Another interesting tea with some good research behind it:
Sideritis Scardica (Greek Mountain Tea) extracts improve cognitive and mood outcomes in older adults
The following research papers and clinical trials support the claim that Sideritis scardica (Mountain Tea) extracts can improve cognitive function, mood, and cerebral blood flow in older adults.
1. The Wightman Study (Primary Clinical Trial)
This is the most direct evidence supporting your claim. It is a double-blind, randomized, placebo-controlled trial specifically targeting healthy older adults (aged 50–70).
- Paper Title: The Acute and Chronic Cognitive and Cerebral Blood Flow Effects of a Sideritis scardica (Greek Mountain Tea) Extract: A Double Blind, Randomized, Placebo Controlled, Parallel Groups Study in Healthy Humans
- Authors: Wightman E.L., Jackson P.A., Khan J., et al.
- Journal: Nutrients (2018)
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Key Findings:
- Cognition: Acute supplementation improved speed and accuracy on cognitive tasks (specifically the Rapid Visual Information Processing task).
- Mood: Chronic consumption (28 days) of the high dose (950 mg) significantly reduced state anxiety.
- Mechanism: The extract significantly increased cerebral blood flow (oxygenated hemoglobin) in the prefrontal cortex during cognitive testing.
- Link to Paper: Read at National Institutes of Health (PMC) | Read at MDPI
2. The Behrendt Study (Stress & Executive Function)
This pilot study focused on cognitive performance under stress. While the age range was broader (25–60), it included older adults and is frequently cited regarding the extract’s ability to mitigate cognitive impairment caused by stress.
- Paper Title: Effect of an herbal extract of Sideritis scardica and B-vitamins on cognitive performance under stress: A pilot study
- Authors: Behrendt I., Schneider I., Schuchardt J., et al.
- Journal: International Journal of Phytomedicine (2016)
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Key Findings:
- The study found that Sideritis scardica extract (combined with B-vitamins) alleviated stress-induced impairment of executive functioning, including working memory and cognitive flexibility.
- Subjects showed improvements in the Trail-Making Test (TMT) and Colour-Word-Test (CWT).
- Link to Paper: Read at ResearchGate
3. The Hofrichter Study (Mechanistic & Pre-Clinical)
While this study used aged mice rather than humans, it is critical for understanding the mechanism of action in the aging brain, specifically regarding Alzheimer’s pathology (Amyloid-β).
- Paper Title: Sideritis spp. Extracts Enhance Memory and Learning in Alzheimer’s β-Amyloidosis Mouse Models and Aged C57Bl/6 Mice
- Authors: Hofrichter J., Krohn M., Schumacher T., et al.
- Journal: Journal of Alzheimer’s Disease (2016)
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Key Findings:
- Extracts enhanced memory in aged, non-transgenic mice as well as Alzheimer’s models.
- Treatment reduced Amyloid-β (Aβ42) load and rescued neuronal loss, suggesting a potent neuroprotective effect relevant to aging.
- Link to Paper: Read at National Institutes of Health (PMC)
Summary of Mechanisms
According to these texts, the extract works through three primary pathways:
- Cerebral Blood Flow: Increasing oxygen supply to the prefrontal cortex (Wightman et al.).
- Monoamine Reuptake Inhibition: Acting similarly to mood-stabilizing drugs by preventing the reuptake of serotonin, noradrenaline, and dopamine (Knörle et al., cited within Wightman).
- Neuroprotection: Reducing oxidative stress and Amyloid-β toxicity in the aging brain (Hofrichter et al.).