Extended Summary
Chocolate is made from cocoa beans through a composite of steps, ranging from fermentation to shelling. Depending on the amount of cocoa, the final product is classified as either white chocolate, milk chocolate, or dark chocolate. White chocolate contains no cocoa; milk chocolate contains some cocoa (< 50% cocoa); dark chocolate is mostly cocoa (> 50% cocoa). As a result, the nutrient content of chocolate varies depending on the specific type. For example, dark chocolate contains more copper and fiber but less vitamin B12 and riboflavin compared to white and milk chocolate. However, because all chocolate is rich in saturated fat and generally contains an appreciable amount of added sugar, it is often labelled a “junk food”. This phrase could mean many things. Here, we define “junk food” as food that negatively impacts health even in low amounts.
Given the overwhelming evidence to support eating less saturated fat and substituting it with unsaturated fat, intuition could lead someone to avoid all sources of saturated fat. But this is not necessarily required for good health. A few foods are exceptions to this guidance, and chocolate is one of them. The reason why is because one-third of chocolate’s fat comes from a long-chain saturated fatty acid called stearic acid, which unlike other types of saturated fat, causes either no change or slightly lowers LDL-C (a risk factor for cardiovascular disease). Let’s also remember that saturated fat is only one component of chocolate. As always, to understand the healthfulness of a food, we must review the entire food matrix (the totality of nutrients and their interactions) and its association with health outcomes at different levels of intake.
Accordingly, in a cohort of more than 37,000 Swedish men, there was a significant 13% reduction in stroke incidence when comparing high (62.9 grams per week) versus low (0 grams per week) chocolate intakes. This finding was corroborated in the Potsdam arm of the EPIC cohort and also the ATBC study. In the former study, participants who consumed 52.5 grams of chocolate per week had a 39% reduction in their risk of heart attacks and stroke relative to participants who consumed 11.9 grams of chocolate per week. In the latter and more recent study, participants that consumed 86.6 grams of chocolate per week had a 12% reduction in all-cause mortality and a 13% reduction in cardiovascular disease relative to non-consumers, in the fully adjusted model.
If we analyse more comprehensive summaries of the evidence base, a meta-analysis of 14 prospective cohort studies, published in 2019, revealed that eating up to 100 grams of chocolate per week significantly reduced the risk of cardiovascular disease. Eating no chocolate was not better than eating some. Around 45 grams of chocolate per week was deemed the maximal reduction in cardiovascular disease risk: 11% less than eating no chocolate. This amount of chocolate in grams equals approximately a single chocolate square per day or a single chocolate bar per week (a snack-sized bar, that is, not one to feed the family!). Evidently, that isn’t much chocolate. The researchers hypothesised that greater amounts of chocolate may neutralise the potential cardiovascular disease benefits due to the high added sugar, possibly risking weight gain. Nonetheless, their results favour low to modest chocolate consumption to reduce the risk of cardiovascular disease.
To add to the observational pool of evidence, a recent randomised controlled trial (RCT) examining hard outcomes adds another layer of confidence to the consistently noted association. COSMOS, the name of the study, was the first randomised, double-blind, placebo-controlled trial examining the long-term impact of cocoa flavonoid supplementation on cardiovascular disease and cancer risk in older adults. The researchers randomised the participants to one of four dietary interventions: active cocoa supplement and active multivitamin; active cocoa supplement and multivitamin placebo; active multivitamin and cocoa placebo; or both placebos. Researchers found that participants supplementing the cocoa extract experienced no significant benefit on the primary outcome of total cardiovascular events. However, when the researchers conducted a separate analysis to account for participants not adhering to the intervention, they calculated a 15% significant reduction in the risk of total cardiovascular events and a 39% reduction in the risk of cardiovascular-related death.
Overall, we do not consider food that positively impacts health in low amounts as “junk food”. We understand that chocolate has a bad reputation due to its saturated fat and sugar content, but the research findings on the food as a whole are generally positive. It should be more widely known that the primary type of saturated fat in chocolate is stearic acid, which appears to have little to no effect on LDL-C compared to other types of saturated fat. The (added) sugar content is a concern, but the benefits of chocolate still appear to outweigh the potential harms in modest amounts (less than 100 grams per week).
