Our outer appearance reflects our inner health status. Many look to the next cream or serum to bring about a youthful glow, but the key lies both within and from the outside. Educated consumers are more aware of the link between nutrition and beauty than ever before and are looking to use nutrition as a tool to achieve their goals.
Skin aging comes from two sources—chronological aging and extrinsic aging. Chronological aging is simply a result of getting older. Extrinsic skin aging is the result of external factors and environmental influence, mainly chronic sun exposure and ultraviolet (UV) irradiation, but also smoking, pollution, sleep deprivation and poor nutrition.
Vitamins, minerals, carotenoids, antioxidants and fats all play important roles in maintaining healthy skin. Star players on the nutrition team to fight extrinsic aging are the B vitamins; vitamins A, C, D, and E; zinc; lutein; lycopene; genestein; epigallocatechin gallate (EGCG) and resveratrol. Skin regeneration requires these nutrients throughout life, and they are also required by skin in increased amounts under certain conditions such as exposure to free radicals and UV radiation. Humans need to ingest these compounds in the right amounts to nourish and protect the skin. Growing research also supports the benefits of topical application of these same compounds to offer benefits from the outside in.
Healthy Aging: Antioxidants
Antioxidants are substances that prevent oxidation, also referred to as oxidative stress. They are nature’s way of protecting your cells from damage. During the process of oxidation, free radicals cause damage to the skin tissues, speeding up the aging process. Antioxidant-rich foods are plant based and many times referred to as phytochemicals.
Scientists at the U.S. Department of Agriculture have developed the Oxygen Radical Absorbance Capacity (ORAC) score, a scale for measuring an antioxidant food's ability to neutralize free radicals. The higher a food's ORAC score, the more powerful it is in combating age-related degeneration and disease. Foods with the highest ORAC scores include spices, cocoa powder (unsweetened) and richly colored fruits and vegetables.
Limited research has been done on the impact of diet on skin aging and health, but there have been a few revealing studies that support our nutrition-skin aging theory. In 2007, researchers from Unilever examined associations between nutrient intake and skin aging appearance using data from the National Health and Nutrition Examination Survey (NHANES). NHANES data comes from 4,025 women aged 40 to 74. Clinical examination was performed by dermatologists, and skin aging was defined as having wrinkled appearance, senile dryness and skin atrophy. The study concluded that higher intakes of vitamin C and linoleic acid and lower intakes of fat and carbohydrate were associated with better skin-aging appearance.1
Vitamin C, essential for collagen synthesis, acts as an antioxidant and also works in synergy with vitamin E to protect cell membranes from free radical damage. Vitamin C is a critical ingredient in topical skin care formulations because of its anti-aging and skin lightening benefits.
The Journal of the American College of Nutrition published a study in 2001 on eating patterns and skin aging of 400+ international subjects. Researchers found that both dark and fair-skinned people who ate plenty of wholesome foods but limited red meat and sugary foods were less prone to wrinkling. Examples of beneficial foods consumed by the study participants included green leafy vegetables, beans, olive oil, nuts and multigrain breads. The researchers speculate that certain foods offered skin protection due to their high levels of antioxidants such as vitamins A, C, and E. They found that monounsaturated fats such as olive oil may offer beneficial protection through the same mechanism. Fatty acids are naturally present in the skin, and monounsaturated fats resist oxidative damage unlike saturated and trans fats.2 Again, the key elements of the healthy skin diet are mirrored in key elements of healthy topical skin care–antioxidants, A, C, and E, phytochemicals and healthy fats. Dietary sources of monounsaturated fats include avocados and almonds. Vitamin E can be found in wheat germ, nuts, seeds and green leafy vegetables. Vitamin A rich foods include sweet potatoes, carrots and liver. Vitamin C can be best obtained from eating bell peppers, broccoli and citrus fruits.
The best way to ensure that one is getting adequate antioxidants is to eat a rainbow of fruits and vegetables every day. The different colors in our produce represent the unique phytochemicals found in the foods. Five to seven servings of colorful plants per day will help prevent skin aging and boost overall health.
Skin Defense: Carotenoids and Lycopene
The human body is amazing in its ability to adapt and protect. There is a constant battle being fought against foreign invaders and harmful toxins. The skin is the body's largest organ in its immune defense system and the body's first line of defense.
The two main types of damage from the sun are UVA and UVB radiation. UVB radiation affects mainly the epidermis and is responsible for sunburn; however, UVB also contributes to immune suppression, premature skin aging and skin cancer. UVA, on the other hand, penetrates more deeply to the dermis where our collagen resides, and plays a substantial role in photoaging.3 Both types of rays cause damage, but UVA causes more skin aging. We all know that we need to apply sunscreen before going out in the sun to prevent sunburn, but did you know that we can increase our skin’s SPF factor by eating certain foods?
Carotenoids. Carotenoids are natural pigments found in fruits and vegetables and are known to protect again sun damage from sunlight. Beta-carotene is a carotenoid that is deposited in the skin and prevents the production of particular enzymes that destroy collagen after being activated by UV light. In addition, beta-carotene acts as an antioxidant and decreases oxidative stress from UVA light, in addition to reducing the redness from sunburn.3 Food sources of beta-carotene include sweet potatoes, spinach and carrots. It is best to obtain beta-carotene from food sources and not supplements.
Lycopene. Lycopene, a potent antioxidant found in tomato foods and watermelon, has been studied and shown to increase the skin’s natural SPF factor. In a study of 20 healthy women aged 21 to 47, participants ingested lycopene from tomato paste to test its ability to protect from UV radiation. Compared with the other women, the tomato-eating group had 33% more protection against sunburn in the form of less redness. The researchers calculated that protection offered by the tomato paste to be equivalent to a sunscreen with a SPF of 1.3. Skin samples taken from groups before and after trial showed an increase in levels of pro-collagen, a molecule which gives skin its structure and loss of which leads to skin aging and lack of elasticity. There was also less damage to mitochondrial DNA in the skin, which is also believed to be linked to skin aging.4
It’s important to note that the most potent form of lycopene comes from cooked tomatoes that have been prepared with olive oil. Absorption of lycopene from cooked tomato paste is 3.8 times that from fresh tomato. The olive oil increases serum lycopene, acting as a transport vehicle.
Skin care companies are beginning to use topical lycopene in their formulations to offer antioxidant protection from the inside out. Although there is no strong published research to support its effectiveness, I would not be surprised to see some published in the future, as there seems to be synergy between topical and oral antioxidant benefits as demonstrated by research on lutein and zeaxanthin.5
Lutein. Lutein is another SPF superstar phytochemical. Lutein acts as a filter, absorbing high-energy wavelengths of visible light, called blue light. Unlike UV light that penetrates the surface layers of the skin, blue light penetrates the entire depth of the skin, potentially damaging every layer. When blue light is absorbed by our skin it can form free radicals that attack skin tissue, leading to wrinkles, redness, age spots and loss of elasticity. Topical products can’t offer protection against this deep damage, so ingestion in the diet is crucial for protection.6
There are some great benefits of topical application of lutein. Lutein has been clinically demonstrated to increase skin moisture and prevent oxidative stress. In a study by Palumbo, et al from 2007, the highest increase in skin hydration and most decrease in oxidative stress were observed in a combination of oral and topical lutein plus zeaxanthin.7 Zeaxanthin is an antioxidant that works synergistically with lutein, and is paired together both in nature and in oral supplements for this reason. Dark green leafy vegetables are the best source of lutein in the diet.
To-do for Healthy Skin
Research continues on other plant extracts that offer nutritional benefits in protection from UV radiation including EGCG (from green tea), genistein (from soy) and resveratrol. The overall trend is clear–food choices can help humans create an internal protection from environmental and photo damage, and these protective factors all come from plants.
The best way to combat the inevitable process of aging, both intrinsic and extrinsic, is to consume a diet rich in colorful fruits and vegetables and healthy fats and low in processed foods. When choosing topical skin care, consider botanical product lines to gain the synergy of ingesting and applying phytochemicals to the body. The old adage “we are what we eat” is true. If we eat a whole-foods based diet, we will be beautiful just like the plants we consume.
1. MC Cosgrove, OH Franco, SP Granger, PG Murray and AEMayes, Dietary nutrient intakes and skin-aging appearance among middle aged American women, Am J Clin Nutr 86 1225–31 (2007)
2. M Purba et al., Skin wrinkling: can food make a difference?, Journal of the American College of Nutrition 20(1) 71-80 (2001)
3. https://www.skincancer.org/risk-factors/uv-radiation/ (Accessed on Jan. 5, 2016)
4. U Heinrich et al., Supplementation with β-Carotene or a Similar Amount of Mixed Carotenoids Protects Humans from UV-Induced Erythema, J Nutrition 13:1 98-101 (2003)
5. MI Rizwan et al., Tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo: a randomized controlled trial, Br J Dermatol Jan 164(1) 154-62 (2011)
6. RL Roberts, J Green and B Lewis, Lutein and zeaxanthin in eye and skin health, Clin Dermatol 27 195-201 (2009)
7. Palombo et al., Beneficial Long-Term Effects of Combined Oral/Topical Antioxidant Treatment with the Carotenoids Lutein and Zeaxanthin on Human Skin: A Double-Blind, Placebo-Controlled Study, Skin Pharmcol and Physiol 20:199-210 (2007)