There’s no sugarcoating this news.
We know too much sugar is bad for us — now, researchers from the University of California, San Francisco (UCSF) say that even when we eat healthfully, each gram of added sugar ages our cells.
The US Food and Drug Administration (FDA) recommends limiting added sugar to 50 grams a day. Sugar comes in many forms — a bar of milk chocolate has about 25 grams, while a 12-ounce soda has about 39 grams.
61.5 grams of added sugar was the average daily intake for the 342 Northern California women in the UCSF study. The participants were mostly around 40 years old.
The study authors were more interested in their biological age, which is the age of our cells and tissues. That number is influenced by genetics and lifestyle habits such as diet and exercise — it may be higher or lower than our chronological age, which is the number of years we’ve been alive.
The researchers tied healthy eating — especially a Mediterranean diet, which emphasizes vegetables, fruits, whole grains, healthy fats, nuts and seeds — to a lower biological age.
Added sugar accelerated biological aging, even if the sugar was part of an otherwise healthy diet.
“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-senior author Elissa Epel, a UCSF professor in the Department of Psychiatry and Behavioral Sciences.
“Now we know that accelerated [biological] aging is underlying this relationship, and this is likely one of many ways that excessive sugar intake limits healthy longevity,” Epel added.
Eliminating 10 grams of added sugar from your daily diet may reduce your biological age by 2.4 months over time, the researchers said.
High levels of sugar in the blood can damage cells, leading to chronic inflammation, which has been associated with heart disease, diabetes, liver disease and cancer.
Sugar fuels obesity — a widespread public health crisis in the US — and tooth decay.
The UCSF findings were published Monday in JAMA Network Open.
The researchers noted the diversity of their study population, which included black and white women, but acknowledged that the dietary information was based on self-reported three-day food records, which may have underestimated or overestimated some nutrients.
A separate study also published Monday suggests that eating a vegan diet for just eight weeks could slow biological aging. One expert noted that the vegan diet had fewer calories than the omnivore diet, and the vegan participants lost weight, which may explain the diet’s effect on the cells.
The analysis is part of Stanford Medicine-led studies into the health outcomes of identical twins. Some of the research is featured in the Netflix docuseries “You Are What You Eat,” which premiered in January.
