The skin benefits of carotenoids
Written and Reviewed by: Elysium Health
- Carotenoids are yellow, orange, and red pigments synthesized by plants.
- Carotenoids are potent antioxidants that can reduce free radicals in the skin and promote resilience against environmental challenges and oxidative stress.
- Carotenoids can help restore healthy, youthful skin by maintaining natural collagen and elastin levels.
Humans and plants have had a long and intimate relationship—well before we were Homo sapiens. One million years ago, our ancestor Homo erectus is thought to have foraged the savannah for grasses and seeds; hunter-gatherers foraged for wild plants; and beginning about 10,000 years ago, we began to domesticate plants (and animals), a process that gave rise to permanent towns and has been called one of the most significant technology developments of the past 15,000 years.
Plants have fed us, inspired our religious and cultural rites, and been the source of our medicine. The theory of coevolution theorizes that humans evolved to depend on plants for essential components of health, such as amino acids and vitamin C, while plants depend on humans and other animals to disperse their seeds. It’s now conventional wisdom that diets rich in fruits and vegetables are associated with better health outcomes.
So it’s no surprise that we get immense benefits from eating plants: fiber we need for healthy digestion, essential vitamins and minerals, healthy fats and proteins. One class of molecules found in plants is especially important. They’re called carotenoids, and scientific research increasingly supports the idea that they are fundamental to our health—especially our skin.
What are carotenoids?
Carotenoids are yellow, orange, and red pigments synthesized by plants, which go by the names astaxanthin, α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene, phytoene, phytofluene, and more. There are roughly 40 carotenoids in the human diet and more than 600 in total. Carotenoids are one of the main pigments in plants, along with chlorophylls, anthocyanins, and flavonoids.
Carotenoids are a type of isoprenoid, the oldest known biomolecules—with some dating back 2.5 billion years. All photosynthetic organisms—plants, algae, and cyanobacteria—synthesize carotenoids and deploy them for turning light energy into chemical energy: photosynthesis. Carotenoids contribute prolifically to photosynthesis. They harvest light energy and transfer it to chlorophylls, absorb and release excess energy, and scavenge and release reactive oxygen species. Beyond photosynthetic organs, carotenoids act as photo-protectors (protection from the sun), antioxidants, color attractants, and precursors of plant hormones.
It’s the massive accumulation of carotenoids in fruits, flowers, and roots that gives them their vivid colors. In leaves, carotenoids are typically concealed by chlorophylls, which in some trees degrade in autumn, leaving the vibrant hues of red, yellow, and orange. One way to think of the beautiful, rich colors of carotenoids as nature’s advertisement. They suggest rewards for animals that pollinate the flowers and disperse the seeds, whether that’s a bird with red-green color vision snagging a ripe cherry or a human picking apples at an orchard.
And it turns out that their accumulation in humans—measured in our blood as mean carotenoids—gives us a variety of health benefits.
Carotenoids and skin health
If you think about it, it makes good sense that carotenoids are essential for human skin health. In plants, they play a multidimensional role in protecting plants from stress as a byproduct of normal cellular function—photosynthesis—as well as environmental stress caused by high-frequency wavelengths of sunlight. If they’re so helpful to plants, why wouldn’t they help us? After all, humans and plants descended from the same prokaryotes billions of years ago.
While we’re very different organisms from plants, we also deal with stress and aging in our skin—our largest organ, our barrier organ—caused by intrinsic and extrinsic or environmental factors. Intrinsic causes of damage and aging include genetic predisposition, reactive oxygen species (ROS), cellular senescence, thinning of the epidermis, degradation of collagen and elastin, loss of moisture retention, and reduced vasculature. These all happen to a greater or lesser extent with the passage of time. The primary environmental cause of skin aging is sun exposure, while other factors like air pollution and nutrition also play a role. All of these factors together result in thinner and more translucent skin, wrinkles, sagging, pigmentation, dryness, and skin conditions.
Carotenoids are our ally in maintaining healthy skin throughout our life. They’re found in the highest concentration in the third and innermost layer of the skin, the hypodermis or subcutaneous fat layer, in adipocytes. Researchers hypothesize that they make their way into the outermost layer, the epidermis, via eccrine (sweat) and sebaceous (oil) glands. Here are some of the ways in which accumulated carotenoids support healthy skin.
1. Neutralizing free radicals
Reactive oxygen species (ROS), or free radicals, are continuously produced in the skin as a result of cellular metabolism and environmental exposures—including sun exposure. Free radicals are highly unstable and reactive because they contain molecules with an unpaired electron, causing them to steal electrons from other molecules. Free radicals impact many cellular components, including proteins, lipids, and DNA, leading to oxidative stress and cellular dysfunction. Carotenoids like lycopene are potent antioxidants that neutralize free radicals to bolster the skin’s resilience to environmental challenges.
2. Downregulating MMPs
Oxidative stress induced by intrinsic and extrinsic factors activates pro-inflammatory pathways in the skin that induce the expression of matrix metalloproteinases (MMPs), which degrade the extracellular matrix—including collagen. MMPs also inhibit collagen synthesis. Carotenoids attenuate these pathways and support the maintenance of collagen in the skin.
3. A healthy inflammatory response
Environmental challenges and urban living generate free radicals in the skin, setting in motion cellular reactions that result in redness and irritation. Carotenoids help balance the skin’s response to these challenges to support a healthy inflammatory response.
Figure. Antioxidant benefits: Carotenoids derived from fruit and vegetables help neutralize ROS and combat oxidative stress induced by environmental challenges (and internal stressors) that can lead to the degradation of collagen in the skin by MMPs.
What do the studies show?
Several studies now show that carotenoids benefit the health and appearance of skin and offer protection from environmental challenges.
A balanced response to environmental exposure
- A double-blind, randomized, placebo-controlled study looked at the effect of a phytonutrient complex containing tomato (lycopene, phytoene, and phytofluene) and rosemary extracts on UVB-induced skin reddening in 149 healthy subjects. The phytonutrient complex increased blood carotenoid levels, reduced gene expression related to inflammation, and decreased skin reddening.
Collagen and elastin maintenance
- One study demonstrated that supplementation with a carotenoid-rich tomato extract reduced levels of TNF-ɑ, an inflammatory marker that stimulates collagen and elastin-degrading MMP-1 expression.
- Another study found that tomato-derived carotenoids down-regulated the expression of the MMP-1 gene, which is normally up-regulated in response to environmental exposure.
- An in vitro study showed that carotenoids increased pro-collagen levels in cultured human dermal fibroblasts that were exposed to oxidative stress.
Skin aging, radiance, and wrinkles
- A double-blind, randomized, placebo-controlled study looked at the effect of a phytonutrient complex containing tomato (lycopene, phytoene, and phytofluene) and rosemary extracts on skin parameters in healthy female subjects aged 35 to 55. The phytonutrient complex increased skin carotenoid levels and reduced facial wrinkles. In addition, many subjects supplemented with this complex reported improved skin radiance in self-assessment surveys.
The role of carotenoids in overall health
Our evolutionary allurement to colorful fruits and vegetables is good news for human health beyond our skin. The carotenoids α-carotene, β-carotene, and β-cryptoxanthin can be converted into vitamin A (retinol), which we need for vision, growth, cell division, reproduction, and immunity. Lutein and zeaxanthin are taken up by the macula of the eye, where they absorb up to 90% of blue light and help maintain our visual function. Carotenoids are also antioxidants that help protect us against cellular damage caused by free radicals.
More broadly, levels of blood carotenoids are a surrogate for fruit and vegetable intake. Eating lots of fruits and vegetables is associated with a variety of benefits. Generally speaking, it means we’re probably filling up on seasonal food, anti-inflammatory food, and getting plenty of fiber, which is great for digestion and the microbiome. More concretely, carotenoids might be one of the most important factors in having a biological age that’s slower than your chronological age. A large observational study found exactly that: the strongest association between any single factor and slower epigenetic aging was blood carotenoid levels.
How to get more carotenoids
With all the benefits of carotenoids, it’s only natural to wonder how you can get more. The answer is straightforward: diet and certain supplements. Below is a list of carotenoid-rich foods. You may notice that many of them are cooked, juiced, or canned. That’s because cooking and processing help release the carotenoids from the food matrix and make them more bioavailable. Take note, too, that having a few grams of fat with carotenoids also increases their absorption. Because they do not need to be released from the plant matrix, carotenoid supplements are more efficiently absorbed than carotenoids in food and are also a great option.
- α-Carotene: Canned pumpkin, carrot juice, cooked carrots, raw carrots, baked winter squash.
- β-Carotene: Carrot juice, canned pumpkin, cooked spinach, baked sweet potato, cooked carrots, cooked collards, cooked kale, cooked turnip greens.
- β-Cryptoxanthin: Cooked pumpkin, raw papaya, sweet red peppers (cooked and raw), orange juice, tangerines.
- Lycopene: Canned tomato paste, canned tomato puree, tomato juice, watermelon, raw tomatoes.
- Lutein and zeaxanthin: Cooked spinach, cooked kale, cooked turnip greens, cooked collards, cooked dandelion greens, cooked mustard greens, cooked summer squash, cooked peas.
- Phytoene: Apricot, carrot, tomato juice, orange.
- Phytofluene: Carrot, tomato sauce, canned tomato, apricot, orange juice.