Study Investigating Rooibos Weight Loss Effect Currently Underway

Rooibos’ anti-oxidant and anti-inflammatory properties could potentially curb obesity. A study led by Dr Hanél Sadie-Van Gijsen, a senior researcher in the Division of Medical Physiology at Stellenbosch University, is investigating this hypothesis.

As a stem cell biologist, she chose to use adipose (fat) stem cells (ASCs) in her research. This is a relatively new method that will provide a much clearer picture of what happens to subcutaneous fat lying under the skin and visceral fat tissue that surrounds organs in the abdominal cavity, as obesity develops and progresses, and in turn, how these fat stem cells respond to green (unfermented) Rooibos.

She says the study is a first of its kind on the African continent and will generate hard scientific data on the possible effects of green Rooibos on the development of fat cells and the function of fat tissue. The project will also enable researchers to learn more about the effects of a high-sugar and high-fat diet on the body.

Given South Africa’s high obesity rates, with 70% of women and nearly 40% of men being overweight, the research project has garnered a lot of attention from the scientific community both locally and abroad.

Dr Sadie-Van Gijsen says obesity is among the most common causes of non-communicable diseases, such as heart disease, hypertension, and type 2 diabetes.

“These debilitating illnesses already afflict millions of South Africans and it is therefore imperative that obesity is studied more closely. Many of the current weight-loss products on the market simply don’t work or have unpleasant side-effects, so we need to develop products that are more effective and tolerable.

“While we know that fat cells store excess calories that are released when the body needs it, we have a very limited understanding of the factors regulating the storing and burning of fat.”

She says for years, scientists have tried to find a way of blocking or suppressing the formation of new fat cells, but that the trouble with this is that fat tissue needs to perform its storage function and when no new fat cells are formed, the existing fat cells only become bigger and more dysfunctional, which triggers metabolic diseases such as diabetes and high cholesterol.

“The truth is that our bodies need fat in order to function optimally: it protects our organs, it keeps us warm and it stores excess calories, which otherwise would remain as glucose and fat in the bloodstream, resulting in diabetes, blocked arteries and fatty liver disease. Fat also forms part of our hormonal system, so we can’t do without it.

“We know that obesity not only means more fat but it also fundamentally changes the way that fat and fat stem cells behave. Many obesity studies only focus on dysfunctional obese fat. However, the Rooibos study will help us to gain a better understanding of how healthy fat changes into dysfunctional fat and will hopefully bring us a step closer to solving the obesity conundrum.”

It’s Rooibos’ anti-oxidant and anti-inflammatory properties that she is particularly interested in as inflammation and oxidative stress are both hallmarks of dysfunctional fat and are responsible for the development of many of the diseases associated with obesity.

She says fat stem cells act as ‘the enemy within’, by becoming active participants in fat tissue inflammation during prolonged obesity.

“By addressing the inflammation and oxidative stress within the fat tissue and fat stem cells, with a product such as Rooibos, we may be able to relieve whole-body inflammation and insulin resistance, while improving the storage function of fat, to help clear glucose and fat from the bloodstream. We also know that even after weight-loss, fat stem cells remain dysfunctional to a degree, and we hope that Rooibos might also be able to relieve this.”

The initial phases of the study will near completion towards the end of the year and will be followed by a more in-depth analysis spanning 12 to 24 months.

For more information on the health benefits of Rooibos, visit