Diet plays a crucial role in overall health, but its effects extend beyond common concerns like weight management and heart disease. A growing body of research suggests that dietary choices influence biological aging, a process distinct from chronological aging. While chronological age refers to the number of years a person has lived, biological age reflects the state of their cells and tissues. It can be influenced by lifestyle factors such as diet, exercise, and environmental exposures.
A recent study focusing on young adult twins provides valuable insights into how dietary patterns shape biological aging. By analyzing epigenetic markers—chemical modifications to DNA that affect gene expression—scientists have developed advanced tools known as epigenetic clocks. These clocks allow researchers to assess how fast an individual’s body is aging at the molecular level.
The findings suggest that suboptimal dietary habits may accelerate aging, even in young adults. Conversely, certain dietary patterns, such as plant-based or balanced diets, appear to slow down biological aging. This article explores the study’s methodology, key findings, and the broader implications for public health and personal well-being.
Biological Aging and Epigenetic Clocks
Biological aging is a complex process influenced by genetics, lifestyle, and environmental factors. Unlike chronological aging, which progresses at the same rate for everyone, biological aging can vary significantly between individuals. Some people may experience faster biological aging due to poor lifestyle choices, while others maintain a younger biological age through healthy habits.
Epigenetic clocks, such as GrimAge and DunedinPACE, measure biological aging by analyzing patterns of DNA methylation. DNA methylation is a chemical modification that regulates gene activity without altering the genetic sequence itself. Scientists have found that specific DNA methylation patterns correlate strongly with health outcomes, including lifespan, disease risk, and aging-related decline.
GrimAge, one of the most widely used epigenetic clocks, estimates biological age by considering DNA methylation markers associated with smoking, inflammation, and metabolic health. The difference between GrimAge and a person’s actual age provides a measure of "age acceleration"—a higher GrimAge indicates that an individual is aging faster than expected.
DunedinPACE, another epigenetic clock, evaluates the pace of aging rather than absolute age acceleration. It calculates how many biological years a person gains per chronological year. A higher DunedinPACE score suggests a faster rate of aging, whereas a lower score indicates a slower pace of aging.
The Study: Twins, Diet, and Aging
To explore the connection between diet and biological aging, researchers analyzed data from the FinnTwin12 study, a population-based twin cohort in Finland. This study focused on 826 twins between the ages of 21 and 25, making it one of the few investigations examining biological aging in young adults.
The researchers used food frequency questionnaires to assess participants’ dietary habits. This method allowed them to categorize individuals into distinct dietary patterns based on the types and quantities of foods they consumed. Biological aging was then measured using the GrimAge and DunedinPACE epigenetic clocks.
Because the study involved twins, researchers could also control for genetic and environmental factors. By comparing identical (monozygotic) and fraternal (dizygotic) twins, they could determine whether observed associations between diet and aging were due to genetic predispositions or modifiable lifestyle choices.
Six Distinct Dietary Patterns
The study identified six primary dietary patterns among participants:
1. High fast food, low fruits and vegetables (F&V): Characterized by frequent consumption of fast food, processed meats, and sugar-sweetened beverages, with minimal intake of fruits and vegetables.
2. Plant-based: Rich in vegetables, fruits, whole grains, and plant-derived proteins, with limited consumption of meat and processed foods.
3. Health-conscious: Emphasized low-fat dairy, lean meats, whole grains, and nutrient-dense foods.
4. Western with infrequent fish: Included a high intake of processed red meats, fast food, and sugary beverages, but with minimal fish consumption.
5. Western with regular fish: Similar to the previous pattern but with more frequent fish consumption.
6. Balanced average: Featured a moderate intake of all food groups, avoiding extreme dietary habits.
Fast Food and Accelerated Aging
The study’s findings revealed that individuals in the High fast food, low F&V group exhibited the highest levels of biological age acceleration. Their GrimAge scores indicated that they were aging faster than their peers, suggesting that poor dietary choices had already impacted their biological markers.
This aligns with previous research linking processed foods, high-fat diets, and excessive sugar consumption to inflammation and metabolic dysfunction. Fast food diets are often high in refined carbohydrates, trans fats, and sodium, all of which contribute to oxidative stress and chronic disease. Over time, these factors may accelerate biological aging by damaging cellular structures and impairing DNA repair mechanisms.
Benefits of Plant-Based and Health-Conscious Diets
In contrast, participants following a Plant-based or Health-conscious diet showed significantly slower biological aging. Their GrimAge and DunedinPACE scores were lower, indicating that their bodies were aging at a slower rate than their chronological age would suggest.
These dietary patterns are rich in antioxidants, fiber, and essential nutrients that support cellular health. Fruits and vegetables contain polyphenols—natural compounds that protect cells from oxidative damage and inflammation. Whole grains and plant-based proteins provide essential amino acids and micronutrients that contribute to DNA stability and repair.
Previous studies have demonstrated similar findings, showing that diets rich in fruits, vegetables, and healthy fats can slow down biological aging and reduce the risk of age-related diseases such as cardiovascular disease and type 2 diabetes.
Role of Genetics and Lifestyle
One of the most intriguing aspects of this study was its twin-based approach, which allowed researchers to separate genetic influences from environmental factors. Identical twins share the same genetic makeup, while fraternal twins share only about 50% of their genes. By comparing dietary habits and biological aging markers within twin pairs, the researchers could determine how much of the association was due to lifestyle choices rather than genetic predisposition.
The results showed that while genetics play a role in biological aging, dietary choices significantly influence the rate at which individuals age. In particular, fraternal twins who followed different diets exhibited greater differences in biological aging than identical twins. This suggests that dietary habits are a key modifiable factor in determining how quickly a person ages.
Lifestyle Factors and Their Influence
Beyond diet, other lifestyle factors influenced biological aging. Participants with higher BMI, lower physical activity levels, and greater alcohol consumption tended to show faster aging. When researchers adjusted for these variables, the impact of diet on aging was still significant, but slightly weaker.
This finding suggests that while diet is a crucial factor, a holistic approach to health—including exercise, weight management, and avoiding harmful habits—is essential for longevity. Physical activity has been shown to enhance mitochondrial function, reduce inflammation, and improve metabolic health, all of which contribute to slower aging.
Gender Differences in Aging and Diet
Interestingly, the study found that the relationship between diet and biological aging differed between men and women. When using the DunedinPACE clock, men showed a stronger correlation between dietary patterns and aging pace, whereas women exhibited a weaker association.
This may be due to hormonal differences, metabolic variations, or lifestyle behaviors that influence how dietary components interact with biological systems. Further research is needed to understand why these gender differences exist and how dietary recommendations might be tailored accordingly.
Implications for Public Health
The findings of this study have important implications for public health and nutrition guidelines. Encouraging young adults to adopt healthier eating habits could have long-term benefits for reducing chronic disease risk and promoting longevity. Since biological aging begins early in life, preventive measures should start in adolescence and young adulthood.
Public health initiatives could focus on increasing awareness about the impact of diet on aging, improving access to healthy foods, and discouraging excessive consumption of processed foods and sugary beverages. Schools, universities, and workplaces could play a role in promoting healthier dietary choices through education and better food options.
Conclusion
This study provides compelling evidence that dietary choices influence biological aging, even in young adults. While genetics play a role, adopting a nutrient-rich diet with plenty of fruits, vegetables, and whole foods can slow aging and promote long-term health.
As research in this field continues, the importance of early dietary habits will become even clearer. By making conscious choices about what we eat, we can positively impact our biological age, reduce disease risk, and improve overall well-being.
The study is published in the journal Clinical Nutrition. It was led by Suvi Ravi from University of Jyväskylä.
