Of all of the nutritional debates on the internet, none is quite as contentious as whether it’s healthier to drink skim milk or whole milk. “Milk is probably the most controversial food in our country,” Larry Tucker, PhD, an exercise sciences professor at Brigham Young University, said in a statement. But while some research has indicated that whole milk is better for your heart—even though it contains more fat and calories—Tucker’s new study, published in Oxidative Medicine and Cellular Longevity, says that drinking skim milk actually slows down the aging process.
Tucker’s team analyzed data on 5,834 U.S. adults’ milk intake. Nearly half of the people in the study drank milk on a daily basis, and another quarter consumed it at least once a week. A little less than a third said that they drink whole milk, another 30 percent said they drank 2 percent milk, 10 percent said they drank 1 percent milk, and 17 percent said they drank nonfat milk. And according to the study’s findings, those who drank 2 percent or whole milk versus skim milk or 1 percent milk added 4.5 years of biological aging.
Tucker reached that conclusion by investigating the relationship between milk intake and telomeres—a compound at the end of our chromosomes that affects how we age. As people get older, their telomeres get shorter. The research showed that the more high-fat milk people drank, the shorter their telomeres were, which would explain why they would age faster. Tucker also found that people who didn’t drink any milk at all also had shorter telomeres, indicating that some milk really does do your body good.
“If you’re going to drink high-fat milk, you should be aware that doing so is predictive of or related to some significant consequences,” Tucker said. “It was surprising how strong the difference was.”
The findings support the current U.S. Dietary Guidelines for Americans, which suggests leaning on “fat-free or low-fat dairy.”
“It’s not a bad thing to drink milk,” Tucker concluded. “You should just be more aware of what type of milk you are drinking.”
And for more advice on how to extend your life, here are 100 Ways to Live to 100.