Take it easy, guys
Vigorous physical activity may increase the risk for vision loss. The findings of a new study has surprised and puzzled researchers. Using questionnaires, Korean researchers evaluated physical activity among 2,11,960 men and women aged between 45 to 79 in 2002 and 2003. Then they tracked diagnoses of age-related macular degeneration from 2009 to 2013. Macular degeneration, the progressive deterioration of the central area of the retina, is the leading cause of vision loss in the elderly. They found that exercising vigorously five or more days a week was associated with a 54 per cent increased risk of macular degeneration in men. The authors write in the journal JAMA Ophthalmology that excessive exercise might affect the eye's choroid, a sensitive vascular membrane that surrounds the retina, but "epidemiologic studies cannot provide any evidence for the mechanism or pathology".
Afteroon surgery safer
Having heart surgery later in the day may be safer than having it in the morning, reported a study in Lancet. Researchers studied 596 patients, half of whom had undergone surgery in the morning and half in the afternoon. They followed their recoveries for 17 months and found that afternoon surgery produced significantly fewer complications. The reason: levels of troponin, a measure of heart muscle damage, were significantly lower in the afternoon group. The genetic mechanisms that protect tissue under stress function differently in the morning and the afternoon - in all organs, not just the heart - and the authors believe that these circadian variations account for their findings.
Fat up, carb down
A new study in Lancet links eating high carbs to a higher risk of mortality, and high fat intake with a lower risk. An international team of scientists studied diet and mortality in 1,35,335 people between 35 and 70 years old in 18 countries, following them for an average of more than seven years. Compared with people who ate the lowest 20 per cent of carbohydrates, those who ate the highest 20 per cent had a 28 per cent increased risk of dying earlier. But high carbohydrate intake was not associated with cardiovascular death. The study shows that it is the guidelines that recommend low saturated fat, or really low amounts of fat, that may actually be harmful.
Unborns at risk
Air pollution may be harmful to babies even before they are born, a new study has found. Researchers in London calculated mothers' exposure to air pollution and traffic noise in various parts of the city from 2006 to 2010; the data on birth weights of 5,40,365 babies born to those women showed the average pollution exposure was 14 micrograms per cubic metre of PM 2.5, the tiny particles that enter the smallest airways in the lungs. For each 5 µg/m³ increase in PM 2.5, the risk of low birth weight increased by 15 per cent, leading to diabetes, heart disease and hypertension in later life.