One of our team members, Dylan, is currently working on his masters at the leading tea university in China. He recently published a paper on the weight loss mechanisms of Pu’erh. So we sat down with him for a little Q&A session to cut through the fat and get to the bottom of it all.
Q1: What lead you to study this topic?
A: I felt that as a tea scientist from America, a place where this issue carries so much weight (no pun intended), I had a certain responsibility to present an honest, reasonable, and scientifically-based conclusion on the topic of tea-induced weight loss. Here in the states, we see brands that market tea as a “miracle weight-loss drug,” for obvious capitalistic reasons. Conversely, there are many veteran tea industry professionals, who see tea for much more than weight-loss effects. These people are connoisseurs, who appreciate tea for it’s flavor, aroma, history, processing, etc. Experts and tea-lovers alike are tired of seeing exaggerated claims by “weight-loss tea companies” delegitimize the otherwise truthful claims about the health effects of regular tea consumption. Furthermore, these experts perceive disreputable weight-loss claims as a shallow brushstroke on an otherwise deeply rich work of art, that being tea connoisseurship. In other words, they feel that the “weight-loss scammers” are making them, and the industry as a whole, look bad. Both sides of the coin on this issue, the capitalists and the connoisseurs, have their own best interests at heart. Although I personally wanted to side with the more wholesome of the two causes, that of the tea lovers, I nonetheless felt that I was in a unique position to provide an unbiased look at what scientists from around the world have reported from their research on the issue. Luckily, there is a boatload of data on this issue – data that doesn’t pick sides. So, I said why not assess the literature and make a reasonable conclusion backed by data.
Q2: Did you expect to hone in on the importance of gut bacteria when you first started?
A: I did not! Theories surrounding the importance gut microbiota (gut bacteria) has to overall human health have only begun to emerge in the last ten-plus years. On top of that, studies involving how tea consumption affects gut microbiota date back to no more than three or four years ago. Since all of the literature on this issue is quite new, gut microbiota was not yet something I naturally associated with weight loss. I had to dig into the research first before I could connect the dots.
Q3: What are the practical takeaways?
A: Takeaway 1: Studies show that regular tea consumption has a small, positive correlation with decreasing weight gain and maintaining a healthy body weight. Key words here are small and positive. Yes, tea seems to help with maintaining healthy body weight. No, it is not a miracle weight-loss drug. The effects are subtle. One cannot rely on tea consumption alone to lose a lot of weight. It will contribute slightly, but healthy diet and exercise habits are still necessary.
Takeaway 2: Drink a wide variety of tea types (green, oolong, black, white, dark). All of these tea types have different tea polyphenol compounds, which react differently with your gut bacteria to benefit your health in different ways. I proposed at the end of my paper that tea polyphenols from different tea types may work synergistically with one another to promote various aspects of human health. This claim still needs to be backed by research, but… I got a hunch (an informed hunch).
Takeaway 3 (for those who want a basic summary of the science). Weight-loss effects seem to be modulated, at least in part, by gut microbiota. Antioxidant compounds in tea (polyphenols) interact with the bacteria in our intestines, causing two big reactions to occur. First, the bacteria break down the polyphenols into much tinier “polyphenol metabolites”, which our bodies can ingest much more effectively than full-sized tea polyphenols. Second, the polyphenols alter the gut bacteria themselves, in terms of quantities and ratios. Both the re-balancing of gut bacteria, and the breakdown of polyphenols into more available forms seem to be highly beneficial to human health in a variety of ways (including boosting metabolic rate, causing more energy expenditure, burning more calories).
Q4: What common tea myths does this debunk?
A: Tea is not a miracle weight-loss drug. However, regular tea consumption does have a small, positive correlation with maintaining a healthy body weight. Both extremes of the tea and weight-loss issue seem to be incorrect.
Q5: Now what are your most burning research questions?
A: Now I’m researching the various ways that tea consumption is beneficial to mental health, both long term and short term. I am researching the effects on mood and cognition by caffeine, L-theanine, catechin compounds, aroma compounds, and other flavonoids. Spoiler alert: gut bacteria are back at it again! In terms of mental health benefits, I also want to see the effects of the tea preparation process itself, edging into the territory of horticulture therapy.
You can read the full article originally published in the journal Molecules if you want to dive into the topic further. Feel free to ask Dylan any questions below and keep the conversation going.