Dark Chocolate Compound Linked to Slower Biological Aging
Higher blood levels of a cocoa compound were linked to slower biological aging in two European studies.
The idea that “you are what you eat” is gaining new meaning as researchers explore how diet shapes biological aging.
In a study led by researchers at King’s College London, higher blood levels of theobromine, a compound found in cocoa, were associated with slower biological aging in two large European population studies.
What is biological aging?
Aging is not just about the number of years lived; people of the same chronological age can differ widely in health, disease risk and survival. This has led researchers to focus on biological aging – a measure of how quickly the body’s cells and tissues decline over time.
One way to estimate this is by using DNA-based markers in blood. These “epigenetic clocks” track chemical tags on DNA that change as we age.
Diet is one of the most studied factors that may shape biological aging. Research has linked overall diet quality, calorie restriction and certain nutrients to slower changes in these DNA markers. One popular area of study includes plant-derived compounds, such as cocoa and coffee. Consumption of these has been linked to lower rates of cardiovascular disease and death. However, these foods contain many compounds, and it has been difficult to pinpoint which ones might matter for aging.
Theobromine is a naturally occurring compound found in high amounts in cocoa and dark chocolate. It belongs to the same chemical family as caffeine but has different effects in the body. Studies in worms and observational work in humans have hinted at health benefits, including longer lifespan. However, there has been no clear evidence that links theobromine to molecular markers of aging in people, separate from caffeine and other cocoa components.
The new study aimed to investigate whether blood levels of theobromine are linked to slower biological aging in humans, and whether this link is specific to theobromine.
Theobromine levels and biological aging
The team analyzed data from two large European cohorts: the TwinsUK study, which included 509 adult women, and the German KORA cohort, used to replicate the findings in 1,160 men and women.
Instead of relying on diet questionnaires, the team measured theobromine directly in blood samples using a mass spectrometry method that captures a wide range of small molecules in serum.
To estimate biological aging, the researchers focused on two DNA-based measures from blood. The first was GrimAge acceleration, a marker strongly linked to the risk of death. The second estimated telomere length, a feature of chromosomes that shortens with age. Other aging clocks were also examined but showed less consistent patterns.
The analysis accounted for age, body mass index, blood cell types and family relationships in the twin cohort. The team also ran multiple checks to rule out confounding, including adjusting for caffeine and related compounds, and using statistical methods designed to deal with closely related variables. The main findings were then tested in the KORA cohort, where blood and DNA samples were taken at the same time.
Across both cohorts, higher levels of theobromine were linked to slower biological aging. The association was strongest for GrimAge acceleration and weaker, but still present, for the telomere-based measure.
No similar links were seen for caffeine or other coffee-related compounds.
A stronger association also appeared in smokers, although this subgroup was small.
What the findings mean for aging research
“Our study finds links between a key component of dark chocolate and staying younger for longer,” said senior author Dr. Jordana Bell, a professor in epigenomics at King’s College London.
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“While we’re not saying that people should eat more dark chocolate, this research can help us understand how everyday foods may hold clues to healthier, longer lives,” she added.
However, the aging measures used are only indications and are not direct readouts of aging or lifespan. It is also possible that theobromine reflects intake of other cocoa compounds, such as flavanols, which were not directly measured.
“This study identifies another molecular mechanism through which naturally occurring compounds in cocoa may support health. While more research is needed, the findings from this study highlight the value of population-level analyses in aging and genetics,” said co-author Dr. Ricardo Costeira, a postdoctoral research associate at King’s College London.
Controlled trials that isolate theobromine intake would help test causality, and laboratory studies could clarify how theobromine interacts with gene regulation.
“This is a very exciting finding, and the next important questions are what is behind this association and how can we explore the interactions between dietary metabolites and our epigenome further? This approach could lead us to important discoveries towards aging, and beyond, in common and rare diseases,” added lead author Dr. Ramy Saad, a honorary research fellow at University College London.
Reference: Saad R, Costeira R, Matías-García PR, et al. Theobromine is associated with slower epigenetic ageing. Aging. 2025. doi: 10.18632/aging.206344
This article is a rework of a press release issued by King's College London. Material has been edited for length and content.
