The Beauty Diet (18 page)

The study, from Duke University, found that when pigskin was irradiated with ultraviolet light, the combination of vitamins C and E provided four times more protection against sunburn than a placebo cream. Plus, the vitamins provided protection against DNA damage in skin cells that can lead to mutations that cause skin cancer.

How do the vitamins relate to the SPF? Generally speaking, you can improve the SPF of sunscreen with the addition of vitamins C and E by a factor of 1 to 4. In other words, if you have an SPF of 15, maybe you will get an SPF of 19 with the vitamins added.

Would you believe the next big thing could be a topical solution that protects against sunburn . . . made from broccoli sprouts? Although it is applied topically, this substance is not a sunscreen, and it does not work by filtering out UV light and preventing its entry into the skin. Instead, it works inside the skin by boosting the production of protective enzymes that defend cells against UV damage. The topical solution can even be applied three days before you go out in the sun, because its protection lasts for several days.

Exercise brings a glow to your cheeks because of the increase in circulation, which helps keep your skin hydrated, promotes healing, brings micronutrients and oxygen to your skin cells, and whisks away dead cells and toxins. However, you can't exactly drop to the floor and do 20 crunches every time you want a healthy glow. Blushing works, but there are side effects involving your dignity. Following are skin-friendly foods that can help give you a beautiful complexion.

Omega-3 fats found in fish oils offer circulatory benefits by reducing blood pressure, preventing platelet clotting, and maintaining the elasticity of arterial walls. Among my Top 10 Beauty Foods, you can obtain a healthy dose of omega-3–rich fish oil from salmon. Other
sources of omega-3–rich fish oils include mackerel, herring, sardines, and trout.

Luckily for us, walnuts have a beneficial effect on circulation because they contain L-arginine, from which the body can create nitric oxide, which opens up blood vessels. An article published in the journal
Circulation
describes a study in which participants with high serum cholesterol levels ate two different carefully constructed diets, one that included olive oil and another that replaced 32 percent of the calories from olive oil with walnuts. Four hours after a meal containing walnuts, brachial artery reactivity was measured by ultrasound. Vasodilation improved significantly after the walnut meal, compared with the olive oil meal. This means walnuts have a direct and almost immediate effect on the blood vessels, helping them open wider to keep blood flowing freely to all areas of the body.

A delicious way to promote circulation to your skin is to drink cocoa or eat dark chocolate with high levels of cocoa flavanols. Researchers have found that cocoa causes an increase in blood flow to the skin, with a corresponding increase in hydration and skin density. The Mars company did a study using its Cocoapro product and found that women who drank high-flavanol cocoa for 12 weeks showed significant improvements in their skin, including an increase in skin hydration and a decrease in skin roughness and scaling. Researchers attributed this improvement to an increase in blood flow to the surface of the skin. A study published in the
European Journal of Nutrition
was based on participants drinking just one serving of cocoa. Within an hour, blood flow to the skin was increased. The article noted that regular consumption of cocoa leads to a significant increase in blood flow in cutaneous (skin) and subcutaneous tissue (beneath the skin).

Like Madonna, your skin is constantly reinventing itself. On the surface, old cells slough off and are replaced by new ones. Underneath, the cells in the dermis begin to lose their strength and flexibility. At the same time as the supporting structures of your skin begin to break down, the production of fresh collagen slows, so skin starts to wrinkle and sag. Collagen makes up 75 percent of the skin, so many people are looking for ways to restore it. It is possible to get collagen injected directly into wrinkles and to buy collagen creams that promise to rebuild the skin (they can't—the molecules of collagen are too large for the skin to absorb). The Japanese even sell marshmallows with collagen added—although there is no evidence that eating collagen will make any difference to your skin.

To rejuvenate your skin, you're going to need fresh collagen that is created on the inside. Following are some ways to enhance collagen synthesis by adding whole, natural, skin-boosting foods to your diet.

Amino acids are the building blocks your body uses to make collagen, so if you want fresh new skin cells, you need to eat some high-quality protein every day. Among my Top 10 Beauty Foods, the highest amount of protein is found in salmon, yogurt, walnuts, and oysters. Other good sources of protein include fish, shellfish, turkey, chicken, beef, lamb, soybeans, eggs, nuts, and dairy products. (See the protein section in
Chapter 1
.)

Because vitamin C it is necessary to the production of collagen, it is important to consume lots of vitamin C–rich foods. Vitamin C has been shown to stimulate the growth of collagen when applied topically, so it is often included in all kinds of antiaging cosmetics. Among my Top 10 Beauty Foods, significant amounts of vitamin C are found in kiwi,
blueberries, sweet potatoes, spinach, and tomatoes. Vitamin C is also found in foods like peppers, oranges, strawberries, lemons, and broccoli. (For more information on vitamin C, see
Chapter 1
.)

A key beauty nutrient, vitamin A is important to skin renewal because it is involved in the proper growth, repair, and maintenance of the skin and helps control sebum levels. We know vitamin A has special significance for the skin because a deficiency of vitamin A makes the skin dry and flaky. Vitamin A is so helpful to skin that it is used in prescription medications, both oral and topical, to combat acne and other problems. More preformed vitamin A from supplements is not necessarily better, however: if you choose a multivitamin, check that at least 20 percent comes from beta-carotene, the precursor to vitamin A. Among my Top 10 Beauty Foods, animal sources of vitamin A are oysters, yogurt, and salmon. Other sources include milk, cheddar cheese, and eggs. Among my Top 10 Beauty Foods, you'll find significant amounts of beta-carotene, the precursor to vitamin A synthesis, in sweet potatoes, spinach, kiwi, and tomatoes. You can also add beta-carotene to your diet with foods like pumpkin, carrots, chilies, mangoes, cantaloupe, and apricots. (For more information on vitamin A, see
Chapter 7
.)

In addition to their antioxidant properties, anthocyanins help stabilize the collagen matrix by means of cross-linking. This means that as your skin renews itself, you'll want these phytonutrients available to strengthen your connective tissue. Among my Top 10 Beauty Foods, anthocyanins are found in blueberries. They are also found in other blue, red, and purple foods, including other types of berries, cherries, pomegranates, plums, red cabbage, grapes, and apples.

The B complex includes eight vitamins important to skin renewal because they are essential to cell reproduction. A deficiency of the B vitamin riboflavin can interfere with proper collagen synthesis, and deficiencies of other Bs can cause problems from scaly skin to acne. Among my Top 10 Beauty Foods, the best source of thiamine (B
1
) and biotin (B
7
) is walnuts, the best source of riboflavin (B
2
) and pantothenic acid (B
5
) is yogurt, the best source of niacin (B
3
) is wild salmon, the best source of folate (B
9
) is spinach, and the best source of cobalamin (B
12
)—which is available only from animal sources—is oysters. Spinach, walnuts, and salmon are all good sources of pyridoxine (B
6
).