The prospect of developing dementia, including Alzheimer’s disease, can be frightening, and, understandably, Brits may want to do as much as they can to limit the chance of developing it. It is thought that one common garden herb may hold therapeutic potential due to its active compounds, which show antioxidant and anti-inflammatory properties. Carnosic acid in rosemary, for example, activates enzymes that part of the body’s natural defence system.

American experts highlighted in 2022 that Rosmarinus officinalis has “long been known as the herb of remembrance and can be a potential cognition enhancer” for Alzheimer’s disease. A study using animals concluded that the administration of the herb “improved cognitive function” in organisms with cognitive deficit, as well as in “normal intact” animals. Researchers added: “The outcomes may be used in the planning of clinical studies provided the included studies are robust enough to account for the heterogeneity observed.

“The cognitive benefits provided by R. officinalis and its mechanisms of action are in synchrony with the fundamental pathophysiology of cognitive deficit and the herb could be a potential treatment for Alzheimer’s disease.”

Further research, published in Antioxidants in February, showed that when diAcCA – a new, stabilised form of carnosic acid – was used to treat mouse models of Alzheimer’s disease, it achieved therapeutic doses of the chemical in the brain, and led to enhanced memory and synaptic density, or more synapses, in the brain, according to News Medical Life Sciences.

Stuart Lipton, MD, PhD, senior author, professor, the Step Family Foundation Endowed Chair at Scripps Research and clinical neurologist in La Jolla, California, said: “By combating inflammation and oxidative stress with this diAcCA compound, we actually increased the number of synapses in the brain.

“We also took down other misfolded or aggregated proteins such as phosphorylated-tau and amyloid-β, which are thought to trigger Alzheimer’s disease and serve as biomarkers of the disease process.”

He added: “We did multiple different tests of memory, and they were all improved with the drug.

“And it didn’t just slow down the decline; it improved virtually back to normal.”

It is unclear as to the exact effects rosemary could have on humans with regards to staving off Alzheimer’s disease, but research so far suggests that it could hold promise.