Antioxidant and anti‐inflammatory effects of Rooibos on cognitive signs of Alzheimer’s Disease in the context of early life adversity

Abstract

AbstractBackgroundMedicinal plants are important in traditional healthcare in Africa especially in low‐resourced communities living under conditions of adversity. In South Africa, the fynbos plant Aspalathus linearis, or Rooibos, has been used for centuries as a restorative herbal tea. Over the past few decades, the immuno‐modulating properties of Rooibos have been firmly established with studies demonstrating potent antioxidant, anti‐inflammatory and anti‐cancer properties. These indications suggest that Rooibos can aid in prevention of Alzheimer’s Disease (AD), which is strongly linked to immune dysregulation. However, the overall efficacy of Rooibos supplementation may depend on individual differences in neuro‐inflammatory priming, which occurs in early development, partly as a result of stress.MethodIn a double‐blind, placebo‐controlled intervention trial, we aimed to investigate the effects of 12 weeks' supplementation with green or fermented rooibos following a washout period on biophysical and behavioural risk profiles for AD. Using a mixed‐factorial design in a sample of 340 adults, we assessed early life stress history and evaluatedclinical signs of neurodegenerationusing a standardised neuropsychological battery, and cognitive effort based on a pupil dilation task. Biochemical profiles were assessed using patient plasma samples for indices of antioxidant and anti‐inflammatory activity using ELISAs.ResultResults are currently pending.ConclusionThis study contributes to our growing understanding of the medicinal properties of Rooibos and how early life stress influences neuro‐immune processes. Given that tea drinking is an economical and widely adopted social‐cultural practice across all age groups, tea is ideal to target in designing low‐cost dietary interventions for neurodegenerative diseases like Alzheimer’s.