With an intense and enveloping aroma, rosemary is an essential ingredient in the preparation of potatoes, soups, sauces and bread. Its essential oil has been shown to improve concentration and to stimulate hair growth. From today, we know that the antioxidants contained in rosemary are also neuroprotective and anti-inflammatory, useful in combating degenerative diseases such as Alzheimer's and Parkinson's and also the consequences that COVID 19 can bring with it in that condition that has taken the name of Long Covid. This emerges from a very recent research that was published in the journal Antioxidants by a team of Californian and Japanese scientists (Satoh et al, Antioxidants, 2022).
The problem of inflammation
Alzheimer's, Parkinson's, acute symptoms of COVID 19 in the lungs and chronic symptoms in the post-illness phase, in that condition called Long Covid that causes mental fog, depression and anxiety, have one feature in common. In particular, they are caused by an inflammatory process. In neurodegenerative diseases, it is cerebral inflammation with the concomitant presence of accumulations of beta amyloid plaques that is the trigger for the development and progression of degeneration. In the acute phase infection caused by the new coronavirus, the most severe damage is observed due to the cytokine storm released following uncontrolled inflammation. And it is always the release of pro-inflammatory substances after healing from the infection that causes neurological problems. The greater the release of pro-inflammatory substances, the greater these effects will be.
The active ingredients of rosemary
Rosemary has two groups of potentially active substances. The first group is given by essential oils, which evaporate to produce the characteristic taste and aroma of rosemary. The other group is represented by phenolic compounds with antioxidant and anti-inflammatory properties, such as carnosic acid and carnosol.
The power of the carnosic acid of rosemary
The carnosic acid of rosemary has been shown to act by counteracting oxidative stress and inflammation, even managing to overcome the barrier between blood and brain and benefiting the brain with its neuroprotective action. The study we are talking about today has precisely set itself the purpose of understanding this action in detail.
Rosemary and neurodegenerations
With regard to neurodegenerations, carnosic acid has been shown to reduce inflammation in the brain by inhibiting the activation of microglial cells. These cells represent the first and main immune line of defense in the central nervous system and, once activated, release pro-inflammatory substances. In itself this process is physiological and meant to be protective. However, in the case of diseases such as Alzheiemer, the microglial cells themselves make a decisive contribution to the loss of neurons, typical of this disease, through the release of inflammatory substances. Therefore carnosic acid has been able to show a neuroprotective action. Not only that, carnosic acid is also associated with an increase in indicators relating to the formation of synapses, namely connections, between neurons.
Rosemary, COVID 19 and Long Covid
Carnosic acid has been shown to bring benefits even in the case of COVID 19 infection in several ways. First, carnosic acid hinders the entry of the virus into the body by binding to the receptor with which the spike protein of the virus binds to human cells. Then, carnosic acid is able to downregulate the release of inflammatory cytokines. Excessive release of these substances could cause what is called acute respiratory distress syndrome, which is a type of respiratory failure that characterizes acute new coronavirus infection. Not only that, an excessive release of inflammatory cytokines with an activation of microglial cells and an increase in neuroinflammation is connected to the long covid. Therefore, by inhibiting inflammation, carnosic acid emerges as a promising ally also against the long-term effects of covid 19.
Thus, rosemary can become a powerful and beneficial ingredient within a healthy and varied diet. The intake of rosemary through the diet is healthy and allows the food to act day by day, counteracting inflammation. For a stronger action there are supplements, but they should be avoided in children, pregnant and breastfeeding women and in those suffering from epilepsy.