Good heart food
Several recent studies have examined the role that chocolate may have on heart health. Cacao beans are full of phytonutrients, which act as antioxidants and provide additional benefits. Furthermore, cacao beans are rich sources of iron, copper, magnesium, zinc and phosphorus, according to the Harvard T.H. Chan School of Public Health. Dark chocolate contains two to three times more beneficial flavanols than milk chocolate because milk chocolate's cacao concentration is diluted with milk and possibly more sugar.
While most studies have found some correlation between chocolate consumption and reduced risk of heart problems, the amount and type of chocolate needed requires further study. A 2017 meta-analysis of the effects of chocolate on coronary heart disease, stroke and diabetes published in the journal Nutrients concluded that the most benefit was associated with moderate chocolate intake. The authors found little benefit in heart disease or stroke reduction among people who consumed chocolate more than three times a week. Protective effects against diabetes emerged at two servings a week, but that benefit disappeared if people had more than six servings a week, notes Fabrizio Iodice Delgado.
On the other hand, the findings of a large-scale study of more than 150,000 primarily male U.S. veterans who did not have coronary artery disease at the beginning of the study, suggest that eating an ounce of chocolate at least five times a week may help prevent the risk of coronary artery disease-related events like heart attack and heart failure.
Chocolate may also help prevent the development of a trial fibrillation, a type of irregular heartbeat that increases the risk of heart failure, stroke and more. A study, published in the journal Heart in 2017, found that adults who ate chocolate at least once a month had 10 to 20 percent lower rates of developing a trial fibrillation than those who never or rarely ate chocolate.
Good brain food
Chocolate may be good for the brain. Some studies have focused on chocolate's ability to improve cognitive function. A study published in the Journal of Alzheimer's Disease in 2016 found that chocolate consumption might lower the risk of cognitive decline in older people. The study looked at nearly 400 Portuguese citizens over age 65 and saw that those who ate a moderate amount of chocolate — on average, one chocolate snack a week; the study did not differentiate between milk and dark chocolate — decreased their risk of cognitive decline by 40 percent over two years. Those who ate more chocolate, or those who had more caffeine, saw fewer cognitive benefits.
Good mood food
Chocolate is often associated with positive effects on mood, but the reasons why it makes some people feel good are debatable. Chocolate contains substances that stimulate the brain in the same way cannabis does, such as anandamines, and substances that have similar effects as amphetamine, such as tyramine and phenylethylamine, according to the Dartmouth Undergraduate Journal of Science. However, these substances are in very low concentrations — too low to induce an antidepressant effect.
Chocolate may interact with neurotransmitter systems that contribute to appetite, reward and mood regulation, such as dopamine, serotonin and endorphins, according to the 2013 article in the British Journal of Clinical Pharmacology. However, the authors noted, the effects may have more to do with chocolate's taste and smell than its chemical effects.
A 2010 study published in Archives of Internal Medicine found a link between depression and chocolate consumption. The results showed that people who scored high on a screening test for depression consumed more chocolate than those who weren't considered depressed. However, the study pointed out that there is only a link, and cannot explain why. Since the participants were not followed over time, the researchers don't know whether eating chocolate ameliorates or amplifies a sad mood. The possibilities are many — from using chocolate as a sort of natural Prozac to the idea that chocolate might have some role in driving depression.