Health effects of chocolate
The health effects of chocolate refer to the possible positive and negative effects on health of eating chocolate.
Unconstrained consumption of large quantities of any energy-rich food, such as chocolate, without a corresponding increase in activity, increases the risk of obesity. Raw chocolate is high in cocoa butter, a fat removed during chocolate refining, then added back in varying proportions during manufacturing. Manufacturers may add other fats, sugars, and powdered milk as well.
Although considerable research has been conducted to evaluate the potential health benefits of consuming chocolate, there are insufficient studies to confirm any effect and no medical or regulatory authority has approved any health claim.
The popular belief that the consumption of chocolate can cause acne is not supported by scientific studies. Various studies point not to chocolate, but to the high glycemic nature of certain foods, like sugar, corn syrup, and other simple carbohydrates, as one potential cause of acne. Chocolate itself has a low glycemic index. Other dietary causes of acne cannot be excluded.
Heart and blood vessels
Reviews support a short-term effect of lowering blood pressure by consuming cocoa products, but there is no evidence of long-term cardiovascular health benefit. While daily consumption of cocoa flavanols (minimum dose of 200 mg) appears to benefit platelet and vascular function, there is no good evidence to support an effect on heart attacks or strokes.
The effect of chocolate on body weight is unclear. A concern is that excessive consumption of dark chocolate may promote high calorie intake and weight gain, a risk factor for many diseases, including cardiovascular disease. As a consequence, consuming large quantities of dark chocolate in an attempt to protect against cardiovascular disease is likely to add excessive calories and induce weight gain.
Chocolate consumption may have potential to cause mild lead poisoning, as some studies have shown that lead may bind to cocoa shells and contamination may occur during the manufacturing process.[unreliable medical source?] In a USDA study in 2004, mean lead levels in the samples tested ranged from 0.0010 to 0.0965 µg lead per gram of chocolate, but another study by a Swiss research group in 2002 found that some chocolate contained up to 0.769 µg per gram, close to the international (voluntary) standard limit for lead in cocoa powder or beans, which is 1 µg of lead per gram. In 2006, the U.S. FDA lowered by one-fifth the amount of lead permissible in candy, but compliance is only voluntary.
Chocolate contains polyphenols, especially flavan-3-ols (catechins) and flavonoids which are under study for their potential effects in the body. The following table shows the phenolic and flavonoid content of three different types of chocolate.
|Type of chocolate||Total phenolics (mg/100g)||Flavonoids (mg/100g)|
In sufficient amounts, the theobromine found in chocolate is toxic to animals such as cats, dogs, horses, parrots, and small rodents because they are unable to metabolise the chemical effectively. If animals are fed chocolate, the theobromine may remain in the circulation for up to 20 hours, possibly causing epileptic seizures, heart attacks, internal bleeding, and eventually death. Medical treatment performed by a veterinarian involves inducing vomiting within two hours of ingestion and administration of benzodiazepines or barbiturates for seizures, antiarrhythmics for heart arrhythmias, and fluid diuresis.
A typical 20-kilogram (44 lb) dog will normally experience great intestinal distress after eating less than 240 grams (8.5 oz) of dark chocolate, but will not necessarily experience bradycardia or tachycardia unless it eats at least a half a kilogram (1.1 lb) of milk chocolate. Dark chocolate has 2 to 5 times more theobromine and thus is more dangerous to dogs. According to the Merck Veterinary Manual, approximately 1.3 grams of baker's chocolate per kilogram of a dog's body weight (0.02 oz/lb) is sufficient to cause symptoms of toxicity. For example, a typical 25-gram (0.88 oz) baker's chocolate bar would be enough to bring about symptoms in a 20-kilogram (44 lb) dog. Of course, baking chocolate is rarely consumed directly due to its unpleasant taste, but other dark chocolates' canine toxicities may be extrapolated based on this figure. Given access, dogs frequently consume chocolate at toxic levels because they like the taste of chocolate products and are capable of finding and eating quantities much larger than typical human servings. There are reports that mulch made from cacao bean shells is dangerous to dogs and livestock.[unreliable medical source?] 
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