PROVO — What are you pouring over your cereal in the morning?
A new study authored by BYU professor Larry Tucker shows drinking 2% milk and whole milk may add years of biological age to adults, while 1% and nonfat milk were associated with younger biological age.
According to a BYU news release, Tucker investigated the relationship between telomere length and milk consumption — both frequency and fat content — in 5,834 U.S. adults to reach that conclusion. “Short telomeres basically means much higher risk of death and much higher risk of disease,” Tucker explained Friday.
“Telomeres are the nucleotide endcaps of human chromosomes,” the release says. “They act like a biological clock and they’re extremely correlated with age; each time a cell replicates, humans lose a tiny bit of the endcaps. Therefore, the older people get, the shorter their telomeres.”
“The older we get, the more biological aging takes place, the more susceptible we are to a wide variety of diseases,” Tucker said.
Tucker said that the difference between skim milk and whole milk consumption was “somewhere around nine years of biological aging difference, which, you don’t find that very often in anything.”
Tucker’s study found that for every 1% increase in milk fat consumed, telomeres were 69 base pairs shorter in the adults studied — which accounts for more than four years of biological age.
Tucker said habits like smoking and lack of exercise are other common causes of shorter telomeres.
Milk is a fiercely debated beverage, what Tucker called “probably the most controversial food in America.”
“There are studies that show that drinking milk increases all-cause mortality,” Tucker said. “And there are some studies that show that drinking milk does the opposite — it decreases all-cause mortality.”
Tucker said there are many possible reasons for these disparities — milk might affect people of different cultures and nationalities differently, for instance. “It may be that many of (the studies) are right and they just are looking at it from a different angle.”
In any case, Tucker said, he agrees with the current U.S. dietary guidelines which recommend consumption of fat-free or low-fat dairy as part of a healthy adult eating pattern. Indeed, the BYU news release says Tucker’s study found that “milk abstainers” actually had shorter telomeres, or older biological age, than adults who consume low-fat milk.
“It’s not a bad thing to drink milk,” Tucker says in the release. “You should just be more aware of what type of milk you are drinking.”
Tucker’s study was published in October 2019 in Oxidative Medicine and Cellular Longevity.