Rosemary’s Health Benefits

Used as a culinary herb in French and Italian dishes, rosemary offers many health benefits. Rosemary quenches inflammation, helps to subdue allergies and improves certain aspects of type 2 diabetes and hypertension. Discover how!

Fragrant rosemary (Rosmarinus officinalis L.) belongs to the mint family. Because of its antioxidant properties, rosemary is a good preservative. It also exerts mild antimicrobial activity, cancer-protecting, and anti-inflammatory effects.

Powerful Antioxidant Activity

Rosemary is among the richest herbs in antioxidants. In fact, more powerful than vitamin C, this pungent herb contains twelve antioxidants that act in synergy to protect cells from free radical damage and improve one’s antioxidant status. Like its cousin, sage, it helps protect fat from oxidation. Carnosic acid, carnosol, and rosmarinic acid in rosemary help to protect chromosomes from damage caused by gamma rays. Therefore, unless contraindicated, drinking rosemary tea a day before and after a diagnostic radiological test could help reduce free radical damage. (Including a little extra garlic, vitamin C and vitamin E would also prove helpful.)

Rosemary’s Cardiovascular Effects

Rosemary can also prove useful for hypertensive individuals.¹ Researchers at the University of Massachusetts have recently discovered that rosemary is an ACE inhibitor. ACE inhibitors block the formation of the hormone angiotensin II. This hormone promotes inflammation within the arteries, accelerates the development of atherosclerosis, and is a very powerful constrictor of blood vessels. As blood vessels constrict, blood pressure increases. Other studies show that rosemary improves the ability of the blood vessels to dilate in healthy young individuals.²

Rosemary and its relative, thyme, help the cardiovascular system in another way. They show significant anti-thrombotic (clotting) action. This is significant because undesirable clot formation is involved in approximately 80% of all heart attacks and the majority of strokes.

Quenches Inflammation

Rosmarinic acid in rosemary (also found in sage and basil) can reduce inflammation in the lungs, especially from diesel particles inhaled from air. These particles actually decrease the quality of life and increase the risk of dying from lung diseases. Rosemary also inhibits allergic inflammation of the bronchial tubes from dust mites.^3,4

Rosmarinic acid helps to protect DNA from the damaging by-products of chronic inflammation. Additionally, rosemary curtails the migration of white blood cells to injured tissues and reduces the release of inflammatory chemicals.⁵ Rosemary inhibits inflammation by at least four known mechanisms.

Allergy Relief

Unlike antihistamines, rosmarinic acid decreases the activation of immune responder cells that promote swelling and other symptoms of allergy-evoked inflammation. It also kills unneeded allergy-activated T-lymphocytes, while sparing the vast number of T-cells that are required to fight bacteria and viruses. Japanese researchers, using rodents, showed that a daily treatment with rosmarinic acid prevented allergic asthma caused by house mites. Some studies show that it also inhibits inflammation in seasonal allergic rhinitis caused by tree, grass, or weed pollens.⁶

Pain Fighter

Not only does rosemary decrease inflammation in the lungs, it also reduces joint pain. Indeed, a mixture of rosemary oil with cold-pressed olive oil can applied to aching muscles and joints. This mixture also improves blood flow to inflamed muscles. Like its relative, basil, rosemary inhibits NF-kappa B, a protein that, when activated, promotes inflammation. Like turmeric and ginger, rosemary inhibits the proinflammatory enzyme, known as COX 2.⁷ Unlike drug COX-2 inhibitors, rosemary does not increase the risk for cardiovascular problems.

Rosemary contains many pain-blocking compounds: carnosic acid, carnosol, ursolic acid, betulinic acid, and rosmanol. Each individual phytochemical showed a similar potency to that observed with ketorolac, a nonsteroidal anti-inflammatory drug.⁸ However, please note that rosemary gets at a major basis of pain, i.e., inflammation!

Germ Fighter

Studies performed from the 1990’s to 2015 demonstrated that the essential oil of rosemary has the highest antimicrobial activity among other essential oils. Rosemary’s compounds work synergistically to provide significant antibacterial and antifungal activity. ⁹

Brain Booster!

Smelling rosemary can cause it to be absorbed in the blood and increase acetylcholine (a major neurotransmitter in the brain). Rosemary contains a dozen compounds that inhibit the breakdown of a major neurotransmitter, acetylcholine, and may be useful in Alzheimer’s.¹⁰ Rosemary aromatherapy may improve memory. Exposure to the aroma of rosemary essential oil can significantly enhance working memory in children.^11,12

Breathing rosemary scent can reduce heart rate and decrease cortisol in the saliva.¹³ In other words, rosemary helps to reduce stress levels. Combined with the scent of lavender, rosemary also decreases anxiety.¹⁴ There is some evidence that rosemary can exert an anti-depressant effect.^15,16

Metabolic Syndrome

The metabolic syndrome is a constellation of complex coexisting cardio-metabolic risk factors such as hyperglycemia, dyslipidemia, inflammation, abdominal obesity, pro-clotting activities, and hypertension. These raise the risk of diabetes mellitus and cardiovascular disease.

As previously mentioned, rosemary is a rich source of phenolic phytochemicals having significant anti-oxidant, anti-inflammatory, and blood pressure-lowering activity. Additionally, this herb reduces elevated blood sugar, lowers blood lipids such as cholesterol and triglycerides, and helps to protect the liver.¹⁷

Early evidence (rodent studies) suggests that rosemary extract may help discourage weight and fat gain on a high fat diet and promote fat loss in the liver.^18,19

Diabetes Aid

The phytochemical carnosic acid (CA) or rosemary extract can effectively improve glucose and lipid metabolism disorder.²⁰ Rosemary’s anti-diabetic compounds fight diabetes in several ways. Some of its constituents act as an alpha-glucosidase inhibitor, a class of oral medications for type 2 diabetes that decreases the absorption of carbohydrates from the intestine. This results in a slower and lower rise in blood glucose throughout the day.

Studies on diabetic rats demonstrated that not only does rosemary extract improve glucose levels, it can block pain from diabetic neuropathy and help protect from diabetic neuropathy.²¹ Early rodent studies suggest that rosemary essential oil can also help protect the kidneys and liver from oxidative stress caused by diabetes.²²

Usage

Rosmarinic acid is easily absorbed from the digestive system. Add it to any dish containing potatoes, tomatoes, squash, peas, or carrots. Pureed fresh rosemary with cold-pressed olive oil for a bread dip beats butter anytime. For medicinal purposes, add one teaspoon of crushed rosemary leaves to one-cup boiling water. Let steep for ten minutes. Strain. Use only one cup of tea daily. Please note the cautions and contraindications below.

Fresh rosemary herb should be stored in the refrigerator inside containers. Dried rosemary–like all herbs– should be kept in an airtight container and placed in a cool, dark, and dry place where it will stay fresh for several months.

Cautions and Contraindications:

Rosemary is generally safe in low amounts. Toxic amounts can produce spasms, vomiting, coma, uterine bleeding, kidney damage, and fluid in lungs. Pregnant women should not use medicinal amounts of rosemary because, if taken medicinally, it can act as an abortifacient.

Because rosemary inhibits non-heme iron absorption, individuals with iron deficient anemia should not use it medicinally. Neither should individuals prone to seizures use rosemary medicinally. Never take rosemary oil internally. Rosemary can turn urine a harmless red color.

Rosemary has the potential for interacting with blood thinners, diuretics, and certain blood pressure medications. Always check with your pharmacist and health care provider before mixing medicinal herbs and drugs to avoid undesirable drug-herb interactions.

1. Kwib YI, et al., Evaluation of clonal herbs of Lamiaceae specis for management of diabetes, and hypertension, Asia Pac J Clin Nut, 2006; 15 (1): 107-18. apjcn.nhri.org.tw/server/APJCN/15/1/107.pdf.↩
2. Sinkovic, A, et al., Rosemary extracts improve flow-mediated dilatation of the brachial artery and plasma PAI-1 activity in healthy young volunteers. Phytother Res. 2010 Aug 23.↩
3. Sanbongi C, et al., Rosmarinic acid in perilla extract inhibits allergic inflammation induced by mite allergen, in a mouse model. Clin Exp Allergy. 2004 Jun; 34(6):971.↩
4. Lukaczer, D, et al., Effects of volatile constituents of a rosemary extract on allergic airway inflammation related to house dust mite allergen in mice. Int J Mol Med. 2005 Aug;16(2):315-9. app.dimensions.ai/details/publication/pub.1071506101.↩
5. Nogueira de Melo GA. Rosmarinus officinalis L. essential oil inhibits in vivo and in vitro leukocyte migration. J Med Food. 2011 Sep;14(9):944-6. www.ncbi.nlm.nih.gov/pubmed/21663474.↩
6. Sanbongi C, et al., Rosmarinic acid in perilla extract inhibits allergic inflammation induced by mite allergen, in a mouse model. Clin Exp Allergy. 2004 Jun;34(6):97. shibaura.pure.elsevier.com/en/publications/rosmarinic-acid-in-perilla-extract-inhibits-allergic-inflammation-2.↩
7. Benincá JP. Analysis of the anti-inflammatory properties of Rosmarinus officinalis L. in mice. Food Chem. 2011; 124(2):468–475.↩
8. Martínez AL. Antinociceptive effectiveness of triterpenes from rosemary in visceral nociception. J Ethnopharmacol. 2012 Jun 26; 142(1):28-34. www.ncbi.nlm.nih.gov/pubmed/22543174.↩
9. Andrade J. Rosmarinus officinalis L.: an update review of its phytochemistry and biological activity. Future Sci OA. 2018 Apr; 4(4): FSO283. www.ncbi.nlm.nih.gov/pmc/articles/PMC5905578/.↩
10. Duke Green Pharmay www.alzheimersweekly.com/2017/03/rosemary-emulates-aricept-donepezil.html.↩
11. Moss, L. Plasma 1,8-cineole correlates with cognitive performance following exposure to rosemary essential oil aroma. Therapeutic Advances in Psychopharmacology, 2012. DOI: 10.1177/2045125312436573.↩
12. British Psychological Society. “Rosemary aroma can aid children’s working memory: Exposure to the aroma of rosemary essential oil can significantly enhance working memory in children.” ScienceDaily. 2 May 2017. www.sciencedaily.com/releases/2017/05/170502204545.htm.↩
13. McCaffrey R. The effects of lavender and rosemary essential oils on test-taking anxiety among graduate nursing students. Holist Nurs Pract. 2009 Mar-Apr;23(2):88-93. www.aromaticscience.com/the-effects-of-lavender-and-rosemary-essential-oils-on-test-taking-anxiety-among-graduate-nursing-students/.↩
14. Atsumi T. Smelling lavender and rosemary increases free radical scavenging activity and decreases cortisol level in saliva. Psychiatry Res. 2007 Feb 28; 150(1):89-96. www.ncbi.nlm.nih.gov/pubmed/17291597.↩
15. Andrade J. Rosmarinus officinalis L.: an update review of its phytochemistry and biological activity. Future Sci OA. 2018 Apr; 4(4): FSO283. www.ncbi.nlm.nih.gov/pmc/articles/PMC5905578/.↩
16. Sasaki K. Rosmarinus officinalis polyphenols produce anti-depressant like effect through monoaminergic and cholinergic functions modulation. Behav Brain Res. 2013 Feb 1; 238():86-94. www.ncbi.nlm.nih.gov/pubmed/23085339.↩
17. Hassani FV. Rosemary (Rosmarinus officinalis) as a potential therapeutic plant in metabolic syndrome: a review. Naunyn Schmiedebergs Arch Pharmacol. 2016 Sep; 389(9):931-49. www.ncbi.nlm.nih.gov/pubmed/27178264.↩
18. Harach T. Rosemary (Rosmarinus officinalis L.) leaf extract limits weight gain and liver steatosis in mice fed a high-fat diet. Planta Med. 2010 Apr; 76(6):566-7. www.ncbi.nlm.nih.gov/pubmed/19918713.↩
19. Zhao Y. Carnosic acid as a major bioactive component in rosemary extract ameliorates high-fat-diet-induced obesity and metabolic syndrome in mice. J Agric Food Chem. 2015 May 20; 63(19):4843-52. pubs.acs.org/doi/abs/10.1021/acs.jafc.5b01246.↩
20. Xie Z. Carnosic acid improves diabetic nephropathy by activating Nrf2/ARE and inhibition of NF-κB pathway. Phytomedicine. 2018 Aug 1; 47:161-173. www.ncbi.nlm.nih.gov/pubmed/30166101.↩
21. Rasoulian B Neuroprotective and antinociceptive effects of rosemary (Rosmarinus officinalis L.) extract in rats with painful diabetic neuropathy. J Physiol Sci. 2019 Jan; 69(1):57-64. www.ncbi.nlm.nih.gov/pubmed/29754274.↩
22. Selmi S. Rosemary (Rosmarinus officinalis) essential oil components exhibit anti-hyperglycemic, anti-hyperlipidemic and antioxidant effects in experimental diabetes. Pathophysiology. 2017 Dec; 24(4):297-303. www.ncbi.nlm.nih.gov/pubmed/28928060.↩