Scientists to assess how rooibos could boost athletes’ performance

One of the hottest topics in sport and exercise science is the role that natural herbs can play in enhancing athletic performance. Already known for its many health benefits, home-grown Rooibos, will be put through its paces over the next few months when a team of scientists from the Cape Peninsula University of Technology (CPUT) and the Prime Human Performance Institute in Durban will test the extent to which the tea could aid sportsmen and women.


Antioxidants in rooibos work to resist cell damage


In a previous study led by Prof Jeanine Marnewick at CPUT’s Oxidative Stress Research Centre, researchers found that Rooibos plays a preventative role in exercise-induced oxidative stress. In other words, Rooibos’ abundance of antioxidants works in unison to resist cell damage which often occurs during high-intensity bursts of exercise.


Prof Simeon Davies who heads up CPUT’s Sports Management Department explains that these studies have demonstrated that during repeated exhaustive exercise bouts Rooibos can reduce physical fatigue allowing for improved performance – both crucial factors in sport.


“In gist, oxidative stress can be defined as an imbalance between oxidants and antioxidants in favour of oxidants – also known as free radicals. Since oxidants are unstable molecules, they can cause damage to vital cell components, such as genetic material, lipids and proteins. Free radicals are derived from organisms and cells inside the body and the outside environment, such as cigarette smoke, heavy metals, pesticides and certain medication, but can also occur as a result of strenuous exercise when our bodies use oxygen to produce energy.


“To prevent free radical damage, the body has a natural defence system of antioxidants that can combat the damage caused by oxidants, but it’s often not sufficient under certain conditions such as strenuous physical activity.


Drinking rooibos daily boosts performance


“The initial oxidative stress study already showed that drinking Rooibos in a concentrated form – equivalent to six cups a day – boosted performance during repeated arm flexion/extension work by around 5%, which may have interesting implications for usage in elite sports where every percentage point counts during competition, but may also allow for improved training that could in itself elevate competition times,” says Prof Davies.


To build on these findings, a further and more comprehensive study will be done in a simulated and controlled hypoxic (low oxygen) environment simulating high altitude (3 500m). The study will involve 50 relatively fit individuals between the ages of 18 and 60. On test day, each participant will consume a specially prepared tonic consisting of water and concentrated Rooibos or a placebo. Physical performance will be measured on calibrated Wattbikes, while oxidative stress and other related stress markers will be measured via blood samples to evaluate the efficacy of Rooibos during strenuous exercise.


Study to investigate rooibos and high altitude sickness


The hypoxic element to the study aims to further investigate Rooibos’ ability to combat high altitude sickness (HAS). This is because exercising at high altitude induces a high degree of oxidative stress, which is often associated with HAS. In a pilot study, led by Prof Davies in 2015, eight climbers supplemented with Rooibos (in a concentrated pill form) while summiting Mount Aconcagua, which at 6 962m is the highest mountain in the Southern Hemisphere.


Many mountaineers who ascend to such high altitudes often need to take prescription medication to prevent HAS, but preliminary findings from the Aconcagua expedition found Rooibos to be an effective supplement that appeared to mitigate the effects of HAS.


Prof Davies says if Rooibos proves successful in the studies that are to follow, it could become a staple food supplement for elite athletes the world-over.


“As a scientist, I continue to be surprised by Rooibos’ health benefits. Of particular interest to the scientific community, is the flavonoid, Aspalathin, which is unique to Rooibos and is what gives it its powerful antioxidant punch. Aspalathin is known to reduce excessive fat production, balance blood sugar, improve glucose absorption in the muscle and increase insulin secretion in the pancreas,” he says.


The study, which will take place at the Prime Human Performance Institute at Moses Mabhida Stadium in Durban will lend scientific credibility to the value that Rooibos supplementation can have on naturally improving athletic performance – something which many adaptogens (plant species that encourage the body to adapt to physical and mental stress) lack.


“It’s exciting to think that a South African indigenous plant such as Rooibos may become athletes’ next must-have supplement,” says Prof Davies. “In the not so distant future, concentrated Rooibos may also become available to consumers in tablet or tonic form to naturally elevate antioxidant levels in the body to help reduce one’s risk of other chronic diseases such as cardiovascular disease and diabetes.”