It is a common belief that when food undergoes various forms of processing, the health benefits of that food are greatly reduced. A team of scientists at the Pennsylvania State University have found that the health benefits of cocoa – or chocolate – are not reduced after processing, and surprisingly, processing actually increases the health benefits of cocoa. The results of their new study have been published in the Journal of Nutritional Biochemistry.
The scientists at Pennsylvania State University designed their study to compare the effects of fermentation and roasting protocols on the ability of cocoa to mitigate obesity, gut barrier dysfunction, and chronic inflammation in high-fat-fed, obese mice. By using mice that are already obese, the team was able to use a model that better simulates the current health situation related to obesity and associated comorbidities since there is a high proportion of people in the United States and other parts of the world with obesity. Thus, there is a need to develop effective dietary interventions.
To make chocolate, cocoa beans have to go through various processes of fermentation and roasting to develop the desirable flavor and aroma compounds. These processes are essential for the consumer, but they alter the polyphenol content, compounds which provide health benefits. These processes have been shown to decrease the total polyphenol concentration by up to 18%.
To test the effects of processing, groups of mice were fed seven different dietary supplements of cocoa powder over eight weeks. The seven supplements were formulated from cocoa beans that had been prepared differently: the preparations ranged from no fermentation and no roasting to extensive fermentation and roasting at high temperature – and various combinations in between. The different cocoa powders were incorporated into the mice’s diet in a concentration of 80 milligrams of cocoa powder to each gram of feed. If you were to scale this up to human consumption, this is equivalent to the amount of cocoa powder in five cups of hot cocoa; at two tablespoons of cocoa powder per cup, this comes out to ten tablespoons of cocoa powder!
The team found that the treatment of mice with dietary cocoa powder reduced the rate of body weight gain in both males and females by up to 57%, regardless of fermentation and roasting protocol. They found that some of the most processed samples seemed to actually have the largest positive impact on the mice in the study! Processing reduced the polyphenolic content in the cocoa, but the composition of polyphenolic chemicals that remained were shifted in such a way that there were more of what the team suspects to be the most effective polyphenols.
Gut permeability – an important contributor to development of fatty liver disease – was reduced by up to 79% by cocoa supplementation. The team also did an analysis of the mice’s intestinal microbiome. This analysis showed that cocoa – regardless of fermentation and roasting protocol – reduced the ratio of Firmicutes to Bacteroidetes, an important measure of flora in the colon which relates to obesity. Thus, the team suggests that the anti-obesity and anti-inflammatory efficacy of cocoa is resilient to changes in polyphenol content and composition induced by fermentation or roasting.
The mechanism through which cocoa imparts health benefits is not well understood, but it is believed that some chemicals can inhibit the enzymes that are responsible for digesting dietary fats and carbohydrates. Thus, the team believes that when mice got cocoa as part of their diet, the compounds in the cocoa powder actually reduced the digestion of dietary fat. When that fat cannot be absorbed, the fat passes through the digestive system. A similar process may also occur in humans.