some patients but does not have a clinically significant benefit for sufferers, according to Prof Lisa Stamp of the University of Otago.

“While current treatments are successful in reducing the amount of uric acid in the blood, there are many patients who fail to reach appropriate urate levels and need additional therapies,” said Stamp. Vitamin C is a popular alternative therapy, but Stamp’s results, published in Arthritis & Rheumatism, indicate it has little value.

Previous studies have found that vitamin C reduces urate levels in people with high levels of uric acid but not yet suffering from gout. “Though vitamin C may reduce risk of developing gout, our data does not support using vitamin C as a therapy,” said Stamp.

Stroke Decline

Despite an ageing population, Australian stroke levels have fallen by 10% over the past 20 years, University of Adelaide research published in Stroke reveals. The results were based on a sample of 148,000 people living in western Adelaide.

“We attribute the decrease in the rate of stroke to two things: first we know the number of smokers has decreased; second, we now have much better management of blood pressure both at GP and specialist levels, and blood pressure drugs have improved,” said Prof Jonathan Newbury of the School of Population Heath.

As other causes decline, atrial fibrillation, a heart rhythm disorder, has risen to account for one-third of strokes. Lead author James Leyden said: “These results demonstrate the need for people with irregular heartbeat to seek medical help as soon as they can, because many of these strokes can be prevented”.

Ecstasy, Alcohol and Pregnancy Don’t Mix

The combination of alcohol and ecstasy use during pregnancy causes more damage to the foetal brain than either on their own, according to Dr Juan Canales of the University of Canterbury.

“The use of drugs during pregnancy poses serious health risks for pregnant women and their babies, who may be born premature, exhibit birth defects and develop behavioural and learning disabilities,” Canales says. He exposed rats to the two drugs and found that the offspring had impaired memories, produced fewer neurons in crucial parts of the brain and were less likely to explore at 3 months of age.

“These effects were minimal in subjects exposed to only one of the drugs, suggesting that the mixing of drugs can have very negative consequences,’’ Canales says.

Queenslanders Still Sunburnt

Years of sun safety messages have failed to prevent Queenslanders from getting frequently sunburned.

A Medical Journal of Australia paper reports that more than 10% of Queenslanders in a large phone survey reported having been sunburned the previous weekend, with male sunburn rates 50% higher than for women. By far the highest rate – 22% – was recorded among men aged 18–24.

Burn frequency was unrelated to socio-economic status, the area of Queensland or even skin colour, but was increased by physically activity and not having a tertiary education.

“We know the five best practice sun safety behaviours are wearing a broad brimmed hat, wrap-around sunglasses and a long sleeve top, using sunscreen, and seeking shade,” said Queensland’s Chief Health Officer, Dr Jeannette Young. “But fewer than 3% of people practise all five in winter. Given that ultraviolet radiation levels are above a UV index of 3 all year round, sun safety is as important in winter as in summer in Queensland.”