As the protective caps located at the tips of chromosomes that safeguard DNA as our cells divide, the shortening of telomeres is seen as a key biological marker of the aging process. A new study has examined the relationship between telomere length and milk with different fat concentrations, suggesting there to be a link between low-fat variants and longer telomeres that can equate to several years of aging, according to the team.
The research was carried out by exercise scientists at Brigham Young University (BYU), who enlisted 5,834 US adults that were separated into different categories of milk drinkers. The goal was to explore how milk consumption habits might impact telomeres, which get shorter each time a cell replicates as we grow older.
Almost half of study participants drank milk daily, while a quarter drank milk at least weekly. A third of the subjects drank full-fat milk, 30 percent drank milk with a two-percent fat content, 10 percent of subjects reported consuming one-percent-fat milk, 17 percent drank milk with no fat, while 13 percent drank no milk at all.
The researchers examined the telomere length of these different groups and were able to tease out some apparent links. Chief among them was an overall correlation between high-fat milk consumption and shorter telomeres.
Subjects who drank two-percent milk had telomeres that were 69 base pairs shorter than those who drank one-percent milk, a figure the researchers equate to four additional years of biological aging. Meanwhile, the telomeres in adults who consumed full-fat milk were 145 base pairs shorter than those who drank non-fat milk.
“It was surprising how strong the difference was,” says BYU exercise science professor Larry Tucker. “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.”
However, correlation does not equal causation and the researchers do recognize some limitations of their study – for example, those who drink low-fat milk may have a healthier lifestyle than those consume high-fat milk. However, they claim to have taken this and other potential confounders into account at the outset of the research and after making statistical adjustments say that those variables would have had little impact on the links they found between milk fat and telomere length. But they also accept that other variables not accounted for may be behind the correlation.
Obviously, more research is required before an explanation for the link between milk-fat and telomere length can be reached, but the researchers suggest that intake of saturated fats like those found in high-fat milk, which are known to trigger inflammatory pathways, alter gut microbiota and increase levels of oxidative stress, is one likely candidate for blame.
Interestingly, those who drank no milk at all had shorter telomeres than the adults who consumed low-fat milk, suggesting the drink has some anti-aging benefits but there could be a sweet spot to be found. The researchers say their research adds weight to the current dietary guidelines for Americans that recommends drinking milk with lower fat content as part of a healthy diet.
“It’s not a bad thing to drink milk,” Tucker said. “You should just be more aware of what type of milk you are drinking.”
The research was published in the journal Oxidative Medicine and Cellular Longevity.
Source: Brigham Young University
