Researchers at King's College London have identified theobromine, a cocoa-derived compound, as being associated with slower biological aging. In a study published on December 10, 2025, in the journal Aging, higher blood levels of theobromine were linked to younger biological ages in participants from two European cohorts. Scientists say the findings are promising but caution that they do not justify eating more dark chocolate without further research.
Scientists from King's College London analyzed blood samples from 509 participants in the TwinsUK study and 1,160 participants in the KORA cohort to explore links between dietary metabolites and biological aging markers.
The team measured levels of theobromine — a plant alkaloid naturally found in cocoa and dark chocolate — in the blood and compared them with measures of biological age based on DNA methylation and telomere length. Individuals with higher concentrations of theobromine tended to have biological ages that appeared younger than their chronological ages, according to the summary published by King's College London via ScienceDaily.
Researchers also examined whether other metabolites from cocoa or coffee showed similar associations. In this analysis, theobromine stood out as the only compound with this specific link to slower epigenetic aging.
To estimate biological age, the study used two approaches. One examined DNA methylation changes that reflect the pace of aging, and the other measured telomere length, the protective caps at the ends of chromosomes that naturally shorten with age and are associated with age-related health risks.
Theobromine is one of several alkaloids present in cocoa. It is widely known to be toxic to dogs and has also been connected in previous human research to potential cardiovascular benefits, including a reduced risk of heart disease, though it has received relatively limited scientific attention compared with other cocoa components.
Professor Jordana Bell, senior author and Professor in Epigenomics at King's College London, said: "Our study finds links between a key component of dark chocolate and staying younger for longer. 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."
Lead researcher Dr. Ramy Saad, of King's College London and also affiliated with University College London as a doctor in Clinical Genetics, said: "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."
The research team, which includes Professor Ana Rodriguez-Mateos, Professor of Human Nutrition at King's College London, is now examining whether theobromine's effects occur independently or in combination with other well-known cocoa components such as polyphenols, which are recognized for their potential health benefits.
Dr. Ricardo Costeira, a Postdoctoral Research Associate at King's College London, noted: "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."
The researchers stress that dark chocolate also contains sugar, fat and other ingredients, so the results should not be interpreted as a recommendation to increase chocolate consumption. More work is needed to understand how theobromine interacts with the body and the epigenome, and how it may influence aging over time.
