Why might the high-carbohydrate diet reduce biological aging?
It’s hard to determine what these biomarker changes mean in terms of actual biological aging in the real world beyond the study. “I wouldn’t necessarily look at this as an age reversal,” says Jessica Cording, RD, registered dietitian and author of The Little Book of Game-Changers. The researchers also wrote in the study that “caution is warranted in interpreting such changes as evidence of biological age reversal.”
Even the study’s researchers are hesitant to apply an actual number of biological years gained based on the findings. “These are years of estimated biological age, not years of life, so it means the blood results looked like those of a younger person,” explains Caitlin J. Andrews, PhD, study co-author and researcher at the University of Sydney’s School of Life and Environmental Sciences.
“Eating more carbs may also mean higher intake of fiber from plant foods, but not necessarily,” says Sandra Zhang, RDN, LDN, registered dietitian and nutritionist at the Frances Stern Nutrition Center at Tufts Medical Center. Cording agrees, noting that all carbohydrates are not created equal. “People tend to think of bread, rice, pasta, and sugar as carbs, but they often forget that vegetables, fruit, nuts, seeds, and legumes also have carbohydrates,” she says. These foods offer a wide array of nutrients, including vitamins and polyphenols to support healthy aging, she points out. This particular study focused on high-quality, complex carbohydrates like those Cording listed. “This could be reflecting more whole foods in a person’s diet,” Cording says. “It’s not just about the carbs.”
While dividing up a diet by its macronutrients is a convenient way to categorize an eating routine, Zhang notes that good nutrition is more than just that: “Different types of fats, carbohydrates, fiber, and protein intake can also influence the inflammation process,” she says.
The quality of diet matters, too, according to Dr. Andrews. “The benefits across the study tended to be associated with the diets that moved further away from a typical Western diet toward more minimally processed, whole food diets,” she says.
What the findings mean for a healthy diet
When it comes to diets, variety is key for longevity, Zhang says. That means including different types of fats from animals and plants, and trying to feature a wide range of nutrients on your plate. “Plant-based proteins do carry the benefits of low-fat and high-fiber, but they are not necessarily easily absorbed and complete, especially for the elderly,” Zhang says.
That’s why Cording suggests a balance of plant and animal proteins. “Make room for beans, nuts, and seeds, along with lean meats. There is room for all of it,” she says. “You want an overall diet pattern that gives you a good balance of protein, fats, and carbohydrates.”
People have been wary of carbs for years, but the latest findings suggest there’s a place for this macronutrient—provided you choose wisely. “Foods like vegetables, fruits, legumes, and whole grains tend to be higher in fiber, more filling, and associated with better long-term health than more heavily processed, carbohydrate-rich foods,” Dr. Andrews says. “More broadly, I think there’s a lot to be said for shifting the focus away from restriction and more toward overall dietary quality and balance.”
