Spring has sprung in most of the country, despite lingering reminders of winter here in Colorado. It’s already been an exciting triathlon season for many athletes who raced St. George & IM Texas. If your “A” race is later in the summer and had hoped to lose “winter weight” by now, you may be looking for a supplement to kick-start your weight loss. There are plenty of attention-grabbing labels, with convincing claims and “two for one” deals, to picqe your interest. However, listen to your inner cynic and keeping walking down the isle. Save the $10 for frozen yogurt as a reward after your long run this weekend.
Weight loss supplements are a dime a dozen and unfortunately are usually a poor return on investment. I have previously written about the efficacy of Green Coffee Bean extract for weight loss, and this article will review three more plant-based products marketed for “increased fat burning!”
The first supplement is the most popular and has been featured on many TV shows and infomercials. It is called Garcinia cambogia, and is also known as brindleberry or Malabar tamarind. G. cambogia is a small tree native to Sri Lanka. It produces small fruit, whose rind when dried, is used as a flavor enhancer in curries, food preservative, and calms ailments such as stomach and bowel cramps (though this has not been substantiated). The active ingredient in G.cambogia is hydroxycitric acid (HCA). This is the ingredient you would look for on a label of Garcinia or product such as Citrilite® or Citrimax®. HCA inhibits the enzyme that activates the storage of fat, reduces appetite, and may also act on genes involved in carbohydrate metabolism.
Claims for purchasing Garcinia are that you can triple your fat loss which is astonishing since every wise consumer knows that if it sounds too good to be true, it probably is! The research on the use of this fruit for fat specific loss has mixed results as most research does, and the trials used very small sample sizes of overweight or obese (according to BMI) subjects. Comparing results was difficult because the methodologies varied and variables were often uncontrolled. Only six studies (Ramos et al., 1995; Girola et al., 1996; Thom, 2000; Mattes and Bormann, 2000; Preuss et al., 2005; Toromanyan et al., 2007) found weight loss found to be significantly higher in the intervention group compared to the control group. (1)
RER (respiratory exchange ratio) s a number that describes the ratio of fat, carbohydrate and protein that is being used for fuel at a given point in time. RER decreased in value, signifying an increase in fat for fuel, when measured during one hour of exercise in six untrained women participating in a random control trial, who were administered 250 mg of HCA. (2) The same trial showed a statistically significant increase in time to exhaustion. The natural physiological adaptation to exercise in an untrained person, is an increase in fat utilization for fuel. With this in mind, I would speculate that if these women exercised they may also have experienced an increase in fat loss without using the supplement. Cyclists who completed a 60 min. time trial at 60% VO2max, exhibited a small, non-significant increase in the use of fat for fuel after supplementing with 2 pills (1 serving), three times a day at 500 mg/serving.
Oluyemi et al., (2007) looked at the effect of G. cambogia extract on red blood cell production in rats. They found a significant increase in hematocrit which was explained by the iron content in G. cambogia, and the presence of antioxidants, which preserve the average life span of red blood cells.
Just as with amount of chlorogenic acid listed on bottles of Green Coffee Bean extract, the concentration or percentage of HCA in G. cambogia usually differs from what is claimed on the label. Seven out of 13 products voluntarily tested by consumerlab.com, contained 14 – 81% of the amount listed on the label that claimed 50-60% standardized HCA. Two brands that were certified to contain their said amounts were: Optimal Health Garcinia Cambogia XT (500 mg) and Genesis Today Garcinia Cambogia (400 mg).
The Dr. Oz website has their own take on G. cambogia, and states that “they” do not endorse or promote a particular brand (10/28/12).” However, when consumerlab.com tested G. cambogia supplements in November 2013, they found three brands promoted on the Dr. Oz show were found to contain less than the amounts claimed on their labels: Miracle Garcinia, Healthy Clip, and Nutritional Sciences. Nutritional Sciences touted their product in a press release “Garcinia Lean, Top Weight Loss Choice after Praised by Dr. Oz.” The press release now leads to a defunct URL.
When shopping for a supplement always be sure to compare serving sizes so that you are comparing the total amount in mg/day. For example, two servings of Garcinia ranged from 500 – 1000 mg depending upon the brand. Most studies used between 1500 – 3000 mg (900 – 1500mg HCA) Garcinia per day, which was taken as two pills, three times per day. Also be wary of interactions with blood thinners and be mindful of hypoglycemia if taking blood glucose medications. Mixing over-the-counter Garcina cambogia supplements with commonly prescribed antidepressant drugs might cause serotonin toxicity, according to a recent case report by Natural Standard.
Pregnant women should not take G. cambogia because HCA inhibits the synthesis and storage of lipids. Even though that may be helpful for weight loss in non-pregnant women, lipids produced by the mother, are transferred through the placenta to the fetus for tissue synthesis. Therefore, HCA may interfere with gestational development. (3)
Resveratrol is a a compound with antioxidant properties found mostly in the skin of grapes but also blueberries, and cranberries. It is noted as decreasing risk factors for disease by activating sirtuins (Sir2), a class of enzymes associated with decreased aging on a cellular level. Research has shown a decrease in blood pressure in obese men and woman which could be interesting to someone looking to replace blood pressure medication with a ‘natural’ product. Who wouldn’t prefer drinking a few glasses of wine instead of taking a supplement or medication? Unfortunately, one would have to drink 68 bottles of red wine to obtain the same benefits on blood pressure. From tests completed in labs, the antioxidant and anti-inflammatory properties could potential help with recovery but effects on oxygen consumption during exercise weren’t proven. As with most flavonoids and polyphenols, they are a great reason to eat a variety of fruits and vegetables, but not worth paying for as a supplement. Resveratrol in the concentration found in supplements, may have estrogenic properties, and should be avoided by breast, ovarian and uterine cancer survivors.
Coleus forskohlii a plant that grows in India and Thailand belongs to the mint family. It is marketed to control blood glucose levels, sup
port heart and respiratory health, and promotes lean body mass for weight loss. Forskohlii is classified as a diterpene, an organic compound that by nature has antimicrobial and anti-inflammatory properties. Studies have proven a decrease in blood pressure and reduced symptoms of asthma, due to relaxation of smooth muscle tissue, but it is more widely known for its potential effect on fat burning. Forskohlii works by increasing the levels of the enzyme responsible for igniting the metabolic cycle of fat breakdown. The theory is that if the levels of the enzyme are elevated, fat metabolism will increase and spare lean mass. Sparing lean mass is always a goal in weight loss products to maintain your basic metabolic burn. Results for decreasing appetite seem promising using this product, but as many of you know – running is a natural appetite suppressant so I wouldn’t waste my money on this! After a long bike ride, or hard swim, the only thing that can dampen my appetite is chocolate. I can’t imagine any supplement controlling that.
As you probably expected, I do not endorse or recommend any of these supplements because the gains are minimal, and I would personally rather spend my money on race registration or higher quality/sustainably produced foods. During the time I began to write this article, summer temps have surfaced, providing more reason to get out and burn those calories the old fashioned way
1. Fabiola Márquez , Nancy Babio , Mònica Bulló & J. Salas-Salvadó (2012) Evaluation of the Safety and Efficacy of Hydroxycitric Acid or Garcinia cambogia Extracts in Humans, Critical Reviews in Food Science and Nutrition, 52:7, 585-594, DOI: 10.1080/10408398.2010.500551
2. Lim, K., Ryu S., Nho HS, et al. Hydroxycitric acid ingestion increases fat utilization during exercise in untrained women. J Nutr Sci Vitaminol, 2003;49(3):163-167.
3. Katie J. Astell, Michael L. Mathai, Xiao Q. Su. Plant extracts with appetite suppressing properties for body weight control: A systematic review of double blind randomized controlled clinical trials. Complementary Therapies in Medicine (2013) 21, 407—416.