Aging may be inevitable, but a change in diet alone can produce positive shifts in "biological age," according to a new study. Participants in their 60s and 70s saw improvements in certain aging-related biomarkers after adjusting their eating habits for just four weeks, drawing renewed attention to the importance of dietary choices in later life.
"Complex Carbohydrates Over High Fat": Results of a Senior Diet Experiment
A research team at the University of Sydney recently reported in the international journal Aging Cell that, in a dietary experiment involving 104 adults aged 65 to 75, biological age declined in some of the diet groups.
The researchers divided participants into four diet groups. Two groups followed an omnivorous diet combining animal and plant proteins, while the other two followed a semi-vegetarian diet in which 70% of protein came from plant sources.
These were further split into high-fat, low-carbohydrate diets and low-fat, high-carbohydrate diets, creating four diets in total. Across all diets, protein was set at 14% of total calories.
The most notable change appeared in the "high-carbohydrate omnivorous diet." By contrast, the high-fat omnivorous diet, which most closely resembled participants' existing eating habits, showed little change in biological age.
"The most pronounced improvements were seen in diets rich in complex carbohydrates and plant-based foods," the researchers said.
Beyond Actual Age: There's a Separate "Body Age"
The key concept in the study is "biological age."
The age we typically refer to is "chronological age," which simply measures the time elapsed since birth. Biological age, however, is calculated based on the body's condition.
That means two people who are both 70 years old could have very different bodies — one with the physical state of a healthy person in their 50s, and another showing more rapid signs of aging.
The researchers calculated biological age by analyzing 20 biomarkers in participants, including cholesterol, insulin and inflammation levels (CRP).
"Chronological age increases at the same rate for everyone, but the pace of biological aging varies from person to person," the University of Sydney team said. "Biomarkers are better indicators of health status and potential lifespan than chronological age."
Why Does Diet Affect the Pace of Aging?
Experts say diet influences the body's inflammation, blood sugar and insulin response.
Diets centered on plant-based foods and complex carbohydrates, in particular, can help reduce blood sugar spikes and lower chronic inflammation.
Conversely, some analyses suggest that diets high in fat may amplify inflammatory responses and metabolic strain in the body.
Lifestyle also has a significant effect on biological age. Lack of exercise, insufficient sleep, smoking, drinking and chronic stress are cited as factors that can accelerate aging.
The researchers cautioned that "it is difficult to conclude from these results alone that a specific diet actually extends lifespan." They emphasized that the study is an early-stage investigation focused on short-term changes in biomarkers.
Caitlin Andrews, the lead researcher, said the study "shows that changes in eating habits, even later in life, can have a positive impact on health," adding that "further research is needed to determine whether this leads to a long-term reduction in disease risk or an extension of lifespan."
