Written by Greg Arnold, DC, CSCS. A combination of rosemary and grapefruit extract significantly improves wrinkling and elasticity in the photo damaged skin of the 90 participating middle-aged women.
Sun exposure has been proven to elicit numerous health benefits, from initiating vitamin D production to strengthening the immune system and reducing stress and anxiety 1. But public awareness of excessive sun exposure increasing skin cancer risk is well established. The American Academy of Pediatrics recommends that sunscreens with a sun-protection factor of at least 15 should be applied to children and teenagers every 2 hours and after swimming, sweating, or drying off with a towel” 2.
Sunlight is composed of two type of ultraviolet rays, UVA and UVB. UVA radiation penetrates deeper into the skin than UVB and is mostly responsible for the cell damage due to reactive oxygen species induced oxidation that can damage DNA 3 as well as the fats and proteins in the skin 4, all of which “contribute significantly to photoaging” 5.
As a result, finding ways to protect skin cells against UVA/UVB damage can provide long-term skin health benefits. In a 2016 study 6, researchers applied 1 of 3 creams to the backs of 90 women with an average age of 52: either a placebo cream (30 women), 100 milligrams of a commercial cream (NutroxsunTM) containing rosemary and grapefruit extract (30 women) or 250 milligrams of the rosemary/grapefruit cream (30 women). Researchers then exposed the backs of these women to 1 Minimal Erythema Dose using methods from previous research 7. Various measures of skin health were assessed before and after the skin exposure.
The researchers noted a significant benefit of the rosemary/grapefruit extract creams compared to the placebo group regarding the level of a type of cell damage in the skin, called malondialdehyde (MDA) 8:
| Cream | Before exposure | 2 weeks after exposure | p - value | 4 weeks | p - value | 8 weeks | p - value |
|---|---|---|---|---|---|---|---|
| 100 mg | 2.61 | 16.9% decrease (2.61 to 2.17) | < 0.0001 | 23% decrease (2.61 to 2.01) | < 0.0001 | 24.2% decrease (2.61 to 1.98) | < 0.0001 |
| 250 mg | 2.72 | 28.7% decrease (2.72 to 1.94) | < 0.0001 | 41.2% decrease (2.72 to 1.60) | < 0.0001 | 37.9% decrease (2.72 to 1.69) | < 0.0001 |
| Placebo | 2.58 | 0.7% increase (2.58 to 2.60) | > 0.05 | 3.2% decrease (2.58 to 2.50) | > 0.05 | 4.3% decrease (2.58 to 2.47) | > 0.05 |
They also measured net change in skin elasticity:
| Cream | Before exposure | 2 weeks after exposure | p - value | 4 weeks | p - value | 8 weeks | p - value |
|---|---|---|---|---|---|---|---|
| 250 mg | 0.7233 | 1.7% increase (0.7233 to 0.7360) | < 0.0001 | 3.1% increase (0.7233 to 0.7462) | < 0.0001 | 4.4% increase (0.7233 to 0.7557) | < 0.0001 |
| 100 mg | 0.7271 | 1.4% increase (0.7271 to 0.7375) | < 0.0001 | 2.8% increase (0.7271 to 0.7475) | < 0.0001 | 3.4% increase (0.7271 to 0.7525) | < 0.0001 |
| Placebo | 0.7214 | 0.5% decrease (0.7214 to 0.7185) | > 0.05 | 0.4% increase (0.7214 to 0.7250) | > 0.05 | 0.2% increase (0.7214 to 0.7233) | > 0.05 |
Finally, a statistically significant decrease in wrinkle depth in the cream groups:
| Cream | Before exposure | 2 weeks after exposure | p - value | 4 weeks | p - value | 8 weeks | p - value |
|---|---|---|---|---|---|---|---|
| 250 mg | 296 micrometers | 10.1% decrease (296 to 268) | < 0.0001 | 14.6% decrease (296 to 253) | < 0.0001 | 15.6% decrease (296 to 250) | < 0.0001 |
| 100 mg | 257 micrometers | 8.2% decrease (257 to 236) | < 0.0001 | 14.7% decrease (257 to 222) | < 0.0001 | 13.7% decrease (257 to 220) | < 0.0001 |
| Placebo | 280 micrometers | 3.5% increase (280 to 290) | > 0.05 | 3.6% decrease (280 to 270) | > 0.05 | 3.5% increase (280 to 290) | > 0.05 |
For the researchers, “this is the first study demonstrating the antioxidant, photo protective, and antiaging efficacy of this combination of plants extracts.
Source: Nobile, Vincenzo, et al. “Skin photoprotective and antiageing effects of a combination of rosemary (Rosmarinus officinalis) and grapefruit (Citrus paradisi) polyphenols.” Food & Nutrition Research 60 (2016).
© 2016 Vincenzo Nobile et al. Creative Commons Attribution 4.0 International License (http:// creativecommons.org/licenses/by/4.0/)
Greg Arnold is a Chiropractic Physician practicing in Hauppauge, NY. You can contact Dr. Arnold directly by emailing him at PitchingDoc@msn.com or visiting his web site at www.PitchingDoc.com
References:
- Schools RT. Feeling Sunny? 25 Healthy Benefits of Sensible Sun Exposure. 2010; Overview of the health benefits of sun. Available at: http://onlineradiologytechnicianschools.com/2010/feeling-sunny-25-health-benefits-of-sensible-sun-exposure/. Accessed May 26, 2017, 2017.
- Barclay L. AAP Issues Guidelines on Limiting Sun Exposure in Children. 2011; Guidelines on limiting sun exposure in children. Available at: http://www.medscape.com/viewarticle/738074. Accessed May 26, 2017, 2017.
- Agar NS, Halliday GM, Barnetson RS, Ananthaswamy HN, Wheeler M, Jones AM. The basal layer in human squamous tumors harbors more UVA than UVB fingerprint mutations: a role for UVA in human skin carcinogenesis. Proceedings of the National Academy of Sciences of the United States of America. 2004;101(14):4954-4959.
- Vile GF, Tyrrell RM. UVA radiation-induced oxidative damage to lipids and proteins in vitro and in human skin fibroblasts is dependent on iron and singlet oxygen. Free Radical Biology and Medicine. 1995;18(4):721-730.
- Tewari A, Sarkany RP, Young AR. UVA1 induces cyclobutane pyrimidine dimers but not 6-4 photoproducts in human skin in vivo. Journal of Investigative Dermatology. 2012;132(2):394-400.
- Nobile V, Michelotti A, Cestone E, et al. Skin photoprotective and antiageing effects of a combination of rosemary (Rosmarinus officinalis) and grapefruit (Citrus paradisi) polyphenols. Food & Nutrition Research. 2016;60.
- ISO. Cosmetics Sun Protection Test Methods – In vivo determination of the sun protection factor (SPF). 2010; method for the in vivo determination of the sun protection factor (SPF) of sunscreen products. Available at: https://www.iso.org/standard/46523.html. Accessed May 26, 2017, 2017.
- Braconi D, Bernardini G, Santucci A. Post-genomics and skin inflammation. Mediators of inflammation. 2010;2010.
