What is β-Carotene?

β-Carotene is a natural plant pigment with a red or orange appearance and is a carotenoid. It is widely found in brightly coloured fruits or vegetables. The body can convert β-Carotene into vitamin A, which is used as an essential vitamin for the maintenance of human health. β-Carotene not only has a nutritional function as vitamin A, but also prevents diseases through its antioxidant, anti-obesity and anti-inflammatory effects. In addition, β-carotene and its cleavage products add colour and flavour to foods and dishes and are therefore widely used as colourants in the food industry.

Food sources

β-Carotene-rich foods include:

• Apricots

• Microalgae (Dunaliella)

• Asparagus

• Broccoli

• Carrots

• Chinese cabbage

• Chives

• Dandelion leaves

• Grapefruit

• Herbs and spices – chilli powder, oregano, paprika, parsley

• Kale

• Ketchup

• Many margarines

• Onions

• Peas

• Peppers

• Plums

• Pumpkin

• Spinach

• Squash

• Sweet potatoes

Benefits of β-Carotene

β-Carotene has multiple benefits for the human body, mainly in the following areas:

Anti-obesity effect

In vitro studies have shown that overexpression of β-carotene oxygenase 1 (BCO1) in adipose tissue and the use of β-Carotene stored in adipocytes to produce vitamin A contributes to fat loss and has anti-obesity effects. BCO1 is the enzyme responsible for the cleavage of β-Carotene to retinaldehyde, the first intermediate in the process of vitamin A formation. Preclinical studies have shown that dietary β-carotene affects lipid metabolism requiring BCO1 expression.

Alleviation of atherosclerosis

BCO1 activity has been reported to be associated with a reduction in plasma cholesterol in humans and mice, and dietary β-carotene reduces hepatic lipid secretion and slows the progression of atherosclerosis in various experimental models. In addition, β-carotene also accelerated the remission of atherosclerosis in a mouse model, independent of weight gain or changes in plasma lipid profile. Experiments in Bco1-/- mice showed that vitamin A production was associated with the effects of β-carotene on atherosclerotic remission. β-carotene also favoured the expansion of regulatory T cells (Tregs) in plaques, and partial suppression of Tregs attenuated the effects of β-carotene on atherosclerotic remission.

Antioxidant effect and improvement of skin condition

β-Carotene can be used to treat or reduce sun sensitivity. beta-Carotene acts as an antioxidant to protect the skin from free radicals. In some studies, supplementation with carotenoids such as beta-carotene has been shown to modestly reduce UV erythema, and when combined with other sunscreen ingredients, it may enhance overall skin protection. When applied topically, beta-carotene may increase epidermal retinyl esters, which are used to brighten the skin.

Hair Strengthening

β-Carotene in conditioning products may help strengthen damaged hair and repair split ends. However, too much vitamin A can have the opposite effect - damaging hair and causing hair loss.

Side Effects

Side effects of beta-carotene include: skin discolouration (yellowish discolouration that eventually disappears), loose stools, bruising, joint pain. Other possible side effects are carcinogenic. Studies have reported that smokers with high beta-carotene levels have a higher risk of developing lung cancer from credible sources and smoking-related cancers compared to other smokers. They also found that non-smokers with high beta-carotene intake had a lower risk of lung cancer.

Referencs：

[1] JOHANA CORONEL . The conversion of β-carotene to vitamin A in adipocytes drives the anti-obesogenic effects of β-carotene in mice[J]. Molecular Metabolism, 2022. DOI:10.1016/j.molmet.2022.101640.

[2] PINOS I, CORONEL J, ALBAKRI A, et al. β-Carotene accelerates the resolution of atherosclerosis in mice[J]. eLife, 2024. DOI:https://doi.org/10.7554/elife.87430.3.