Does dark chocolate or cocoa benefit your heart?
Dark chocolate with a high cocoa content appears to be good for your heart, but the evidence is still based on studies that track people over time rather than test a treatment directly. A small daily portion of dark chocolate is worthwhile, but large amounts are not, because of the calories.
Dark chocolate with a high cocoa content has been linked in multiple studies to beneficial effects on the heart and blood vessels. Flavanols, the active compounds in cocoa, help blood vessels relax through nitric oxide, reduce inflammation, and lower the tendency of blood platelets to clump together. How strong these effects are in practice has not been fully proven in people; some of the evidence comes from laboratory and mechanism studies.
What this means in concrete terms: in three large studies in which more than 192,000 people were followed for years, eating five or more portions of dark chocolate per week was linked to a 21% lower risk of type 2 diabetes. That also matters for your heart, because diabetes substantially raises the risk of cardiovascular disease. For each additional portion per week, the risk falls by around 3%. The same studies also show favourable associations with blood pressure and the health of blood vessels. However, you cannot draw a firm cause-and-effect conclusion from this.
Dark chocolate contains saturated fat, but that does not appear to cancel out the beneficial effect. A wide-ranging review concluded that dark chocolate, despite its fat content, is not linked to a higher risk of cardiovascular disease. What matters is the food as a whole, not any single ingredient.
For milk chocolate the opposite applies. It showed no protective effect and was instead associated with weight gain. The beneficial effects are specific to dark chocolate with a high cocoa content. In addition, chocolate is calorie-dense: eating too much leads to weight gain, which is itself a risk factor for cardiovascular disease. Experts speak of 'moderate amounts', although an exact portion size is rarely defined.
The evidence is mainly associative, based on people followed over time and reviews of existing studies. There are no well-designed studies in people that directly prove protection against heart disease. Some of the biological mechanisms have so far only been demonstrated in laboratory settings.
Is coffee good or bad for your heart?
For most healthy adults, three to four filtered cups per day is associated with a beneficial effect on the heart and blood vessels. Pregnant women are an important exception: for them, the maximum is around two cups per day.
Are calcium supplements bad for your heart?
Calcium supplements may be associated with an increased heart risk, but not all studies confirm this. It is best to get calcium from your diet, and discuss with your doctor whether a supplement is truly necessary for you.
Is the Mediterranean diet really good for your heart, and why?
For people at increased heart risk, the Mediterranean diet is the best-supported dietary choice currently available. Both large studies in people and dozens of population studies confirm a lower risk of heart attack and stroke.
Do omega-3 (fish oil) supplements benefit my heart?
Fish oil reliably lowers triglycerides and can slightly reduce the risk of a heart attack in people with existing heart disease or high risk, but it does not demonstrably lower the overall risk of death. Always discuss its use with your doctor if you have a condition or are on medication.
Is a calcium score of my heart worth doing?
For people between 40 and 75 years old in a grey zone regarding statins, a calcium score is a well-supported tool for making a well-considered decision about medication together with your doctor.
Does CoQ10 help your heart or your energy levels?
For people with moderate to severe heart failure, CoQ10 has the most convincing evidence; for energy or sports performance in healthy people the evidence is too weak to promise anything, though the supplement is safe.