Rosemary: Brain tonic

23:30, Aug 14 2014

The 1866 publication Treasury of Botany offers a possible reason for dying rosemary plants.

"There is a vulgar belief in Gloucestershire and other counties that rosemary will not grow well unless where the mistress is 'master'. So touchy are some of the lords of creation upon this point, that we have more than once had reason to suspect them of privately injuring a growing rosemary in order to destroy this evidence of their want of authority." 

I rather like that. I would like it even better if rosemary grew well in my garden. It doesn't. And there aren't even any lords a-lording anywhere in the vicinity.

The problem is, it's not growing in a particularly well-drained spot (see growing conditions below) and it gets shaded by some taller growing plants. But it does give me a few offerings for roast dinners and rosemary shortbread, and I have enough to get me by on the sniff factor.

Sniffing it is all-important. Next time you find yourself in the vicinity of a rosemary bush, bend down and take a whiff of its aroma. This fragrant, evergreen herb is thought to help you remember things. Scientists say that the scent of rosemary is, in fact, an effective memory stimulant.

Ancient Greek scholars already knew that. They wore rosemary around their heads to help them remember their studies. Early Europeans threw it into the tombs of loved ones to help them remember them, and Shakespeareans are forever harping on about rosemary for remembrance ("There's rosemary, that's for remembrance; pray, love, remember."). An 16th century herbal book recommended taking rosemary for "weakness of the brain."


And it seems there is some truth in it. Recent studies suggest that the smell of rosemary could indeed improve long-term memory. It does this by inhibiting the breakdown of acetylcholine, a neurotransmitter that plays a role in the part of the brain responsible for memory. It works by inhibiting acetylcholinesterase, which degrades acetylcholine. That's important to note, because acetylcholinesterase is among the key enzymes that promote Alzheimer's. Rosemary has also been shown to increase blood flow to the brain, further aiding memory and concentration.

Studies have focused on participants' ability to do mental arithmetic as well as studying their prospective memory. For the former, volunteers subjected to the scent of rosemary showed noticeable improvement in aspects of cognition, with greater speed and accuracy. The latter study focused on remembering events in the near future, including tasks to be completed at a certain time. Those exposed to the aroma of rosemary did 60-75 per cent better than those not exposed to it.

How does it work by scent? A study by Mark Moss and Lorraine Oliver at Northumbria University (2012) says: "Volatile compounds (e.g. terpenes) may enter the blood stream by way of the nasal or lung mucosa. Terpenes are small organic molecules which can easily cross the blood- brain barrier and therefore may have direct effects in the brain by acting on receptor sites or enzyme systems."

So there you have it. Smelling rosemary just might help you to remember things better. But there's even more to rosemary. As well as these memory-boosting credentials, rosemary also contains carnosic acid and rosmarinic acid. Carnosic acid is an antioxidant that helps deter free radicals in the brain that can cause oxidative stress and contribute to neurodegeneration.

Rosmarinic acid has several beneficial properties, including antioxidant, anti- inflammatory, antiviral and antibacterial.

You can take rosemary as a simple tea (steep a handful of leaves in freshly boiled water for 10-15 minutes for drinking), or to spark your memory or increase your concentration, try this.

Pick a sprig of rosemary, crush the leaves in your hands and inhale. Or you can buy rosemary essential oil and put a few drops in an oil burner or diffuser to take in the aroma.

Like the Ancient Greeks, this could be something to do when studying for a test, or for boosting your brain function overall.


Rosemary is readily available and can be grown easily in everyone's backyard.

Even non-green thumbs can grow this herb.

If you have sun you can grow rosemary. It's a hardy plant that likes free-draining soil. In fact, it doesn't mind it on the dry side at all. Its small drought-resistant leaves can cope with dry spells - in its natural Mediterranean habitat it can survive on just a spray of sea air. Poor or sandy soils are fine. Though if you have some lime, your rosemary plants will benefit from that.

An easy solution is to add crushed eggshells to the soil around the plant.

If you don't have the right spot in your garden, grow your rosemary in a pot and sit it by your back door for easy access.

You should water it occasionally, if necessary, but there's no need to feed it.

The Southland Times