Johannesburg - While there is no cure for Alzheimer’s disease (AD), preliminary studies with Rooibos extracts have shown that the tisane may be able to reduce the risk and onset of neurodegenerative diseases.
Health experts say AD is a progressive illness that destroys memory and other important mental functions. It affects an estimated 55 million people worldwide.
And in recent decades, there has been a significant rise in Alzheimer’s cases globally and in South Africa. This is largely due to unhealthy lifestyles, which often lead to chronic illnesses like diabetes, hypertension and cardiovascular disease, with another risk being old age.
As life expectancy increases, more people are reaching ages where neurodegenerative diseases are becoming more common, necessitating the development of new, more effective therapies.
Two prominent South African scientists, who have been studying Rooibos and brain health for several years, attribute the tisane’s neuroprotective effect to its combination of polyphenolic compounds. This includes other rare antioxidants, like Aspalathin and nothofagin, that help the body to detoxify and rid itself of harmful free radicals caused by oxidative stress. Over time, oxidative stress leads to inflammation and many pathophysiological (abnormal) conditions in the body. Some of these include Parkinson’s disease, chronic fatigue syndrome, heart disease and Alzheimer’s.
Some animal studies have also shown that Rooibos extracts might positively influence specific memory and cognitive function pathways, however, further examination is needed before firm conclusions can be drawn.
Novel research being done by Dr Taskeen Fathima Docrat, a scientist at Cape Peninsula University of Technology (CPUT), aims to unravel the intricate biological mechanisms that are involved in brain health to gain a clearer understanding of how and to what extent Rooibos can prevent Alzheimer’s disease.
“We’ve delved explicitly into the intricate world of epigenetics, which is the study of how our behaviours and the environment can change the way our genes work without altering the underlying DNA sequence,” she said.
“Unlike genetic changes, epigenetic changes are reversible and can change how your body reads a DNA sequence.”
Docrat explained that mitochondria are known as the powerhouse of a cell because they are responsible for generating energy in the form of adenosine triphosphate.
“Sometimes, mitochondria don’t work as well as they should due to another disease or condition in the cell;this is called mitochondrial dysfunction.”
Docrat said many conditions could lead to secondary mitochondrial dysfunction, including AD, as well as muscular dystrophy and Type 1 diabetes.
“We’ve been particularly interested in understanding how Rooibos could influence oxidative stress-related biomarkers, and gene and microRNA regulation related to mitochondrial dysfunction in Alzheimer’s disease.
“This line of research takes a holistic approach by examining multiple factors and their interactions.”
Docrat said scientists were comparing the effects of fermented (red) and unfermented (green) Rooibos to help us understand the potential benefits of the types of Rooibos types.
“Comparing the effects of different Rooibos types not only contributes to a more nuanced understanding of their potential impacts in protecting against Alzheimer’s, but also provides insights into how variations in processing might influence their bioactive properties.
“Although we are still busy with these studies, preliminary findings look promising, suggesting that Rooibos could positively impact these factors.”
Docrat said the insights being gathered would guide the design of future human clinical trials to explore Rooibos’s effects in real-world scenarios.
“Currently, we are laying the foundation for potentially developing supplements that could act preventatively.”
Another prominent researcher, from Stellenbosch University and a professor of molecular physiology, Ben Loos, has done extensive research in the past 12 years, on AD and neuronal ageing and malignant brain tumours, as well as neuronal injury and trauma.
Loos’s research has focused specifically on autophagy activity, an intracellular degradation process that allows cells to recycle damaged components to generate energy and provide building blocks to create new cellular structures.
“In gist, autophagy acts as a housekeeping mechanism to ensure that damaged parts of the cell are rapidly digested (eaten) and cleared from the cell,” Loos said.
He said that in recent years, defects in autophagy function, which happened with ageing, had been associated with the development of cancer and AD.
“Various animal models and cellular studies indicate that increased autophagy activity may play a role in improved longevity and a longer lifespan,” he said.
Loos’s aim is to prevent or delay the dying of cells.
He said that over the past few years, it had become clear that the biggest risk for the development of AD was ageing.
“We all age differently. Some age poorly – usually associated with poor lifestyle choices, while others age healthily so, we started to look at the molecular hallmarks of ageing, which include mitochondrial dysfunction, oxidative damage and the accumulation of toxic protein aggregates.
“In doing so, we came across the potential health benefits of Rooibos and were curious about how it would impact these markers. If it acted on some of those parameters positively, we thought, it could likely reduce the risk of neurodegeneration.”
Loos said their current research assessed the effect of Rooibos extract on damaged/diseased mitochondria, mimicking AD, which had shown that when the neurons were treated with the extract, mitochondrial volume increased.
“This indicates that Rooibos is indeed acting on a very important part that controls cell energetics and cell health. Preliminary data also shows that the Rooibos extract preserves cell membrane integrity,” Loos said.
Applying leading-edge imaging technologies to unravel the molecular make-up of a dying and diseased cell, allowed Loos and his team to gain a deeper understanding of cell dynamics and how they respond (fight) to survive a stressful event.
Loos said he and his team had designed the research in a way that could be more translatable to humans.
“The cells are all treated with an equivalent amount of either three or six cups of Rooibos, so that a low and high concentration can be compared. We also use fermented (red) and non-fermented (green) Rooibos.
“Our results show that at both low and high concentrations of fermented and non-fermented Rooibos extract, mitochondrial function was improved.”
And once Loos and his team have completed their current study, they plan to turn their focus to how effective Rooibos impacts the process of “rubbish removal” in the neuron (autophagy).
“If we can show that Rooibos extracts increase the cell’s ability to remove toxic protein cargo, such as amyloid beta, by enhancing autophagy, this would be a massive finding. Autophagy, which increases upon fasting or exercise, has been shown to directly rescue diseased Alzheimer’s neurons.
“Such a finding would be very direct evidence of the effect of Rooibos on cell health and healthy ageing.”
Loos said he and his team also wanted to introduce an even better model for AD, where the production of the toxic proteins could be switched on, allowing them to measure whether the presence of Rooibos could decrease the toxic burden.
“In the future, we would like to measure the effect of Rooibos on the mitochondria and autophagy in human blood cells, to have an even better translational value,” he said.
Docrat and Loos’s research approaches offer multifaceted insights into Rooibos's potential benefits against Alzheimer’s, covering cellular and molecular aspects.
The studies are particularly vital as World Alzheimer’s Month, in September, is aimed at raising awareness and discussion around the disease and the worldwide necessity of finding new potential disease-modifying therapies.
To date, only symptomatic treatments exist, all trying to counterbalance the neurotransmitter disturbance.
Treatments capable of stopping or at least effectively modifying the course of Alzheimer’s, are encouraged given the rise in incidence. And by 2050, the number of cases is set to increase to 139 million, with low- and middle-income countries experiencing the most significant increase.
Rooibos research is supported by the South African Rooibos Council, in collaboration with the Department of Science and Innovation Sector Innovation Fund Programme.
The Saturday Star