WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
If you've walked through the herbal section of a greenhouse, one fragrance you may detect is rosemary. A woody, perennial herb, rosemary is related to other members of the mint family such as basil and oregano.
The Latin name Rosmarinus officinal means "dew of the sea," which lends this popular perennial a sort of mystical elegance.
With its origins in the Mediterranean, silver-tinged rosemary is very hardy and versatile. Its evergreen essence is a savory culinary marvel cooked in meats such as lamb, chicken or pot roasts, but it's equally delicious in vegetable dishes such as potatoes, tomatoes and squash.
Because it's quite strong, it doesn't take much to create a pleasant flavor with rosemary or rosemary oil, whether you use it whole, or dry the leaves and crumble them into a powder for sprinkling into or onto foods. Drying it quickly helps keep its color and essential oils.
Culinary experts say the best time to harvest rosemary is just prior to blooming in the late summer or fall. Long stems can be hung upside down in a dark area with good air circulation, or you can also freeze the sprigs, strip off the leaves and refreeze them in plastic storage bags.
Rosemary is easy to grow in most areas. You just need to bring it indoors if you live in areas that have below freezing temperatures in the winter. I enjoy rosemary nearly every day in my salad. I simply snip off a few branches, strip the leaves and cut them very finely with a sharp knife.
Rosemary's Remarkable History, aka What We Forgot
Rosemary has a long tradition in the realms of traditional medicine and was used for everything from growing hair to soothing muscle pain to improving the circulatory and immune systems.
Ancient Greek scholars are said to have worn rosemary garlands on their heads during examinations to jog their memories, and Shakespeare mentioned rosemary in five of his plays. One of his most famous characters, Olivia, mentioned rosemary as an herb for remembrance (although she met a tragic end soon thereafter).
"A Modern Herbal,"1 published by Maud Grieve in 1931, included an amazingly thorough list of herbs and plants, with folksy information on their uses down through the ages. One use she revealed for rosemary is quite interesting:
"It was an old custom to burn rosemary in sick chambers, and in French hospitals it is customary to burn rosemary with juniper berries to purify the air and prevent infection. Like rue, it was placed in the dock of courts of justice, as a preventative from the contagion of gaol-fever."
Gaol, or jail, was where a number of prisoners contracted a typhus-like, highly infectious disease. The physicians of the period may have been on to something, because modern-day scientists have identified rosemary as an herb with anti-bacterial qualities.
It begs the question: if rosemary's link to memory and infectious disease was understood 500 years ago and beyond, what might Renaissance scholars have known that we forgot?
Health Advantages of Rosemary
Such historical anecdotes may have helped prompt scientists to compare the effects of essential oils with commonly used antibiotics. One of the more recent studies found that rosemary and oregano oils:
"Resulted in the same amount of growth in chickens as the antibiotic avilamycin, and that the oils killed bacteria, too. Additional findings have shown that essential oils help reduce salmonella in chickens, and another study found that a blend of several oils can limit the spread of salmonella among animals."2
Science has churned out multiple studies to substantiate many of the early health claims of this fragrant herb, finding that besides being an excellent source of antioxidants and anti-inflammatory compounds, benefits include:
- Enhanced memory and concentration — Scientists say they proved for the first time that the fragrance of rosemary enhanced memory during a study published in 2012 in Therapeutic Advances in Psychopharmacology.3
- Diabetes protection — Greek and Mexican oregano, marjoram and rosemary were determined to be a natural way to keep glucose levels in check.4
- Neurological defense — A review concluded that "carnosic acid (in rosemary) may be useful in protecting against beta amyloid-induced neurodegeneration in the hippocampus."5
- Prevents brain aging — Carnosic acid, a compound in rosemary, was effective against brain aging in a Japanese study.6
- Cancer protection — Compounds in rosemary were reported to have antiproliferative effects on leukemia and breast cancer cells.7 Another review reported it to be beneficial against inflammation, and tumor-protective.8
- Macular degeneration protection — Carnosic acid was found to be a protective agent against this most common age-related eye-related problem in the U.S.9
The Nutritional Benefits and Healing Power of Rosemary
A good source of calcium, iron and vitamin B6, rosemary also contains copper, magnesium and potassium. It's an excellent source of fiber, vitamins A and C, folate, calcium and iron, as well.10
Manganese may be the most prominent mineral, working with an important antioxidant called superoxide dismutase to decrease the risk of cancer, particularly breast cancer.11
Rosemary's numerous B vitamins include pantothenic acid, pyridoxine and riboflavin, and its folate content is necessary for DNA synthesis. Just prior to conception, many of the compounds in rosemary help prevent neural tube defects in newborns.
Europeans often use rosemary to help with digestive troubles. Commission E in Germany even approved rosemary extracts as a bona fide treatment, even though anecdotal evidence rather than scientific studies support that hypothesis.
Alzheimer's and dementia have been extensively explored in the realms of conventional medicine, most often to find pharmaceuticals that can either prevent it or to boost memory. However, the results have never been deemed "clinically significant."
Can Eating Rosemary Help You Live Longer?
About 300 individuals, 100 years old and older, were found living in a remote Italian village. Scientists at first thought they lived so long because of their Mediterranean diet. However, rosemary was consumed regularly and in large amounts in the centenarians' diets.
According to coronary/cardiac researcher Dr. Alan Maisel, who was given permission to research the village with a team of scientists, the impressive age factor may have been augmented by fresh mountain air or long hikes in the mountains, but previous studies on rosemary made it the probable reason for the extraordinarily long-lived seniors. Maisel noted:
"Rosemary contains an ingredient that fights off free radical damage in the brain.
This active ingredient, known as carnosic acid (CA), can protect the brain from stroke and neurodegeneration that is due to toxins and free radicals which are thought to be one of the contributors to stroke and conditions such as Alzheimer's and dementia."12
The researchers established that the carnosic acid content in rosemary activates a "signaling pathway" to protect brain cells from damage, but additionally, caffeic acid and rosmarinic acid throw powerful antioxidant and anti-inflammatory support behind the other compounds in rosemary to reduce liver disease, heart disease and asthma.
When Science Kicks in, Alternative Health Is Often Validated
You might think of pine when you detect a waft of rosemary. The scent comes from 1,8-cineole, a terpene also found in bay leaves, wormwood, sage and eucalyptus. It's the compound scientists have used in dementia patients, which brings about increased surges of a neurotransmitter called acetylcholine.
"These compounds do this by preventing the breakdown of the neurotransmitter by an enzyme. And this is highly plausible — inhalation is one of the best ways of getting drugs into the brain.
When you eat a drug it may be broken down in the liver which processes everything absorbed by the gut, but with inhalation small molecules can pass into the bloodstream and from there to the brain without being broken down by the liver."13
In another review, researchers observed speed as well as accuracy, since the speed at which an individual is able to recall is a useful predictor of cognitive function during aging. The scientists' overall conclusion gives a nod to the fact that higher concentrations of rosemary essence improves all the above.
"Although less pronounced, the chemical also had an effect on mood. However, this was a negative correlation between changes in contentment levels and blood levels of 1,8-cineole, which is particularly interesting because it suggests that compounds given off by the rosemary essential oil affect subjective state and cognitive performance through different neurochemical pathways."14
The oil did not seem to improve either alertness or attention, but one study conclusion was that the studies:
" … [G]ive us a clue that further research into some of the chemicals in essential oils may yield therapeutics and contribute to our understanding of memory and brain function."
There Are Different Types of Memory
Memory can be separated into three categories:15
- Past memory, made up of your experiences, such as where you lived and went to school.
- Working memory, which has to do with the moment-by-moment organization of your day.
- Future memory, which relates to what you intentionally "remember to remember."
Mark Moss, a psycholobiogoly professor at Northumbria University, worked with a team in the exploration of rosemary and its effectiveness as an essential oil to help improve future memory. In one series of experiments, both lavender and rosemary oil were tested for their effects on 60 "older" participants, who thought they were testing vitamin water.16
The same volunteers were then taken into rooms permeated with the same two essences, or nothing at all, after which they were tested on their memories. Objects were placed in odd spots around the room, which they were asked to recall while they simultaneously underwent what was described as "distracting but fun" word puzzles.
The requirements included challenges such as, "When you come across a question about the queen in the word puzzles, can you remind me to call the garage?"
Researchers found two things to be significant: Volunteers from the rosemary infusion room did "statistically significantly better" than those in the "nothing" room, and the subjects in the lavender room did much worse, no doubt because the lavender's modus operandi is to encourage relaxation and sleep.
Incidentally, traces of compounds in rosemary oil were found in the blood samples of the study participants in the rosemary room. That measurable effect may mean that rosemary and other essential oils could offer valuable clues to science in regard to what rosemary may offer for brain function and memory.
Rosemary Precautions
Rosemary has been reported to be safe in small amounts but potentially problematic when used excessively. Side effects can include:
- Vomiting
- Spasms
- Coma
- Pulmonary edema (fluid in the lungs)
Additionally, extremely large amounts may also cause miscarriage, so rosemary supplementation is not advised for pregnant women.17