Herb of the month: Tagetes erecta
Tagetes erecta (African marigold) is part of a group of plants known as ornamental marigolds. The genus is native to Central and South America but now available worldwide and is in the Asteraceae family. Another ingredient derived from the flowers is a carotenoid called Lutein.
Historical uses:
In Ayurveda and Unani systems of medicine, African marigold has been used topically for wound healing, eye pain and insect repellent. It also has a history of being used for intestinal parasites and worms. Other uses were for gynaecologic problems and flu/cold-like symptoms.
Fun fact:
The dried ground-up flowers are used in chicken feed to enhance the colour of yolks in eggs and the yellow colour of the chicken skin.
Part used:
- Aerial parts (flowers)
Major chemical constituents:
Carotenoids (including lutein), polyphenols, and flavanol’s.
Therapeutic actions of lutein:
- Antioxidant, blue light filter, immunomodulation, photoprotection
Therapeutic actions of Tagetes erecta (African marigold)
- Anti-inflammatory, diuretic, antimicrobial, insecticidal, and respiratory effects
Key benefits based on traditional and clinical use:
- Helps maintain eyesight
- Supports eye health in conditions associated with sun damage: cataracts and age-related macular degeneration (AMD)
- Can reduce the risk of developing cataracts
Evidence for clinical use:
1. Eye health and reducing AMD
When taken alone or combined with other ingredients, Lutein can improve some aspects of vision in patients with AMD. A large trial called the Age-Related Eye Disease Study version 2 (AREDS2) revised the original AREDS formula, which contained (vitamin C, vitamin E, Zinc, copper, and beta-carotene) and removed beta-carotene. It was replaced with 10mg of lutein and 2mg of zeaxanthin, and it was found that the revised formulation reduced the progression to late AMD by 15% compared to the beta-carotene formula.
2. Cataracts
Population-based research has found higher blood levels or higher dietary intake of lutein is associated with a 25-27% reduced risk of getting cataracts. Research shows people with lower intakes of lutein and zeaxanthin could decrease the risk of needing cataract surgery by 32% by taking 10 mg lutein plus 2mg zeaxanthin orally for around 4.7 years. However, it didn’t reduce the risk of surgery in those with higher intakes of lutein and zeaxanthin already.
3. Can reduce the risk of developing cataracts.
An observational study of the dietary intakes of 35,551 women followed over 10 years found that those with higher dietary intakes of lutein and zeaxanthin had significantly less risk of cataracts. Another prospective study of 93,676 postmenopausal women 50 to 79 years of age at enrolment found diets rich in lutein and zeaxanthin are moderately associated with decreased prevalence of nuclear cataracts in older women.
Cautions/Contraindications:
Tagetes erecta (African Marigold) can cause an allergic reaction in individuals sensitive to the Asteraceae/Compositae family. This family includes ragweed, chrysanthemums, marigolds, daisies, and many other herbs. Topically it can cause contact dermatitis.
Orally, dietary and supplemental lutein is generally well tolerated. Doses up to 20 mg daily have not resulted in adverse effects.
Note: Always consult your healthcare professional to determine if supplementation is suitable for you.
