There may be days when you feel younger than your actual age, but a new study shows there is a way for your body to actually be younger than you are. Researchers from the University of California at San Francisco found eating a healthy diet with limited sugar is associated with having a younger biological age at the cellular level.
That effect over a long time could help you look and feel younger, and actually live longer.
UCSF scientists looked at how three different measures of healthy eating impacted an epigenetic clock, which is a biochemical test used to approximate both health and lifespan. They found the better people ate, the younger their cells looked.
But there was one factor that trumped all others. Even when people in the study ate healthy diets, every gram of added sugar they ate was associated with an increase in epigenetic aging.
"The diets we examined align with existing recommendations for preventing disease and promoting health, and they highlight the potency of antioxidant and anti-inflammatory nutrients in particular," said Dorothy Chiu, Ph.D., a postdoctoral scholar at the UCSF Osher Center for Integrative Health. "From a lifestyle medicine standpoint, it is empowering to see how heeding these recommendations may promote a younger cellular age relative to chronological age."
But the detrimental effects of added sugar was an eye-opener for the researchers.
"We knew that high levels of added sugars are linked to worsened metabolic health and early disease, possibly more than any other dietary factor," said study co-author Elissa Epel. "Now we know that accelerated epigenetic aging is underlying this relationship, and this is likely one of many ways that excessive sugar intake limits healthy longevity."
The study looked at the eating habits of 342 women and their average daily sugar intake was 61.5 grams. This ranged from 2.7 grams on the low side to 316 grams of added sugar on the high side.
For reference, a standard milk chocolate bar has 25 grams of added sugar, while the average 12-ounce can of soda has 39 grams. The current recommendation from the US Food and Drug Administration is no more than 50 grams of added sugar per day.
The study participants' diets were scored on how they compared to three different healthy eating measures, the Mediterranean Diet, a diet linked to a lower risk for chronic disease and the Epigenetic Nutrient Index, which is based on nutrients linked to anti-oxidative and anti-inflammatory processes and DNA maintenance and repair. These nutrients include vitamins A, C. B12, and E, as well as folate, selenium, magnesium, dietary fiber and isoflavones.
Those who adhered to any of the diets had a significantly lower epigenetic age, as measured by a saliva test, than those who didn't eat as healthy. The Mediterranean diet, which is rich in anti-inflammatory and antioxidant foods, had the strongest correlation to a lower epigenetic age.
Sugar intake was looked at separately and researchers found consuming foods with added sugar was tied to accelerated biological aging, even if the participants ate an otherwise healthy diet.
"Given that epigenetic patterns appear to be reversible, it may be that eliminating 10 grams of added sugar per day is akin to turning back the biological clock by 2.4 months, if sustained over time," said co-senior author Barbara Laraia, Ph.D., RD, a UC Berkeley professor in the Food, Nutrition and Population Health program. "Focusing on foods that are high in key nutrients and low in added sugars may be a new way to help motivate people to eat well for longevity."