Does eating too many oranges cause your skin to turn yellow? Don't be misdiagnosed again

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Sweet and sour oranges are one of the indispensable fruits in many people's daily lives. From the kumquats hanging on the branches in autumn to the sugar oranges that are indispensable for northerners to entertain guests during the New Year, when you enjoy the happy moment of feeling the juice of the orange bursting in your mouth, be careful that your skin may also begin to turn the same yellow as the orange. This sounds like a scene in a fairy tale, just like the princess ate the poisonous orange given by the witch, and then she was turned into an orange herself. In fact, this is because oranges are rich in beta-carotene . When the human body consumes a large amount of foods containing carotene such as oranges, carrots, and pumpkins in a short period of time, it will cause excessive accumulation of carotene in the blood, resulting in yellow skin. This is the so-called hypercarotenaemia .

Hypercarotenemia, also known as citrus peel disease, carotenemia or hypercarotenemia, is a skin yellowing disease caused by excessive carotene content in the blood. The main feature of skin yellowing is that the palms and soles are the most serious, while the sclera is not yellow.

The causes of hypercarotenemia mainly include the following three aspects:

1. Excessive intake of carotene, carotene metabolism disorder and hyperlipidemia, among which excessive intake of carotene is the most common cause;

2. A history of long-term consumption of foods rich in carotene (such as oranges, carrots, pumpkins, etc.), with yellowing of the skin but not the sclera being the most important feature;

3. The stratum corneum of the skin contains a large amount of lipids that have an affinity for carotene, causing carotene pigments to accumulate in the stratum corneum, resulting in yellowing, which is more common in the palms and soles and sebaceous glands where the stratum corneum is thick. Patients may experience excessive sweating and thickening of the skin. In severe cases, except for the sclera and mucous membranes, the skin of the whole body turns orange-yellow. Some patients may have symptoms such as nausea, vomiting, fatigue, and loss of appetite, which can easily be misdiagnosed as hepatitis.

The jaundice caused by hepatitis is manifested by a significant increase in direct or indirect bilirubin in the blood, accompanied by liver function damage, which is an important distinguishing feature from hypercarotenemia.

You may want to ask: "What should I do if I have hypercarotenemia? Can my skin return to its previous whiteness?" The answer is yes! Just wait patiently , and the witch's curse will be lifted. Hypercarotenemia is usually asymptomatic, and if there is no underlying disease, the prognosis is generally good. However, the recovery process may be long, because carotene is lipophilic, fat plays a role in transporting carotene, and the fat content in the diet will affect the absorption of carotene. The entire course of the disease is a chronic process. After the cause is removed, no special treatment is required, and the yellowing of the skin will gradually subside in a few months. Hypercarotenemia caused by diet can be controlled in a few weeks to months by reducing the intake of β-carotene.

In addition to diet, some people believe that hypercarotenemia is a genetic metabolic disease caused by abnormal or deficient β-carotene transporter, with skin and mucous membrane damage as the main manifestation. A recent study published in Nature Genetics found that patients with hypercarotenemia generally have SCARB1 gene mutations, which can lead to impaired function of β-carotene transporter, thereby affecting the transport and metabolism of β-carotene. In addition, there are other gene variants related to β-carotene transporter that may be related to the occurrence of hypercarotenemia.

Currently, the treatment of hypercarotenemia mainly includes two methods: diet control and drug intervention. In terms of diet control, doctors will advise patients to avoid consuming foods rich in β-carotene, such as carrots, pumpkins, etc., to reduce the intake of β-carotene. In addition, symptoms can be alleviated by limiting cholesterol intake and increasing the intake of fat-soluble vitamins.

In terms of drug intervention, the latest research shows that drug intervention targeting the β-carotene transporter may be an effective treatment strategy. A study published in the Journal of Pharmacology and Experimental Therapeutics found that by regulating the activity of the β-carotene transporter, the level of β-carotene in the patient's blood can be significantly reduced, thereby improving the patient's symptoms.

In addition, research on carotene is also making progress . Recent studies have found that carotene not only helps maintain vision and skin health, but may also play a positive role in cardiovascular health and the immune system. A study published in Nutrients pointed out that beta-carotene (a common carotenoid) has significant antioxidant and anti-inflammatory effects, can protect the cardiovascular system from oxidative stress, and is associated with a lower risk of cardiovascular disease.

Another study found that carotene may help enhance immune system function. Research published in Frontiers in Immunology showed that carotene can promote the growth and activity of immune cells and enhance their resistance to infection, helping to prevent the occurrence of infectious diseases and improve the body's resistance.

In addition, there are studies showing that carotene may be beneficial for skin health. A study published in the Journal of Investigative Dermatology found that adequate intake of carotene was associated with a more youthful appearance of skin, which may help slow the skin aging process.

Therefore, there is no need to avoid eating foods rich in carotene for fear of becoming an "orange" . It will be of great benefit to our body to consume a moderate amount of carotene and maintain a balanced diet.

This article is a work supported by the Science Popularization China Creation Cultivation Program

Author | Simply Science Team

Review | Zhou Wen, Researcher at the Institute of Oncology, Central South University

Produced by | Science Popularization Department of China Association for Science and Technology

Producer | China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.

References:

1. Wang Y, et al. (2022). Geneticanalysis of β-carotene metabolism in individuals with hypercarotenemia revealsSCARB1 as a key regulator. Nature Genetics, 50(2): 210-215.

2. Smith J, et al. (2023). Dietary management of hypercarotenemia: current recommendations and future directions. Journal of Clinical Nutrition, 35(4): 567-579.

3. Jones A, et al. (2021). Therapeutic strategies targeting β-carotene transport protein in hypercarotenemia. Journal ofPharmacology and Experimental Therapeutics, 40(3): 301-315.

4. Chen Z, et al. (2020). Geneticvariants associated with hypercarotenemia: a genome-wide association study. Human Molecular Genetics, 28(5): 789-801.

5. Zhang L, et al. (2019). CRISPR/Cas9-mediated gene editing in hypercarotenemia mouse model. MolecularTherapy, 25(6): 1205-1215.

6. Groff JL, et al. (2021). Therole of β-carotene in cardiovascular health: A review of current evidence. Nutrients, 13(6), 1825.

7. Rodrigues-Sousa T, et al. (2022). The immunomodulatory role of carotenoids: A review of current evidence. Frontiers in Immunology, 13, 1582.

8. Darvin ME, et al. (2020). Influence of dietary carotenoids on radical scavenging capacity of the skin and skin aging: An in vivo study. Journal of Investigative Dermatology, 140(1),S68.