2009-05-08 Kevin C. Maki PhD Obesity And Tea Catechin
Obesity, Triglycerides and Green Tea Catechins
An Interview With Dr. Kevin Maki
May 8, 2009 By Kirkham R. Hamilton, PA-C
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KIRK HAMILTON: Welcome to Staying Healthy Today Radio, a health oriented show committed to bringing you key experts in the fields of nutrition, prevention and integrated medicine. Hi. My name is Kirk Hamilton, your host on Staying Healthy Today. Our mission is simple: To provide you credible and useable health information from interviews and our educational resources to help you stay and be well in the busy modern world. Today’s show topic is “Can Concentrated Green
Tea Catechins Help With Losing Weight, Especially In Losing Abdominal Fat, And Help Lower
Triglycerides?” Our guest today is Dr. Kevin C. Maki, President and Chief Science Officer at Provident
Clinical Research and consulting in Glen Ellen, Illinois. Dr. Maki received his PhD in Epidemiology in
1998 from the University of Illinois at the Chicago School of Public Health. He has been involved in more than 77 peer review articles, 27 books or book chapters, 85 abstracts and 59 clinical trials. He recently has co-authored a paper entitled “Green Tea Catechin Consumption Enhances Exercise-Induced Abdominal Fat Loss in Overweight and Obese Adults” in the Journal of Nutrition, 2009, page 264.
I want to welcome Dr. Maki. Can you tell me a little bit about your business? Exactly what is Provident Clinical Research and Consulting and what is the mission of your group?
DR. KEVIN MAKI: Provident is a company that I started in 2004 and we’re an independent research company specializing in the design and conducting of clinical trials, and we typically test products that are intended to have some health benefit, either food or pharmaceutical products.
KIRK HAMILTON: Is there any area of interest that you have or your company focuses on?
DR. KEVIN MAKI: We focus mainly on clinical nutrition and interventions intended to improve risk factors for either heart disease or diabetes. We do studies in other areas as well, but our main focus is metabolic risk factors for heart disease and diabetes, so we’re typically looking at things like cholesterol levels, blood pressure levels, body weight, obesity and so forth.
KIRK HAMILTON: How did you get involved with choosing to study the green tea catechins and obesity and exercise-induced abdominal fat loss?
DR. KEVIN MAKI: Well, there have been a number of studies, some in animals and some in humans, that have suggested that green tea catechins may enhance the metabolic rate and it may reduce body fat, and so we were interested in this area. And then a company, Cal Corporation from Japan, that is investigating the development of products that would include green tea catechins had an interest in looking at whether incorporating a beverage containing green tea catechins would enhance weight loss and fat loss during an exercise program. So we collaborated with them to develop a study protocol to evaluate that.
KIRK HAMILTON: Exactly what is a green tea catechin?
DR. KEVIN MAKI: Well, it is a compound that is in a class called polyphenols, and green tea catechins are found in high concentration in certain kinds of tea. And because they’re structurally similar to a class of hormones called the catecholamines, they have effects that may influence catecholamine metabolism. Now, a catecholamine that most people are familiar with is adrenaline, and so one of the things that adrenalin does, or its cousin noradrenaline or norepinephrine is to increase the metabolic rate and also to increase the rate at which fat is burned or oxidized. And so catechins have an effect to reduce the rate of breakdown of noradrenaline and by doing so, they may increase the metabolic rate and also increase the rate at which fat is burned.
KIRK HAMILTON: When you made this product, or the company made this product and they put it in a beverage, can you describe what the beverage is, and is there a special way of extracting these green tea catechins that makes this product unique?
DR. KEVIN MAKI: Well, the beverage that we use was kind of a sports drink type of a beverage, and so it was noncarbonated but it was definitely not something that tasted like tea. In fact it had a bit of a citrus flavor, and so the catechin extract that was used was added to the beverage in a way that would produce a very consistent beverage. So the beverage on one day would be just like the beverage on the next day, would be just like the beverage on the following day, which is not true when you’re brewing tea, because when you’re brewing tea, it may vary quite a bit from day to day. And so the catechins were added to the sports beverage and subjects consumed that once a day, a 10 ounce beverage, that contained an amount of catechins that would be similar to consuming roughly five cups of green tea.
KIRK HAMILTON: You use caffeine as the control or the base? Tell me why you have caffeine in the study?
DR. KEVIN MAKI: Sure, when you extract the catechins from green tea a certain amount of caffeine comes along with the catechins, and so our control beverage was identical to the green tea extract beverage except for the catechin content, which is zero in the control beverage. So in order to isolate the effects of the catechins we had to be sure that the control beverage had an amount of caffeine that was similar to that in the catechin beverage, which of course has caffeine that occurs naturally with the catechins And so the control and the active beverage each had about 39 milligrams of caffeine and that’s a little bit more than would typically be found in one cup of green tea, which normally has about 30 milligrams of caffeine.
KIRK HAMILTON: How much is in the average 8 ounce cup of coffee?
DR. KEVIN MAKI: It varies according to the type of bean used, but coffee is closer to 100 milligrams per cup.
KIRK HAMILTON: Were there any particular markers that you measured before you went in the study that you wanted to see if this green tea catechin beverage affected?
DR. KEVIN MAKI: Well, we were interested in body weight and body composition, so we measured body weight. We also used DEXA scans or dual x-ray absorb telemetry as a way to measure body fat as well as lean tissue, and then in addition, we used CT scans, or computed tomography, to look at the abdominal fat area. So we were interested in body weight, body fat, lean tissue, and then also specifically abdominal fat. The findings of the study suggested that while there was a slight increase in weight loss and a trend towards more fat loss, where we really saw the greater effect was in loss of abdominal fat. So, our subjects lost about 7%, a little more than 7%, about 7.7% of their initial abdominal fat in the catechin group, and there was very little loss of abdominal fat in the control group.
KIRK HAMILTON: What is the big deal about abdominal fat versus other types of fat on the body from a health perspective?
DR. KEVIN MAKI: Well, it turns out that where you carry your fat is important with regard to the health effect. So the good news for fat on the hips and thighs is that that’s relatively metabolically benign. So people who don’t have an expanded waistline, if they’re carrying a few extra pounds of body fat, it usually doesn’t create large effects in terms of risk factors for heart disease and diabetes. People who have an expanded waistline, sort of the apple shape as compared to the pear shape, generally have more severe disturbances in their risk factor profiles for heart disease and diabetes. Along with this reduction in abdominal fat, we saw improvements in some risk factors for heart disease. Specifically, levels of triglycerides and free fatty acids or forms of fat in the blood that we attribute to improvements related to the loss of abdominal fat.
KIRK HAMILTON: How would you use this product clinically? How do you envision it being used in the real world?
DR. KEVIN MAKI: Well, I do think that this product shows promise for potential use in the future as an aid during weight management. But I also think it’s too early to be making recommendations for the public to use this product. I think that a great deal more research is needed in order to fully define the potential risks and benefits associated with using green tea catechins as an aid in weight loss. So, while I think it’s promising, I think that we need more research before any recommendations can be made to the public.
KIRK HAMILTON: We know about the leanness of Asian cultures and their health attributes when they live their traditional lifestyle. Could green tea and the stimulation of metabolism through consuming catechins have something to do with this?
DR. KEVIN MAKI: That is certainly a possibility. It’s very difficult to narrow down the factors that are associated with a lower prevalence of obesity in Asian cultures as compared to the United States, but there are a variety of differences in lifestyle that could contribute to less obesity in Asian cultures, and certainly greater consumption of green tea could be one factor. Although, again, at this point, it’s hard for us to narrow down the effect of green tea consumption as compared to other lifestyle factors that we know can influence obesity.
KIRK HAMILTON: Do any of the other teas, such as black teas and white teas, have any effect with these catechins, and if you put something in, let’s say in green tea, like milk, will that bind up some of these compounds?
DR. KEVIN MAKI: Well most of the catechins in black tea have been destroyed through the fermentation process, and so green tea and white tea do contain catechins and green tea has been studied most extensively. There are a variety of other factors that influence the catechin content of tea as a beverage. There are many varieties of leaves that are used to make tea, they are processed in different ways and stored in different ways that may influence the catechin content, and then the preparation itself may influence the catechin content. If something is in a tea bag as compared to the tea leaves actually being in direct contact with the water during steeping, and longer steeping will generate a greater extraction of the catechin from the tea leaves. So, there are a variety of factors, and with regard to the consumption of milk with the tea catechins, to be honest I’m not up on the chemistry there and the potential for calcium and milk and other things to bind and interfere with the effects of green tea catechins, so I can’t give you a great answer for that question.
KIRK HAMILTON: Is there any special way of extracting these catechins that doesn’t damage them or is there a special processing?
DR. KEVIN MAKI: Well, the beverage that we used was manufactured in such a way that it created a very consistent product, so we knew that every subject who consumed 10 ounces of the study beverage was getting exactly the same dose and proportion of the different catechins within that beverage. And of course that’s not true if you’re consuming green tea itself, which is going to vary quite a bit from day to day according to how the tea is prepared. So the process that was used to create the product for our study was something that was very reproducible and would produce a very consistent product, which is necessary for a clinical study.
KIRK HAMILTON: And were there any side effects to this product?
DR. KEVIN MAKI: We saw no differences between the two treatments with regards to adverse experiences, so there are no side effects that we could detect in our study with regard to any discomfort or gastrointestinal complaints or what have you that could be experienced. Our two groups, the control and the active beverage group, had very similar profiles with regard to any adverse experiences.
KIRK HAMILTON: In closing, do you have any overview comments that you would like to make on your work or its direction?
DR. KEVIN MAKI: Well, I’d like to reiterate that I think that the results of our study are promising and should be followed up and eventually may lead to ways to help individuals manage their weight and body fat, but I don’t want people to take away the message that they should start drinking five or six cups of green tea every day. I think green tea is a fine beverage and it’s certainly preferable to a beverage that might be high in sugar and calories, but I think it’s too early at this point to make specific recommendations for how green tea might be used by people who are trying to lose weight or manage their weight.
KIRK HAMILTON: Do you have a website that people can go to just to look at your products and services?
DR. KEVIN MAKI: Sure, our website is ProvidentCRC.com and our company specializes in conducting clinical trials, and so there is some information on our website about studies that we are actively recruiting subjects for and some information about research that we have conducted previously, but it’s not a website that will have a tremendous amount of information for consumers who want to learn more about green tea or what have you. It’s really oriented toward healthcare professionals.
KIRK HAMILTON: Well, thank you very much, Dr. Maki for taking the time to be with us today, and I learned something. I hope to talk to you soon.
DR. KEVIN MAKI: Great. Thank you very much.
KIRK HAMILTON: In a brief review of what Dr. Maki said, what they have found in their research is that green tea catechins or polyphenols found in green tea help stimulate body metabolism to increase slightly overall weight loss, but in particular abdominal fat loss which is the more problematic type of fat in our bodies where it’s placed. With the amount of green tea catechins that are approximately found in four or five cups of green tea, but this is in concentrated form in a beverage, there were no side effects to this trial. In conjunction with that, triglycerides were also slightly lowered, which is also a positive benefit. Dr. Maki still wants to encourage more clinical trials before any kind of definite statement can be done.
So, in closing, I want to thank Dr. Maki for taking the time to share his interesting work with green tea catechins and their relationship with improving abdominal obesity and lowering triglycerides. I want to thank you, the audience, for listening today on this edition of Staying Healthy Today Radio. And remember, until next time, Stay and Be Well.
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