Rosemary Extract: Cancer Fighter, Brain Protector, and More!

What is rosemary extract?

The extract is from rosemary (Rosmarinus officinalis Linn.), a common household plant that has grown in the Alps since the Middle Ages, and is now found throughout the world. According to folklore, rosemary takes its name from the Virgin Mary, who draped her cloak on a rosemary bush, and then placed a white flower on top of the cloak. The flower turned blue overnight, and the plant became known as the “Rose of Mary.”

Rosemary has been used for thousands of years as a savory spice, food preservative, in cosmetics and hair products, and as an herbal medicine for a variety of health disorders. Until now however, the exact chemical pathways involved in its beneficial effects have remained unknown.

There are hundreds of research papers and studies on the extensive antioxidant capabilities of rosemary. Before retiring from the U.S. Department of Agriculture, botanist Dr. James Duke established the landmark Phytochemical Database that lists all the known chemical compounds in more than 1,000 edible plants, including the most common herbs and spices. According to Duke, rosemary contains more than two dozen antioxidants, and it is the only compound in his database (CRC Handbook of Biologically Active Phytochemicals, 1992) to have immune regulating, anti-inflammatory, and antioxidant activities.

Although rosemary extract has been used commercially as an antimicrobial food preservative for years, now we know for certain that it also has a lot to offer as a nutritional supplement, 1 especially in the prevention of some types of cancer, allergies, and the progression of Alzheimer’s disease.2

Why take rosemary extract?

There are lots of excellent antioxidants that combat free radical damage. However, rosemary extract contains more than two dozen antioxidants, and provides potent protection against chronic diseases, including Alzheimer’s, one of the most dreaded diseases of today.

Rosemary extract:

  • Provides powerful antioxidant protection
  • Protects brain cells from the normal effects of aging
  • May slow down the progression of Alzheimer’s disease
  • Protects cells from carcinogens
  • Inhibits growth of cancer cells
  • Helps reduce allergy symptoms, especially to dust mites
  • Increases potency of vitamin E
  • Helps reduce hypertension

What makes rosemary extract so special?

Antioxidants have been proven to deactivate free radicals, but not all antioxidants are equal. In most cases, once an antioxidant has neutralized a free radical it is no longer useful as an antioxidant because it becomes an inert compound. Or even worse, it becomes a free radical itself.

That’s where rosemary extract is significantly different. It has a longer life span of antioxidant activity. Not only that, it contains more than two dozen antioxidants, including carnosic acid, one of the only antioxidants that deactivates free radicals through a multilevel cascade approach.

In vitro studies have shown that as carnosic acid attacks free radicals it is transformed into at least four other antioxidant compounds, each with the ability to neutralize additional free radicals. Most antioxidants do not have this same capacity. Instead, they neutralize a free radical and are transformed into an inert compound, or even worse, they become free radicals themselves.

When rosemary extract is combined with other antioxidants its potency increases. For instance, vitamin E must be re-cycled after quenching a free radical before it can quench another. But when it is combined with rosemary extract, the carnosic acid, which starts the cascade effect, rejuvenates vitamin E back to its original state, so it can attack additional free radicals. 1 3

Protects and supports brain function

Rosemary has been used for thousands of years as a memory enhancer, and now scientists are proving its cognition-enhancing properties. In fact, many are saying that given the side effects and ineffectiveness of pharmaceutical dementia treatments, rosemary extract may well provide a natural, effective, and well-tolerated treatment for dementia. 4

New research points to the fact that carnosic acid protects the brain, without the side effects that accompany many of the pharmaceutical drugs used to treat neurodegenerative disease.

Two new studies led by Stewart Lipton, MD, PhD, from the Burnham Institute for Medical Research in La Jolla, California, and Takumi Satoh, MD, PhD, from Iwate University, in Japan, show that carnosic acid activates a signaling pathway that protects brain cells from free radical damage seen in stroke and other conditions such as Parkinson’s and Alzheimer’s diseases.5 6

Other studies indicate that rosmarinic acid—another antioxidant found in rosemary—which is also antiviral, antibacterial, and anti-inflammatory, protects brain cells from beta-amyloid toxicity. Beta amyloid plaque is produced when a brain protein known as amyloid precursor protein, or APP, is chopped into pieces by enzymes. This causes brain neurons to degenerate and die and most researchers consider it to be the culprit in Alzheimer’s disease.

Researchers at the Nagoya University Graduate School of Medicine, Nagoya, Japan, examined the protective effects of rosmarinic acid on laboratory animals with cognitive dysfunction resulting from amyloid beta protein. After several doses of rosemary extract, the animals exhibited a higher level of performance on memory tests, including a maze run and object recognition. The researchers concluded that daily intake of rosemary extract may protect against the memory impairment that accompanies Alzheimer’s disease. 7

Anxiety and stress are two of the symptoms that can accompany dementia. Consequently, a study showing that rosemary extract produces a calming effect on the mind while supporting short and long-term memory is also significant, and is an added bonus for anybody. 8


Whether you have seasonal allergies or you sneeze your head off from the microscopic dust mites in your house, you know the misery of trying to breathe with a stuffy, runny nose or tight bronchial tubes. Rosemary extract’s anti-inflammatory properties reduce allergic reaction, including asthma.

In a 21-day randomized, double blind, placebo-controlled study at the Kyoto Prefectural University of Medicine, Kyoto, Japan, patients with seasonal allergies took a supplement with rosemary extract or a placebo. Those taking the rosemary extract experienced a significant decrease in overall symptoms, including runny nose, and itchy, watery eyes, when compared to the placebo group. In addition, the treatment significantly decreased the numbers of neutrophils and eosinophils (white blood cells that protect against invading organisms) in nasal mucous. 9

Studies done on laboratory animals have also shown that rosemary extract decreases the inflammation that accompanies the allergic reaction resulting from exposure to dust mites, 10 as well as asthma, leading researchers to conclude that rosemary extract may be beneficial to asthmatic patients.11

Cancer preventative

Although no human studies have been done, a number of in vivo and in vitro studies have demonstrated that rosemary extract prevents cancer cells from growing. 12 13 A recent study on human cancer cell lines at the University of British Columbia, Canada, found that rosemary’s antioxidant and anti-inflammatory properties inhibit the growth of human leukemia and breast cancer cells. 14

A study at Ben-Gurion University, Beer Sheva, Israel, also looked at the effect that rosemary extract has on human leukemia cells. The researchers concluded that it inhibits the cells from growing and that it can be used with other natural anticancer compounds to inhibit the growth of cancer cells. 15

The antioxidants in rosemary have also been found to be chemopreventative (able to prevent the development of cancer) in human liver and bronchial cells. 16


High blood pressure is usually a result of a combination of stress, high cholesterol, inflammation and sticky blood platelets. Chronic stress causes a constriction of blood vessels and the formation of sticky blood platelets, which can result in a blood clot. When blood vessels are constricted there is less room for blood to flow, and plaque may further constrict the blood vessel. If blood platelets stick together and form a clot, the vessel may be completely clogged and surrounding tissue is deprived of oxygen and nutrients. This leads to heart attack and stroke.

Rosemary extract is one possible remedy for reducing risk of hypertension. A survey of traditional treatments of hypertension and diabetes in Morocco found that rosemary is a popular herbal treatment.17

Scientific studies have also shown that the antioxidants in rosemary inhibit the oxidation of LDL (bad cholesterol) 18 and platelets from sticking together, 19 both big factors in cardiovascular disease.


Time and time again natural solutions to what ails humans are being “rediscovered” by modern science. Synthetic drugs are increasingly being shown to do more harm than good, and more and more people are turning “back to nature” to find treatments and remedies that are time-tested, effective and side-effect free.

So whether you are looking for a safe, natural remedy to help you get through the allergy season, help prevent some of the most dreaded diseases of our time, or protect your memory and stave off brain aging, rosemary extract may be just what you’ve been looking for.


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