Consuming 40 grams of polyphenol-rich cocoa powder was associated with a significant reduction in the activation of a protein called NF-kappaB, which is known to be play a key role in some inflammatory pathways.
“NF-kappaB is a transcriptional modulator of genes involved in inflammation and has a crucial role in atherosclerosis and other inflammatory diseases,” explained researchers in Nutrition, Metabolism and Cardiovascular Diseases. “Nowadays, it is considered a major therapeutic target.
“To our knowledge, there are no [other] studies in human volunteers on the effect of cocoa powder on NF-kappaB activation.”
Cocoa’s benefits
The health benefits of polyphenols from cocoa have been gathering increasing column inches in the national media. To date studies have reported potential benefits for cardiovascular health, skin health, and even brain health.
The majority of science into the potential benefits of cocoa have revolved around cardiovascular benefits of the flavanols (also known as flavan-3-ols or catechins), and particularly the monomeric flavanol (-)epicatechin.
Recently, however, scientists from the University of Reading in England and Mars reported that cocoa may also affect gut microflora and possess prebiotic potential.
Study details
The new study attempts to understand the mechanism behind the potential benefits and ascertain if there is the biological plausibility to support the reported health benefits.
Led by Emilio Sacanella, the researchers recruited 18 healthy volunteers aged between 19 and 49 and randomly assigned them to one of three groups: The first group received 40g of cocoa powder with milk, providing 62.1 milligrams of flavanols and 3.2 mg of flavonols per day; the second groups received the same cocoa dose with water (not milk); and the final group received only milk. The cocoa powder was supplied by Nutrexpa S.A.
After three weeks of intervention, the researchers report that NF-kappaB levels decreased significantly in the cocoa powder in water group, but not in the cocoa-milk group. Levels increased in the milk group, they added.
On the other hand, both cocoa groups experienced decreases in levels of intercellular adhesion molecule 1 (ICAM-1), which is reported to play a role in the early development of atherosclerosis.
The role of milk
“Although greatly controversial, milk might diminish the urinary excretion of some phase II metabolites of epicatechin,” said the researchers. “Cocoa-polyphenols that are not absorbed (mainly procyanidins) could reach the colon where they are degraded to phenolic acids by the intestinal microbiota and are absorbed in the organism.
“The effect of milk on the excretion of microbial phenolic acids after acute ingestion of cocoa powder has been studied and showed that milk significantly diminishes the urinary excretion of some phenolic acids related to the metabolism of cocoa-polyphenols such as caffeic, ferulic, 3,4-dihydroxyphenylacetic, protocatechuic, 4-hydroxybenzoic, 4-hydroxyhippuric, hippuric acids.
“Therefore, in general terms, metabolites derived from cocoa powder consumption seem to have greater bioavailability after cocoa-in-water than after cocoa-in-milk intake,” they added.
“Cocoa consumption could confer beneficial anti-inflammatory effects mediated by inhibition of the NF-kB-dependent transcription pathway or by direct interaction with certain cytokines and the food matrix could play a crucial role in the modulation of this effect,” they concluded.
Source: Nutrition, Metabolism and Cardiovascular Diseases
Published online ahead of print, doi:10.1016/j.numecd.2011.03.015
“Cocoa consumption reduces NF-kappaB activation in peripheral blood mononuclear cells in humans”
Authors: M. Vazquez-Agell, M. Urpi-Sarda, E. Sacanella, S. Camino-Lopez, et al.