Imagine a common sprig of rosemary or sage gracing your roast chicken! Now, imagine that this modest herb may harbor a powerful ally in the fight against Alzheimer’s.
Yes, that’s right.
Recent breakthroughs spotlight a compound called carnosic acid, an antioxidant and anti-inflammatory powerhouse present in these kitchen staples. In its natural form, carnosic acid is unstable, yet innovative science has transformed it into a stabilized prodrug, diAcCA, capable of crossing the blood-brain barrier and selectively activating in damaged, inflamed brain cells. While still in the pre-clinical stages, this discovery lights a spark of hope, hinting that everyday herbs might play a role in slowing, or even preventing, cognitive decline.
What is Alzheimer's?
Alzheimer's disease is a brain disorder that gradually destroys memory and thinking skills. It's the most common type of dementia in older adults.
It is a progressive disease that destroys important mental functions. In this disease, brain cell connections and the cells themselves degenerate and die, eventually destroying memory and other important mental functions. The main symptoms of Alzheimer’s are memory loss and confusion. Although there’s no proper cure for Alzheimer’s, prevention of the disease is possible with a healthier lifestyle, nutritious diet, and proper exercise.
What does the study say?
In a recent study published in the journal Antioxidants, researchers from the Scripps Research Institute discovered a compound called carnosic acid – found in rosemary and sage – with impressive antioxidant and anti-inflammatory properties. They suggest that this compound could be beneficial for neurodegenerative disorders like Alzheimer’s.
Researchers Piu Banerjee and Dr. Stuart Lipton shared their findings with Fox News Digital. They said, “In this study, we observed that administering this drug to mice that had advanced Alzheimer’s-like disease significantly improved the number of neurons, as well as the number of synapses or connections between the brain cells.”
They also noted, “It reduced inflammation caused by current anti-amyloid antibody therapies and improved learning and memory behavior in the mice that received the drug.”
Banerjee explained that carnosic acid is a “prodrug,” meaning it’s inactive until it enters the body, where it gets activated by oxidative and inflammatory stress. “It specifically targets cells undergoing oxidative and inflammatory stress, without affecting healthy, normal brain cells,” she added. This makes it a safer option for treatment.
The researchers believe carnosic acid might help reduce inflammation in aging brains. However, they urge caution. Courtney Kloske, director of scientific engagement for the Alzheimer’s Association, stressed that while studying mice helps us understand the disease, we really need to conduct human studies for a complete picture. “These findings are intriguing, but more research is needed to see how these compounds affect people living with or at risk for Alzheimer’s,” she advised.
Banerjee and Lipton also noted that just cooking with sage and rosemary won’t deliver the same anti-inflammatory benefits. "Critically, one cannot take sufficient herbs safely to produce the same effect as our new drug,” Banerjee explained. Kloske added, “At this point, no one should consume these herbs or carnosic acid to prevent or treat Alzheimer’s or other cognitive impairments.”
Origins and key compound: Carnosic acid in rosemary and sage
Rosemary (Rosmarinus officinalis) and sage have both storied reputations—ancient scholars hung rosemary in their robes to boost memory. Modern research confirms that carnosic acid, alongside carnosol and rosmarinic acid, provides potent antioxidant and anti-inflammatory effects that can reach the brain.
These compounds activate the Nrf2 pathway, which spurs the production of endogenous enzymes that combat oxidative stress – one of Alzheimer’s disease’s key drivers.
From kitchen to lab: Creating diAcCA
Carnosic acid’s instability limited its therapeutic potential – until researchers at Scripps created diAcCA, an acetylated prodrug version. When consumed, diAcCA converts into its active form in the gut, crossing into the bloodstream and, crucially, the brain.
In mouse models mimicking Alzheimer’s (5xFAD strain), three months of diAcCA treatment led to restoration of memory and learning to near-normal levels, increased synaptic density in hippocampal circuits, and reduced neuroinflammation and diminished amyloid-β and phosphorylated tau accumulation.
These results were consistent across behavioral tasks, histology, and biochemistry, with no observed toxicity at all.
Mechanisms at work: A multi-front attack
diAcCA (and its metabolite carnosic acid) appear to combat Alzheimer’s via several reinforcing mechanisms:
Antioxidant defense: Activates Nrf2, turning on protective genes that tackle oxidative stress and stabilize cell redox balance.
Anti‑inflammatory action: Blocks cytokine release (IL-1β, IL-6, TNF‑α) and inhibits inflammasome activation, reducing harmful microglial activity.
Neurotrophic support: Boosts nerve growth factor, BDNF, and synaptic resilience.
Cholinergic enhancement: Rosemary’s 1,8‑cineole component inhibits acetylcholinesterase, helping sustain acetylcholine levels vital for memory.
Reduced neurotoxic proteins: Helps clear amyloid‑β and tau aggregates via synaptic and inflammatory pathways.
The future ahead:
While diAcCA hasn’t yet been tested in people, several encouraging signals emerge:
FDA classifies carnosic acid as “Generally Recognized as Safe”, which may speed early‑stage trials. diAcCA appears well tolerated in mice, with even digestive system benefits, while smaller human trials using rosemary/sage extracts showed improved cognitive speed and memory performance in older adults.
Meta‑analyses of animal studies reflect moderate‑to‑strong cognitive gains from rosemary extract. Banerjee expressed hope for the future, stating, “I hope our drug will start human clinical trials soon. If it proves to be effective, it will be a great new drug for those suffering from Alzheimer’s. We are cautiously optimistic for its success in human clinical trials!”
NB: This article is intended for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment
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