A good bite of dark chocolate may improve your brain function, alleviate stress, and increase longevity, while its excessive consumption leads to obesity and related health risks. The beginning of 2023 also brought bad news that heavy metals were detected in dark chocolate. Another “neither with you nor without you” type of relationship? Here are your scientific arguments.
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Brief history and the manufacture of chocolate
Cocoa was already cultivated 5300 years ago in Central America. Aztecs used it as a drug for the prevention of different ailments. Chocolate was known to increase overall longevity, sexual appetite, and fertility. These health benefits are due to the presence of cocoa and its main antioxidant phytonutrients: polyphenols and flavonoids (mostly catechins, anthocyanins, and proanthocyanidins).
Manufacturing of chocolate is a multistep process consisting of:
- fermentation: the chocolate aroma is formed
- drying: moisture content is reduced to 6–8% for the preservation of cocoa beans
- roasting: 120–140 °C temperature is applied for the decontamination of cocoa beans and also for the generation of chocolate flavor and aroma
- grinding and refining: the texture of the chocolate is dependent on this step
- conching: proper viscosity is achieved, excess moisture is removed from the cocoa, and the desired color is developed
- tempering: to obtain a stable product.
During this whole procedure, unfortunately, the nutrient loss is quite notable. Polyphenol content drops almost 10 times from its original form.
Nutrition values of dark chocolate
High quality dark chocolate with a high cocoa content contains a good amount of soluble fiber together with minerals. A 100-gram bar of dark chocolate with 70–85% cocoa contains:
- 11 grams of fiber,
- 1.8 mg of copper (196% of the Daily Value, also called as DV),
- 12 mg of iron (66% of the DV),
- 228 mg of magnesium (57% of the DV),
- and is plenty of manganese, potassium, phosphorus, zinc, and selenium
Bioactivity and associated health benefits of cocoa
Dark chocolate is rich in total phenolic compounds that provide bitterness, acid taste, cocoa flavor, and astringency.
- Polyphenols (of different types, e.g. phenolic acids, stilbenes, flavonol and flavan-3-ols, and anthocyanins) are one of the major components in cocoa beans (5-6%). Cocoa polyphenol has a preventive role against cancer, cardiovascular diseases, metabolic disorders, and inflammatory diseases. Among non-flavonoids, a commonly occurring compound in the cocoa bean is resveratrol, showing biological activities such as antiproliferative, cardioprotective activities, chemopreventive and anti-inflammatory, antioxidant activities, etc.
- Non-polyphenol bioactive components of cocoa are methylxanthine compounds, among which caffeine and theobromine are the predominant ones. Theobromine increases the level of HDL cholesterol in the blood. It can stimulate heart muscle and also relaxes bronchial smooth muscles in the lungs. Its antioxidant role is used to treat depressive disorders, while its antioxidant effect is helpful for scavenging free radicals.
Cocoa’s health benefits include:
- Protection from diabetes and obesity: It improves insulin sensitivity by reducing insulin resistance.
- Maintenance of healthy lipid profile: a moderate amount of dark chocolate consumption will lead maintenance of blood cholesterol levels in a healthier direction by reducing the amount of LDL (low-density lipoprotein) cholesterol, sometimes called “bad” cholesterol) and total cholesterol while it has no significant effects on HDL (high-density lipoprotein) cholesterol, sometimes called “good” cholesterol, due to its ability to absorb cholesterol in the bloodstream and carry it back to the liver) levels.
- Stimulation of brain functions: The different chemical compounds listed above stimulate cognitive function and also positively modulate mood swings.
- Anti-inflammatory effect: cocoa enhances the expression of mRNA, especially anti-inflammatory cytokines IL10 (small proteins that play a crucial role in preventing inflammatory and autoimmune pathologies) while it also has some direct influence on immune cells.
- Reduction of cardiovascular mortality by about 50%.
- Prevention of degenerative diseases such as Alzheimer’s disease.
Health risks
According to scientific news that came to light at the beginning of this year, the cadmium and lead content of some dark chocolate bars can be worrisome and due to the fact that these heavy metals can cause developmental problems, exposure poses the greatest risk for pregnant people and young children. Too much cadmium can also damage the liver and kidneys. A healthier chocolate alternative you can enjoy in moderation is vegan chocolate.
The bottom line
Cocoa is a good source of flavanols that have been found to have health benefits, including antioxidant properties supporting heart health, improving blood flow and lowering blood pressure, increasing insulin sensitivity, reducing diabetes risk, etc.
However, dark chocolate is also a concentrated source of calories and eating too much of it may result in weight gain and associated health risks. The higher the percentage of cocoa, the higher the flavanol content, meaning that you’d need a smaller serving of chocolate to deliver the same amount of flavanols – still, the amount of chocolate you would have to eat to get the appropriate amount of flavanols would be large enough to tip the scales on the downside.