After a few months of taking a predominantly plant-based diet, a friend notices that her skin starts to show an orange hue. “Is it harmful?”, she asked. “Excellent, it shows that you eat enough fruits and vegetables!”, I said. Indeed, it is a healthy sign!
What causes orange hue to the skin?
The orange colour is the results of the cumulation of excess beta-carotene under the skin [1]. Beta-carotene is a type of carotenoids, the natural pigments of plants which gave the plants their bright colours. Many fruits and vegetables are rich in beta-carotene include carrot, pumpkin, sweet potato, papaya, butternut squash, bell pepper, and cantaloupe [2]. Not surprisingly, they are all quite yellowish. However, dark leafy green vegetables such as lattice and spinach are also rich in beta-carotene. The darker green colour of chlorophyll is masking the orange pigment of beta-carotene. So, you don’t see them.
The small intestine absorbs about one-third of the beta-carotene from our food. Upon absorption, the beta-carotene may be converted into retinal and eventually retinol (vitamin A) to be transported to the liver [1]. However, the rate of conversion depends on the intake of beta-carotene and vitamin A stores in the body. Between 10% to 80% of the beta-carotene is absorbed into the bloodstream without conversion. They are transported by the lipoproteins (i.e. cholesterols) and stored in the liver and fatty tissues throughout the body as well as underneath the skin [1].
What is beta-carotene?
The main functions of beta-carotene in the body are as a provitamin A and an antioxidant [3]. As a provitamin A, beta-carotene is converted into vitamin A as and when the body needs. The healthy functioning of all surface tissues, including the skin, the lining of the respiratory tract, the gut, the bladder, the inner ear and the eye, depends on vitamin A. Vitamin A supports the renewal of our skin cells and ensures mucous production on the surface tissues to prevent infections. It is also needed for good vision at low light, maintaining a healthy immune system, as well as for growth and reproduction [4]. As an antioxidant, beta-carotene can bind to the free radicals in the body preventing them from harming the cells in the body [5].
What are the health benefits of higher beta-carotene level?
An indicator of good health
The carotenoid status in the skin has become as an objective measurement of fruit and vegetable intake, which in turn is an indicator of health status [6]. A specific technology, Resonance Raman spectroscopy, is developed as a simple non-invasive way to measure the carotenoid status in the skin [7].
More attractive look
Beta-carotene can affect human facial appearance. It makes one more radiant and attractive. This is the finding of a randomized control study conducted by the University of Western Australia [8].
Prevent degeneration of the eyes
According to the Age-Related Eye Disease 2 Study, the risk of developing age-related macular degeneration, a degeneration disease of the eyes that cause blurry vision, can be reduced by 25% through a higher intake of vitamins C and E, beta-carotene, zinc, and copper [9].
Lower mortality rate
A study in Finland reports that higher beta-carotene level in the blood is associated with a lower death rate from cardiovascular disease, stroke, cancer, and other causes of mortality, based on the analysis of data from 29,103 men over 31 years [10]. Similarly, an earlier meta-analysis of seven observation studies also concludes that higher intake of beta-carotene is associated with a lower death rate from all causes [11].
A few words of caution
Naturally, if you increase the intake of fruits and vegetables, your beta-carotene level will rise. There is no need to take any beta-carotene as a food supplement. Research shows that supplementing with high doses of beta-carotene can have a higher risk of lung and stomach cancer [12]. Hence, I will not recommend taking any beta-carotene supplement as a short-cut.
Conclusion
Want to have good health, look more attractive, prevent degeneration of your eyes, and reduce the risk of chronic diseases? Eat more fruits and vegetables! In time, you will find carotenoids, such as beta-carotene, begin to cumulate under the skin to give it an orange hue. Don’t be alarmed. It is a sign of good health!
References
[1] N. Maharshak, J. Shapiro, H. Trau, Carotenoderma – a review of the current literature, Int. J. Dermatol. 42 (2012) 178–81. doi:10.1177/1087054706286698.
[2] Top 10 Foods Highest in Beta Carotene, (n.d.). https://www.myfooddata.com/articles/natural-food-sources-of-beta-carotene.php (accessed April 5, 2019).
[3] T. Grune, G. Lietz, A. Palou, A.C. Ross, W. Stahl, G. Tang, D. Thurnham, S. Yin, H.K. Biesalski, Beta-carotene is an important vitamin A source for humans, J. Nutr. 140 (2010) 2268S–2285S. doi:10.3945/jn.109.119024.
[4] C. Gilbert, What is vitamin A and why do we need it?, Community Eye Heal. 26 (2013) 65. https://www.ncbi.nlm.nih.gov/pubmed/24782580.
[5] J. Fiedor, K. Burda, Potential role of carotenoids as antioxidants in human health and disease, Nutrients. 6 (2014) 466–488. doi:10.3390/nu6020466.
[6] G. Grosso, A. Micek, J. Godos, A. Pajak, S. Sciacca, F. Galvano, P. Boffetta, Health risk factors associated with meat, fruit and vegetable consumption in cohort studies: A comprehensive meta-analysis, PLoS One. 12 (2017) e0183787. doi:10.1371/journal.pone.0183787.
[7] S. Scarmo, B. Cartmel, H. Lin, D.J. Leffell, I. V Ermakov, W. Gellermann, P.S. Bernstein, S.T. Mayne, Single v. multiple measures of skin carotenoids by resonance Raman spectroscopy as a biomarker of usual carotenoid status, Br. J. Nutr. 110 (2013) 911–917. doi:10.1017/S000711451200582X.
[8] G. Rhodes, L.W. Simmons, Y.Z. Foo, The carotenoid beta-carotene enhances facial color, attractiveness and perceived health, but not actual health, in humans, Behav. Ecol. 28 (2017) 570–578. doi:10.1093/beheco/arw188.
[9] H.M. Rasmussen, E.J. Johnson, Nutrients for the aging eye, Clin. Interv. Aging. 8 (2013) 741–748. doi:10.2147/CIA.S45399.
[10] H. Jiaqi, W.S. J., Y. Kai, M. Satu, A. Demetrius, Serum Beta Carotene and Overall and Cause-Specific Mortality, Circ. Res. 123 (2018) 1339–1349. doi:10.1161/CIRCRESAHA.118.313409.
[11] L.-G. Zhao, Q.-L. Zhang, J.-L. Zheng, H.-L. Li, W. Zhang, W.-G. Tang, Y.-B. Xiang, Dietary, circulating beta-carotene and risk of all-cause mortality: a meta-analysis from prospective studies, Sci. Rep. 6 (2016) 26983. doi:10.1038/srep26983.
[12] N. Druesne-Pecollo, P. Latino-Martel, T. Norat, E. Barrandon, S. Bertrais, P. Galan, S. Hercberg, Beta-carotene supplementation and cancer risk: a systematic review and metaanalysis of randomized controlled trials, Int. J. Cancer. 127 (2010) 172–184. doi:10.1002/ijc.25008.