Cocoa compounds may ease exercise-related heart function

By Stephen Daniells, 10-Mar-2010

Consumption of a beverage rich in cocoa flavanols may boost blood flow to the muscles and ease the demands on the heart during exercising, says a new study from Australia.

After exercising, overweight and obese people had blood pressure that was 14 per cent lower following consumption of a high flavanol-containing beverage compared with people consuming a low flavanol-containing beverage, according to findings published in the British Journal of Nutrition.

“These findings suggest that the consumption of cocoa flavanols […] could allow for safer and more efficient exercise performance in an at-risk population such as that included in the present study, thus placing less stress on the cardiovascular system during exercise,” wrote the authors, led by Narelle Berry from the University of South Australia.

The study adds to an ever-growing body of science supporting the cardiovascular benefits of consuming cocoa flavanols. Indeed, only last month NutraIngredients reported on another study by the Australian scientists that found Regular consumption of cocoa flavanols may decrease blood pressure in people with mild hypertension, but only at high doses (J. Hypertension, doi:10.1038/jhh.2009.105).

Blooming market

Euromonitor estimates the global market for functional chocolate at $371.9m in 2009, growing to $460.3m in 2012. In 2002 it was worth only $141.5m.

According to Mintel’s Global New Products Database (GNPD), of 123 global product launches since 2005, 36 have been in the US, with Japan and Germany next at nine. Of those launches 40 made weight management claims, 22 made cardiovascular claims, 17 made cognitive claims and 15 made digestive health claims.

Not chocolate, it’s cocoa

Mary Wagner, chief technology officer for Mars Botanical, a scientific division of Mars Inc, recently told NutraIngredients that the benefits of the bean revolve around the flavanols (also known as flavan-3-ols or catechins), and particularly the monomeric flavanol (-)epicatechin.

Mars’ interest in the active compounds started about 20 years ago when its scientists sought to understand the flavour components of chocolate. The bitter and astringent compounds were isolated, and further study and clinical work showed the health benefits of the monomers and the tannins, particularly (-) epicatechin, she said.

The new study was sponsored by Mars and the company supplied the cocoa drink used.

Study details

The Adelaide-based researchers recruited 21 people with an average BMI of 31.6 kg/m2, and an average age of 54.9, and and asked them to eat a low-flavanol diet throughout the course of the study. The subjects were randomly assigned to one of two groups: One group consumed a single serving of a high-flavanol beverage containing 701 mg of flavanols, and the other group consumed a low-flavanol beverage containing only 22 mg of flavanols. This was followed by a three to seven day washout period before crossing over to the other intervention.

Two hours atfter the flavanol drink, the participants cycled for 10 minutes at 75 per cent of their maximum heart rate. While no differences were obsrved in the blood pressure pre-execrise, a significant difference was observed in responde to exercise.

Indeed, the increases in diastolic blood pressure were 68 per cent lower in the high flavanol group, while mean blood pressure was 14 per cent lower.

Furthermore, flow-mediated dilation (FMD), a measure of a blood vessel's healthy ability to relax, was increased by 6.1 per cent following consumption of the high flavanol beverage, compared with 3.4 per cent in the low flavanol group, added the researchers.

“The results of the present study provide further support for acute consumption of cocoa flavanols to improve FMD, and they provide new evidence that cocoa flavanols can also attenuate the blood pressure responses to exercise,” wrote the researchers.

“Furthermore, these improvements in FMD and blood pressure response to exercise add to growing evidence that high flavanol cocoa consumption may benefit individuals with cardiovascular risk factors,” they concluded.

Mars Botanical’s Risa Schulman will give a presentation at the upcoming NutraIngredients Antioxidants 2010 Conference in Brussels, on the topic of cocoa flavanols. For more information and to register, please click here .

Source: British Journal of Nutrition
Published online ahead of print, doi: 10.1017/S0007114509993382
“Impact of cocoa flavanol consumption on blood pressure responsiveness to exercise”
Authors: N.M. Berry, K. Davison, A.M. Coates, J.D. Buckley, P.R.C. Howe