Rosemary: Health Benefits, Precautions, Drug Interactions
Rosemary (Rosmarinus officinalis) is a fragrant evergreen herb native to the Mediterranean. It is used as a culinary condiment, to make bodily perfumes, and for its potential health benefits.
The herb not only tastes good in culinary dishes such as rosemary chicken and lamb, but it is also a good source of iron, calcium, and vitamin B6. It is typically prepared as a dried whole herb or a dried powdered extract, while teas and liquid extracts are made from fresh or dried leaves.
Rosemary is a member of the mint family Lamiaceae along with many other herbs, such as oregano, thyme, basil, and lavender. The name rosemary derives from the Latin ros meaning “dew” and marinus meaning “sea” – “sea dew.”
The herb has been hailed since ancient times for its medicinal properties. Rosemary was traditionally used to help alleviate muscle pain, improve memory, boost the immune and circulatory system, and promote hair growth.
This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods.
Possible health benefits of rosemary
Rich source of antioxidants and anti-inflammatory compounds- these are thought to help boost the immune system and improve blood circulation. Laboratory studies have shown rosemary to be rich in antioxidants, which play an important role in neutralizing harmful particles called free radicals.
Improving digestion – In Europe rosemary is often used to help treat indigestion – Germany’s Commission E has approved it for the treatment of dyspepsia. However, it should be noted that there is currently no meaningful scientific evidence to support this claim.
Enhancing memory and concentration – blood levels of a rosemary oil component correlate with improved cognitive performance, according to research in Therapeutic Advances in Psychopharmacology, published by SAGE.
Rosemary has leaves shaped like needles
and pink, white, blue, or purple flowers.
Neurological protection – scientists have found that rosemary is also good for your brain. Rosemary contains an ingredient, carnosic acid, that is able to fight off free radical damage in the brain.
According to a study published in Cell Journal, carnosic acid “may be useful in protecting against beta amyloid-induced neurodegeneration in the hippocampus.”1
Prevent brain aging – Kyoto University researchers in Japan revealed that rosemary may significantly help prevent brain aging.
Cancer – Research published in Oncolocy Reports found that “crude ethanolic rosemary extract (RO) has differential anti-proliferative effects on human leukemia and breast carcinoma cells.
Another study, published in Bioscience, Biotechnology and Biochemistry, concluded that rosemary may be an effective herbal anti-inflammatory and anti-tumor agent.3
In addition, a report published in the Journal of Food Science revealed that adding rosemary extract to ground beef reduces the formation of cancer-causing agents that can develop during cooking.
Protection against macular degeneration – a study published in the journal Investigative Ophthalmology & Visual Science, led by Stuart A. Lipton, M.D., Ph.D. and colleagues at Sanford-Burnham Medical Research Institute, revealed that a major component of rosemary, carnosic acid, can significantly promote eye health.
This could have clinical applications for diseases affecting the outer retina, such as age-related macular degeneration – the most common eye disease in the U.S.
Precautions and side effects
Rosemary is usually safe when taken in low doses. However, extremely large doses can trigger the following side effects (although rare):
- pulmonary edema (fluid in the lungs)
High doses of rosemary may cause miscarriage. Therefore it’s not advisable for pregnant women to take any supplemental rosemary.
According to the University of Maryland Medical Center5, rosemary can affect the activity of some medications, including:
- Anticoagulant drugs – blood-thinning medications, such as Warfarin, Aspirin, and Clopidogrel.
- ACE inhibitors – drugs used for treating high blood pressure, including lisinopril (Zestril), fosinopril (Monopril), captpril (Capoten), and elaropril (Vasotec).
- Diuretics – medications that increase the passing of urine, such as hydrocholorothiazide and furosemide (Lasix).
- Lithium – a medication used to treat the manic episodes of manic depression. Rosemary can act as a diuretic and subsequently cause lithium to reach toxic levels in the body.