Rosemary: Benefits, Uses, and Side Effects

Rosemary is an herb that can potentially help improve gut health, boost memory, and improve mood. It also helps to reduce inflammation, relieve pain, and protect the immune system. Moreover, rosemary can help protect against macular degeneration, stimulate circulation, detoxify the body, and heal many skin conditions.

This herb is considered to be sacred by ancient Romans, Greeks, Egyptians, as well as Hebrews and is particularly prevalent in Italian cultural cuisine. It is also known as ‘Dew of the Sea’ or ‘Old man’.

What is Rosemary?

Rosemary is a fragrant, woody herb native to the Mediterranean region. Its scientific name is Rosmarinus officinalis and it belongs to the Lamiaceae family, with other herbs, such as thyme, oregano, lavender, and basil. It has fine needle-like leaves with a silver touch and pink, purple, white, or blue flowers.

Rosemary has a warm, bitter, and astringent taste. Unlike many other herbs that lose their potency when dried, rosemary retains its taste even in the dried form. It gives a wonderful flavor and aroma to soups, sauces, stews, and chicken roasts.

Rosemary is rich in nutrients that help boost your immunity, reduce muscle pain, and improve your memory. Many people also use it for hair growth. It is available in many forms from fresh and dried to powdered forms for cooking. Rosemary tea, extracts, and essential oil are also used for these benefits. ^[1]

Rosemary Nutrition

According to USDA, fresh rosemary has a very high reserve of vitamins such as vitamin A, vitamin C, vitamin B6, thiamin, and folate. It contains minerals like magnesium, calcium, and iron. Moreover, it has abundant antioxidants in the form of phenolic compounds like diterpene, carnosol, and rosmarinic acid. The essential oils in it contain powerful ingredients such as cineol, camphene, borneol, bornyl acetate, α-terpineol, and α-pinene. ^{[3] [4] [5] [6]}

Aside from the nutrients mentioned above, the herb contains dietary fiber. It is low in cholesterol and sodium but high in saturated fats.

Health Benefits of Rosemary

The top health benefits of rosemary include:

May Help Maintain Gut Health

One study showed that in test subjects with colitis, treatment with rosemary extract was effective to reduce colon tissue lesions and colitis. This, in turn, helps maintain gut health and fight gut diseases like irritable bowel syndrome (IBS) and colitis. ^{[7] [8]}

Rosemary has traditionally been used as a natural remedy for upset stomach, constipation, gas, bloating as it helps in relaxing the muscles of the intestine. Adding it to your diet can help you regulate your bowel movements and your gastrointestinal system. ^{[9] [10]}

May Aid in Hair Growth

Rosemary oil may help to promote hair growth, prevent baldness, slow graying, and treat dandruff.

A comparative study published in 2015 shows that rosemary oil is effective in treating alopecia by boosting hair growth. At six months, a significant increase in hair count was noted for the group treated with rosemary oil. It also promotes healing by increasing microcirculation of the scalp and decreases hair loss after shampooing. ^[11]

To know more, check out our guide on the Benefits of Rosemary Oil for Hair and How to Use it.

Possibly Anti-inflammatory

Rosemary has potentially anti-inflammatory and antioxidant properties.

Carnosol and carnosic acids are two powerful compounds found in rosemary. These compounds have been linked to reducing inflammation of muscles, blood vessels, and joints. This may make it an effective treatment and preventive measure for many diseases, including gout, arthritis, and injuries from physical exertion or surgery. ^{[12] [13]}

Rosemary contains a significant amount of antioxidants possibly including rosmarinic acid, caffeic acid, and betulin acid. These antioxidants help to boost your immune system. ^{[14] [15]}

Rosemary has a warm, bitter, and astringent taste. Photo Credit: Shutterstock

May Help Enhance Memory

One of the earliest documented uses of rosemary was as a cognitive stimulant. ^{[16] [17]}

Evidence shows that it may help improve memory alertness, intelligence, and focus.

As per a research study, rosemary prevents beta-amyloid plaques and suppresses acetylcholinesterase (AChE) activities. It has also been linked to stimulating cognition in the elderly as well as those suffering from other acute cognitive disorders. ^{[18] [19]}

The carnosic acid in rosemary has neuroprotective properties. A 2016 study suggests that it helps to reduce oxidative stress and enhances the synthesis of nerve growth factor which is vital for nerve tissue. ^[20]

May Reduce Liver Damage

Rosemary has been used for its protective effect on the liver in traditional medicine. ^[21]

A 2015 animal study published in the Saudi Journal of Biological Sciences revealed that extracts of the leaves of rosemary and olive helped in reducing liver cirrhosis, due to their potential antioxidant activities. ^[22]

May Relieve Stress

Rosemary may have a calming effect on those who suffer from anxiety.

An animal study conducted on the effects of rosemary concluded that the herb is effective in improving the symptoms of anxiety. These beneficial effects were observed even with repeated administration two weeks later. Furthermore, it may also reduce cortisol (the stress hormone) levels, which helps ease tension in the body. ^[23]

A randomized controlled trial performed on students suggested that rosemary may help in improving sleep quality. ^[24]

While it may be therapeutic as alternative medicine, if you are suffering from symptoms of stress, or irregular sleep, consult with your doctor before trying out this herb.

May Balance Hormones

Carnosol in rosemary decreases androgen receptor expression and also disrupts estrogen receptors in certain cells. It also lowers the release of DHT (dihydrotestosterone) hormone, which helps improve prostate health and enhance hair growth. ^{[25] [26] [27]}

May Aid in Skin Care

The antioxidants in the essential oils of rosemary help improve skin health. It has a potentially anti-aging effect and helps heal blemishes and may increase the natural shine. Also, its extracts with citrus supplements prevent skin against UV light damage, much better than the supplements alone. ^{[28] [29]}

In a research study on the effects of rosemary extracts on skin damage, Dr. Alice L. Pérez Sánchez states that the herb actually helps protect you against UV-induced damage through its antioxidant effects. ^[30]

Might Limit Weight Gain

Rosemary herbal extracts exert possible anti-inflammatory and anti-hyperglycemic effects, which may promote weight loss. Research shows that treatment with rosemary extract resulted in significant weight loss and increased excretion of lipids through bowel movements. ^{[31] [32] [33]}

According to another study, carnosic acid-rich rosemary can be used as a preventive treatment for metabolic disorders. ^[34]

May Have Antibacterial & Antimicrobial Abilities

Rosemary is specifically powerful against bacterial infections. It is linked to preventing staph infections, which are highly contagious and can cause lethal boils and blisters. It also eradicates various gram-negative and gram-positive bacteria completely. ^[35]

Due to its antibacterial qualities, rosemary intake has been shown to prevent the growth of H. pylori bacteria, a dangerous pathogen that is associated with gastritis, and stomach ulcers. ^[36]

Other Benefits

• Oral Health: One study showed that an herbal mouthwash containing rosemary and other herbs was as effective as chlorhexidine in the treatment of gingivitis. You can steep the herb in a glass of hot water and then gargle or swish the water in your mouth to eliminate bacteria ^[37]
• Stimulates Blood Flow: Research shows that rosemary may act as a stimulant for the body and boost the production of red blood cells and blood flow. Rosemary also has an anti-thrombotic effect and it helps prevent blood clots. ^{[38] [39]}
• Relieves Pain: As an analgesic substance, rosemary essential oil can be topically applied to the affected area to soothe the pain. ^[40]
• Detoxifies the Body: Rosemary is slightly diuretic in nature, meaning that it can help flush out toxins efficiently during urination. ^{[41] [42]}
• Increase Movement: Cineole in rosemary oil, taken either orally or via inhalation, boosts body activities by enhancing locomotion, according to a study. ^[43]
• Macular Degeneration: The presence of carnosic acid in rosemary helps to prevent age-related macular degeneration, which affects the outer retina of the eye. ^[44]

How to Use Rosemary?

Rosemary comes in various forms like fresh leaves, dried leaves, oil, and extracts. As it has a strong flavor, use it sparingly in your dishes. Mentioned below are some of the ways to use it.

• Rosemary Butter: Rosemary leaves can be used to flavor the butter that you use for steak, pasta, or baked potatoes. Just chop the leaves finely and mix them with the butter.
• Flavoring: You can also add this herb in soups, roast potatoes, chicken to give them an extravagant flavoring. Add a few fresh or dried leaves while cooking and you will have a perfect aromatic soup.
• Rosemary Salt: You can make rosemary flavored salt. Just add leaves from one stem in about 3 cups of salt and mix properly. Let the mixture sit for 15 days and you will be able to use it.
• Rosemary-infused Oils: Bring 2 cups of olive oil to a slight simmer and then remove it from heat. Put 3 – 4 rosemary sprigs into a clean airtight jar and pour the olive oil in it. You can use the oil for cooking in a week. You can also make rosemary oil by following this recipe.

Side Effects

Although the plant is classified as safe by the FDA even at higher concentrations, its long-term excessive use has side effects like:

• Vomiting
• Skin irritation
• Itchy scalp in bald patients
• Increase blood glucose level in diabetics
• Induce convulsions like epilepsy
• Muscle spasms
• Coma

Other risks include:

• Pulmonary Edema: There is some evidence that rosemary leaves in excess quantity can cause pulmonary edema or fluid accumulation in the lungs. Rosemary may interact with diuretic medications often prescribed for this condition, therefore it is recommended you avoid taking rosemary If you take diuretic medications for this or any other reason. It is always best to check with your doctor. ^[45]
• Fertility: Long-term high consumption may lead to a decrease in sperm count, density, and mobility in men. In pregnant women, it may lead to miscarriage and abortion. ^[46]
• Drug Interactions: It may interact negatively with certain drugs like Warfarin (anticoagulant), Lithium, Lasix (diuretic), and others. Be sure and check with your doctor or pharmacist before starting any new herbal supplements.

Note: If you are allergic to other members of the mint family, you may experience discomfort if you consume or apply rosemary or its oil, but the reactions are typically mild.