A Chocolate Bar A Day Keeps the Doctor Away

Actually it is 2 chocolate bars a day. Dark chocolate containing flavanols and added plant sterols reduces serum cholesterol and LDL cholesterol as well as blood pressure.
Plant sterols are natural compounds found in foods such as vegetable oils, fruit, cereals and vegetables. They can lower the circulating cholesterol levels. The FDA has recognized that the consumption of plant sterols may reduce the risk of cardiovascular disease by lowering the LDL cholesterol.

In a double-blind placebo controlled cross over study the first aim was to examine the effect of the regular consumption of a flavanol containing chocolate bar (CocoaVia) with added plant sterols on serum cholesterol levels in a free-living population. All participants were on a steady AHA diet and their body weight didn’t change during this trial. Serum total cholesterol level was reduced with 3% and LDL cholesterol with 4%.

Also regardless of plant sterols content the consumption of the chocolate bars reduced diastolic (8%) and systolic blood pressure (8%) due to the flavanols. The participants were all normotensive (didn’t have high blood pressure).
The trial didn’t use chocolate bars with low flavanols concentration thus it is possible that the lower blood pressure could be attributed to other factors.

Dark chocolate has the most flavonoids. This is the substance that improves blood flow and vascular function and diminishes clotting and reduce blood pressure. Alas some confectionery makers often take out the flavanols, stripping the chocolate of its main health-promoting properties because flavonols also makes the chocolate taste bitter.

Short study period (8 weeks) how will these measures hold on the long term?

Allen, R.R. (2008). Daily consumption of a dark chocolate containing flavanols and added sterol ester affects cardiovascular risk factors in a normotensive population with elevated cholesterol. The Journal of Nutrition, 138(4), 725-731.