What Nutrients Are in the Skins of Sweet Potatoes?

You may have wondered if you can eat the skin of baked sweet potatoes. Well, yes you can —and you should! The copper-colored skin that wraps around a whole sweet potato contains most of the healthy vitamins, minerals and antioxidants, including a host of phytochemicals that have protective and disease-preventing properties. Eating the skin of a baked sweet potato will reward you with anti-inflammatory and anticancer benefits from the wealth of nutrients this root vegetable offers.

Although TGI Fridays makes a dehydrated sweet potato skin snack from sweet potatoes, it packs a boatload of calories — 200 per small package (40 grams). Compare that to a 60-gram whole fresh sweet potato baked with skin, with only 54 calories.

Dehydrated sweet potato skins have more total fat —11.4 grams per package — compared to a whole, small, 60-gram sweet potato with the skin on, which has 0.1 gram. Most of the calories in dried sweet potato come from its carb content, with a 40-gram bag serving up 23 grams of carbs. And consider the sodium factor — 157 milligrams in a package of dried sweet potato skin snacks as opposed to 21.6 milligrams in a whole sweet potato with skin.

Doesn't it make sense that eating sweet potato skins in their natural form is a healthier option?

Dietary fiber not only slows digestion to help manage your weight, it can help you improve blood cholesterol levels and lower your risk of heart disease, stroke and even Type 2 diabetes, according to the American Heart Association. Dietary Guidelines recommends you include between 22.4 and 33.6 grams of fiber a day, depending on your gender and age.

Most of the dietary fiber in sweet potatoes is in the skin, but the potato as a whole is a good source of both soluble and insoluble fiber. Fiber helps you have a well-functioning digestive tract and keeps you regular by providing bulk to your stool. Eating your baked potato with the skin will provide 3.3 grams of total fiber or 13 percent DV per 100-gram serving; a cooked sweet potato without the skin has 2.5 grams or 10 percent DV per 100 grams.

To put the serving of 100 grams into perspective, one medium-size sweet potato, 5 inches long and 2 inches in diameter, weighs about 114 grams.

Carbohydrates provide fuel for energy and help with fat metabolism. USDA recommends that your intake of carbs should be from 45 to 65 percent of your daily caloric intake, which amounts to about 130 grams per day. Eating a sweet potato with the skin will provide 7 percent of your daily value for healthy complex carbohydrates, with 21 grams per 100-gram serving.

Your body needs protein for energy and many other functions, including building and maintaining your bones, muscles and skin. USDA recommends that 10 to 30 percent of your calories should consist of protein, which amounts to about 56 grams for men and 46 grams for women. Although not a large contributor, most of the protein is in the sweet potato skin. The skin and flesh of a baked sweet potato contain 5.6 grams of protein, while a potato without the skin has only 1.2 grams per 100 grams.

Read more: How Much Protein Is Right For You?

Sweet potatoes are an excellent source of a variety of minerals, most of which are concentrated in the skin of the vegetable. The skin also protects the sweet potato from loss or degradation of nutrients while cooking.

Supplying 25 percent of your daily value for manganese, a sweet potato with skin contributes 12 percent more DV than a skinless potato per 100 grams. Manganese is an important antioxidant that helps in the production of enzymes needed to metabolize proteins and fat. It also aids in the formation of bones, blood clotting and helps ensure fertility.

Potassium is an electrolyte vital for the control of your blood sugar levels, in addition to regulating fluid balance, muscle contraction and nerve signals. Per 100 grams, eating the skin and flesh of a sweet potato offers 475 milligrams or 14 percent DV, compared to eating a potato without the skin that only has 230 milligrams or 7 percent DV of potassium.

Magnesium is another important mineral in sweet potato. A potato with skin supplies 27 milligrams or 7 percent DV, compared to a potato without skin, with 18 milligrams or 5 percent DV. Your body needs magnesium for calcium absorption to help maintain bone health and deter osteoporosis.

Other minerals in sweet potatoes baked in skin are: calcium, 38 milligrams; iron, .7 milligrams; phosphorus, 54 milligrams; zinc, .3 milligrams;and copper, .2 milligrams.

A baked sweet potato with its skin is a superior source of vitamin A, with 1,403 micrograms or 561 percent DV, according to NIH. As an antioxidant, vitamin A is important for your immune system, but also ensures that you have normal vision. Dietary Guidelines recommends an intake of 700 micrograms for adult women and 900 micrograms for men every day, so one whole sweet potato with skin more than meets your entire DV.

Other antioxidants in sweet potatoes include vitamins C, E and K. Sweet potatoes, baked in skin, are especially rich in vitamin C, with 19.6 milligrams or 33 percent DV per 100 grams. Antioxidants scavenge free radicals, which are potentially damaging oxidizing agents in your body. Free radical reactions are associated with degenerative diseases such as cancer, asthma, senile dementia, diabetes and eye disease.

The B group of vitamins is important for providing energy, helping your body detoxify and maintaining brain function. Vitamins in sweet potatoes with skin include thiamine, riboflavin, niacin, pantothenic acid, folate and B6. The vitamin B6 content in sweet potatoes helps reduce your blood levels of homocysteine, an amino acid that has been implicated as a risk factor in cardiovascular diseases.

Read more: List of Antioxidant Vitamins

Sweet potatoes contain phytochemicals, which include antioxidant, antimutagenic, anti-inflammatory, antimicrobial and anti-carcinogenesis properties. One such substance in sweet potatoes, called anthocyanin, has been shown to be one of the components proven to inhibit the growth of specific cancer cells.

BioMed Research International published a study in 2015 that used purple-fleshed sweet potato, both peeled and unpeeled (skin on), on anti-cancer activities. Results of the study showed that sweet potato has elements that inhibit the growth of breast cancer, gastric cancer and colon cancer cells and induces death of the cells. The author surmised the therapeutic potential of sweet potatoes was the result of its high anthocyanin content.

Sweet potatoes have a high content of beta-carotene —690 micrograms in each small potato. Beta-carotene is a carotenoid responsible for the orange-colored flesh in sweet potatoes and is a precursor to vitamin A. Carotenoids have many potential health benefits, one being that they may decrease the risk of men developing prostate cancer.

A study investigated the association between carotenoids and colorectal polyps and cancers among Japanese men. The conclusions of the study, published in the International Journal of Clinical Oncology, supported the evidence that suggested carotenoids provide protective effects against the development of colorectal cancer.

The high content of vitamin A in sweet potatoes has a role in supporting the health of your skin. Vitamin A stimulates the production of white blood cells, helps maintain healthy endothelial cells and regulates skin cell growth, according to the Harvard T.H. Chan School of Public Health.

A study published in the European Journal of Pharmaceutics and Biopharmaceutics in 2013 reported that a diet high in carotenoids, including beta-carotene, may help prevent cell damage that leads to premature skin aging and other skin diseases.

Along with the high content of vitamin A, other antioxidant vitamins in potatoes — vitamins C and E — are beneficial to your skin. By neutralizing free radicals that cause oxidative stress and damage to your epidermis cells, the antioxidant capacity can help repair and protect your skin from the destructive forces resulting from age, exposure to UV rays and pollutants. Many anti-aging skin creams contain vitamin A in the form of retinol to minimize the appearance of fine lines, blemishes, sagging skin and wrinkles.

Read more: Beta Carotene Conversion to Retinol

The high content of vitamins A, C and E in sweet potatoes also plays a role in promoting good vision. A deficiency in vitamin C is often associated with the development of cataracts. Vitamin E may help people with early signs of the eye disease to reduce the risk of age-related macular degeneration.

Vitamin A helps maintain the proper structure of your retina. A deficiency of vitamin A can contribute to poor night vision, and even blindness. In addition, dryness and ulceration of the cornea has been linked to vitamin A deficiency.

An essential role of vitamin A involves the formation of the photosensitive pigments that absorb light and initiate the visual process, as reviewed in a study published in Journal of the South Carolina Academy of Science in 2014.

Insomnia is a common symptom of magnesium deficiency. A deficiency in magnesium may also be linked to a higher risk of depression, stress and anxiety, all of which can disturb your ability to sleep. If you have low magnesium levels, you may experience restless sleep and waking frequently during the night.

Eating sweet potatoes can help increase the magnesium level in your body, which may lead to a deeper, more sound sleep by maintaining healthy levels of GABA, a neurotransmitter that promotes sleep, explains Psychology Today.

Consistent, good-quality sleep is critical to mental and physical well-being and may decrease your risk of developing a number of medical conditions, says Harvard Medical School.

Read more: The Dosage of Magnesium for Anxiety

With less than 4 grams of sugar in a small baked sweet potato, you might wonder why these little root vegetables are so sweet. The answer is due to an enzyme that, when heated, breaks down the starch into maltose, a type of sugar. You can enhance the sweetness even more by baking sweet potatoes in their skin slowly on low heat. That allows the enzymes time to convert the starch to sugar, suggests Food Revolution Network. A temperature of 135 F activates the sweet potato enzyme, but raising the temperature to around 170 F stops the reaction.

Read more: Sweet Potatoes & Yams as Diet Foods