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Rosemary

An aromatic herb rich in carnosic acid — its very scent may sharpen alertness, and it doubles as a natural antioxidant preservative.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden)Last reviewed July 2026Food guide

FoodsHerbs & spicesBrainAntioxidant

Rosemary is a Mediterranean herb packed with antioxidant diterpenes (carnosic acid) and rosmarinic acid. It’s one of the more intriguing culinary herbs for the brain — partly through its aroma.

Key takeaways

  • Rich in carnosic acid and rosmarinic acid — potent antioxidants.
  • The aroma of rosemary has produced small improvements in alertness, mood and memory in human studies.1
  • Rosemary extract is a widely used natural food antioxidant/preservative.
  • Culinary use is very safe; concentrated rosemary oil should not be swallowed in quantity.

What it is

Rosemary (Salvia rosmarinus) contains antioxidant polyphenols and diterpenes, chiefly carnosic acid, plus fragrant volatile compounds like 1,8-cineole that are absorbed via the lungs when you smell it.

The evidence

Studies of rosemary aroma report modest effects on cognitive performance and mood in healthy adults,1 and carnosic acid is a strong antioxidant with neuroprotective activity in lab models.2 Human clinical proof of memory benefits from eating rosemary is still limited.

How to use

Use fresh or dried rosemary generously in cooking (it pairs well with roasting). Its antioxidants also help protect fats in food from going rancid.

Safety

Safe as a food herb. Avoid medicinal doses of rosemary oil, especially in pregnancy; the essential oil is potent.

Bottom line: a fragrant antioxidant herb whose very scent may lift alertness a little — lovely and safe in cooking, with the concentrated oil treated cautiously.

References

Educational summary, not a prescription.

  1. Moss M, et al. Aromas of rosemary and lavender essential oils differentially affect cognition and mood in healthy adults. Int J Neurosci 2003. pubmed.ncbi.nlm.nih.gov
  2. Therapeutic effects of rosemary and its active constituents (carnosic acid) on nervous system disorders. 2020. pmc.ncbi.nlm.nih.gov

This article summarises nutrition science for education and is not a substitute for individual medical advice.