Plant-Based Polyphenols Could Be the Secret to Long-Term Heart Protection

A long-term study has found that eating more foods rich in polyphenols could improve heart health over time. These natural compounds, found in plants like berries, coffee, and olive oil, appear to slow the progression of heart disease risk. Researchers say even small dietary changes toward plant-based foods may bring lasting benefits for the heart, gut, and brain.

The research, part of the TwinsUK study, originally tracked around 30,000 participants—mostly female twins—recruited since 1993 by King's College London. Scientists analysed urine samples to measure polyphenol metabolites and found that higher levels were linked to lower cardiovascular risk scores and increased HDL, the so-called 'good' cholesterol.

Polyphenols are natural defence molecules that plants produce to protect themselves. When humans consume them, these compounds seem to work in multiple ways. One key effect is boosting nitric oxide in blood vessels, which helps them relax and improves blood flow.

The study also showed that people with a diet high in polyphenol-rich foods had a slower increase in heart disease risk over time. Foods like nuts, beans, whole grains, herbs, and spices—alongside berries and olive oil—can raise polyphenol intake. Experts suggest that meeting with a registered dietitian can help tailor these dietary changes to individual health needs.

Cardiovascular disease remains the world's leading cause of death. But unlike some risk factors, diet is one area where people can take direct action to protect their heart health.

The findings highlight how gradual shifts toward more plant-based foods may support long-term heart health. Higher polyphenol intake was consistently associated with better cholesterol levels and reduced cardiovascular risk. For those looking to make changes, nutritionists recommend incorporating more berries, nuts, and whole grains into daily meals.