What's the buzz

What's the buzz

Shark brains similar to humansResearchers have found that shark brains share several features with human brains, which could help them work on a shark repellent.

Scientists at the University of Western Australia (UWA) say sharks and other cartilaginous fish have highly developed sensory systems and relatively large brains.

Editor Kara Yopak from UWA’s Oceans Institute said the study suggested that people may have more in common with sharks than previously thought.

According to Dr Yopak, sharks and their relatives represented the earliest jawed vertebrates.

“Despite broad divergence, there are a number of common features of the brain that evolved at least as early as cartilaginous fishes and persist across all vertebrates,” News.com.auquoted her as saying.

“For instance, one of the papers shows that with great white sharks, the area of the brain that receives visual input is quite large, and suggests the relative importance of vision in these animals is quite high.  “This information may direct researchers’ efforts towards targeting the visual system when developing repellents for sharks,” Yopak added.

Culprit behind high cholesterol identified

Canadian scientists have discovered that a protein called resistin, secreted by fat tissue, causes high levels of “bad” cholesterol (low-density lipoprotein or LDL), increasing the risk of heart disease.

  The research proved that resistin increases the production of LDL in human liver cells and also degrades LDL receptors in the liver. As a result, the liver is less able to clear “bad” cholesterol from the body. Resistin accelerates the accumulation of LDL in arteries, increasing the risk of heart disease.

The research also showed that resistin adversely impacts the effects of statins, the main cholesterol-reducing drug used in the treatment and prevention of cardiovascular disease.

Dr. Shirya Rashid — senior author of the study and assistant professor in the department of medicine at McMaster University — noted that a staggering 40 per cent of people taking statins are resistant to their impact on lowering blood LDL. 

“The bigger implication of our results is that high blood resistin levels may be the cause of the inability of statins to lower patients’ LDL cholesterol,” said Dr. Rashid.

Heart and Stroke Foundation spokesperson Dr Beth Abramson noted that the research reconfirms the importance of maintaining a healthy weight and cholesterol level, two critical factors in the prevention of heart disease.

High blood cholesterol is a major risk factor for heart disease and stroke. It can lead to a buildup of plaque in the artery walls and narrowing of the arteries, causing a condition called atherosclerosis, which can make it more difficult for blood to flow through the heart and body.

Playing sports could make middle-aged people smarter

High-intensity interval training not only makes middle-aged people healthier, it can also boost their mental ability, according to a Montreal Heart Institute (MHI) study. Dr Anil Nigam of the MHI and University of Montreal led the study, in collaboration with the Montreal Geriatric University Institute.

 High-intensity interval training involves alternating between short periods of low and high intensity aerobic exercise – for example, a series of 30 seconds of sprinting followed by 30 seconds of walking or jogging.

“We worked with six adults who all followed a four-month programme of twice weekly interval training on stationary bicycles and twice weekly resistance training. Cognitive function, VO2max and brain oxygenation during exercise testing revealed that the participants’ cognitive functions had greatly improved thanks to the exercise,” Dr. Nigam said.

VO2max is the maximum capacity of an individual’s body to transport and use oxygen during exercise. It impacts on the body’s ability to oxygenate the brain and is related to cognitive function.

“Our participants underwent a battery of cognitive, biological and physiological tests before the program began in order to determine their cognitive functions, body composition, cardiovascular risk, brain oxygenation during exercise and maximal aerobic capacity,” Dr. Nigam explained.  “After the programme was finished, we discovered that their waist circumference and particularly their trunk fat mass had decreased.

We also found that their VO2max, insulin sensitivity had increased significantly, in tandem with their score on the cognitive tests and the oxygenation signals in the brain during exercise,” Dr Nigam said.

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