Chocolate is often thought of as a ‘guilty pleasure’ but research continues to show that adding to chocolate to your diet can be very beneficial.
What exactly is chocolate?
Chocolate is made from the cocoa bean; cocoa or cacao refers to the natural product and chocolate is the processed version which has sugar, fat, possibly milk and other additives.
Cocoa naturally contains many minerals, including potassium, phosphorus, copper, iron, zinc and magnesium. Although chocolate does contain the stimulants caffeine and theobromine, it also contains stress reducing valeric acid.
Cocoa or cacao?
The main difference between cocoa and cacao is in the roasting. Cacao powder is produced by cold-pressing unroasted cocoa beans, cocoa powder looks the same but the cocoa beans have been roasted at a high temperature, this changes the structure of the cocoa bean which in turn lowers the nutritional value and alters the enzyme content.
Flavanols and methylxanthines
One of the main ingredients in chocolate that contributes to its health effects is the phytonutrient known as cocoa flavanols. The beneficial effects of the flavanols have been attributed to their antioxidant effects, regulation of gene expression and signalling pathways and changes they bring about in cell membrane and receptor functions.
The other significant bioactive ingredients are caffeine and theobromine – methylxanthines - found in cacao and also in coffee and tea. Methylxanthines have several mechanisms of action, the most significant is thought to be their action as antagonists of adenosine receptors in the central nervous system. Adenosine receptors have multiple physiological roles including controlling the release of neurotransmitters, for example dopamine and glutamate. Methylxanthines are stimulants of the nervous system, diuretics and smooth muscle relaxants, enhancing arousal, mood, and concentration levels.
Milk or dark?
Due to high sugar content and other potentially undesirable ingredients, milk chocolate is a sweet and not a healthy food. Comparing the sugar content of milk and dark chocolate in a 40g serving produces these results:
- 70% dark chocolate contains 3 teaspoons of sugar (4 g sugar = 1 teaspoon)
- 85% contains 1.5 teaspoons of sugar
- Milk chocolate contains around 5.5 teaspoons of sugar
Dark chocolate contains more flavanols than milk chocolate. The more ‘non-fat’ cocoa solids a chocolate product contains, the more antioxidant cocoa flavanols it can contain. Adding other types of fat, such as milk, vastly reduce the beneficial cocoa flavanol content.
Eating dark chocolate - the benefits
Although raw cacao will undoubtedly offer the best benefits to health, research has shown that there are benefits from consuming dark chocolate (i.e. 70% plus), for example:
Inflammation and chocolate
Inflammation plays a key role in the onset and development of most chronic diseases. A study comparing individuals who did not consume chocolate for one year with individuals who regularly consumed dark chocolate showed a significant association between moderate levels of cocoa ingestion and inflammation. Serum CRP levels were significantly lower in subjects consuming 20g cocoa every 3 days compared to subjects with either no or greater cocoa consumption.
Stress and chocolate
A Swiss study found that dark chocolate had a positive impact on cortisol levels – a hormone produced through stress. Several health issues can be affected by high cortisol levels, including weight gain, disrupted sleep, elevated blood sugar levels, food cravings and other health issues.
Findings of a Swiss study included; “the daily consumption of dark chocolate resulted in a significant modification of the metabolism of healthy and free living human volunteers with potential long-term consequences on human health within only 2 weeks treatment,” the researchers wrote, “this was observable through the reduction of levels of stress-associated hormones and normalization of the systemic stress metabolic signatures.”
Heart disease and chocolate
Polyphenols that are found in cocoa have been shown to play a role in reducing cardiovascular stress through the inhibition of LDL cholesterol oxidation; it is the oxidation of LDL which is critical in the onset of atherosclerotic diseases. These compounds also increase the vasodilation of blood vessels to promote circulation. A study in elderly patients has shown that cocoa intake was associated with reduced blood pressure and total cardiovascular mortality. A case control study in Italy reported an inverse relationship between chocolate consumption and heart attack.
The gut and chocolate
The bacteria in our gut ferments the polyphenols and fibre found in cocoa. Chocolate stimulates the growth of beneficial bacteria in the gut – such as Bifidobacteria and Lactobacillus spp; Cacao and/or chocolate modifies intestinal flora in the same way as prebiotics and probiotics.
Weight control and chocolate
Studies have shown eating just a small amount of chocolate before a meal can trigger satiety signals in the brain, subsequently leading to reduced consumption.
In an animal study, cocoa consumption led to a significant reduction in total body weight and changes in other parameters such as white adipose tissue weight and serum triglycerides. DNA analysis on liver and mesenteric fat tissue samples showed a reduction in expression of various genes associated with fatty acid transport and synthesis in the liver, and increased expression of genes associated with thermogenesis.
Diabetes and chocolate
In animal models and in a limited number of human studies, flavanols and methylxanthines have been found to have positive effects on glucose homeostasis through a number of mechanisms – including reducing postprandial glycemic response and improving insulin sensitivity.
The brain and chocolate
Flavanols are associated in the brain with learning and memory, especially the hippocampus where there may be beneficial actions via neuroprotection and with improved blood flow. Animal intervention and a few human observation and intervention studies have reported protective effects in relation to age and disease related cognitive decline.
A 2016 study reported better performance on a range of memory and cognitive tests when chocolate consumption was increased.
For some, cocoa can trigger a migraine, which may be down to a well-known migraine trigger, the amino acid tyramine (also found in other foods). As chocolate contains caffeine, this may also be an issue for people with sensitivity to caffeine, especially when it affects sleeping. And of course, all things in moderation as overconsumption of any type of chocolate can lead to weight gain.
In summary, it is clear from research undertaken that raw cacao and dark chocolate do carry some very significant health benefits. But as mentioned, all things in moderation as dark chocolate does still contain added sugars.
- Crichton G E (et al) 2016 – Chocolate intake is associated with better cognitive function: The Maine-Syracuse Longitudinal Study, Appetite, 1;100:126-32
- Franco R et al (2013) – Health benefits of methylxanthines in cacao and chocolate. Nutrients, 5(10, 4159-4173
- Latif R (2013) – Chocolate / cocoa and human health: a review, Neth J Med, 71(2):63-71(2)
- Martin F P J et al (2009) – Metabolic Effects of Dark Chocolate Consumption on Energy, Gut Microbiota, and Stress-Related Metabolism in Free-Living Subjects. Journal of Proteome Research, 8, 12, 5568-5579
- Senturk T and Gunay S (2014) – The mysterious light of dark chocolate. Arch Turk Soc Cardiol, 43, 2, 199-207
- Sokolov A N et al (2013) – Chocolate and the brain: neurobiological impact of cocoa flavanols on cognition and behaviour. Neuroscience and Biobehavioural Reviews, 2445-2453