Cholesterol is a significant contributor to heart disease, but certain types of cholesterol, in particular high-density lipoprotein (HDL) cholesterol, actually has a negative correlation with cardiovascular disease. At the same time, daily intake of cocoa in the form of dark chocolate has been shown to reduce oxidation of the cholesterol associated with heart disease, low-density lipoprotein (LDL) cholesterol. The mechanisms responsible for these effects of cocoa on cholesterol metabolism have yet to be fully elucidated.

Midori Natsume, Food and Health R&D Laboratories, Meiji Seika Kaisha Ltd., Japan, and colleagues have analyzed the effects of cocoa polyphenols on cholesterol using cultures of human liver and intestinal cells. Production of the proteins, apolipoprotein A1 (ApoA1), the major component of HDL, and apolipoprotein B (ApoB), the main component of LDL, were studied.

Polyphenols from cocoa powder increased ApoA1 levels and decreased ApoB levels in both the liver and intestine. The polyphenols also enhanced the activity of sterol regulatory element binding proteins (SREBPs). SREBPs attach to DNA and activate genes that boost ApoA1 levels, increasing “good” cholesterol.

• Cacao Polyphenols Influence the Regulation of Apolipoprotein in HepG2 and Caco2 Cells
  A. Yasuda, M. Natsume, N. Osakabe, K. Kawahata, J. Koga,
  J. Agric. Food Chem. 2011.
  DOI: 10.1021/jf103820b

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