Healthy hearts & Rooibos

According to the following article titled “Rooibos Science Cafe“, posted on 26th June 2015, and written by Nelia Vivier for Get It Cape Town, Rooibos may help prevent the development of heart disease – in a safe and affordable way.


An apple a day keeps the doctor away – and a few cups of Rooibos, your cardiologist. Results from an intervention trial on the health properties of Rooibos show that the fynbos beverage may help prevent the development of heart disease – in a safe and affordable way.


Trial shows rooibos may help prevent heart disease


Prof Jeanine Marnewick from the Oxidative Stress Research Centre at the Cape Peninsula University of Technology, professes an equal love for science (ever since claiming her older brother’s microscope set) and Rooibos, the latter evoking her childhood.


Her 18-year-long scientific affair with Rooibos started with her PhD and involvement with HIV babies. “The research meant a lot to me, came too close to my heart and took its toll,” she remembers. It sparked a lifelong research interest in the fynbos tea’s health properties.

‘Growing up in Kimberley the smell of Rooibos always greeted me when I opened the door to my granny’s house. I loved sipping it slowly, sweetened with condensed milk’

“With global research into green tea ongoing, we were now looking at a uniquely South African product – one that is yet to be cultivated with any success in other parts of the world,” she recalls. “Despite anecdotal evidence (soothing colicky babies and clearing up eczema, etc) no verified data, trials or publications existed on Rooibos.


“My laboratory team wanted to verify its properties and specifically how people could benefit from a prevention point of view,” she explains. Starting at base level, they conducted in vitro studies before going onto in vivo and field studies.


“Wanting to explore the physiological effect of Rooibos to prevent damage on a cellular level, the results with regards to experimentally induced liver and oesophagus, skin and colon-induced cancer (for which they had a referenced data base) were fantastic.”


Rooibos known to be safe for conducting human studies


The outcome of the experimental trials left Jeanine in a good space to move on to human intervention trials in the prevention of the development of heart disease, a multifactorial disease where oxidative stress plays an important role. “Being a ‘generally recognised as safe’ or GRAS product, and having been consumed since the 1700s Rooibos was known to be safe for conducting human studies without danger of toxicity or adverse effects,” she says.


“I knew we were going to see some interference with the oxidative stress profile, but it could easily have had no significant reaction on a cellular level. When the overwhelmingly positive results started coming in, I couldn’t believe it,” she shares her reaction to the first human data in a controlled clinical trial environment.


Clinical results from rooibos trial look promising


The trial showed that Rooibos is particularly effective at reducing oxidative damage to lipids (fats), helping to prevent or slow down atherosclerosis, or hardening of arteries.


“We measured the effect of Rooibos by looking at two markers in the blood that are indicators of oxidative lipid damage, namely conjugated dienes (CDs or molecule with two double bonds) and malondialdehydes (MDAs)”, Jeanine explains.


“MDAs are end-products of radical oxidative decomposition of polyunsaturated fatty acids (the good stuff!). It causes defects in protein synthesis and enzyme inactivation in human cells. Patients with coronary artery disease usually have a higher MDA level than normal.


“Oxidative damage in lipids is accepted as a very important step in the development of atherosclerosis. CDs are formed during the early stages of oxidation (destruction) of important cellular components such as lipids.”


They also monitored oxidative stress by measuring the ratio of oxidized versus reduced – meaning “ready to reduce free radicals” glutathione (GSH, a simple molecule that serves as an endogenous antioxidant as part of our body’s defence mechanism against free radicals).


Every time you breathe in oxygen, energy is produced and with it free radicals. When an imbalance between free radicals and protective antioxidants exists, oxidative stress is induced and bad stuff happens – damage to DNA, changes in the fat structure of the cells, and other markers as precursors to certain diseases.


Result-wise, they observed a decrease of nearly 35 per cent in CDs in the blood of the Rooibos-drinking participants and a 50 per cent decrease in MDAs. Their results showed a significant improvement – and therefore decreased risk of heart disease – in the study participants who drank six cups of Rooibos per day. Rooibos also had a positive effect on the cholesterol profile, lowering the bad type and raising the good. These encouraging results echo some of those found elsewhere on our website in blogposts like this one, about the anti-ageing potential of rooibos.


Rooibos ambassadors


Rooibos has taken the spirited scientist from East to West – experiencing Japanese awe over its caffeine-free properties, and visiting tea houses all over America. She’s equally at home with Singapore scientists and members of Worcester’s Herbal Club.


“Best yet is working with students; the international ones have never heard of the fynbos tea,” she says. “They bring new energy and become ambassadors for Rooibos in countries like Norway, Belgium, and France, to name a few. I’ve seen students bloom into dedicated researchers.”


Rooibos, honey-bush and many other fynbos being out there in nature, future clinical trials beckon. For now the intricate composition of Rooibos remains a mystery. Rather than being defeated, it exhilarates the scientist, known for her perseverance.


“The tip of the iceberg,” she believes, “even without pinpointing its components, Rooibos bears promise for further discoveries. “ Jeanine plans to do a follow-up heart trial next and one on Rooibos and exercise. Research like this also helps to cut a swathe through the wellness hype, as does the transparency of the certificate of analysis for exports.


Taking time out, “I love being creative. I do beading, but always end up giving it away,” she concludes. “I enjoy excellent food such as a grass-fed rib-eye steak with a glass of Shiraz at Arugula Bistro and Bread in Welgemoed Forum.”