Chocolate: health benefits

In this Article (Index)

• What is Chocolate?
• Chocolate's composition: Bioactive chemicals
• Chocolate and its Health Benefits
• Brain & cognitive health
• Mood boosting
• Dark Chocolate Reduces Depression
• Probiotic effects
• Diabetes
• Cardiovascular Disease, Cancer, and Overall Death
• Sleep and Chocolate
• Theobromine
• Caffeine
• Magnesium in Chocolate and Sleep
• When to eat chocolate?
• Weight Gain
• Risks

What is Chocolate?

Cocoa or Cacao

Cocoa (or Cacao) is the raw material used to make chocolate. It originates from the fruit of the cacao trees (Theobroma cacao L.). The trees are native to Central and South America where it was domesticated some 7,000 years ago and fermented into an alcoholic beverage. It was considered a gift of the gods.

The main sources of cocoa are found in Africa, with 68% of the global production (Ivory Coast, Ghana, Cameroon), Asia with 17% (Indonesia), and America with 15% (Ecuador, Brazil).

The fruit of the cacao tree or cacao pod weighs about 1 lb (450 g) and contains between 20 and 60 seeds known as beans. These beans are bitter, and they are fermented to improve their flavor. Then they cleaned, dried, roasted, and further processed into cocoa solids and cocoa butter, the main ingredients of chocolate.

Chocolate

Chocolate like cacao, are words derived from the Nahuatl language in Mexico.

Chocolate is prepared from cocoa butter, cocoa solids, sugar, vegetable oils, flavorings, and emulsifiers.
These ingredients are thoroughly mixed in a process called "conching," and tempered to make it shiny and smooth.

Dark chocolate contains 50 to 90% cocoa and less added sugar than milk chocolate which has a lower cocoa content (10 to 50%), milk, milk solids, and far more added sugar. Casein, a protein found in milk also serves as an emulsifier.

Switzerland has the highest intake of chocolate per capita with 31.7 g per day, followed by the U.S. with 24.7 g, which is equivalent to roughly 3 bars of chocolate per person per week. (11)

Chocolate's composition: Bioactive chemicals

Cocoa's components

Cocoa beans contain carbohydrates, fiber, proteins, lipids, minerals, and bioactive components.

After processing, it is the cocoa butter that contains lipids or fats, made up of oleic, stearic, and palmitic acids.

Cocoa solids on the other hand have a higher content of minerals, polyphenols, vitamins, and other compounds.

The minerals include magnesium, copper, potassium, and iron.

The stimulant compounds in cocoa are theobromine, caffeine, theophylline, and some alkaloids that act upon the central nervous system.

Antioxidant flavonols

Cocoa beans, are rich in bioactive compounds and have high concentrations of polyphenols such as flavonoids, including flavonols, natural antioxidant agents such as epicatechin. (1)

Dark chocolates are a better source of polyphenols than milk chocolate or cocoa powder drinks because milk has been shown to reduce the absorption of antioxidants from chocolate.

Chocolate and its Health Benefits

Polyphenols in chocolate and other bioactive compounds provide many health benefits. (1)

It has a positive effect on mood, and acts as an anti-depressant, enhancing well-being.

The antioxidant, anti-inflammatory, and vasodilating effects of chocolate improve blood circulation to the brain, scavenge free radicals, promote neural growth, and improve cognition. Its flavonoids offer protection against neurodegenerative diseases.

Polyphenols also reduce the risk of cardiovascular disease, and type-2 diabetes and have cancer-protective properties.

Chocolate also acts upon the gut microbiota as a prebiotic, and this impacts immunity and mood in a positive way.

The following sections explore each of these health benefits of chocolate.

• Brain & cognitive health
• Mood boosting
• Dark Chocolate Reduces Depression
• Probiotic effects
• Diabetes
• Cardiovascular Disease, Cancer, and Overall Death
• Sleep and Chocolate
• Weight Gain

Brain & cognitive health

Flavonols are beneficial for the brain and have been shown to promote the formation of new blood vessels, and the creation of new neurons, especially in the areas involved in learning and memory. This effect improves cognition and could lower the risk of developing Alzheimer's disease. (8)

A Meta-analysis that reviewed 19 studies (18) found that "the biomolecules contained in cocoa may offer promising tools for managing cognitive decline, if provided in adequate dosages and duration of treatment." The study concluded that "these observations reinforce the beneficial effect of cocoa consumption against CD [Cognitive Decline]."

How Does Chocolate Promote Brain Health?

Chocolate's polyphenols improve blood flow which enhances oxygenation, and removes waste (metabolites) they also improve insulin sensitivity which impacts brain aging. Furthermore, the probiotic effects of chocolate, which promote gut microbiome diversity may also have an effect. These microbes break down polyphenols into metabolites, some of which have a role in preventing neurodegeneration, like protocatechuic acid (PCA). (18)

Mood-Boosting Properties of Chocolate

Dark Chocolate Reduces Depression

Chocolate has a positive effect on mood. People tend to eat more chocolate when they are stressed.

A randomized trial using 60 women who, for 8 weeks, ate either 12 6/day of 78% dark chocolate or milk chocolate, investigated the effects of chocolate on depression and sleep.

Dark chocolate "significantly reduced" their depression score compared to the milk chocolate eaters. However, no difference was noticed regarding sleep quality, weight, BMI, waist, and hip circumference. (7)

How does chocolate improve your Mood?

There are many ways that chocolate exerts its mood-improving effects, and it does so through its chemical makeup.

Chocolate contains amines like tryptophan, phenylethylamine, tyrosine, and tyramine which have an effect on mood.
Tyrosine, an amino acid contained in chocolate is used by the body to synthesize dopamine, a chemical messenger (neurotransmitter) in the brain that contributes to feelings of happiness, motivation, and focus.

Phenylethylamine has a stimulating "amphetamine-like" effect on the brain leading to the release of norepinephrine and dopamine.

Chocolate also causes the brain to release endorphins, that interact with the opioid receptors in the brain causing pleasant feelings. (1)

Methylxanthines found in chocolate, like theobromine, have similar positive mood effects to caffeine. The amount of theobromine in 40 g of dark chocolate is considered optimal. (10)

Chocolate also contains very small amounts of Anandamide (0.5 mg/g) a lipid that binds to cannabinoid receptors in the brain and mimics the psychoactive effects of tetrahydrocannabinol (THC) found in marijuana. (1)

Finally, its interaction with the gut microbiome may also contribute to its mood-enhancing effects as we will see in the next section.

Probiotic Effects

A randomized trial studied healthy adults eating either 30 g/day of 85% cocoa chocolate, 70% cocoa, or no chocolate for 3 weeks, and evaluated their mood and gut microbiome, since the gut-brain axis mediated by microbes affects emotional health. (14)

The trial found that "daily intake of dark chocolate significantly reduced negative affect in the 85% cocoa chocolate group..., but not in the 70% cocoa chocolate [group]."
There were other interesting observations:

• The reduction in negative feelings in the 85% group was attributed to the higher polyphenol content in the 85% chocolate (400 mg) vs. the 250 mg found in the 70% chocolate.
• Gut microbial diversity was significantly higher in the 85% chocolate group in comparison to the "no chocolate" group.
• 85% chocolate increased levels of Blautia obeum a microbe that promotes good mood through its synthesis of butyrate a short chain fatty acid (SCFA), that modulates how the brain works, affects appetite, and also counteracts leaky gut.
  Studies with mice and rats revealed its anti-depressant-like effects. Human studies have shown that patients suffering from Major depressive disorder, autism, and schizophrenia have lower levels of Blautia in their guts.

This study (2) that investigated the effects of chocolate on sleep (discussed further down) also revealed that dark chocolate exerts a prebiotic effect that modifies the diversity and abundance of the gut microbiota.

Chocolate intake increased SCFA production (more for the evening group than the morning one) vs. the no-chocolate control group.

Chocolate increased the relative abundance of Akkermansia (low abundance of it is associated with obesity and type-2 diabetes), Ruminococcus whose abundance grows in those eating high-carb diets with fiber. The abundance of Methanobrevibacter grew for night intake of chocolate; it is a bacteria that isn't abundant in obese people.
Chocolate intake reduced Firmicutes and Lachnospiraceae species (2)

Diabetes

A study using data from over 192,000 subjects (16) investigated the association between type-2 diabetes risk and chocolate consumption. They found the beneficial effects of dark chocolate:

• Having 5 or more servings of any type of chocolate per week showed a significantly 10% lower rate of type-2 diabetes compared with those who never or rarely ate chocolate.
• Dark chocolate is even better: 5 or more servings of dark chocolate per week was linked to a 21% lower risk of type-2 diabetes.
• No significant effects were found for milk chocolate.
• Dose matters: each additional serving per week of dark chocolate added a 1% to 5% (average 3%) risk reduction.
• Milk chocolate but not dark chocolate was positively associated with weight gain. This means that more intake, causes more weight gain.

Increased consumption of dark, but not milk, chocolate was associated with lower risk of T2D. Increased consumption of milk, but not dark, chocolate was associated with long term weight gain. Drake C, Roehrs T, Shambroom J, Roth T., (2013) (16)

Fasting glucose

Another study pointed out that eating chocolate in the morning lowers fasting glucose by 4.4%. It probably does so by slowing down the digestion and absorption of sugars and carbohydrates. Other studies have observed an inverse relation between chocolate consumption and Type-2 diabetes incidence (more chocolate, less diabetes). However, glucose levels during the night intake of chocolate remained fairly constant and didn't drop. (2)

Weight Gain

A meta-analysis reported that chocolate supplementation during several weeks does not change body weight or body fat distribution and that a daily intake of 30 g or less of chocolate "revealed significant reduction of body weight and BMI."(9)

The lack of weight gain was observed in another study (2) where, despite eating 100 g of chocolate every day over a 2-week period, an extra 542 kcal per day, participants in both morning and evening groups "did not gain significant body weight ." They lost their sweet-eating pangs compared to the no-chocolate control group. Chocolate satiated their "sweet tooth."

Eating chocolate reduced overall energy intake by around 300 kcal/day for morning eaters and 150 kcal/day for evening eaters, but this didn't completely compensate for the additional 542 kcal/day provided by the chocolate.

The participants consumed milk chocolate (18.1 g cocoa, 31 g fat, 58.4 g carbohydrates -of which 57.5 g were sugar), 6.3 proteins, and 1.8 g fiber per 100 g of chocolate). It had 215 mg of theobromine, 2.06 mg of caffeine, and 854 mg of total polyphenols, mostly epicatechin and catechin per 100 g of chocolate.

The authors suggest that the increase in their polyphenol intake (+854 mg/day), mainly epicatechin and catechin contributed to the non-fattening effect. (2)

Cardiovascular Disease, Cancer, and Overall Death

Many studies have shown a link between chocolate consumption and cardiovascular health. The European Food Safety Authority (EFSA) took this into account and suggested a daily intake of 10 g of high-flavanol dark chocolate as it might contribute to vasodilatation and cardiovascular disease (CVD) prevention without the risk of adding weight. (13)

An analysis using data from 27,000 subjects followed up for up to 30 years (12) found significantly lower mortality among those eating the most chocolate compared to those eating the least:

• 13% risk reduction in cardiovascular disease (CVD) mortality.
• 16% risk reduction in heart disease mortality.
• 12% risk reduction in cancer mortality.

It also showed that a main contributor to the drop in overall mortality was the effect that chocolate had on blood pressure, reducing it.

Sleep and Chocolate

Some sources suggest that eating chocolate in the evening provokes insomnia. The argument is that chocolate interferes with the parasympathetic nervous system (PSNS) whose job is to relax and reduce the body's activities as it gets dark. The body will try to digest the chocolate's sugars and fats instead of unwinding. Furthermore, stimulants like theobromine, caffeine, and amines like will keep the brain overstimulated. Thiamin and Phenylethylamine found in chocolate will increase the release of norepinephrine, enhancing attention and arousal.
Below discuss the effects of some of chocolate's compounds and we mention two studies that investigated the effects of chocolate on sleep and their conflicting findings.

Magnesium in Chocolate and Sleep

Dark chocolates are rich in magnesium with around 250 mg/100 g, (3) it is also found in leafy vegetables and helps regulate the body's circadian rhythm, the internal clock that regulates sleeping, waking, and body temperature.
Magnesium has been found to improve sleep quality. (4)

Caffeine

Caffeine is a compound found in chocolate that is well known for promoting alertness, focus, and insomnia.

Research (15) showed that a moderate dose of caffeine (400 mg) at bedtime, 3 hours prior to bedtime, or 6 hours prior to bedtime each have significant effects on sleep disturbance relative to placebo, so the recommendation is to refrain from substantial caffeine use for a minimum of 6 hours prior to bedtime. Note that you would have to eat 300 g of dark chocolate to ingest 400 mg of caffeine. By the way, the European Food Safety Authority advises that 50 g of chocolate may interfere with your sleep.

Theobromine

Theobromine is found in tea and chocolate, it is also produced when the body breaks down caffeine. It has one-fifth of the stimulant effect of caffeine but stays longer in the body.

The caffeine to theobromine ratio in chocolate is 1 to 5, with roughly 130 mg of caffeine and 750 mg of theobromine in 100 g of dark chocolate. Dark chocolate, unsweetened baking chocolate, and cocoa powder contain more theobromine than milk chocolate and chocolate syrups (100 g of milk chocolate contains about 150 mg of theobromine). (8)

Theobromine decreases blood pressure significantly and reduces the feeling of calmness. (6)

A study using data from 5,587 participants of the 2007– 2008 National Health and Nutrition Examination Survey (NHANES), found that of all the factors that influenced sleep (they analyzed alcohol, caffeine, vitamins, minerals, water, and nutrients), only the intake of theobromine differentiated groups.
This study found that "long sleep (9+ h) was also associated with reduced consumption of theobromine."(5) This suggests that a lower intake of chocolate and therefore theobromine promotes longer sleeping times.

A smaller study, investigating the effects of nighttime and morning intake of chocolate (2) reported that consuming it in the evening or night didn't cause insomnia. The study didn't find that sleep was disturbed in either group, however, evening consumption promoted a more regular timing of sleep onset than morning eaters (60 min vs 78 min).
Furthermore, morning chocolate promoted afternoon siesta frequency vs. a control group who didn't eat chocolate.

When to eat chocolate?

During the Morning

As mentioned above, the high flavonoid content of chocolate can have positive effects on cognition, and mental and cardiovascular health. Studies support the suggestion that the beneficial effect is obtained by eating cocoa only in modest amounts, preferably dark chocolate, during the activity hours of the day and in the early part of the day to avoid problems of weight gain. (1)

A randomized study conducted in 2021 (2) evaluated the effects of chocolate on weight, energy burn, satiety, and sleep if taken at night or during the morning in comparison to a control group. It involved 19 women who ate 100 g of chocolate each day.

Morning consumption

• Waist circumference decreased by 1.7%.
• Lower fasting glucose and increased lipid oxidation (25.6%), burning more fat.

Evening consumption

• They were less hungry than the morning eaters and the no-chocolate control group.
• They increased physical activity by 6.9%, and their bodies dissipated more heat (burning more calories) after meals (1.3%) than the control group. Carbohydrate oxidation increased by 35.3%

Carbohydrate burn

Eating chocolate at night promotes the oxidation of carbohydrates. It is possible that the added carbs are stored overnight as glycogen in the muscles and liver, and as the body has a limited carb storage capacity, these are readily available for use the following day. The study suggests that "chocolate intake at evening/night could be advisable for next morning performance during high intensity exercises or prolonged exercises." (2)

Risks

Research has raised some concerns about the heavy metal content of chocolate. (11)

Cocoa beans absorb these heavy metals from the soil, and processing tends to concentrate them in the cocoa.

Lead (Pb), Cadmium (Cd), Nickel (Ni), and Arsenic (As) are toxic metals with carcinogenic effects, which can also cause permanent damage to the kidney, neurological system, and bones. The European Union set maximum admissible levels for Cd in chocolate in 2019. However, research shows that some chocolates surpass the admissible levels.
The heavy metal quantities, however, are small, and you would have to consume 42 g of dark chocolate per day to the cadmium level and 80 g to surpass the acceptable level for lead. Values that can easily be ingested by frequent chocolate consumers. The risk for children is higher, as they have a lower body weight. (17)

Weight gain. Chocolate is an energy-dense food, it contains sugars, fats, and carbohydrates. Dark chocolate has less added sugars and is a healthier option, but both milk and dark chocolates should be eaten in the context of a balanced diet, and in moderation, to avoid unnecessary weight gain.