Yesterday was family afternoon and board games. We spent a good time playing Trivial until we got two green questions in a row. The Science and Nature section, our favourite. What is the largest organ of the human body? What carotenoid is responsible for the yellow color of corn?
Two questions that seemed unconnected but are actually very connected.
1st answer: The skin is our first barrier of protection
The skin is the largest organ in the human body and has transcendental importance. It fulfills many functions, among which is that of serving as a barrier. The skin is the first line of defense against environmental stress factors, it is our external cover, it separates the organism from the environment, and at the same time it connects it. The skin prevents harmful substances or pathogenic microorganisms from entering the interior and is responsible for regulating body temperature. It protects us.
As skin ages, the number and size of cells decrease and become thinner due to a constant reduction in collagen, elastin, and hyaluronic acid. Therefore, the skin loses its effectiveness as a protective barrier and temperature regulation is less efficient. The visible signs of skin aging are spots, wrinkles and dilated vessels, among others.
If this has worried you, there’s good news, as only a third of skin aging is determined by our genes and related to the passage of time. The rest is due to external environmental factors to which we are exposed, which can be controlled or modified.
Among external factors, the sun is the main cause of the visible signs associated with aging. We only have to compare the skin of our buttocks with that of our face, which is subjected to solar radiation daily. Other factors, such as environmental pollution, toxins (such as tobacco), stress and lack of sleep accelerate aging and worsen inflammatory skin diseases.
However, a diet rich in fruits and vegetables delays the signs of aging and improves the appearance of the skin, and this is where we want to stop in this article.
2nd answer: Zeaxanthin, the carotenoid responsible for the yellow color of corn
Carotenoids are natural yellow, orange, and red pigments synthesized in all photosynthetic organisms and some fungi. We find them in fruits and vegetables such as corn, carrots, tomatoes, mangoes or lettuce. In fact, zeaxanthin provides the yellow color to the ear of corn. They are molecules of 40 carbon atoms with conjugated double bonds. A chemical structure gives carotenoids spectroscopic properties, and therefore color.
Carotenoids are essential for plant survival and plant function, since they are involved in the absorption of energy for photosynthesis, but they also protect the photosynthetic apparatus from damage caused by environmental conditions (protection against radiation and antioxidant defense). In addition, they have been identified as signaling molecules in plants and a key role is attributed to them in the interaction of plant species with the environment.
Carotenoids have parallel functions in plants and in our bodies.
Plant carotenoids are our vitamins and antioxidants. Three arthropod species biosynthesize carotenoids (due to lateral gene transfer from fungi), but the rest of the animal species require external uptake. These carotenoids accumulate in organs such as fatty tissue, liver, and skin. Carotenoids are versatile compounds with multiple functions, both in plants and animals. An example of these functions is protection against reactive oxygen species, which in excess can damage cell structures and cause oxidative stress.
In plants, this occurs when the energy available for photosynthesis is greater than the plant can use. In this context, carotenoids act like “sunglasses” protecting the plant when light energy is too high, converting it into heat.
As for animals, carotenoids protect both vision and skin. In the skin, as in plants, they have an antioxidant effect and protect against ultraviolet radiation. For example, zeaxanthin, the carotenoid responsible for the yellow color of the ear of corn, provides protection against the damaging effect of ultraviolet rays. In fact, inflammation and the acceleration of cell division in response to UV exposure have been shown to be improved by dietary zeaxanthin. A diet rich in fruits and vegetables, and also with many colors, is necessary to avoid the visible signs of aging and maintain skin health.
The “one health” concept
The concept of “one health” was introduced two decades ago to name the fact that human health, animal health and ecosystem health are interconnected. Plants are an important foundation of our health, and maintaining biodiversity is ensuring it, in the present and in the future. The famous American biologist Jonas Salk said it: “There is no human health without planetary health.”