Rosemary is an aromatic evergreen shrub with leaves similar to hemlock needles. It is native to the Mediterranean and Asia, but is reasonably hardy in cool climates. It can withstand droughts, surviving a severe lack of water for lengthy periods. In some parts of the world, it is considered a potentially invasive species. The seeds are often difficult to start, with a low germination rate and relatively slow growth, but the plant can live as long as 30 years. Forms range from upright to trailing; the upright forms can reach 1.5 m (5 ft) tall, rarely 2 m (6 ft 7 in). The leaves are evergreen, 2–4 cm (0.8–1.6 in) long and 2–5 mm broad, green above, and white below, with dense, short, woolly hair.
The plant flowers in spring and summer in temperate climates, but the plants can be in constant bloom in warm climates; flowers are white, pink, purple or deep blue. Rosemary also has a tendency to flower outside its normal flowering season; it has been known to flower as late as early December, and as early as mid-February (in the northern hemisphere).
1. Antioxidants and anti-inflammatory compounds
Rosemary is a rich source of antioxidants and anti-inflammatory compounds, which 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.
2. Improving digestion
In Europe, rosemary is often used to help treat indigestion. In fact, Germany’s Commission E has approved rosemary for the treatment of indigestion. However, it should be noted that there is currently no meaningful scientific evidence to support this claim.
3. Enhancing memory and concentration
According to research outlined in Therapeutic Advances in Psychopharmacology, the aroma from rosemary can improve a person’s concentration, performance, speed, and accuracy and, to a lesser extent, their mood.
4. Neurological protection
Scientists have found that rosemary may also be good for your brain. Rosemary contains an ingredient called carnosic acid, which can fight off damage by free radicals in the brain. Some studies in rats have identified that rosemary might be useful for people who have experienced a stroke. Rosemary appears to be protective against brain damage and might improve recovery.
5. Prevent brain aging
Some studies have suggested that rosemary may significantly help prevent brain aging. The therapeutic ability of rosemary for prevention of Alzheimer’s shows promise, but more studies are needed.
Research published in Oncology Reports found that “crude ethanolic rosemary extract (RO)” slowed the spread of human leukemia and breast carcinoma cells.” Another study, published in Bioscience, Biotechnology and Biochemistry, concluded that rosemary might be useful as an anti-inflammatory and anti-tumor agent.
Also, 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.
7. Protection against macular degeneration
A study published in the journal Investigative Ophthalmology & Visual Science, led by Dr. Stuart A. Lipton, Ph.D. and colleagues at Sanford-Burnham Medical Research Institute, revealed that a carnosic acid, which is a major component of rosemary, can significantly promote eye health.