Health/Fitness « Weekly Gravy

Why does one person take a lot of risks and another proceed with more caution? Researchers came closer to that answer with a new study that shows risk-taking behavior may be related to characteristics in the brain. The study found there is no one risk area in the brain. Instead, there are many regions where anatomy is altered in people who take risks. Yet there is a connection between genes, lower levels of gray matter and risky behavior, researchers concluded. “People have different tendencies to engage in behavior that risks their health or that involve uncertainties about the future,” senior author Gideon Nave said in a University of Pennsylvania news release. He’s an assistant professor of marketing at the university’s Wharton School. The research team gathered brain scans and genetic data from more than 12,600 people of European ancestry and then from another 13,000 people. All were aged 40 to 69 and enrolled in the UK Biobank. Investigators used self-reported risky behaviors — smoking, drinking, sexual promiscuity and driving above the speed limit — to create an overall indicator of risk tolerance. They estimated the relationship between total gray matter volume across the brain and the risk-tolerance score. Higher risk tolerance was correlated with overall lower gray matter volume, researchers said, though only an association was seen. Gray matter carries out the basic functions of… read on > read on >

Enlarged spaces in the brain that fill with fluid around small blood vessels may be a harbinger of impending dementia, a new Australian study suggests. Typically, these so-called perivascular spaces help clear waste and toxins from the brain and might be linked with changes in the aging brain, researchers say. “Dilated perivascular spaces, which are a common MRI finding, especially in the elderly, are not just an incidental finding,” said study author Dr. Matt Paradise, a psychiatrist and research fellow at the Centre for Healthy Brain Ageing at the University of New South Wales in Sydney. “Instead, they should be taken seriously, and assessing their severity may be able to help clinicians and researchers better diagnose dementia and help predict the trajectory of people with cognitive decline.” Paradise noted, however, that the study does not prove that enlarged perivascular spaces cause thinking and memory problems, only that there is an association. “Dilated perivascular spaces may be a marker of the disease process, but not necessarily drive it,” he explained. ‘The underlying mechanisms for dilated perivascular spaces are complex and need unraveling.” One neurologist agreed that relationship between these enlarged spaces and dementia is complicated. “We all have perivascular spaces. They are natural, but they’re usually very small, so small that when we do pictures of the brain, we don’t usually see them,” explained Dr. Glen… read on > read on >

There have long been theories that women’s menstrual cycles align with the moon, and now a new study suggests there’s some truth to that. Using years of records kept by 22 women, researchers found that for many, menstrual cycles “intermittently” synced up with the phases of the moon. The link happened only about one-quarter of the time for women aged 35 or younger, and just 9% of the time for older women. There was a great deal of variance, though, among individuals. And for a few women, there were hints that excessive exposure to artificial light at night could have thrown off any moon-menstruation synchrony. One expert called the findings “interesting,” and said they might reflect remnants of a lunar influence that benefited humans’ ancient ancestors. Early primates were nocturnal creatures, so a degree of moon-influenced behavior would make sense for them, according to Deena Emera. Emera, who was not involved in the study, is an evolutionary geneticist based at the Buck Institute’s Center for Reproductive Longevity and Equality, in California. Mating is risky business, Emera noted, as it makes animals vulnerable to predators. So mating during the new moon, under cover of more darkness, would be a “reasonable strategy,” she said. That also means there would be an advantage to ovulation being timed to the new moon. “I think any [moon-menstruation] synchronization seen today… read on > read on >

Think your dog is smart? New research suggests one way to find out. Most dogs can’t learn words without extensive training, but a few with exceptional abilities learn words without any formal training, researchers report. They learn words simply by playing with their owners. The team of Hungarian researchers investigated how quickly two of these talented pooches could learn new words. Their study included a Border Collie named Whisky from Norway — already famous for her spontaneous categorization skills — and a Yorkshire terrier named Vicky Nina, from Brazil. “We wanted to know under which conditions the gifted dogs may learn novel words. To test this, we exposed Whisky and Vicky Nina to the new words in two different conditions — during an exclusion-based task and in a social, playful context with their owners,” said study first author Claudia Fugazza, a member of the Family Dog Project research team at Eötvös Loránd University, in Budapest. “Importantly, in both conditions the dogs heard the name of the new toy only four times,” Fugazza said. In the exclusion-based task, the dogs were presented with seven familiar dog toys, along with a new one. Their ability to choose the new toy after hearing its new name was tested. The dogs failed this test. But the dogs quickly learned the name of a new toy after hearing it just… read on > read on >

Vitamin D is an essential nutrient, and recent research has suggested it may also help guard against severe COVID-19. But how much is enough, and how hard is it to get the right amount of vitamin D? “We know that a large percentage of the population has suboptimal levels of vitamin D. In fact, as many as half of the U.S. population may be deficient in vitamin D,” said Kristin Gustashaw, clinical dietitian at Rush University Medical Center in Chicago. “This can possibly lead to symptoms including fatigue, tiredness, hair loss, delayed wound healing, decreased immune health, muscle pain and more, with no other known causes. “Part of the difficulty of maintaining vitamin D levels is because there are not a large variety of foods that contain much vitamin D,” Gustashaw added in a medical center news release. The vitamin is accessible to people through some foods, supplements and even sunshine. Food sources include egg yolks, milk, cheese, beef or calf liver and certain fish, such as salmon, mackerel, tuna and sardines. Other foods are fortified with vitamin D, including certain cereals, breads, soy milk and orange juice. Gustashaw also recommends that people should get out in the sun for at least 15 to 30 minutes a day, but says they should be sure to get a constant source of the nutrient from their diet… read on > read on >