What does the evidence say about chocolate and health?

Chocolate has been called a medicine for about five hundred years. In the 16th century the royal physician Francisco Hernández reported to Spain a range of conditions he believed chocolate and its additives could treat. By 2009, dark chocolate had a popular resurgent interest after public attention to health claims about its polyphenolic antioxidants. So what does modern evidence say? Mostly: something small, and not settled.

Start with what a bar is. One hundred grams of milk chocolate supplies 540 calories and is 52 percent sugar and 30 percent fat, and commonly eaten chocolate is high in fat and sugar, which are associated with an increased risk of obesity when eaten in excess.

The interest in cocoa comes from polyphenols, especially flavan-3-ols, also called flavanols. Cocoa beans contain them, but they are susceptible to heat degradation during processing, so the flavanol content in chocolate is relatively low and highly variable. Processing matters: one study reported that light dutching destroyed 60 percent of natural cocoa's original antioxidants and heavy dutching 90 percent.

The research is modest. Reviews support a short-term lowering of blood pressure from cocoa products, but there is limited evidence of long-term cardiovascular benefit. Research has shown that flavan-3-ols may affect vascular function, blood pressure and blood lipids, with only minor effects demonstrated as of 2019.

Regulators have reached different verdicts on related claims. In 2015 the European Commission approved a claim that 200 milligrams a day of cocoa flavanols may contribute to maintenance of vascular elasticity and normal blood flow. In 2023 the US Food and Drug Administration said there is very limited credible scientific evidence linking cocoa flavanols to reduced risk of cardiovascular disease, citing few credible studies, questionable methodology, short duration and inconsistent results.