喝牛奶是一个好方法add protein to your diet和build strong teeth and bones. It has also been linked with a心脏病和中风的风险降低和较低的肥胖率. However, experts are divided onwhether low-fat milk or whole milk is healthier. Now, according to the latest research — drinking low-fat milk is associated with alonger life span.
Brigham Young University运动科学教授Larry Tucker，Phd，追踪了5,834名成年人，以确定牛奶消耗是否与端粒长度有关生物衰老的迹象.
Theresearch, published in the journal Oxidative Medicine and Cellular Longevity, found those who drank low-fat milk had longer telomeres (and less biological aging) than those who drank high-fat milk, including 2% and whole milk. Tucker equates the difference to an additional four-and-a-half years of cellular aging.
According to Tucker, a significant difference in theamount of saturated fatbetween low-fat and high-fat milk could be the reason for the decrease in biological aging. In whole milk, 50% of the calories are from fat compared to 21% for 1% milk (and between 0 and 2% in skim milk).
“High-fat dairy is higher in fat than people realize,” he says. “Unlike other foods thatcalculate fatbased on percentage of calories, milk fat is calculated by the percent of milk’s weight.”
Diets that are high in fat — especially saturated fat — are associated withincreased risk of cardiovascular disease,chronic inflammation,negative changes to gut bacteria,lower breast cancer survival rates和evenneurological changes in the brain. Based on such findings, theU.S. Dietary Guidelinesrecommend choosing fat-free or low-fat dairy products, including milk, yogurt and cheese.
WHY WHOLE MILK CAN STILL BE HEALTHY
“减少饱和脂肪消耗的建议主要是基于研究表明，全脂乳制品中存在饱和脂肪的较高摄入量raise LDL or ‘bad’ cholesterol levels，这可能会增加心脏疾病,” explains study co-author Marcia de Oliveira Otto, PhD, assistant professor at UTHealth School of Public Health. However, “an increasing number of large studies examining the link between saturated fats present in dairy foods and heart disease do not support that hypothesis.”
In particular, Otto cites heptadecanoic fatty acid (a saturated fatty acid in milk fat), which could reduce the fragility of brain arteries and lower the risk of dying from a stroke. In一项研究, adults with higher levels of heptadecanoic fatty acid in their blood were 42% less likely to die from stroke.
Moreover, other research supports the benefits of consuming whole milk and other high-fat dairy products: Higher intake of whole milk and full-fat yogurt was associated with a lower risk of cardiovascular events and total mortality, according toresearch published in The Lancet.
THE BOTTOM LINE
“An important take-home message from our study is making judgments about whether foods are healthy solely based on fat content leads to confusion and misinformation,” says de Oliveira Otto. “Since dairy foods are important sources of essential nutrients, reducing dairy consumption may not necessarily lead to better health.”