A potato is a hybrid by descent. A 2025 study of 128 genomes looked at the potato lineage, which includes cultivated potatoes and 107 wild relatives. It traces back to an ancient cross between the tomato lineage and the Etuberosum lineage, about 8 to 9 million years ago. Genes from both parents help the plant make tubers.
Cultivated potatoes were later domesticated from wild species native to the Andes of southern Peru.
A potato is not one food, because cooking changes it so much. In a 2025 study of 205,107 Americans, every 3 weekly servings of French fries went with a 20% higher risk of type 2 diabetes. Baked, boiled or mashed potatoes showed no link.
Boiled potatoes ranked first among 38 foods for fullness, scoring 3.2 times as high as white bread. In one trial, the glycemic index of potatoes ranged from 56 to 89, depending on variety and cooking method. The glycemic index measures how quickly a food raises blood sugar.
Cooling cooked potatoes changes them too. After 24 hours in the fridge, boiled potatoes had more resistant starch (from 3.3% to 5.2% of the starch). Resistant starch is starch your small intestine does not digest. With a vinegar dressing, the blood sugar response of 13 healthy adults was 43% lower.
Raw potatoes also hold glycoalkaloids such as solanine, natural toxins that rise when a tuber turns green or sprouts. In the UK, potatoes do not count toward 5 A Day, because the NHS (the UK health service) treats them as a starchy food.
Health benefits of potatoes
The top findings from 30 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★★Lower blood pressure with more potassiumIn people with high blood pressure, the top number fell by 3.5 points (3.5 mm Hg systolic) across 22 trials of potassium. This tested potassium, not potatoes (a medium potato has about 905 mg), and applies to people whose kidneys handle potassium normally.
- ★No weight gain from potatoes in overweight adultsIn 90 overweight adults eating 5 to 7 servings of potatoes a week for 12 weeks, weight changed modestly in every group. No group ate zero potatoes, so it cannot show that potatoes help.
- ★Blood sugar no worse than rice in diabetesIn 24 adults with type 2 diabetes, 100 g of baked potato daily was no worse than 75 g of rice for blood sugar. In a separate dinner trial, potato meals gave lower overnight glucose than rice.
- ★Boiled potatoes ranked first for fullnessIn a test of 38 foods, people rated how full they felt for 2 hours after a 240 kcal serving. Boiled potatoes scored 323%, with white bread set at 100%.
- Population studyFries linked to a higher risk of diabetesIn three US cohorts and a meta-analysis, every 3 weekly servings of fries went with a 20% higher risk of type 2 diabetes. Baked, boiled or mashed potatoes showed almost no difference (relative risk 1.01).
All 30 studies, strongest evidence first
With high blood pressure, more potassium cut systolic pressure 3.5 mm Hg
This meta-analysis, which pools results from many studies, combined 22 randomized trials (1,606 people) and 11 cohort studies. Diastolic pressure fell 2.0 mm Hg, and higher potassium intake went with a 24% lower risk of stroke. It tested potassium itself, not potatoes, and the authors say the benefit applies to people whose kidneys handle potassium normally. A medium potato has about 905 mg.
Regular potatoes did not cause weight gain in overweight adults
In this 12-week randomized trial, 90 overweight adults in three groups were all told to eat 5 to 7 servings of potatoes a week. Two groups also cut 500 kcal a day on a low or high glycemic index diet, and one got no diet advice. Weight and body composition changed modestly in every group, with no differences between groups, and glucose tolerance, insulin and triglycerides did not change. No group ate zero potatoes, so it cannot show that potatoes help.
Baked potato was no worse than rice for blood sugar in diabetes
In this randomized crossover trial, 24 adults with type 2 diabetes ate both foods in turn, 12 weeks each. Every day they had 100 g of baked potato or 75 g of white rice with the same calories. No outcome changed differently between the two, though the potato period had a 4.5 cm smaller waist and 1.7 percentage points less body fat. The Alliance for Potato Research and Education paid for the study, and one author reports speaking fees from it.
Potato dinners matched rice for after-meal blood sugar in type 2 diabetes
This randomized crossover trial gave 24 adults with type 2 diabetes a mixed evening meal built around basmati rice or potato. The potato was boiled, roasted, or boiled and then cooled for 24 hours; all three gave lower overnight glucose than rice on a continuous monitor. Insulin after the meal was higher with the cooled potatoes than with rice, while boiled and roasted did not differ. It tested one dinner each, so long-term effects are unknown.
Fries or instant mash meant 13 to 16% less energy than rice
In this randomized crossover trial, 26 healthy adults ate as much as they wanted of baked French fries, instant mashed potatoes or rice. Each came with meatballs or a vegetarian substitute, and pizza followed 2 hours later. Blood sugar after the pizza was lower after both potato dishes than after rice, while insulin after the first meal was higher. The Alliance for Potato Research and Education contributed funding, and the authors report no conflicts.
Chilled boiled potatoes with vinegar cut blood sugar response 43% versus fresh
In this crossover trial, 13 healthy adults ate 50 g of available carbohydrate as white bread or as boiled potatoes. The potatoes were freshly boiled, stored at 8°C for 24 hours, or stored and dressed with a vinaigrette. Cold storage raised resistant starch from 3.3% to 5.2% of the starch and, on its own, lowered the insulin response by 28%. Healthy people ate one meal each.
Potato glycemic index ranged from 56 to 89 by variety and cooking
Two small crossover trials in healthy adults (10 and 12 people) compared 50 g carbohydrate portions with white bread. The low end was boiled red potatoes eaten cold, and the high end boiled red potatoes. Roasted California white potatoes scored 72, baked Russets 77 and instant mashed potatoes 88. Russets that were cooked ahead, refrigerated and reheated gave a smaller blood sugar rise than Russets eaten right after cooking.
Boiled potatoes ranked first of 38 foods for fullness
Groups of 11 to 13 people each ate a 240 kcal (1,000 kJ) serving of one food and rated their fullness for 2 hours. Boiled potatoes scored 323% against white bread at 100%, and croissants lowest at 47%. Fullness scores rose with the weight, protein, fiber and water of the food and fell with its fat. It tested a single serving of boiled potatoes, not fries.
Purple potatoes cut diastolic pressure 4 mm Hg in people with hypertension
In this crossover trial, 18 adults with hypertension (high blood pressure) took part, 14 of them already on blood pressure drugs. They ate 6 to 8 small microwaved purple potatoes twice a day for 4 weeks, and none for another 4 weeks. Systolic pressure fell 5 mm Hg, while fasting glucose, cholesterol and HbA1c did not change and weight did not rise. It was a small trial of a pigmented variety, not ordinary white potatoes.
Purple potato daily reduced arterial stiffness; white potato did not
In this crossover trial, 14 healthy adults ate 200 g a day of cooked purple potato or white potato for 14 days. The purple potato was rich in anthocyanins, purple-red pigments (288 mg a day), and a 7-day washout separated the periods. Pulse wave velocity, a measure of artery stiffness, fell after the purple potato, while blood pressure, cholesterol, glucose, insulin and CRP did not change. Only 14 people took part, for 2 weeks.
The top glycoalkaloid dose made one volunteer vomit; lower doses did not
This single-dose study had only 2 to 3 volunteers per treatment. They drank glycoalkaloids (solanine and chaconine) at 0.30 to 0.70 mg/kg of body weight, or ate mashed potato with 0.95 to 1.25 mg/kg. The mashed potato held nearly 200 mg per kg, a level once treated as the upper limit of safety. The one person who vomited did so about 4 hours after the top dose; clearance took over 24 hours, so daily intake could build up.
Daily potato chips raised blood markers of inflammation and oxidative stress
This pilot study had 14 healthy volunteers, 6 of them smokers of more than 20 cigarettes a day. They ate 160 g of chips with 157 µg (micrograms) of acrylamide daily for 4 weeks. Acrylamide in blood, oxidized LDL, interleukin-6, CRP and a liver enzyme all rose, and the markers fell somewhat 28 days after stopping. It was small and tested chips, so it says little about boiled or baked potatoes.
Resistant potato starch raised the gut bacteria Bifidobacterium and Akkermansia versus placebo
This randomized placebo-controlled trial tested a potato starch supplement at 3.5 and 7 g a day. The bacteria rose on 3.5 g a day for 4 weeks. On 3.5 g, bowel movements linked to diarrhea or to constipation were both fewer. This was a purified supplement, not cooled potatoes, and the study was run for the starch maker, which employs one of the authors.
Fries, not baked or boiled potatoes, went with 20% higher diabetes risk
This study combined three US cohorts (205,107 people, 22,299 diabetes cases, 5.2 million person-years) with a meta-analysis of 13 cohorts. The fries result is per 3 weekly servings, for type 2 diabetes; baked, boiled or mashed potatoes had a hazard ratio (relative risk) of 1.01. Swapping 3 weekly servings of potatoes for whole grains went with an 8% lower risk, and 19% lower for French fries. Swapping them for white rice went with a higher risk, and food questionnaires show links, not cause.
Total potatoes: no clear links; fried ones went with 16% higher diabetes risk
This meta-analysis covered 51 articles with 103 studies. For total potatoes, high against low intake gave 1.07 times the risk of hypertension, 1.08 for diabetes and 0.97 for cardiovascular disease. Nonfried potatoes also showed a small 5% higher diabetes risk. The authors call for more cohort studies by potato type.
Each daily fries serving went with 66% higher type 2 diabetes risk
This meta-analysis of 28 reports found each extra daily serving of French fries (150 g) also went with a 37% higher risk of hypertension. Total potatoes showed no link with death, heart disease, stroke or colorectal cancer. A daily serving of boiled, baked or mashed potatoes went with a 9% higher diabetes risk and no clear link with hypertension. Evidence quality was mostly low, and moderate for French fries.
Frequent fries went with 17% higher hypertension risk; chips did not
Three US cohorts followed 187,453 people who did not have hypertension at the start. Frequent here means French fries 4 or more times a week, and potato chips gave 0.97 times the risk. Baked, boiled or mashed potatoes showed a borderline 11% higher risk. Replacing one daily serving of baked, boiled or mashed potatoes with non-starchy vegetables went with a 7% lower risk.
Swedes eating more potatoes had no higher heart disease or stroke risk
Two cohorts followed 69,313 people for 13 years, with 10,147 major heart events and 4,003 deaths from cardiovascular disease. Every 3 weekly servings of potatoes gave 1.00 times the risk of major events, meaning no change. Boiled potatoes, fried potatoes and French fries each showed no trend. Sweden is a high-potato country.
Spaniards eating the most potatoes had no higher blood pressure or hypertension
Of the two Spanish cohorts, PREDIMED followed older adults who ate 81.9 g of potatoes a day for 4 years. SUN followed university graduates who ate 52.7 g a day over 6.7 years. In SUN, the top fifth against the bottom fifth had a hazard ratio of 0.98. Intakes were modest, and cooking methods were not compared.
Chinese potato eaters had up to 40% higher hypertension risk than non-eaters
This cohort followed 11,763 adults for 11.3 years, with 4,033 new cases. The three intake groups had hazard ratios of 1.40, 1.20 and 1.12 compared with people who ate none. Among people who ate potatoes, more did not mean more risk: higher intake went with a lower risk. So the picture is mixed, and the groups may differ in other ways.
Potatoes were not linked to earlier death from any cause or cancer
This meta-analysis of 20 prospective cohort studies counted 25,208 deaths from all causes, 4,877 from cancer and 2,366 from cardiovascular disease. The hazard ratio was 0.90 for death from any cause and 1.09 for cancer death. Only three studies covered cardiovascular death, and two of them found no link. The authors say more studies are needed.
Potato intake was not linked to cancer overall or at most sites
This meta-analysis covered 20 cohort studies (785,348 people, 19,882 cases) and 36 case-control studies. High against low intake gave 1.04 times the risk for all cancers combined. Colorectal, pancreatic, breast, prostate, lung and other cancers showed no link, nor did boiled, fried, mashed, roasted or baked potatoes. The certainty of the evidence was low or very low.
In a subgroup, fried potatoes went with about double the death risk
This cohort followed 4,440 people aged 45 to 79 from an osteoarthritis study over 8 years, with 236 deaths. The higher risk was for eating fried potatoes 2 or more times a week. Overall potato intake showed no link (hazard ratio 1.11), and neither did unfried potatoes. The fried-potato result came from a subgroup analysis with few deaths, and the authors say larger studies must confirm it.
One more daily potato serving: 1.28 lb extra gain over 4 years
Three US cohorts followed 120,877 women and men in 4-year periods between 1986 and 2006. Potato chips went with 1.69 lb more, while vegetables, whole grains, fruit, nuts and yogurt went with less weight gain. The abstract does not split potatoes by cooking method, and a link does not prove that potatoes caused the gain.
Swapping some potatoes went with 9 to 12% lower gestational diabetes risk
This cohort followed 15,632 women in the Nurses’ Health Study II for 10 years, with 854 first-time cases of gestational diabetes (diabetes during pregnancy). Across 21,693 pregnancies, women who ate more potatoes before pregnancy had higher rates. Swapping 2 weekly servings for other vegetables, legumes or whole grains went with lower risk. Diabetes and diet were self-reported, more than 90% of the women were white, and the authors say cause cannot be assumed.
Higher acrylamide intake was not linked to most common cancers
This meta-analysis of 32 publications covered 14 cancer sites, comparing high with low acrylamide intake. Acrylamide forms when potatoes and other starchy foods are fried or baked, so it comes from many foods, not potatoes alone. Summary risks ranged from 0.87 to 1.14 for most sites. There was a borderline link for kidney cancer (1.20) and for endometrial and ovarian cancers in never-smokers.
Chilled cooked potatoes had more resistant starch than hot or reheated ones
This lab analysis tested three varieties (Yukon Gold, Dark Red Norland and Russet Burbank), baked or boiled. They were served hot (65°C), chilled (4°C) or reheated after 6 days at 4°C. Baked potatoes had more resistant starch than boiled, and levels varied with cooking method and temperature but not with variety. This measured the potato, not health outcomes in people.
Boiling cut potassium by 50% in cubes and 75% in shredded potato
This lab study measured potassium and other minerals in potatoes. Leaching (soaking in water) alone did not lower potassium, and boiling also lowered phosphorus, magnesium, zinc, manganese and iron. People who must limit potassium should boil small pieces, the authors advise; everyone else can boil potatoes whole or bake, roast or microwave them.
Light turned potatoes green, raising glycoalkaloids up to 290 mg per kg
This lab study kept six varieties under six kinds of light (dark, UVA, blue, green, red and white), measuring peel color, pigments and glycoalkaloids. The highest levels were in yellow-skinned varieties. Red- and purple-skinned varieties greened later, which the authors link to their anthocyanin pigments shading the tuber. For comparison, 200 mg per kg is an old safety limit in some countries, according to EFSA (the European Food Safety Authority).
Glycoalkaloids weakened the gut barrier and worsened colon damage in bowel-disease-prone mice
This study used cultured cells and mice, not people, at glycoalkaloid levels the authors say match a normal diet. Solanine and chaconine made layers of gut cells leakier as the dose rose. Intestine from mice with a genetic risk of inflammatory bowel disease was more affected than normal mouse intestine. Frying concentrates glycoalkaloids, according to the authors.
Who should be careful with potatoes
Most people can eat potatoes freely. Take a little care if one of these applies:
- Green or sprouted potatoes. Light turns potatoes green and raises their glycoalkaloids, including solanine. EFSA found 2,000 to 7,300 mg per kg in sprouts against 10 to 150 mg per kg in whole tubers. In a volunteer study, one person vomited at 1.25 mg per kg of body weight. Ordinary potatoes are a small concern, but skip ones that are green or sprouting.
- Kidney disease or a potassium limit. A medium potato has 905 mg of potassium, 19% of the Daily Value (the amount on US food labels). In a lab test, boiling small pieces cut potassium by 50 to 75%, so ask your renal (kidney) dietitian before relying on it.
- French fries and chips. In cohorts, fries go with a higher risk of diabetes and high blood pressure. Frying also forms acrylamide, which causes cancer in animal tests but was not clearly linked to most cancers in people. Treat them as an occasional food and cook to golden yellow, not brown.
How to choose, store and eat potatoes
- Boiled or baked: boiled potatoes ranked first of 38 foods for fullness. Baked, boiled or mashed potatoes showed no link with type 2 diabetes in three large US cohorts (hazard ratio 1.01).
- Cooked, then chilled: 24 hours at 8°C raised resistant starch from 3.3% to 5.2% of the starch. Chilled potatoes also had more than hot or reheated ones in a lab test. A vinaigrette on top cut the blood sugar response by 43%.
- Fried: every 3 weekly servings of French fries went with a 20% higher diabetes risk, so keep fries and chips occasional.
Pick firm potatoes with smooth skin and no green patches, sprouts or soft spots. Store them unwashed in a cool, dark, well-ventilated place for up to five weeks. The UK Food Standards Agency once advised against keeping raw potatoes in the fridge. It now says fridge storage does not materially raise acrylamide, so either works.
Residues are no reason to skip potatoes: in USDA (US Department of Agriculture) tests of 709 samples in 2023, none was above the legal limit.
Sources
- Schrenk D, Bignami M, Bodin L, et al. Risk assessment of glycoalkaloids in feed and food, in particular in potatoes and potato-derived products. EFSA J. 2020.
- Mensinga TT, et al. Potato glycoalkaloids and adverse effects in humans: an ascending dose study. Regul Toxicol Pharmacol. 2005.
- Sa G, Zao X, Yuan J, Cheng L, Yu B. Light-quality-dependent greening and steroidal glycoalkaloid accumulation in potato tubers: regulatory mechanisms and postharvest strategies to reduce food safety risks. Foods. 2025.
- Bethke PC, Jansky SH. The effects of boiling and leaching on the content of potassium and other minerals in potatoes. J Food Sci. 2008.
- Mousavi SM, Gu X, Imamura F, et al. Total and specific potato intake and risk of type 2 diabetes: results from three US cohort studies and a substitution meta-analysis of prospective cohorts. BMJ. 2025.
- Pelucchi C, Bosetti C, Galeone C, La Vecchia C. Dietary acrylamide and cancer risk: an updated meta-analysis. Int J Cancer. 2015.
- Holt SH, Miller JC, Petocz P, Farmakalidis E. A satiety index of common foods. Eur J Clin Nutr. 1995.
- Leeman M, Östman E, Björck I. Vinegar dressing and cold storage of potatoes lowers postprandial glycaemic and insulinaemic responses in healthy subjects. Eur J Clin Nutr. 2005.
- Raatz SK, Idso L, Johnson LK, Jackson MI, Combs GF Jr. Resistant starch analysis of commonly consumed potatoes: content varies by cooking method and service temperature but not by variety. Food Chem. 2016.
- Acrylamide. Food Standards Agency (UK). 2018.
- Potatoes. University of Nebraska–Lincoln Extension.
- Pesticide Data Program annual summary, calendar year 2023. USDA Agricultural Marketing Service.
History of potatoes
Potatoes began in the Andes. According to Wikipedia, they were first domesticated in southern Peru and northwestern Bolivia, around Lake Titicaca, about 7,000 to 10,000 years ago. A genome study of cultivated and wild potatoes places their origin in wild species native to the Andes of southern Peru. The Quechua and Aymara peoples later made chuño, a freeze-dried potato that keeps.
Spanish travelers brought potatoes to Europe in the second half of the 16th century, after the Spanish conquest of the Inca Empire. Many Europeans were slow to trust them.
In France, the pharmacist Antoine-Augustin Parmentier was captured by the Prussians during the Seven Years’ War and had to eat potatoes. The French knew them only as hog feed. In 1772 he proposed them as food for dysentery patients in a contest held by the Academy of Besançon. He won the prize in 1773.
Ireland shows how much a nation can lean on one crop. More than three million Irish people depended completely on potatoes for food when late blight struck in 1845. The Great Famine lasted until 1852. Roughly one million people died, and more than a million emigrated.
DNA from herbarium specimens showed that the blight came from a single strain, HERB-1. It stayed in circulation for over 50 years and is different from the strains found today.
Today the potato is one of the world’s big crops. World production reached 390 million tonnes in 2024. China grew the most, at 94.8 million tonnes, followed by India, Ukraine, the United States and Russia.
Sources
- Hardigan MA, Laimbeer FPE, Newton L, et al. Genome diversity of tuber-bearing Solanum uncovers complex evolutionary history and targets of domestication in the cultivated potato. Proc Natl Acad Sci U S A. 2017.
- Zhang Z, et al. Ancient hybridization underlies tuberization and radiation of the potato lineage. Cell. 2025.
- Yoshida K, Schuenemann VJ, Cano LM, et al. The rise and fall of the Phytophthora infestans lineage that triggered the Irish potato famine. Elife. 2013.
- Potato. Wikipedia.
- Great Famine (Ireland). Wikipedia.
- Antoine-Augustin Parmentier. Wikipedia.
- 5 A Day: what counts?. NHS.
Frequently asked questions about potatoes
Are potatoes good for you?
For most people, yes. A medium potato (213 g) has 164 calories, 4.5 g of fiber and 905 mg of potassium. It also has 42 mg of vitamin C (47% of the Daily Value) and 37% of the Daily Value of vitamin B6.
In cohort studies, baked, boiled or mashed potatoes showed no link with type 2 diabetes (hazard ratio 1.01). French fries went with a 20% higher risk per 3 weekly servings. Those are links, not proof, and no potato finding here reaches strong evidence.
Are potatoes fattening?
Potatoes themselves are not high in calories, with 77 calories per 100 g raw, but frying and toppings add a lot. In a 12-week trial, 90 overweight adults were told to eat 5 to 7 servings a week, and potatoes did not cause weight gain. Boiled potatoes also ranked first of 38 foods for fullness.
In three US cohorts, though, each extra daily serving of potatoes went with 1.28 lb more weight gain over 4 years. Potato chips went with 1.69 lb.
Are potatoes bad for blood sugar or diabetes?
Potatoes raise blood sugar, but how much depends on how they are cooked. The glycemic index ranged from 56 for boiled red potatoes eaten cold to 89 for boiled red potatoes. This site lists an estimate of 73.
In two small trials in type 2 diabetes, baked potatoes for 12 weeks did not worsen blood sugar control compared with rice. Boiled, roasted or cooled potato dinners gave the same after-meal blood sugar as rice. Both trials had 24 people, and the first was paid for by the potato industry, so check portions with your care team.
Can you eat green or sprouted potatoes?
It is best not to. Light turns potatoes green and raises glycoalkaloids such as solanine. EFSA found 2,000 to 7,300 mg per kg in sprouts against 10 to 150 mg per kg in whole tubers.
In the studies EFSA cites, peeling lowered glycoalkaloids by roughly 25 to 75% and boiling by 5 to 65%. So cooking does not make a green potato safe. Choose firm potatoes without green patches or sprouts, and keep them in the dark.
Are cold potatoes healthier?
Cooling does raise resistant starch, but no trial here shows a lasting health benefit. Boiled potatoes kept at 8°C for 24 hours rose from 3.3% to 5.2% resistant starch. With a vinegar dressing, the blood sugar response of 13 healthy adults fell 43%. In 24 adults with type 2 diabetes, a cooled-potato dinner gave the same after-meal blood sugar as rice but a higher insulin response.
How much potassium is in a potato?
A medium potato (213 g) has 905 mg of potassium, 19% of the Daily Value, or 425 mg per 100 g. That is more than the 9% in a medium banana on this site.
In a meta-analysis of 22 trials, more potassium lowered systolic blood pressure by 3.5 mm Hg, an effect seen in people with high blood pressure. If your kidneys limit potassium, boiling small pieces cut it by 50 to 75% in a lab test, but ask your renal dietitian first.
Are sweet potatoes healthier than white potatoes?
Neither is simply better, and no study here compares them head to head. Per 100 g, this site lists 77 calories and 2.1 g of fiber for potatoes, against 76 calories and 2.5 g for sweet potatoes. Sweet potatoes have 787 µg of vitamin A, while white potatoes have none. White potatoes have more potassium (425 mg against 230 mg), and the listed glycemic index is 73 against 46.
Are French fries bad for you?
French fries have the clearest warning signs in the studies here, though the risks look moderate. Every 3 weekly servings went with a 20% higher risk of type 2 diabetes. Eating them 4 or more times a week went with a 17% higher risk of high blood pressure.
Swapping 3 weekly servings of fries for whole grains went with a 19% lower diabetes risk in the 2025 BMJ cohort. These are links from food questionnaires, not proof.