Recently, I came across an article that has the promising title “Another reason to drink wine: It could help you burn fat, study suggests”. Having spent a lot of time on trying to find ways to increase or improve fat burning (fat oxidation), especially during exercise, I was intrigued although a little sceptical...
Are there ways to increase fat oxidation?
In the last 20 years I have not seen anything that really increases fat oxidation to a significant degree. Caffeine in some cases, green tea in some cases, perhaps, and that is about it. Many nutrients and a huge number of nutrition supplements and herbal remedies have been claimed to increase fat oxidation but when investigating it a little further the claims cannot be backed up by evidence. Since I like a good bottle of wine, and red wine may have a number of other health benefits as well, I wanted to look into this a little more. So, I first read the article with the promising title and then the original study that apparently suggested that red wine helps you burn fat.
What does the original study say?
When reading the paper, the authors refer to a previous study, published in 2012, in which they gave a grape derived extract of phytochemicals to mice who were fed a high fat diet. In that study it was observed that mice gained weight and accumulated more fat in their bodies than mice on a low fat diet. It seemed, however, that giving the mice the grape extract, reduced some of the negative effects.
In the current study the authors used cells from the 2012 mice study and exposed these cells to a number of chemicals that were present in the grape extract. Of the chemicals tested ellagic acid was the most potent. The researchers then also exposed human liver and fat cells to ellagic acid and observed some alterations in the way fats were metabolized from by the cells.
It seemed that giving mice the grape extract reduce some negative effects
So all the evidence collected was about an isolated compound called ellagic acid that was given to cells in a test tube. Although the compound was also added to human liver cells, most data was obtained from mice.
What conclusions can be drawn from the study?
Although the study may be very well controlled and conducted we cannot draw too many conclusions from it. In fact the authors are very careful with their conclusions and state that their results suggests that ellagic acid may have effects on fat metabolism but also state that further study is essential to understand the effects of ellagic acid.
What are the weaknesses in the study design?
The mice were not given red wine, they were not even given grapes. The test results were in cells, not living humans. So to extrapolate from observations with a single very specific compound in test tubes to how red wine is going to solve the obesity problem is a bit of a stretch to say the least. Would a human liver cell actually be exposed to the same levels of ellagic acid as were used in the test tubes? Are there other compounds in wine that would interact with ellagic acid, or fat burning? From this study we don’t even know is ellagic acid is actually absorbed in humans. So many questions are still on the table. Not an example of bad science, just an example of bad reporting.
The mice were not given red wine, they were not even given grapes.
Of course the findings are interesting but before we can draw any conclusions that red wine increases fat burning in humans, we first need to do:
1. Studies in humans
2. Studies with red wine
3. Studies that actually measure fat burning
Until that time, I remain sceptical. I will keep drinking the occasional glass of red wine, but it may not be with the purpose of burning more fat!
Meshail Okla, Inhae Kang, Da Mi Kim, Vishnupriya Gourineni, Neil Shay, Liwei Gu, Soonkyu Chung. Ellagic acid modulates lipid accumulation in primary human adipocytes and human hepatoma Huh7 cells via discrete mechanisms. The Journal of Nutritional Biochemistry, 2015; 26 (1): 82 DOI: 10.1016/j.jnutbio.2014.09.010