What are carotenoids?
Carotenoids are a large family of natural pigments, mainly produced by plants, algae and certain bacteria. Their bright colors range from yellow to orange to red. For example, beta-carotene, lutein, zeaxanthin and lycopene are some of the best-known carotenoids. Carotenoids are found in many colorful fruits and vegetables, such as carrots, red peppers, apricots, spinach and tomatoes. Beyond their visual functions in plants (participation in photosynthesis), they are of great interest to human health for their multiple beneficial effects, notably their antioxidant properties and their role in vision.
What are the different types of carotenoids?
There are over 600 naturally occurring carotenoids, although only around 50 have actually been studied for their functions in the human body. Among the most common are
Beta-carotene: often considered a precursor of vitamin A (known as provitamin A). Found in carrots, sweet potatoes and certain dark-green leafy vegetables, it contributes to eye health and immune system support.
Lutein and zeaxanthin: Mainly concentrated in the retina (especially the macula) of the eye. They help prevent certain types of retinal degeneration. Found in spinach, kale, corn and egg yolks.
Lycopene: responsible for the red coloring of tomatoes, pink grapefruit and watermelon. Its antioxidant properties are being studied in particular for the prevention of cardiovascular disorders and certain cancers.
Astaxanthin: Found in certain micro-algae and in salmon flesh, it is receiving increasing attention for its antioxidant and anti-inflammatory action.
Although these carotenoids have similar chemical structures, they differ in terms of their location in the body and their effects on natural health.
How do carotenoids work as antioxidants?
Carotenoids are classified as antioxidants, meaning they help neutralize free radicals produced during metabolic processes or under the influence of external factors (pollution, UV rays, oxidative stress...). Free radicals are unstable molecules capable of damaging cells by attacking cell membranes or DNA. An excess of free radicals can accelerate aging and increase the risk of chronic disease.
By capturing or "deactivating" these free radicals, carotenoids help protect tissues and preserve cell structure. Each carotenoid can target different types of free radicals and exert its function in specific tissues (skin, retina, etc.). Regular consumption of carotenoid-rich foods, or the use of carefully selected supplements, can support the body's defense mechanisms.
Why are carotenoids important for vision?
Certain carotenoids, in particular lutein and zeaxanthin, are concentrated in the macula of the eye, the area responsible for detailed vision (central vision). They act as filters against the blue light emitted by screens, helping to protect the retina's photoreceptors. In this way, they can help slow the development of age-related eye problems such as age-related macular degeneration (AMD).
In addition, beta-carotene, as a provitamin A, acts as a reserve for vitamin A once metabolized in the body. Vitamin A is crucial for night vision and the normal functioning of visual cells (retinal rods). Vitamin A deficiency can lead to vision problems, including night-blindness and damage to eye tissue.
How to optimize carotenoid absorption?
Carotenoids are fat-soluble substances, meaning they need fat to be properly absorbed by the intestine. To improve their bioavailability, we recommend :
Combine consumption of carotenoid-rich vegetables or fruit with a source of healthy fats (olive oil, avocado, oilseeds).
Lightly cook certain vegetables to break down the cell wall and release more carotenoids (e.g. cooked tomatoes release more lycopene than raw tomatoes).
Vary sources (carrots, peppers, spinach, squash, etc.) to benefit from a wide range of carotenoids.
A moderate intake of fiber and fat can optimize the transport and storage of carotenoids in the body. However, it is important to maintain a balanced diet to avoid excess.
What impact do carotenoids have on skin health?
Carotenoids contribute to skin photoprotection, particularly against UV rays. Their antioxidant function can limit the oxidative stress induced by sun exposure, thus preserving the integrity of skin cells and collagen. Regular consumption of colorful fruits and vegetables, rich in beta-carotene or lycopene, can provide a lightly tanned complexion while contributing to skin resistance.
However, carotenoids do not replace traditional sun protection (sunscreens, clothing) in the event of prolonged sun exposure. Rather, they support the skin in the face of external aggression. Several studies also suggest that beta-carotene, in synergy with other antioxidants (vitamin C, vitamin E, polyphenols), can help delay the appearance of wrinkles.
Are carotenoids available in dietary supplements?
Yes, many dietary supplements offer concentrated extracts of specific carotenoids (beta-carotene, lutein, zeaxanthin, astaxanthin, etc.). They are available in capsule, oily capsule or tablet form. Additional intake may be considered in certain situations:
Eye health support: as a supplement to a diet rich in green and yellow vegetables, to protect the retina.
Preparing for the sun: some formulations combine beta-carotene and other antioxidants to prepare the skin for summer or more intense exposure.
Unbalanced diets: if consumption of colored fruits and vegetables is insufficient.
However, it is advisable to remain vigilant with regard to doses, as excessively high intakes of beta-carotene can discolor the skin (carotenemia) and, in heavy smokers, high doses could increase certain health risks (according to specific epidemiological studies). Medical or dietary advice is often recommended before starting a supplement.
How can I avoid the degradation of carotenoids in food?
Carotenoids are sensitive to oxidation, excessive heat and light. To preserve their benefits in food, it's best to :
Store fruits and vegetables away from direct light, preferably in a cool place (the refrigerator for some products).
Limit cooking times and temperatures: steaming or lightly stir-frying often retains more nutrients than prolonged frying.
Avoid leaving fresh juices or preparations out in the open too long, as exposure to oxygen can degrade pigments.
In short, a kitchen that respects raw materials, with appropriate preparation and cooking times, helps maximize carotenoid content.
Is there a risk of over-consumption of carotenoids?
In the majority of cases, dietary intake from natural sources (vegetables, fruit) presents no significant risk of overdosage. The body manages these compounds relatively well when the diet is balanced. However, excessive beta-carotene supplementation can lead to a yellowish discoloration of the skin (particularly on the palms of the hands and soles of the feet), known as carotenoderma. This is harmless, and gradually disappears when over-consumption ceases.
Nevertheless, as mentioned above, some studies point out that very high doses of beta-carotene could have undesirable effects in heavy smokers (slight increase in the risk of lung cancer). It is therefore advisable to respect the indicated doses and maintain a balanced ratio between various antioxidants (vitamin C, E, selenium, polyphenols) rather than focusing on a single nutrient.
What are the recommendations for getting the most out of carotenoids?
To optimize the benefits of carotenoids:
Vary your diet: include colorful vegetables and fruit (green, red, orange, yellow) every day.
Combine with the right fats: cook with a drizzle of olive oil, a few nuts or a piece of avocado to enhance their absorption.
Cook in moderation: opt for gentle cooking (steam, wok, low-temperature oven) to limit pigment destruction.
Supplement if necessary: consider taking a supplement in cases of increased need, difficulty in consuming sufficient plant foods, or particular vulnerability (visual health, high oxidative stress, etc.).
Combine with other micronutrients: the synergy between different antioxidants (vitamins, minerals, polyphenols) is often more effective than a single carotenoid in large quantities.
By following these principles, carotenoids can provide significant support to natural health, particularly in terms of vision, antioxidant protection and skin well-being.
