We regularly face primary challenges in deciding what to eat to maintain youthful and healthy skin, defining a healthy diet, and determining the role of diet in aging. The topic currently receiving the most attention is ways to maintain healthy skin and delay skin aging. The skin is the primary barrier that protects the body against external aggressions. Skin aging is a complex biological process that is categorized as chronological aging and photoaging and is affected by internal and external factors. With the rapid breakthrough of medicine in prolonging human life and the rapid deterioration of environmental conditions, it has become urgent to find safe and effective methods to treat skin aging. The importance of diet for the skin, which is the main way for the body to obtain energy and nutrients, is also demonstrated by scientific studies. Tehi skin is the organ with the largest contact area between the human body and the external environment and is a barrier separating the human body from the environment. It not only protects the body from external environmental damage and prevents water loss from the body, but also has a certain cosmetic effect. The aging of organs occurs from the moment we are born. The skin, the largest organ of the human body, shows obvious signs of aging due to age, exposure to ultraviolet radiation (UVR), and chemical pollution. With the development of science and technology and the increase in human living standards, people pay more attention to skin aging and try to understand it better. Many people, especially women, spend a significant part of their daily expenses on cosmetics and medicines for the treatment and prevention of skin aging. This huge demand continues to drive research into the prevention and treatment of skin aging. While aging refers to the body's ability to adapt to the physiology and psychology of the environment, which gradually decreases and leads to death, it is characterized by accumulation of macromolecular damage, impaired tissue regeneration, gradual loss of physiological function integrity and increased risk of death. Aging is caused by a combination of internal factors (hormone levels, genotypes, endocrine metabolism, etc.) and external factors (ultraviolet radiation, nutritional levels, chemical pollution, etc.). Skin aging can be divided into chronological aging and photoaging (or internal and external aging). As the name suggests, chronological aging of the skin occurs throughout the body, and photoaging occurs in areas of the body that are exposed to light. Chronological aging caused by internal factors occurs naturally and is not easy to change, but it is possible to delay photoaging by changing external factors. Chronological aging and photoaging are two skin aging processes that, although related, have different clinical manifestations and pathogenesis. Chronological aging usually occurs after a certain age and is influenced by factors such as ethnicity, individual, and skin region. It is mainly characterized by dry skin, dullness, lack of elasticity and fine wrinkles. Photoaging is a process that mainly develops with exposure to UV rays, which results in skin wrinkles, relaxation, roughness, yellowish or grayish-yellow, capillary enlargement and pigmented spot formation, etc. Researchers have used many models in recent years to explain the molecular mechanism and mitigation mechanism of skin aging. These patterns include cell senescence, oxidative stress, high-frequency chromosomal abnormalities, single gene mutations, and chronic inflammation. Oxidative stress plays an important role in the processes of skin aging and skin damage, and its main feature is the increase of intracellular reactive oxygen species (ROS). Oxidative metabolism of the skin and exposure to UV leads to the production of ROS. ROS accumulation causes DNA damage and induces inflammatory response in the skin. Decreased antioxidant enzymes inhibit collagen production by activating nuclear factor kappa B (NF-kB) and activator protein1 (AP-1). Reactive oxygen species, the key point in protecting and improving skin health
It is the prevention and detoxification of the formation of . Reasonable nutrition and a balanced diet are important measures to delay aging and prolong life. Nutrition is closely related to skin health and is essential for all biological processes of the skin, from youth to aging or disease. Nutritional levels and eating habits can repair damaged skin and can also damage skin. In recent years, the relationship between health-nutrition-eating habits and skin health has been demonstrated. The first point in nutrition is water consumption. The appearance of the skin on the lips and limbs is a direct reflection of the moisture status of the body. So how much water is good for the skin every day? Research shows that drinking more water and drinking more than 2 L of water per day significantly affects skin physiology and promotes superficial and deep hydration of the skin. However, the effects of water on the skin may differ from water intake, and these effects are more pronounced in people who drink less water. Although trace elements (iron, iodine, zinc and copper, etc., which are less than 0.01-0.005% of the body mass) are found less in the body, they have strong physiological and biochemical effects. Trace elements have been found to be closely associated with skin immunity and inflammation. Zinc content in the skin ranks third among all tissues and is an essential element for the proliferation and differentiation of skin epidermal keratinocytes. In the skin, copper is involved in extracellular matrix formation, synthesis and stabilization of skin proteins, and angiogenesis. Clinical studies have shown that copper helps increase skin elasticity, reduce facial fine lines and wrinkles, and promote wound healing. Iron is a catalyst for biooxidation.
Studies have shown that ultraviolet radiation and iron content in women's postmenopausal skin cells increase rapidly, reducing the skin's antioxidant capacity and leading to aging. Dietary selenium deficiency weakens the skin's UV-B-induced antioxidant ability, making the skin more susceptible to oxidative stress due to ultraviolet radiation. Vitamin deficiency also affects skin health. For example, vitamin C deficiency causes symptoms of scurvy, such as fragile skin and impaired wound healing. Vitamins as antioxidant defense components of the skin are mostly taken from food, and therefore the content of vitamins in the diet is closely related to the antioxidant capacity and physiological functions of the skin. High-fat diets delay skin healing by reducing protein synthesis while promoting skin oxidative stress and inflammatory responses, and can also impair skin morphological changes and matrix remodeling. In addition, high-salt, spicy, and over-vegetarian diets are also thought to be harmful to skin health. Therefore, it is important to eat scientific, reasonable, healthy and varied dietary habits and antioxidant-rich foods to maintain skin health. According to the free radical theory, lipid peroxidation, DNA damage and inflammation are the major causes of skin aging, disease and dysfunction. This has led to a medical revolution that emphasizes antioxidants and free radical scavengers for the prevention and treatment of skin aging. Polyphenols are secondary metabolites of plants and are widely found in vegetables, fruits, tea and other plants. Due to their prominent antioxidant properties, polyphenols have become one of the most important compounds to be used in cosmetics and nutritional cosmetology to combat skin aging. In recent years, tea polyphenols, curcumin, flavonoids, silymarin, and grape resveratrol have been the most studied polyphenols with anti-aging properties.
With their antioxidant and anti-inflammatory effects, polyphenols reduce oxidative damage and inflammation in the skin, mainly by inhibiting collagen degradation, increasing collagen synthesis and inhibiting inflammation. In addition to the food-derived antioxidants mentioned above, which can be used as functional food ingredients to alleviate skin aging, the combined use of different types of antioxidants has also been reported. Some studies have reported that dietary probiotics and products can also alleviate skin aging. Skin aging is a complex and long biological process affected by genetic and environmental factors. Oral supplementation alone is not enough to improve the skin. The combination of oral and external skin penetration should be the safest and most effective way to cure skin aging. For this reason, the evaluation of individual genetic analyzes and the analysis of the current state of the skin will make an important contribution to the formation of the right nutritional composition in order to protect and improve the individual's skin health. Stay healthy, stay beautiful.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146365/