Do we need to rethink weight loss supplements? This week saw two studies come out which looked at the effect of a couple of very different substances on weight loss in the obese. A lot of people think of weight loss when they think of green tea. Its extract is a popular ingredient in a lot of fat loss supplements, and has been used for centuries in its native China by people wanting to shed a few kilos.
The substance studied in the first paper, epigallocatechin-3-gallate, is the main bioactive compound in green tea. It is thought to speed up the metabolism and to cause fat to be burned as a fuel source over carbohydrate. The researchers gave either a high dose of this extract, equivalent to several cups of green tea, or a placebo, to a group of eighty three obese Spanish women daily for three months. While the researchers were pleased that consumption at these levels did not cause any liver damage, they were surprised to see no acceleration in fat loss or improvement in cardiac risk factors in the experimental group over the placebo, particularly as green tea is one of the oldest and best regarded weight loss aids.
Perhaps, it's important to realise that Green Tea has many many bioactive compounds and simply having an extract of one particular compound may not offer the synergistic effects of having green tea in its intended form and that is as a tea; hot or cold. We do know that Green Tea has many other health benefits and better to stay hydrated with it than with sugar laden soft drinks.
Probiotics & Weight Loss
Meanwhile, in Canada, researchers were performing a similar study using one of the newest strategies – probiotics. A cohort of obese women lost significant amounts of fat over the placebo control when supplementing with twice a day doses of friendly gut bacteria, Lactobacillus rhamnosus, for three months. The presence of the bacteria increased concentrations of the satiety hormone leptin in the blood. Interestingly, this effect was not seen in men participating in the study, whereas the weight loss in females was significant, and was maintained for another three months past the initial diet phase of the experiment.
So should we trade our kettles in for home microbiology labs? The effects of green tea have always been a bit hit and miss in scientific studies, yet people have sworn by it to lose fat for a long time. Probiotics are a very new area, and while it's easy to get excited about great results like these, as green tea illustrates, the results of scientific experiments can be really variable. Don't toss your favourite mug yet.
It's become increasingly relevant that our gut bacteria has a huge impact on our health and decreased ratio of good bacteria in our gut can result in some negative health consequences. So have some yogurt and get healthy!
(1) Mielgo-Ayuso J, Barrenechea L, Alcorta P, Larrarte E, Margareto J, Labayen I. Effects of dietary supplementation with epigallocatechin-3-gallate on weight loss, energy homeostasis, cardiometabolic risk factors and liver function in obese women: randomised, double-blind, placebo-controlled clinical trial. Br J Nutr. 2013 Dec 3:1-9.
(2) Sanchez M, Darimont C, Drapeau V, Emady-Azar S, Lepage M, Rezzonico E, Ngom-Bru C, Berger B, Philippe L, Ammon-Zuffrey C, Leone P, Chevrier G, St Amand E, Marette A, Doré J, Tremblay A. Effect of Lactobacillus rhamnosus CGMCC1.3724 supplementation on weight loss and maintenance in obese men and women. Br J Nutr. 2013 Dec 3:1-13.