Get that Natural “Glow”
When it comes to nurturing outer beauty, the best results come from optimizing nutrition from the inside out: providing nourishment tailored to hair, skin, and nails to maintain a healthy glow.
There is a long list of beauty-boosting nutrients, and many of the foods and nutrients that benefit skin also benefit hair and nails. This is because all three are made of similar kinds of tissue, like keratin. In addition to specific nutrients, many lifestyle habits may also contribute to healthy hair, skin, and nails, such as adequate, restorative sleep, stress management, hydration, and avoiding or minimizing exposure to harmful substances, like tobacco smoke, pollution, and excessive alcohol.1 Unbalanced hormone levels, especially thyroid hormone imbalances, can also negatively impact the health and appearance of hair, skin, and nails. If hair loss, brittle nails, and/or dry skin are persistent issues, a health care provider can rule out a hormonal imbalance.
In addition to adopting a healthy lifestyle, optimizing nutrition can make a big impact on the look and health of hair, skin, and nails. In fact, many different nutrient deficiencies and insufficiencies are linked with hair loss, slow growing, brittle hair and nails, and undesirable skin changes, like dermatitis and rashes. These nutrients include vitamin K, B vitamins, dietary protein, essential fatty acids, and vitamin A.2
The micronutrient triage theory, developed by Bruce Ames, PhD, proposes that when faced with a nutrient deficiency or insufficiency, the body will prioritize certain nutrient requirements and shunt other nutrients to primarily support the biological functions most important to staying alive and reproducing – at the expense of other bodily functions.3 Since healthy, shiny hair, strong nails, and radiant skin are less critical to survival, the body would theoretically divert nutrients away from growing hair and nails and repairing skin toward more important functions. Based on this theory, the body’s nutrient stores likely have to be running on a full tank for optimal hair, skin, and nails.
The following are some of the most important nutrients to emphasize if healthier hair, skin, and nails is a priority.
Phytonutrients and Antioxidants
Free radicals and oxidative stress are true beauty-killers when it comes to healthy hair, skin, and nails. Because all the tissues of the body are vulnerable to damage from oxidative stress, all tissues of the body benefit from phytonutrients and antioxidants that help to quench free radicals. This includes vitamins and minerals with antioxidant activity, such as vitamins C, A, and E, selenium, and zinc. Specific phytonutrients found to protect skin, which is especially susceptible to oxidative stress, include the following:
- Carotenoids: found in orange-colored fruits and vegetables and dark leafy greens; i.e. beta-carotene and lutein
- Polyphenols, flavonoids, and quercetin: found in onion, apples, blueberries, broccoli, and tea
- Curcumin: the main phytonutrient in turmeric
- Silymarin: the bioactive component of milk thistle
- Genistein: an isoflavone found in soybeans
- Proanthocyanins: found in dark blue, purple and black fruits and vegetables, as well as in grape seeds
- Resveratrol: a polyphenol found in red grapes, red wine, and mulberries4
A 2011 double-blind, randomized, placebo-controlled study found that a combination of a variety of antioxidant components (omega-3 fatty acids, vitamin C, B vitamins, coenzyme Q10, and carotenoids such as lutein and beta-carotene) may improve the health and appearance of the skin. Ultraviolet (UV) light exposure may lead to the accumulation of reactive oxygen species, and antioxidant nutrients can help address free radicals. Moreover, a 2016 double-blinded, placebo-controlled, crossover study showed that carotenoids may protect the skin against UVB/UVA and UVA1 light exposure, as well as inhibit radiation-induced gene expression.
Protein and Collagen
Hair, skin, and nails are made mostly of a protein type called keratin, which forms a protective barrier and provides firm structure in the epithelial outer layer. Another important protein is collagen, an important component of skin and other connective tissues; it can be thought of as the glue that holds tissues together.5
The building blocks of both of keratin and collagen must come from dietary protein in the form of amino acids to maintain their strength and function. Keratin is synthesized from 20 different amino acids, while collagen is synthesized from just three. Critical amino acids for collagen synthesis are proline, glycine, and lysine with help from nutrient co-factors including vitamins C, A, and E, copper, and zinc.6-8 Collagen supplementation has been found to improve nail growth and strength, promote healthy scalp and hair growth, and potentially reduce the appearance of fine lines and wrinkles. One way collagen may improve skin’s texture and appearance is by increasing the amount of water-holding glycosaminoglycans (GAGs) in the skin, which improves hydration and elasticity.9,10
Vitamins and Minerals
Vitamins and minerals (micronutrients) play a major role in maintaining healthy hair, skin, and nails, as well as supporting overall metabolic health, tissue repair, and maintenance.
- Biotin, also known as vitamin B7, stimulates keratin production.11 While an overt deficiency is rare, biotin is not stored in the body, and biotin supplementation is often recommended to improve hair and nail growth. Deficiencies of other B vitamins, including B12, riboflavin, niacin, and pyridoxine may also manifest as dry, inflamed skin, thinning hair, and brittle nails.12 Biotin is found in egg yolk, fish, meat, organ meats, sunflower seeds, peanuts, and sweet potatoes.
- Iron facilitates oxygenation of the blood and tissues and is also important for healthy hair, skin, and nails – especially hair growth.13 Insufficient levels of iron and hemoglobin, the protein that transports oxygen to tissues and cells, can negatively impact the appearance of hair, skin, and nails. Common signs of iron deficiency anemia include thin, brittle nails, hair thinning, hair loss (alopecia), and pale complexion.14 Iron is found in red meat, organ meats, spinach, shellfish, lentils, and pumpkin seeds.
- Silicon/silica is a trace mineral that improves collagen synthesis and plays a role in the formation of elastin and GAGs. It has been shown to improve keratin structure to support skin firmness and may increase the thickness and strength of hair and nails. Silica also plays an important role in calcium metabolism and bone health. Silica-rich foods include beans, bananas, root vegetables (carrots, beets, radish, potatoes), and brown rice.15
- Vitamin A promotes protein synthesis in the skin’s epidermal layer, stimulates the formation of collagen and elastin, and protects collagen from degradation and damage from ultraviolet (UV) light.13,16 Vitamin A-rich foods include carrots, winter squash, sweet potato, spinach and other dark leafy greens, and tuna.