A two-week study in 34 older adults given high-flavanol cocoa found blood flow to the brain increased by 8% after one week and 10% after two weeks (14).
Further studies suggest that daily intake of cocoa flavanols can improve mental performance in people with and without mental impairments (15, 16, 17).
These studies indicate a positive role of cocoa on brain health and possible positive effects on neurodegenerative diseases like Alzheimer’s and Parkinson’s. However, more research is needed.
Summary Flavanols in cocoa can support neuron production, brain function and improve blood flow and supply to brain tissue. They may have a role in preventing age-related brain degeneration, such as in Alzheimer’s disease, but more research is needed.
In addition to cocoa’s positive impact on age-related mental degeneration, its effect on the brain may also improve mood and symptoms of depression (2).
The positive effects on mood may be due to cocoa’s flavanols, the conversion of tryptophan to the natural mood stabilizer serotonin, its caffeine content or simply the sensory pleasure of eating chocolate (12, 18, 19).
One study on chocolate consumption and stress levels in pregnant women found that more frequent intake of chocolate was associated with reduced stress and improved mood in babies (20).
Furthermore, another study discovered that drinking high-polyphenol cocoa improved calmness and contentment (12).
Additionally, a study in senior men showed that eating chocolate was linked to improved overall health and better psychological well-being (21).
While the results of these early studies are promising, more research on the effect of cocoa on mood and depression is needed before more definite conclusions can be drawn.
Summary Cocoa may exert some positive effects on mood and symptoms of depression by reducing stress levels and improving calmness, contentment and overall psychological well-being. However, more research is needed.
Though overconsumption of chocolate is certainly not good for blood sugar control, cocoa does, in fact, have some anti-diabetic effects.
Test-tube studies indicate that cocoa flavanols can slow down carbohydrate digestion and absorption in the gut, improve insulin secretion, reduce inflammation and stimulate the uptake of sugar out of the blood into the muscle (22).
Some studies have shown that a higher intake of flavanols, including those from cocoa, can result in a lower risk of type 2 diabetes (22, 23).
Additionally, a review of human studies showed that eating flavanol-rich dark chocolate or cocoa can reduce insulin sensitivity, improve blood sugar control and reduce inflammation in diabetic and nondiabetic people (22).
Despite these promising results, there are inconsistencies in the research with some studies finding only a limited effect, slightly worse control of diabetes or no effect at all (22, 24, 25).
Nevertheless, these results combined with the more concrete positive effects on heart health indicate cocoa polyphenols may have a positive impact on both preventing and controlling diabetes, though more research is required.
Summary Cocoa and dark chocolate may reduce your risk of diabetes and maintain healthy blood sugar levels. However, there are some conflicting results in the scientific evidence, so more research is needed.
Somewhat paradoxically, cocoa intake, even in the form of chocolate, may help you control your weight.
It’s thought that cocoa may help by regulating the use of energy, reducing appetite and inflammation and increasing fat oxidation and feelings of fullness (26, 27).
A population study found that people who consumed chocolate more frequently had a lower BMI than people who ate it less often, despite the former group also eating more calories and fat (28).
Additionally, a weight loss study using low-carbohydrate diets found that a group given 42 grams or about 1.5 ounces of 81% cocoa chocolate per day lost weight faster than the regular diet group (29).
However, other studies have found that chocolate consumption increases weight. Yet, many of them did not differentiate between the type of chocolate consumed — white and milk chocolate do not have the same benefits as dark (30, 31).
Overall, it appears that cocoa and cocoa-rich products may be helpful in achieving weight loss or maintaining weight, but further studies are needed.
Summary Cocoa products are associated with a lower weight, and the addition of cocoa to your diet may help achieve faster weight loss. However, more research is needed on this topic to determine exactly what type and how much cocoa is ideal.
Flavanols in fruits, vegetables and other foods have attracted a great deal of interest due to their cancer-protective properties, low toxicity and few adverse side effects.
Cocoa has the highest concentration of flavanols out of all foods per weight and can significantly contribute to their amount in your diet (32).
Test-tube studies on components of cocoa have found that they have antioxidant effects, protect cells against damage from reactive molecules, fight inflammation, inhibit cell growth, induce cancer cell death and help prevent the spread of cancer cells (32, 33).
Animal studies using a cocoa-rich diet or cocoa extracts have seen positive results in reducing breast, pancreatic, prostate, liver and colon cancer, as well as leukemia (32).
Studies in humans have shown that flavanol-rich diets are associated with a decrease in cancer risk. However, the evidence for cocoa specifically is conflicting, as some trials have found no benefit and some have even noticed an increased risk (34, 35, 36).