Two spice rack herbs could reverse Alzheimer's Disease and might help diabetes and heart disease

Experts have found a way of reducing inflammation in the brain which is a trigger for Alzheimer's Disease by using a compound found in the herbs

The herb rosemary has long been linked with memory. Going back as far as Shakespeare's Hamlet Ophelia says.: “There’s rosemary, that’s for remembrance.

And now researchers have discovered a compound found in rosemary - and in its fellow herb sage - could hold the key to reversing Alzheimer's Disease. Carnosic acid is an antioxidant and anti-inflammatory compound that works by activating enzymes that make up the body’s natural defence system.

Pure carnosic acid however is too unstable to be used as a drug. But now a team of scientists from Scripps Research Institute in Calafornia have now synthesised a stable form - diAcCA - which is fully converted to carnosic acid in the gut before being absorbed into the bloodstream.

The research, published in Antioxidants showed that when diAcCA was used to treat mice, it achieved therapeutic doses of carnosic acid in the brain and led to enhanced memory. It also restored nerve connections which could help counteract the progression of cognitive decline.

The Scripps team concluded: "Collectively, these findings underscore the promise of diAcCA as a potential therapeutic for human Alzheimer's Disease." While the trials have been done in mice the compound is considered safe for humans which means the team is calling for testing on people to be "expedited".

According to the NHS there are more than 944,000 people in the UK who have some form of dementia. One in 11 people over the age of 65 have dementia in the UK.

The number is increasing because people are living longer. It is estimated that by 2030, the number of people with dementia in the UK will be more than 1 million.

And Office for National Statistics (ONS) figures show "dementia and Alzheimer’s disease" were the leading cause of death in the UK in 2022. Collectively they accounted for 65,967 deaths (11.4% of the total), up from 61,250 (10.4%) in 2021.

Researchers have previously found brain inflammation us linked with Alzheimer's Disease. In 2012, a study funded by Alzheimer’s Research UK found a mutation in a gene called TREM2 could increase the risk of Alzheimer’s.

As the TREM2 gene makes a protein heavily involved in regulating the brain’s inflammatory response, scientists suggested that inflammation might in fact play a role in the very initial stages of Alzheimer’s.

Now the Scripps team is hopeful their new drug will not only save lives but improve them. And it is hoped the drug will not have any major side-effects.

The study explained it had previously been difficult to use carsonic acid as a drug or supplement because of the instability of the compound. However the team had created a derivative of it which could reach the gut before breaking down.

They said this meant the mice absorbed 20% more carsonic acid that they would have done by trying to ingest it in it pure form. It also meant more of the compound was able to pass through the blood-brain barrier and treat the brain inflammation.

Analysis of tissue samples showed the drug also markedly decreased inflammation in the brain. The unique drug is activated by the very inflammation that it then combats and thus is only active in areas of the brain undergoing inflammatory damage and limiting the potential side effects of carnosic acid, which is on the US Food and Drug Administration’s “generally regarded as safe” (GRAS) list, easing the way for clinical trials.

Senior author and professor Stuart Lipton said the team treated the mice with the compound over the course of three months. The group examined the mice by testing their spatial learning and memory in behavioural tests and then analyzing brain tissue under the microscope.

He said: "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.”

In addition to reducing inflammation in the brain, the scientists found it even "soothed baseline inflammation in the oesophagus and stomach as it was converted to carnosic acid". Prof Lipton sees a potential for diAcCA to work in tandem with Alzheimer’s treatments currently on the market.

He also hoped diAcCA can be fast-tracked through clinical trials because of its safety profile. He thinks it could also be explored as a treatment for other disorders marked by inflammation, such as type 2 diabetes, heart disease, and other forms of neurodegeneration such as Parkinson’s disease.