The Beauty Diet (8 page)

Mighty minerals.
Sweet potatoes help keep your bones strong and teeth sparkling with 40 milligrams of calcium per cup (more on calcium in
Chapter 6
). They are also a good source of magnesium (see
Chapter 6
), which plays a critical role in hundreds of chemical reactions in the body, as well as a source of manganese, a trace mineral that helps keep bones strong and blood glucose levels normal. Sweet potatoes also have a significant amount of potassium, which is vital for the sodium/potassium balance in the body (more on potassium a little later). I often recommend potassium-rich foods for those retaining water due to excess consumption of sodium-rich foods.

Fiber.
It's more exciting than you think. Fiber helps you stay slim, helps control the level of cholesterol in your blood, and helps prevent problems from developing in your intestinal tract. One cooked sweet potato contains 4 grams of dietary fiber.

If you have limited your sweet potato consumption to once a year on Thanksgiving, use my Beauty Diet to add its orange goodness to your meals every week! Sweet potatoes can be dressed up or down, roasted or mashed, even cooked fast in the microwave oven if you're in a hurry. As a fabulous alternative to fatty French fries, try my tempting Grilled Sweet Potato "Fries" (see
Chapter 9
).

Although their beauty nutrients are similar, true yams and sweet potatoes are not even botanically related. Yams are large and starchy and are grown in tropical and subtropical countries

(nearly 100 percent comes from West Africa). Real yams can be found in the United States in international markets.

Sweet potatoes have pointy ends and are widely available throughout the United States. They are so commonly mistaken for yams that you may notice the sign in the grocery store says "yams" and then, underneath, "sweet potatoes." However, sweet potatoes are sweeter than true yams and have more protein. The light variety has a thin skin and is roughly the same color on the outside as a baking potato. The dark or garnet variety has a thicker skin and is reddish brown in color on the outside and orange on the inside. If you had "candied yams" for Thanksgiving, chances are you were eating delicious sweet potatoes.

Spinach is a versatile, affordable, readily available, low-calorie leafy green vegetable that is loaded with beauty-enhancing nutrients. I included it in my Top 10 Beauty Foods because of its exceptional lutein content, which keeps our eyes healthy and bright. Spinach also contains a significant amount of beta-carotene, as well as vitamin C, several B vitamins, magnesium, iron, calcium, potassium, zinc, dietary fiber, and even omega-3 fatty acids, making it a wonderfully nutrient-dense vegetable. Following are some of the beneficial micro-nutrients in this super-food:

Lutein and zeaxanthin.
One cup of cooked frozen spinach is ranked number one among vegetables by the USDA National Nutrient Database for Standard Reference (Release 20) for its content of the related antioxidants lutein and zeaxanthin. Lutein is particularly important to eye health. The human body easily absorbs lutein and deposits it in the region of the retina called the
macula
and in the lens of the eye, where lutein is able to filter light and prevent oxidation of proteins or lipids within the lens. Lutein acts like "natural sunglasses" by protecting your eyes and also helps prevent damage to your cells, keeping your skin, brain, and heart in great condition. A Harvard University study published in the
Journal of the American Medical Association
found that consuming 6 milligrams of lutein (60 grams of fresh spinach) a day was associated with a 43 percent lower risk of macular degeneration. In addition, studies indicate that people who eat leafy greens are protecting themselves against cancer, cardiovascular disease, and age-related disorders.

Beta-carotene.
Spinach is an excellent source of beta-carotene, a key beauty nutrient. One cup of cooked frozen spinach (boiled and drained) has 13,750 micrograms of beta-carotene, nearly as much as a baked sweet potato and more than a cup of boiled carrots!

Alpha-lipoic acid.
Spinach has a special gift for you: the antiaging, anti-inflammatory, antioxidant compound alpha-lipoic acid. Alpha-lipoic acid works synergistically with other antioxidants in the skin to reduce the damaging inflammatory effects of sun exposure. It replenishes other antioxidants like vitamins C and E, plus it helps regulate glucose metabolism and keep blood sugar levels stable. It protects cell and mitochondrial lipid membranes from free-radical damage and is especially protective to the mitochondria in nerve cells. This means it may play a role in preventing the effects of aging on the brain. Alpha-lipoic acid boosts cellular levels of glutathione, an antioxidant of tremendous importance in overall health and longevity and essential to the functioning of the immune system.

Vital vitamins.
Spinach is a helpful source of vitamin C. One cup of cooked spinach has 18 milligrams of vitamin C. Spinach is also an unusually good plant source of the fat-soluble antioxidant vitamin E, which helps protect you from accumulating damage caused by free radicals (see
Chapter 3
for more on vitamin E). Previous research has suggested that vitamins C and E and beta-carotene—all found in spinach—may protect against cataracts. Spinach is also impressive as a source of folate (vitamin B
9
). One cup of raw spinach has 58 micrograms—about 15 percent of your recommended dietary allowance of 400 micrograms. Among its other roles, folate is necessary for the production and maintenance of new cells, including red blood cells, because it is needed to replicate DNA.

Mighty minerals.
Among vegetables, spinach contains an unusually high amount of magnesium, which plays a vital role in hundreds of the body's chemical reactions (see
Chapter 6
). With 167 milligrams per cup, raw spinach is also a good source of heart-healthy potassium. Spinach is rich in calcium, although much of it is unavailable, because oxalic acid in spinach binds with calcium, preventing its absorption. It's also rich in iron. To increase your absorption of iron from
spinach, drink a glass of orange juice or otherwise include some vitamin C with your meal.