Therapies based on a hormone people make while exercising may be the next frontier in treating Alzheimer’s disease, according to a new study. Researchers have found that the exercise-induced hormone irisin may reduce both the plaque and the tau tangles characteristic of the disease. Before this, this same team developed the first 3D human cell culture models of Alzheimer’s disease, which it was able to use in this new research into the impact of irisin on amyloid beta in the brain. Physical exercise had already been shown to reduce amyloid beta deposits in mouse models of Alzheimer’s, but it wasn’t clear how. The increase of circulating levels of the muscle-derived hormone irisin through exercise regulates glucose and lipid metabolism in fat tissue. It also increases energy expenditure by accelerating the browning of white fat tissue. Past research has shown that irisin is present in human and mouse brains. Its levels are lower in patients with Alzheimer’s. “First, we found that irisin treatment led to a remarkable reduction of amyloid beta pathology,” said study author Se Hoon Choi, of the Genetics and Aging Research Unit at Massachusetts General Hospital in Boston. “Second, we showed this effect of irisin was attributable to increased neprilysin activity owing to increased levels of neprilysin secreted from cells in the brain called astrocytes,” he said in a hospital news release. Neprilysin…  read on >  read on >

Children need to get up off the sofa and move more, according to a new study that linked childhood sitting time with heart damage in young adulthood. That was true even when the adult’s blood pressure and weight were healthy, according to researchers. “All those hours of screen time in young people add up to a heavier heart, which we know from studies in adults raises the likelihood of heart attack and stroke,” said study author Dr. Andrew Agbaje, of the University of Eastern Finland in Kuopio. “Children and teenagers need to move more to protect their long-term health,” he explained in a news release from the European Society of Cardiology. This was the first study to investigate the cumulative effect of smartwatch-assessed sedentary time in young people and cardiac damage later in life, the study authors noted. Kids who were part of the Children of the 90s study wore a smartwatch activity tracker for seven days at age 11, and then repeated this at age 15 and age 24. The researchers assessed the weight of the heart’s left ventricle by echocardiography, a type of ultrasound scan, at 17 and 24 years of age. Results were reported in grams relative to height. The researchers then analyzed the association between sedentary time between age 11 and 24 and heart measurements between age 17 and 24. The…  read on >  read on >

The degenerative joint disease osteoarthritis affects 15% of the global population over age 30, so by 2050 that could be nearly 1 billion people, researchers say. Living longer and obesity are both major contributors. “With the key drivers of people living longer and a growing world population, we need to anticipate stress on health systems in most countries,” said study author Jaimie Steinmetz, lead research scientist at Institute for Health Metrics and Evaluation (IHME) in Seattle. “There is no effective cure for osteoarthritis right now, so it’s critical that we focus on strategies of prevention, early intervention, and making expensive, effective treatments like joint replacements more affordable in low- and middle-income countries,” she said in an institute news release. The research was part of the Global Burden of Disease Study 2021, and used 30 years of osteoarthritis data, from 1990 to 2020, in more than 200 countries. The study found that cases increased rapidly over the past three decades because of aging, population growth and obesity. While around 256 million people had osteoarthritis in 1990, that number jumped to 595 million people in 2020, a 132% increase. The study found that obesity was responsible for about 20% of the disability of osteoarthritis in 2020. For people aged 70 and older, osteoarthritis ranked seventh in causes for years lived with disability. The condition is expected to…  read on >  read on >

People can help reduce their odds of developing atrial fibrillation or stroke through one piece of standard medical advice: stay fit. According to a new study in 15,000 people, physical fitness was found to have a lower likelihood of these conditions. The findings will be presented this weekend at the European Society of Cardiology Congress 2023, in Amsterdam, the Netherlands. “This was a large study with an objective measurement of fitness and more than 11 years of follow-up. The findings indicate that keeping fit may help prevent atrial fibrillation and stroke,” study author Dr. Shih-Hsien Sung, of the National Yang Ming Chiao Tung University in Taipei, Taiwan, said in a meeting news release. Research participants did not have atrial fibrillation, or a-fib, an irregular and often rapid heart rhythm, at the study start and were referred for a treadmill test between 2003 and 2012. Researchers assessed their fitness using the Bruce protocol, where each person was asked to walk faster and at a steeper grade in successive three-minute stages. Then the team calculated participants’ fitness according to the rate of energy expenditure the participants achieved, which was expressed in metabolic equivalents (METs). The study followed the participants, who started at an average age of 55, and of whom 59% were male, looking for new-onset a-fib, stroke, myocardial infarction and death. After adjusting for other potentially…  read on >  read on >

Walkable neighborhoods — with sidewalks, parks and paths — encourage pregnant women to get more exercise, which leads to good outcomes for both mom and baby. New research looks at the influence of these walkable communities on this activity, which is considered safe for pregnant women. “Gestational diabetes is a growing issue and low birth weight and preterm babies are always a concern, they can just have so many more complications,” said Karen Conway, a professor at University of New Hampshire Peter T. Paul College of Business and Economics. “At the end of the day, the data shows walkable communities mean mom and the baby are both in better health.” To study this, Conway and co-author Andrea Menclova, associate professor of economics at the University of Canterbury in New Zealand, combined walkability measures created by the U.S. Environmental Protection Agency (EPA) with federal government data on physical activity and pregnancy outcomes. A 10-point increase in the walkability index — the equivalent of transitioning from the “least walkable” to the “most walkable” category — was associated with a more than 70-minute increase in weekly exercise among pregnant women. That same change increased the likelihood of a full-term birth by almost a full percentage point. It also led to a 27-gram (nearly 1 ounce) increase in birth weight; a 27% reduction in likelihood of gestational diabetes, and…  read on >  read on >

Women who have larger breasts tend to exercise less or less intensely, according to a new study that suggests having breast reduction surgery could be a game changer. Australian researchers looking at exercise participation for women in this category called for more accessible, publicly funded breast reduction and other interventions. The study used survey results from nearly 2,000 women who were in the involved in the Parkrun program, which promotes 5K running and walking events. Participants were in Australia, England and South Africa. Women with bigger breasts reported that reducing their breast size would improve their exercise performance and frequency. And among the survey participants, the 56 women who had already undergone breast reduction surgery said they lead healthier and more active lifestyles. “Women who had undergone breast reduction reported increased overall frequency, enjoyment and willingness to exercise in a group,” said lead author Dr. Claire Baxter, a clinical registrar in reconstructive surgery at the Flinders Medical Centre in Bedford Park, Australia. “Our study found that breast size affects exercise habits and that breast reduction surgery changes their willingness to exercise,” she said in a Flinders news release. The study promotes the importance of regular exercise for weight and ischemic heart disease and also points out barriers for Australian Government subsidies for reduction mammoplasty. “As well as the need for patients to have macromastia [enlarged…  read on >  read on >

Having good fitness while young can really pay off when it comes to cancer risk later in life. New research found that cardiorespiratory fitness — the ability to do aerobic exercise — was associated with up to 42% lower risk of nine cancers, including head and neck, esophagus, stomach, pancreas, liver, colon, kidney and lung. Researchers used Swedish registry data up to the end of 2019, covering background information, medical diagnoses and deaths for male conscripts who started their military service between 1968 and 2005. The conscripts were age 16 to 25 when they started their service and had a battery of assessments at that time, including height, weight (body mass index), blood pressure, muscular strength and cardiorespiratory fitness. Those who had a low level of cardiorespiratory fitness were slightly more likely to be obese and more likely to have a history of alcohol and substance misuse. They were also more likely to have parents with lower educational attainment than their counterparts who had a higher fitness level. More than 365,000 conscripts had a low level of cardiorespiratory fitness. More than 519,000 had a moderate level and nearly 341,000 had a high level. The final analysis included more than 1 million men, about 7% of whom later developed cancer in at least one site during an average monitoring period of 33 years. Those with higher…  read on >  read on >