Chocoholics will undoubtedly be pleased to hear indulging in their favourite treat more than once a week could ward off heart disease.
Enjoying the indulgence in moderation has previously been linked to reduced blood pressure, however, scientists from the Baylor College of Medicine in Houston wanted to better understand how it affects the vessels feeding the heart.
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More than 333,000 people were followed for around nine years, with their chocolate consumption noted.
Those who indulged more than once a week were 8% less likely to develop coronary artery disease than the participants who treated themselves less often.
Coronary artery disease occurs when the vessels that feed the heart narrow or become blocked, restricting blood flow so the vital organ is starved of oxygen. In severe cases, this can trigger a heart attack.
“Our study suggests chocolate helps keep the heart’s blood vessels healthy,” said study author Dr Chayakrit Krittanawong.
Heart disease is behind one in four deaths in the UK and US.
A diet high in sugar or saturated fat is not generally associated with cardiovascular health, however, the antioxidants in dark chocolate have been said to have benefits.
“In the past, clinical studies have shown chocolate is beneficial for both blood pressure and the lining of blood vessels,” said Dr Krittanawong.
“I wanted to see if it affects the blood vessels supplying the heart (the coronary arteries) or not. And if it does, is it beneficial or harmful?”
The scientists looked at six studies carried out over the past five decades, with a total of more than 330,000 participants.
Over an average of nearly nine years, 14,043 participants developed coronary artery disease and 4,667 had a heart attack.
Coronary artery disease can just trigger chest pain, known as angina. A heart attack occurs if the blood supply to the vital organ is cut off entirely or its energy demands become much greater than its oxygen intake.
Results, published in the European Journal of Preventive Cardiology, revealed the participants who ate chocolate more than once a week were 8% less likely to develop coronary artery disease than those who did so less than once every seven days.
“Chocolate contains heart healthy nutrients such as flavonoids, methylxanthines, polyphenols and stearic acid which may reduce inflammation and increase good cholesterol,” said Dr Krittanawong.
Flavonoids, a type of antioxidant, have been found to reduce blood clots and improve vessel health.
Methylxanthines “have been shown to have beneficial effects on cardiovascular function”, wrote the scientists.
Polyphenols “facilitate nitric oxide synthesis”, a chemical that has been described as “vital for a healthy cardiovascular system”.
Finally, stearic acid can “reduce mean platelet volume”. In severe cases, high levels can lead to blood clots.
The scientists did not look into if one type of chocolate, like dark or milk, is more beneficial than other.
Optimal portion sizes are also unclear, however, the scientists stressed people should not overindulge.
“Moderate amounts of chocolate seem to protect the coronary arteries but it’s likely that large quantities do not,” Dr Krittanawong.
“The calories, sugar, milk, and fat in commercially available products need to be considered, particularly in diabetics and obese people.
“Chocolate appears promising for prevention of coronary artery disease, but more research is needed to pinpoint how much and what kind of chocolate could be recommended.”