- A King’s College London study found higher blood levels of theobromine were linked with a younger biological age
- The association showed up across two European cohorts using DNA based ageing measures and telomere related markers
- It does not prove dark chocolate slows ageing and the researchers are clear that eating more chocolate is not the takeaway
A compound naturally found in cocoa has been linked with signs of slower biological ageing, according to researchers at King’s College London.
The molecule is theobromine, an alkaloid present in dark chocolate and cocoa products.
Rather than looking at how much chocolate people said they ate, the study measured theobromine in participants’ blood and compared it with markers that estimate biological age.
Biological age is meant to reflect how the body is functioning, not just the number of birthdays someone has had.
In this study, ageing was assessed using blood based measures including DNA methylation patterns, which shift over time and are commonly used to estimate the pace of ageing.
The researchers analysed data from two European cohorts, including TwinsUK and the German KORA study.
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Across both groups, people with higher circulating theobromine tended to show a biological age that looked younger than their chronological age.
They also checked whether other cocoa or coffee related metabolites showed a similar pattern. In their analysis, theobromine was the standout, with other measured compounds not showing the same association.
To estimate biological ageing, the team used two approaches.
One focused on DNA methylation signals linked to the pace of ageing. Another drew on telomere related measures.
Telomeres are protective caps on chromosomes that tend to shorten over time and are often discussed in relation to ageing and age related disease risk.
The study suggests theobromine levels tracked with these ageing readouts.
Even if the result holds up, it is important not to overread it.
This is an association study, not proof that theobromine causes slower ageing.
Higher theobromine in blood could be a marker of diet, lifestyle, metabolism or other factors that also influence ageing biology.
The researchers are now looking at whether theobromine acts alone or alongside other cocoa components, including polyphenols, which are already studied for potential health effects.
They also spell out the obvious point that gets lost in headlines: chocolate is not a supplement.
Many chocolate products come with plenty of sugar and fat, and changing intake on the basis of one early finding is not a smart move.
What this study does offer is a plausible lead for future research into how diet derived metabolites might interact with the epigenome and ageing pathways.
Reference: Saad R et al. Theobromine is associated with slower epigenetic ageing. Aging. 10 December 2025.
