Total polyphenol intake and mortality in the PREDIMED trial

Researchers studied 7,447 Spanish adults aged 55 to 80 who had a high risk of heart disease. They estimated how much polyphenols, natural plant compounds found in foods such as fruit, vegetables, coffee, tea, and nuts, the participants ate using food questionnaires. After about five years, 327 people had died. Those eating the most polyphenols had a 37% lower chance of dying than those eating the least, but this was an association rather than proof that polyphenols caused the difference.

What this means for you: This supports eating a varied diet rich in plant foods, but it does not prove that polyphenol supplements will help. The study cannot fully separate polyphenols from other healthy habits, so there is no clear reason to buy a supplement.