Rosemary is a rich source of antioxidants and anti-inflammatory compounds that have been shown to protect against free radical damage in the brain. Historically associated with improved memory, it has also been found to help inhibit the formation of amyloid beta proteins characteristic of Alzheimer’s disease.
Antioxidant
A powerful antioxidant, rosemary helps preserve lipid (fat) membranes, which comprise 60% of the brain. Numerous studies have demonstrated that rosemary compounds activate the Nrf2 cell defense pathway, which releases an array of anti-oxidizing and detoxification enzymes that protect neurons from oxidative cell death. Research now clearly outlines a direct association between free radical damage and neuron death in Alzheimer’s disease, especially in brain regions with accumulations of beta-amyloid. Brain cells are more susceptible to free radical damage than any other cell types for several reasons including their high oxygen consumption, high lipid content and relatively low endogenous antioxidant capacity.
Anti-Inflammatory
Rosemary’s ability to upregulate the brain’s cellular antioxidant defenses is in turn responsible for its potent anti-inflammatory effects. Microglial cells are the major inflammatory cells of the brain which, once activated, produce large amounts of pro-inflammatory cytokines that play a direct role in Alzheimer’s pathology. By triggering Nrf2, rosemary helps counteract microglial activation and other neuroinflammatory responses.
Beta-Amyloid
Rosemary inhibits the production of beta-amyloid in the brain by promoting alternative, non-toxic pathways for the processing of amyloid precursor proteins. It has also been found to help reverse the cellular signs and symptoms of neurodegeneration and cognitive impairment from beta-amyloid toxicity.
Cognition & Memory
Alzheimer’s disease is associated with the progressive death of cholinergic neurons from beta-amyloid toxicity, free radical activity and inflammatory cascades in the brain. The loss of cholinergic neurons leads to lower amounts of acetylcholine, a neurotransmitter critical for memory, cognition, and attention. In animal trials, rosemary has been found to boost acetylcholine levels, resulting in enhanced memory. It is also worth noting that rosemary essential oil constituents are known to positively impact brain function in humans.
Studies:
[1] The Therapeutic Potential of Rosemary (Rosmarinus officinalis) Diterpenes for Alzheimer's Disease
[2] Neuroprotective effects of carnosic acid on neuronal cells under ischemic and hypoxic stress
[3] Neuroprotective effects of carnosic Acid in an experimental model of Alzheimer's disease in rats
[7] Evidence of oxidative damage in Alzheimer's disease brain: central role for amyloid beta-peptide
[8] Oxidative stress and neurodegeneration: where are we now?
[11] Mitochondrial dysfunction is a trigger of Alzheimer's disease pathophysiology
[14] Protection from cyanide-induced brain injury by the Nrf2 transcriptional activator carnosic acid
[19] Dual mechanisms of NF-kappaB inhibition in carnosol-treated endothelial cells
[22] Carnosic acid, a pro-electrophilic compound, inhibits LPS-induced activation of microglia
[23] Mitochondrial alterations, oxidative stress and neuroinflammation in Alzheimer's disease
[27] The protective role of carnosic acid against beta-amyloid toxicity in rats
