Potatoes are underground tubers that grow on the roots of the potato plant, Solanum tuberosum. This plant is from the nightshade family and related to tomatoes and tobacco.
Native to South America, potatoes were brought to Europe in the 16th century and are now grown in countless varieties worldwide. They’re generally eaten boiled, baked, or fried and frequently served as a side dish or snack. The potato belongs to the Solanaceae or nightshade family whose other members include tomatoes, eggplants, peppers, and tomatillos. They are the swollen portion of the underground stem which is called a tuber and is designed to provide food for the green leafy portion of the plant. If allowed to flower and fruit, the potato plant will bear an inedible fruit resembling a tomato.
Potatoes are just plants, after all—starchy nightshades grown underground to be exact. That’s the same family as tomatoes, peppers, and eggplant. And potatoes share vitamin and mineral content with their conventionally healthy cousins.
The white or gold varieties of potato—sweet potatoes are different and often considered healthier anyway—have vitamin C, potassium, vitamin B6, and certain polyphenols. Since they’re mostly carbohydrates, potatoes also contain a small amount fiber. What is there mostly takes the form of resistant starch and insoluble fiber.
A majority of potatoes’ helpful nutrients aren’t hiding deep inside. They’re right on the surface, in the skin. So, when you cook potatoes, wash them thoroughly to remove dirt, but don’t peel them. You’re throwing a significant percentage of the nutrition in the garbage or compost.
There are plenty of nutrients to make potatoes worthwhile parts of your plate. And they are a staple food around the world. But overeating these starchy vegetables can be detrimental to weight management. That’s partly because plain potatoes are high glycemic and fairly calorie dense.
What Nutrients are Hiding in Potatoes?
- Insoluble fiber
- Resistant starch
- Vitamin C
- Vitamin B6
- Vitamin B9 (folate)
- from various polyphenols (including catechin and lutein)
What Are the Benefits of Potatoes ?
Potatoes are a very popular food source. Unfortunately, most people eat potatoes in the form of greasy French fries or potato chips, and even baked potatoes are typically loaded down with fats such as butter, sour cream, melted cheese and bacon bits. Such treatment can make even baked potatoes a potential contributor to a heart attack. But take away the extra fat and deep frying, and a baked potato is an exceptionally healthful low calorie, high fiber food that offers significant protection against cardiovascular disease and cancer.
Our food ranking system qualified potatoes as a very good source of vitamin B6 and a good source of potassium, copper, vitamin C, manganese, phosphorus, niacin, dietary fiber, and pantothenic acid.
Potatoes also contain a variety of phytonutrients that have antioxidant activity. Among these important health-promoting compounds are carotenoids, flavonoids, and caffeic acid, as well as unique tuber storage proteins, such as patatin, which exhibit activity against free radicals.
Blood-Pressure Lowering Potential of Potatoes
UK scientists at the Institute for Food Research have identified blood pressure-lowering compounds called kukoamines in potatoes. Previously only found in Lycium chinense, an exotic herbal plant whose bark is used to make an infusion in Chinese herbal medicine, kukoamines were found in potatoes using a new type of research called metabolomics.
Until now, when analyzing a plant’s composition, scientists had to know what they were seeking and could typically look for 30 or so known compounds. Now, metabolomic techniques enable researchers to find the unexpected by analyzing the 100s or even 1000s of small molecules produced by an organism.
“Potatoes have been cultivated for thousands of years, and we thought traditional crops were pretty well understood,” said IFR food scientist Dr Fred Mellon, “but this surprise finding shows that even the most familiar of foods might conceal a hoard of health-promoting chemicals.” Another good reason to center your diet around the World’s Healthiest Foods!
In addition to potatoes, researchers looked at tomatoes since they belong to the same plant family—Solanaceae—as Lycium chinense. Metabolomic assays also detected kukoamine compounds in tomatoes.
The IFR scientists found higher levels of kukoamines and related compounds than some of the other compounds in potatoes that have a long history of scientific investigation. However, because they were previously only noted in Lycium chinense, kukoamines have been little studied. Researchers are now determining their stability during cooking and dose response (how much of these compounds are needed to impact health).
Vitamin B6—Building Your Cells
If only for its high concentration of vitamin B6—1 medium potato contains over one-half of a milligram of this important nutrient—the potato earns high marks as a health-promoting food.
Vitamin B6 is involved in more than 100 enzymatic reactions. Enzymes are proteins that help chemical reactions take place, so vitamin B6 is active virtually everywhere in the body. Many of the building blocks of protein, amino acids, require B6 for their synthesis, as do the nucleic acids used in the creation of our DNA. Because amino and nucleic acids are such critical parts of new cell formation, vitamin B6 is essential for the formation of virtually all new cells in the body. Heme (the protein center of our red blood cells) and phospholipids (cell membrane components that enable messaging between cells) also depend on vitamin B6 for their creation.
Potatoes are Rich in Vitamin B6—Brain Cell and Nervous System Activity
Vitamin B6 plays numerous roles in our nervous system, many of which involve neurological (brain cell) activity. B6 is necessary for the creation of amines, a type of messaging molecule or neurotransmitter that the nervous system relies on to transmit messages from one nerve to the next. Some of the amine-derived neurotransmitters that require vitamin B6 for their production are serotonin, a lack of which is linked to depression; melatonin, the hormone needed for a good night’s sleep; epinephrine and norepinephrine, hormones that help us respond to stress; and GABA, which is needed for normal brain function.
Potatoes are Rich in Vitamin B6—Cardiovascular Protection
Vitamin B6 plays another critically important role in methylation, a chemical process in which methyl groups are transferred from one molecule to another. Many essential chemical events in the body are made possible by methylation, for example, genes can be switched on and turned off in this way. This is particularly important in cancer prevention since one of the genes that can be switched on and off is the tumor suppressor gene, p53. Another way that methylation helps prevent cancer is by attaching methyl groups to toxic substances to make them less toxic and encourage their elimination from the body.
Methylation is also important to cardiovascular health. Methylation changes a potentially dangerous molecule called homocysteine into other, benign substances. Since homocysteine can directly damage blood vessel walls greatly increasing the progression of atherosclerosis, high homocysteine levels are associated with a significantly increased risk for heart attack and stroke. Eating foods rich in vitamin B6 can help keep homocysteine levels low. In addition, diets high in vitamin B6-rich foods are associated with overall lower rates of heart disease, even when homocysteine levels are normal, most likely because of all the other beneficial activities of this energetic B vitamin.
A single baked potato will also provide you with over 3 grams of fiber, but remember the fiber in potatoes is mostly in their skin. If you want the cholesterol-lowering, colon cancer preventing, and bowel supportive effects of fiber, be sure to eat the potato’s flavorful skin as well as its creamy center.
Potatoes are Rich in Vitamin B6—Athletic Performance
Vitamin B6 is also necessary for the breakdown of glycogen, the form in which sugar is stored in our muscle cells and liver, so this vitamin is a key player in athletic performance and endurance.
What Are the Health Benefits of Potatoes ?
Potatoes are stuffed with phytonutrients, which are organic components of plants that are thought to promote health, according to the USDA. Phytonutrients in potatoes include carotenoids, flavonoids and caffeic acid.
The vitamin C in potatoes acts as an antioxidant. These substances may prevent or delay some types of cell damage, according to the National Institutes of Health. They may also help with digestion, heart health, blood pressure and even cancer prevention.
Purple potatoes are especially good sources of phytonutrients and antioxidants. A 2012 study published in the Journal of Agriculture and Food Chemistry found that six to eight small purple potatoes twice a day helped lower blood pressure and risk of heart disease and stroke among people who were overweight and suffering from hypertension. Despite the carbohydrates in purple potatoes, the participants did not gain weight.
Potatoes may help lower blood pressure for several reasons. Jarzabkowski said that the fiber found in potatoes could help lower cholesterol by binding with cholesterol in the blood. “After it binds, we excrete it.”
Potatoes are also a good source of potassium. “All potatoes are potassium rich,” Jarzabkowski said. “They have even more potassium than a banana, and a lot of it is found in the [potato’s] skin.” She noted that the outer potato peel also contains a good deal of fiber. Potassium is a mineral that helps lower blood pressure, according to the U.S. Food and Drug Administration.
Potassium, too, can help lower blood pressure through its actions as a vasodilator (blood vessel widener). Scientists at the Institute for Food Research have discovered that potatoes contain chemicals called kukoamines, which are associated with lowering blood pressure.
Brain functioning and nervous system health
The B6 vitamins in potatoes are critical to maintaining neurological health. Vitamin B6 helps create useful brain chemicals, including serotonin, dopamine and norepinephrine, according to the University of Maryland Medical Center. This means that eating potatoes may help with depression, stress and even perhaps attention deficit hyperactivity disorder (ADHD).
Potatoes’ high level of carbohydrates may have some advantages, including helping maintain good levels of glucose in the blood, which is necessary to proper brain functioning. A 1995 study published in the American Journal of Clinical Nutrition found that modest increases in glucose could help enhance learning and memory. Potassium, which encourages the widening of blood vessels, also helps ensure your brain gets enough blood.
Vitamin C can help prevent everything from scurvy to the common cold, and potatoes are full of this nutrient, with about 45 percent of the recommended daily intake per medium baked potato, according to the Washington State Potato Commission.
Some people think potatoes and other members of the nightshade family — such as eggplants, tomatoes and peppers — trigger arthritis flares. However, there is limited scientific evidence to support this hypothesis, according to the Arthritis Foundation. The organization suggests that people with arthritis try cutting nightshade vegetables from their diets for two weeks to see if symptoms improve.
Some studies suggest these vegetables may actually help reduce arthritis symptoms, the foundation said. For example, a 2011 study published in the Journal of Nutrition found that potatoes might reduce inflammation.
The largest health benefit offered by potatoes is how they can help with digestion due to their high fiber content, Jarzabkowski said. Potatoes’ high level of carbohydrates makes them easy to digest, while their fiber-filled skin can help keep you regular.
Potatoes give your heart plenty of reasons to swoon, due to the fiber content. Jarzabkowski said fiber is associated with clearing cholesterol from blood vessels; vitamins C and B6 help reduce free radicals; and carotenoids help maintain proper heart functioning.
Additionally, B6 plays a crucial role in the methylation process, which, among other things, changes the potentially dangerous molecule homocysteine into methionine, a component in new proteins, according to Harvard. Too much homocysteine can damage blood vessel walls, and high levels of it are associated with increased risk of heart attack and stroke.
Jarzabkowski described how potatoes could be a win for athletes. “Potatoes can help restore electrolyte balance,” she said. “Sodium and potassium, which are found in potato peels, are two important electrolytes, and athletes lose them in sweat.” Electrolytes are necessary for optimum body function, and having too few can cause cramps, as many athletes know.
According to Organic Facts, vitamin C, vitamin B6, potassium, magnesium, zinc and phosphorous can all help keep skin as smooth and creamy as, well, mashed potatoes. These nutrients are all present in potatoes.
A 2017 study published by the Journal of Nutritional Biochemistry found that consuming purple potatoes might reduce the risk of colon cancer. Purple potatoes are high in antioxidants and anti-inflammatory properties that can reduce levels of interleukin-6 or IL-6, a protein linked to cancer cell growth within the colon. The study looked at groups of pigs on three different diets, one of which was supplemented with purple potatoes. At the end of the study, pigs that ate purple potatoes had levels of IL-6 six times lower than the other groups. While the study has not yet been replicated on humans, researchers anticipate that the results will transfer because a pig’s digestive system is similar to a human’s.
What is the Safety and Side Effects of Potatoes ?
Eating potatoes is generally healthy and safe.
However, in some cases, people need to limit their consumption — or avoid them altogether.
Food allergies are a common condition, characterized by a harmful immune reaction to proteins in certain foods. Potato allergy is relatively rare, but some people may be allergic to patatin, one of the main proteins in potatoes.
Those who are allergic to latex may be sensitive to patatin as well due to a phenomenon known as allergic cross-reactivity (34Trusted Source).
Plants of the nightshade family, such as potatoes, contain a class of toxic phytonutrients known as glycoalkaloids.
The two main glycoalkaloids in potatoes are solanine and chaconine.
Glycoalkaloid poisoning after eating potatoes has been reported in both people and animals.
However, reports of toxicity are rare and the condition may go undiagnosed in many cases.
In low doses, glycoalkaloids usually cause mild symptoms, such as headache, stomach pain, diarrhea, nausea, and vomiting.
In more serious cases, the symptoms include neurological disorders, rapid breathing, fast heartbeat, low blood pressure, fever, and even death.
In mice, long-term intake of glycoalkaloids may increase the risk of cancer in the brain, lungs, breasts, and thyroid.
Other animal studies indicate that the low levels of glycoalkaloids likely found in the human diet may exacerbate inflammatory bowel disease (IBD) .
Normally, potatoes contain only trace amounts of glycoalkaloids. A 154-pound (70-kg) individual would have to eat over 13 cups (2 kg) of potatoes (with the skin) in one day to get a lethal dose.
That said, lower amounts may still cause adverse symptoms.
The levels of glycoalkaloids are higher in the peel and sprouts than other parts of the potato. It’s best to avoid eating potato sprouts.
Potatoes rich in glycoalkaloids have a bitter taste and cause a burning sensation in your mouth, an effect that may be a warning sign of potential toxicity. Potato varieties containing high amounts of glycoalkaloids — over 25 mg per cup (200 mg per kg) — cannot be marketed commercially, and some varieties have been banned.