Scientists find dark chocolate ingredient that slows aging

The study, published on December 10 in Aging, analyzed how much theobromine was present in participants' blood and compared those levels with biological aging markers measured in blood samples.

What Biological Age Reveals

Biological age reflects how well a person's body is functioning, rather than the number of years they have lived. This measure is based on DNA methylation, a collection of tiny chemical tags on DNA that shift as we grow older.

The research team examined data from two European groups, including 509 people from TwinsUK and 1,160 from KORA. Individuals with higher amounts of theobromine in their bloodstream tended to have a biological age that appeared younger than their chronological age.

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."

Theobromine Stands Out Among Cocoa Compounds

The team also investigated whether other cocoa or coffee metabolites showed similar patterns. Their results suggested that theobromine was the only compound with this specific association.

To estimate biological age, the researchers used two approaches. One method examined DNA changes that reflect the pace of aging. The second measured telomere length, which refers to protective structures at the ends of chromosomes. Telomeres naturally shorten with age and are linked to age-related health risks.

How Plant Molecules Influence Aging

Many plant compounds in foods can influence how genes operate by turning them on or off. These compounds, known as alkaloids, can interact with cellular systems that regulate gene activity and contribute to long-term health.

Theobromine is one such alkaloid. Although it is widely known for being toxic to dogs, it has been connected to possible benefits in humans, including a reduced risk of heart disease. Despite this, it has received relatively limited scientific attention until now.

Next Questions for Aging Research

Dr. Ramy Saad, lead researcher at 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 team, which includes Professor Ana Rodriguez-Mateos, a Professor of Human Nutrition at King's College London, is now examining whether theobromine's effect occurs on its own or if it works alongside other well-known components of dark chocolate such as polyphenols, which are recognized for their positive effects on health.

Why More Chocolate Is Not a Shortcut

Dr. Ricardo Costeira, a Postdoctoral Research Associate at King's College London, said: "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."

Although the findings are encouraging, the researchers caution that increasing dark chocolate consumption is not automatically beneficial. Chocolate also contains sugar, fat and other ingredients, and more work is needed to fully understand how theobromine interacts with the body and how it may influence aging.