New research shows that small changes in diet practiced for less than a calendar month can potentially improve your biological age – supporting the key functions that together lead to healthier lives later in life.
While it's not the first study to investigate the role different diets have on key aging biomarkers, this work out of the University of Sydney demonstrates just how little you may have to do to invest in your health as you get older.
It's these biomarkers that make the so-called "super-agers" not only live longer but live without the chronic conditions that become more prevalent with the passing of each calendar year.
"As we age, our health tends to decline," says lead researcher Caitlin Andrews from the University of Sydney's School of Life and Environmental Sciences. "It’s an inconvenient biological truth. This is where the idea of biological age comes in: it doesn’t just measure the passage of time but asks how well your body is holding up under its share of wear and tear."
In the new study, Andrews and colleagues investigated whether a four-week dietary intervention could rapidly improve biomarkers in 104 individuals aged between 65 and 75 years.
As part of the Nutrition for Healthy Living study, participants were randomly assigned one of four diets – omnivorous high-fat (OHF), omnivorous high-carbohydrate (OHC), semi-vegetarian high-fat (VHF), or semi-vegetarian high-carbohydrate (VHC).
While each diet delivered the right amount of energy required from protein each day, the protein's source varied: omnivores got half their protein requirement from animal sources, while the semi-vegetarian plans delivered 70% of it in the form of plant-based foods. To align the data as closely as possible, the 104 participants all had a body mass index (BMI) between 20 and 35, were non-smokers and non-vegetarians, had no serious food allergies, and had no chronic health conditions.
Data from 20 biomarkers – such as blood pressure, cholesterol, and insulin levels - were then incorporated using the Klemera-Doubal Method (KDM) to score the participants before and after the four weeks.
Interestingly, the OHF group had health markers that barely changed from their baseline measures, while the other three all showed improved biological age.
Statistically speaking, the biggest improvement was seen in the OHC group, where individuals' daily energy was made up of 28-29% fat and 53% carbohydrates, in addition to the 14% protein. In this group, which saw carbs dominate, they scored 3.5 to 4 years younger in biological age compared with the OHF group.
It's worth noting that the “high-carb” diets excluded refined sugars and/or ultra-processed foods, with the macronutrient largely sourced from complex carbohydrates (whole foods, high in fiber and lower in fat).
Still, the researchers stress that the findings do not prove that aging can be reversed (unfortunately, that's a universal experience for us all). The results, though preliminary, do suggest that short-term, non-drastic changes in diet could boost the body's response to stress, inflammation, and metabolic function.
“Longer-term dietary changes are needed to assess whether dietary changes alter the risk of age-related diseases,” says Associate Professor Alistair Senior, from the School of Life and Environmental Sciences and the Charles Perkins Centre, who supervised the research.
“It’s too soon to say definitively that specific changes to diet will extend your life. But this research offers an early indication of the potential benefits of dietary changes later in life. Future research should explore whether these findings extend to other cohorts and whether the changes recorded are sustained or predictive of long-term outcomes," he adds.
It pays to keep in mind that the participant pool was small, the trial only lasted four weeks, and these older individuals had no serious health issues.
But it does, however, show promise that some tiny changes for short periods could be more beneficial than we realize. And it gives us more insight into how biological signs of aging may be more malleable – and sensitive to our lifestyle choices – than we currently believe.
The research was published in the journal Aging Cell.
Source: University of Sydney
Fact-checked by Mike McRae
