A healthy diet—rich in key nutrients—can result in radiant skin and healthy hair.

We're bombarded with ads for the latest hair products—from shampoos to gravity-defying gels—designed to give you gorgeous, enviable locks. But the part of the great-hair-day story that is often left out is how what you eat affects how your hair looks.

Even though hair is technically "dead" (it's made up of dead cells composed of keratin, a fibrous protein, and has no blood, nerves, or muscles), it's actually the second fastest growing cell in your body (bone marrow is the first).

It all starts from the follicle: at the base of the follicle is the papilla—from which hair grows. Capillaries surrounding the follicles (each follicle has its own blood supply) nourish the cell production and growth of each individual strand. Why this is important: if you aren't eating a healthy diet—with enough key nutrients and protein—your hair follicle won't be nourished and your hair will look lackluster and might even fall out. (Hormonal fluctuations and stress—both emotional and physical—can also affect the density and shine of your locks.)

So then, what should you be eating for shiny, lustrous locks? Start with these basics:

√ Peanuts and almonds: You may have heard about the benefits of biotin for hair health in a shampoo ad, or read in a magazine that taking biotin supplements can make your hair grow faster (and your nails stronger). There is some truth to this. Biotin is a B vitamin essential for hair growth and overall scalp health. Our bodies make their own biotin in the intestines, and it's also found in many common foods. A biotin deficiency is therefore very rare, so supplements are usually unnecessary if you're eating a balanced diet that includes some high-biotin foods.

Peanuts are a great choice, as they're also high in B vitamins and folate, which contribute to healthy hair. Other biotin-rich foods are almonds, sweet potatoes, eggs, onions, and oats. Salmon has a small amount of biotin compared to these others, but is still a good option as it's a key part of the Mediterranean diet.

"Biotin is a B vitamin essential for hair growth and overall scalp health."

√ Lentils: These legumes are especially high in both folate and iron, two powerful nutrients that nourish your mane. Folate is a B vitamin that aids the creation of red blood cells; iron helps those blood cells carry oxygen and nutrients to all body cells. With iron deficiency, a condition known as anemia, cells can't get enough oxygen to function properly. The result can be devastating to the whole body, causing weakness, fatigue, and in some cases, even hair loss. So load up on iron-rich lentils for sturdy tresses — and if you're a premenopausal woman, consider taking a multivitamin that contains iron to replace iron lost during menstruation. Other good non-red meat sources of iron include fish (sardines, halibut, haddock, perch, salmon, and tuna); beans (lima beans, red kidney beans, split peas); and pumpkin, sesame, or squash seeds.

√ Oranges and strawberries: Juicy citrus fruits often get the credit as the best vitamin C–packed fruit, but just eight strawberries deliver 100 percent of your daily needs (something most people don't realize). Strawberries are a juicy, delicious source of vitamin C, which is largely responsible for the health of collagen. Hair follicles require collagen, a structural fiber, for optimal growth. Even minor vitamin C deficiencies can lead to dry, splitting hair that breaks easily, so eating vitamin C–rich foods like strawberries, oranges, grapefruit, kiwifruit, red and green bell peppers, kale, broccoli, papaya, and pineapple can all help you grow stronger, more resilient strands.

"Vitamin C is largely responsible for the health of collagen. Hair follicles require collagen, a structural fiber, for optimal growth."

√ Chicken: Protein is key to healthy hair—and skinless chicken breast is another healthy source of protein. It's rich in B vitamins — folate, B6 and B12 — that maintain strong, silky locks. These vitamins play an important role in the creation of red blood cells, which carry oxygen and nutrients to all body cells, including those of the scalp, follicles and growing hair. When the body is deprived of B vitamins, the cells can starve, causing shedding, slow growth or weak strands that are prone to breaking.

In addition to providing zinc and folate (nutrients that promote hair health), chickpeas are a great vegetarian source of iron-rich protein, an important combination for hair growth and repair. Because hair gets its structure from hardened proteins called keratin, people who don't have enough protein in their diet experience slower growth and weaker strands. To increase the absorption of iron from chickpeas, couple with a vitamin C–rich food such as tomatoes, bell peppers, or citrus fruit.

This all goes to show that you really are what you eat—take in healthy foods like those followed in a Mediterranean diet—and your body will be better off. This holds true, too, when it comes to beauty—how your skin, your hair, and even your nails look: a nutrient-rich diet and a healthy lifestyle is where beauty begins.

Eat well & be healthy,