Adding cocoa powder to the diet of high-fat mice and liver disease significantly reduced the severity of their condition. This is according to a new study by Penn State researchers who suspect the results have an impact on humans.
Cocoa powder, a popular food ingredient most commonly used in making chocolate, is high in fiber, iron, and phytochemicals that are reported to have positive health benefits, including antioxidant polyphenols and methylxanthines, according to study lead Joshua Lambert , Professor of Food Science at the College of Agricultural Sciences.
While it is generally considered a luxury food due to its high sugar and fat content, epidemiological and human intervention studies have shown that consuming chocolate is associated with a reduced risk of cardio-metabolic diseases such as stroke, coronary artery disease and type 2 Diabetes is linked. Therefore, it made sense to investigate whether cocoa consumption has an influence on the non-alcoholic fatty liver disease, which is often associated with obesity in humans. “
Joshua Lambert, Principal Investigator and Professor, Food Science, College of Agricultural Sciences, Penn State
This study has several strengths, explained Lambert. A commercially available cocoa product was used in a “physiologically achievable dose” – meaning that its equivalent could be duplicated by humans. “If you do the calculations, people get about 10 tablespoons of cocoa powder a day,” he said. “Or if you follow the directions on the Hershey box of cocoa powder, that’s about five cups of hot cocoa a day.”
The high-fat mouse is an established, diet-related model for obesity, Lambert added. By waiting for the mice to become obese before starting cocoa treatment, the researchers were able to test the protective effects of cocoa in a model that better simulates the current public health situation in relation to non-alcoholic fatty liver disease.
Lambert pointed out that this is important because a significant proportion of the world’s population is already obese and non-alcoholic fatty liver disease. “Given the high proportion of people in the US and other parts of the world who are obese, there is a need to develop potentially effective dietary interventions, rather than just preventative ones,” he said.
For this study, researchers looked at changes in fatty liver disease, markers of oxidative stress, antioxidant response, and cell damage in high-fat, obese mice treated with a diet supplemented with 80 mg of cocoa powder per gram of food – about a pinch per quarter of a teaspoon – for eight weeks.
In results recently published in the Journal of Nutritional Biochemistry, the researchers reported that cocoa-treated mice gained weight at a 21% lower rate and had lower spleen weights – indicating less inflammation – than the high-fat control mice.
At the end of the study, mice that were supplemented with cocoa powder had 28% less fat in their livers than the control mice. Mice treated with cocoa had 56% less oxidative stress and 75% less DNA damage in the liver compared to high-fat control mice.
The mechanisms by which cocoa provides health benefits are not fully understood, but previous studies in Lambert’s laboratory have shown that extracts from cocoa and some of the chemicals in cocoa powder can inhibit the enzymes responsible for digesting dietary fat and carbohydrates.
The result, he suggests, is that when mice are given cocoa as part of their diet, these compounds in the cocoa powder prevent dietary fat from being digested. When it cannot be absorbed, the fat passes through the digestive system. A similar process could occur in humans with cocoa, he suspects.
Given this new information about cocoa powder, Lambert does not recommend that obese people – or anyone else – simply add five cups of hot cocoa to their daily routine and do nothing else in their diet. However, based on what he learned in this study, he advises replacing other foods, especially high-calorie snacks, with cocoa.
“These exchanges are potentially beneficial, especially when combined with an overall healthy diet and increased physical activity,” he said. “If you go to the gym and work out and your reward is going home and having a cup of cocoa, this can be something to help you get off the couch and move around.”
Sun, M. et al. (2021) Diet cocoa relieves non-alcoholic fatty liver disease and increases markers for antioxidant response and mitochondrial biogenesis in high-fat mice. The Journal of Nutritional Biochemistry. doi.org/10.1016/j.jnutbio.2021.108618.