Are Potatoes Bad for Blood Pressure?

Potatoes are not inherently bad for blood pressure, and the research on this question is far more mixed than most dietary advice suggests. Several large studies have found no meaningful link between eating potatoes and developing hypertension, while others show a modest association that largely disappears when you separate how potatoes are prepared from the potato itself. The honest picture involves cooking method, what else is on your plate, and the surprisingly strong blood-pressure-lowering nutrients that potatoes deliver when they are not deep-fried and buried in salt.

What the Biggest Studies Actually Found

The most cited research linking potatoes to higher blood pressure comes from three large US cohort studies that followed nurses and other health professionals over more than 20 years. That analysis found that eating four or more servings of baked, boiled, or mashed potatoes per week carried a pooled hazard ratio of 1.11 compared with eating less than one serving a month. That sounds worrying, but the confidence interval crossed 1.0, meaning the increase was not statistically significant. French fries, on the other hand, did show a significant link, with a hazard ratio of 1.17. Interestingly, potato chips showed no association at all.¹

A study in China found something even more puzzling. At first glance, people who ate more potatoes had higher rates of hypertension. But when the researchers removed non-consumers from the comparison, the direction flipped: among people who ate potatoes at all, those who ate more actually had a lower risk.² That reversal suggests the people who eat zero potatoes differ from potato eaters in ways that are hard to fully adjust for, like overall diet quality or socioeconomic factors.

Two Spanish cohorts muddied the waters further. The PREDIMED trial and the SUN cohort together included tens of thousands of adults, and neither found any significant association between potato intake and blood pressure changes or hypertension incidence. The highest-intake group in PREDIMED actually had a slight (non-significant) drop in systolic blood pressure compared with the lowest-intake group.³ The most plausible explanation for the discrepancy with the US data: Spaniards tend to prepare potatoes differently. Boiling and stewing dominate the Mediterranean kitchen, while Americans consume a heavier share of fries and processed potato products.

How Cooking Method Changes the Picture

If one theme emerges from the research, it is that the cooking method matters far more than the potato itself. The INTERMAP study, which examined dietary patterns and blood pressure across populations in multiple countries, found no association between total potato intake and blood pressure, and no association for boiled, mashed, or baked potatoes specifically. The only preparation that tracked with higher readings was fried potato, and only in US women, where higher fried potato intake was linked to a systolic blood pressure about 2.3 mmHg higher and diastolic pressure about 1.1 mmHg higher, even after adjusting for body weight.⁴

A 2.3 mmHg difference may sound trivial, but at the population level, even small shifts in average blood pressure translate into meaningful changes in stroke and heart attack rates. And the frying signal almost certainly reflects more than cooking oil alone. French fries typically arrive with generous salt, come alongside burgers or other calorie-dense foods, and are eaten in contexts (fast food, pub meals) where overall meal quality tends to be low. Disentangling the frying itself from everything that accompanies fries is one of the persistent challenges in this research.

The US cohort data reinforces this distinction. In the BMJ analysis, when researchers modeled what would happen if you swapped one daily serving of baked, boiled, or mashed potatoes with a serving of non-starchy vegetables, hypertension risk dropped by about 7 percent.¹ That is worth knowing, but it says more about the benefits of non-starchy vegetables than about any harm from potatoes. Any starchy food replaced with greens or broccoli would probably show the same pattern.

Clinical Trials Tell a Different Story

Observational studies track what people eat over time and look for patterns, but they cannot prove that potatoes cause anything. Randomized controlled trials, which assign specific foods to participants, give a cleaner picture. And the trial data on potatoes and blood pressure actually leans positive.

A controlled feeding study gave pre-hypertensive and hypertensive adults four different dietary treatments for 17 days each: a control diet, the same diet supplemented with baked or boiled potatoes, one supplemented with French fries, and one supplemented with a potassium gluconate pill. All three supplemented treatments added the same amount of extra potassium. The baked and boiled potato treatment produced a systolic blood pressure drop of about 6 mmHg over the treatment period, compared with roughly 2.6 mmHg on the control diet. The French fries treatment did not worsen blood pressure or impair blood vessel function either, though it did not produce quite the same benefit as the non-fried versions.⁵

That same trial revealed something else worth noting: eating baked or boiled potatoes reduced sodium retention more effectively than even the potassium supplement did. Potassium and sodium play tug-of-war in your kidneys. When you take in more potassium, your body sheds more sodium in urine, and less sodium means less fluid retention and lower pressure on your blood vessel walls. A medium baked potato with skin delivers roughly 900 milligrams of potassium, which puts it among the richest common food sources of the mineral. Most adults in the US fall well short of recommended potassium intake, so potatoes can help close a gap that directly affects blood pressure regulation.

Potatoes Inside a Healthy Eating Pattern

One of the most practical questions is whether potatoes fit into an eating pattern specifically designed to lower blood pressure. The DASH diet (Dietary Approaches to Stop Hypertension) emphasizes fruits, vegetables, whole grains, and low-fat dairy while limiting sodium and saturated fat. Potatoes are not traditionally highlighted in DASH guidance, partly because of their starch content and the lingering reputation from the observational data above.

A randomized trial tested what happens when you deliberately include potatoes in a DASH-style diet for people with and without type 2 diabetes. The results showed a trend toward improved blood pressure and body composition measurements in both groups. The researchers concluded that both fried and non-fried potatoes could fit within a DASH pattern for people without diabetes, and non-fried potatoes fit well for those with type 2 diabetes.⁶

Another trial compared the cardiometabolic effects of white potatoes versus white rice in people with type 2 diabetes and features of metabolic syndrome. The potato group showed no negative effects on blood pressure, blood sugar control, or blood lipids compared with the rice group, and modestly improved some measures of body composition and vascular health.⁷ That comparison matters because rice and potatoes often occupy the same spot on a plate, and many people assume potatoes are the worse choice. In a controlled setting, there was no evidence for that assumption.

Chlorogenic Acid and Colored Potatoes

Beyond potassium, potatoes contain chlorogenic acid, a polyphenol found especially in the skin and in higher concentrations in purple and red-fleshed varieties. A randomized trial in healthy volunteers found that chlorogenic acid lowered systolic blood pressure by about 2.4 mmHg and diastolic pressure by about 1.5 mmHg compared with a control.⁸ These are modest reductions from a single exposure, but if the effect holds up over long-term dietary intake, it represents a genuine cardiovascular benefit layered on top of what potassium already provides.

Purple and blue potato varieties contain anthocyanins, the same antioxidant pigments found in blueberries and red cabbage. Animal research on extracts from purple sweet potato has shown reductions in systolic blood pressure along with improved markers of kidney and liver health in rats with high blood sugar.⁹ Animal findings do not translate directly to people, and the extract doses in such studies tend to be higher than what you would get from eating a serving of purple potatoes. Still, the direction of the evidence suggests that choosing colored potato varieties when available gives you bioactive compounds that standard white potatoes have in smaller amounts.

It is worth being clear about what these bioactive compounds can and cannot do. No one is going to control hypertension by eating purple potatoes alone. But in the broader context of a potassium-rich, polyphenol-rich diet, potatoes are a legitimate contributor rather than a food you need to avoid.

What Really Happens When You Fry a Potato

If the cooking-method story is straightforward for blood pressure, the broader health picture of frying adds another layer. When starchy foods are cooked at high temperatures, they produce acrylamide, a compound that forms from the reaction between natural sugars and the amino acid asparagine. Frying also generates advanced glycation end products, sometimes called AGEs. A review of the literature on both compounds links chronic exposure to increased inflammation, metabolic disruption, and other health problems.¹⁰

These compounds do not raise blood pressure in the way sodium does, through direct fluid retention. Instead, they promote oxidative stress and low-grade inflammation in blood vessel walls, which over time can stiffen arteries and impair the normal dilation response that keeps blood pressure in check. This is likely part of why fried potato intake tracks with higher blood pressure in observational studies even after adjusting for salt and calorie intake: the frying itself alters the food’s chemical profile in ways that chip away at vascular health.

The practical takeaway is that the occasional plate of fries is not going to give you hypertension. The controlled feeding trial described earlier found no acute harm from a single 330-calorie portion of baked fries consumed as part of an otherwise normal diet.⁵ The concern is frequency and context: if fried potatoes are your dominant form of potato several times a week, you are accumulating acrylamide and AGE exposure alongside the extra sodium and calories that typically come with them.

Why the Reputation Got So Bad

Potatoes occupy an awkward cultural position. They are vegetables, technically, but dietary guidelines in many countries classify them as starches rather than counting them toward vegetable servings. That classification was driven by their high glycemic index, not by blood pressure evidence, but it set the stage for potatoes to be grouped with refined carbohydrates in the public imagination.

The US cohort studies published in the BMJ received heavy media coverage, and the headline that potatoes “raise blood pressure” stuck. What received less attention was that the hazard ratio for plain potatoes was not statistically significant, that potato chips showed zero association, and that the Spanish cohorts found no link at all. The studies also could not control for everything that accompanies potato consumption in the American diet. People who eat baked potatoes four or more times a week may also eat them loaded with butter, sour cream, and bacon. In the Spanish cohorts, where potatoes are more often part of vegetable stews or tortilla española, the same food showed no effect.

The glycemic index concern feeds into the story too. Potatoes spike blood sugar faster than most vegetables, and chronically elevated blood sugar can damage blood vessels over time. But the trial comparing potatoes to white rice in people with type 2 diabetes found no difference in glycemic control between the two starches.⁷ If you are going to eat a starch at dinner, a potato is no worse than rice for blood sugar and delivers considerably more potassium. Cooling a cooked potato before eating it (or reheating it after cooling) also increases its resistant starch content, which slows digestion and blunts the glycemic spike.

People with Existing Hypertension

If you already have high blood pressure, the evidence is actually somewhat encouraging. The controlled feeding trial that showed a 6 mmHg systolic drop from baked and boiled potatoes specifically enrolled pre-hypertensive and hypertensive adults.⁵ The DASH-plus-potato trial included people with type 2 diabetes, a group at especially high cardiovascular risk, and still showed favorable trends.⁶

There is one important caveat for people with advanced kidney disease. When kidneys are severely impaired, they lose the ability to excrete potassium efficiently, and the high potassium content that makes potatoes helpful for most people can become dangerous. If your doctor has told you to follow a potassium-restricted diet, potatoes do need to be limited or prepared in ways that leach potassium, like peeling, cutting into small pieces, and soaking in water before boiling. For everyone else, the potassium in potatoes is a feature, not a bug.

Practical Ways to Keep Potatoes Blood-Pressure Friendly

The research points toward a few straightforward habits that let you keep potatoes in your diet without worry:

Choose non-fried methods most of the time. Baking, boiling, steaming, and roasting with a light coat of oil all preserve the potassium and polyphenol content without generating high levels of acrylamide or AGEs.
Leave the skin on. Much of the potassium and chlorogenic acid sits in or just below the skin. Peeling removes a meaningful portion of the nutrients that benefit blood pressure.
Go easy on the sodium. A plain baked potato has almost no sodium. The salt shaker, salty toppings, and processed potato products like instant mashed potatoes or seasoned fries are where the sodium load comes from.
Pick colored varieties when you can. Purple, red, and blue-fleshed potatoes deliver anthocyanins on top of the standard nutrient package.
Pair potatoes with vegetables and lean protein. Context matters enormously. A potato alongside a salad and grilled fish is a different dietary event than a loaded baked potato next to a steak.

Glycoalkaloids and Green Potatoes

A separate safety question that sometimes gets tangled into the blood pressure conversation involves solanine and chaconine, naturally occurring toxins called glycoalkaloids. These build up when potatoes are exposed to light and turn green, or when they sprout. At low doses they cause stomach upset; at high doses they can produce fever, rapid breathing, and paradoxically low blood pressure from their effects on the nervous system.¹¹ This has nothing to do with normal blood pressure regulation and everything to do with acute poisoning, which is extremely rare in adults. The standard advice is simple: cut away any green portions and discard potatoes that are heavily sprouted or bitter-tasting. Modern commercial potato varieties are bred to keep glycoalkaloid levels well below harmful thresholds under normal storage conditions.