Rosemary, the aromatic herb native to the Mediterranean, has long been a staple in kitchens worldwide. Beyond its culinary appeal, however, research is increasingly highlighting its potential benefits for brain health, inflammation, and immune function, with some studies suggesting it may even offer promise in the fight against Alzheimer's disease.
Historically, rosemary has been associated with memory and mental clarity, with ancient Greek and Roman scholars using it to sharpen concentration. Modern research lends some support to this idea: in one study, participants who inhaled rosemary's scent performed better on memory tasks than those in an unscented environment. The herb is thought to stimulate blood circulation, including to the brain, delivering more oxygen and nutrients, which may improve mental clarity. Its aroma may also reduce anxiety and improve sleep, indirectly supporting focus and memory retention.
Rosemary contains compounds that interact with brain neurotransmitters. One such compound, 1,8-cineole, helps prevent the breakdown of acetylcholine, a chemical essential for learning and memory. By preserving acetylcholine, rosemary may help support cognitive performance, particularly with age. Additionally, the herb is rich in antioxidants, which protect brain cells from oxidative stress, a major factor in cognitive decline.
One of the most powerful phytochemicals in rosemary is carnosic acid, an antioxidant and anti-inflammatory agent that shields brain cells from damage linked to Alzheimer's. In 2025, researchers developed a stable version called diAcCA, which in pre-clinical studies improved memory, increased the number of synapses, and reduced harmful proteins like amyloid-beta and tau. Notably, diAcCA only activates in inflamed brain regions, potentially minimising side effects, and studies in mice have shown no toxicity and significant cognitive improvements, raising hopes for human trials.
Rosemary's benefits may extend beyond the brain. It has been traditionally used to ease digestion, relieve bloating, and reduce inflammation. Compounds such as rosmarinic acid and ursolic acid have anti-inflammatory effects, and rosemary may also soothe skin conditions like acne and eczema, with carnosic acid offering anti-ageing benefits by protecting against sun damage. Rosemary oil also has antimicrobial properties, which show promise in food preservation and potential pharmaceutical applications.
For most people, rosemary is safe in food, teas, or aromatherapy. However, concentrated doses can pose risks, including vomiting or, rarely, seizures, particularly in those with epilepsy. There is also a theoretical risk of uterine contractions, so pregnant individuals should avoid high doses, and because rosemary can interact with medications such as blood thinners, it is advisable to consult a healthcare provider before taking large amounts in supplement form. As research continues into compounds like diAcCA, rosemary could play a role in future treatments for Alzheimer's and other chronic conditions.
