Do Potatoes Lower Blood Pressure?

Potatoes can modestly lower blood pressure under certain conditions, but the effect depends heavily on how they are prepared, what variety you eat, and what they replace in your diet. A few small clinical trials show promising drops in systolic blood pressure from plain, non-fried potatoes, while large observational studies suggest that eating fried potatoes regularly is linked to higher blood pressure. The honest picture is more nuanced than either “superfood” or “starch bomb” framing would have you believe.

What Human Trials Have Found

The most direct evidence comes from a randomized controlled trial that fed baked and boiled potatoes to adults with elevated blood pressure. Participants eating potatoes saw their systolic blood pressure drop by about 6 mmHg over the treatment period, compared with roughly 2.6 mmHg in the control group. That difference was statistically significant when the two groups were compared directly, even though the broader analysis across all treatment arms (which also included French fries and a potassium supplement) did not reach significance by the more conservative overall test.¹ A roughly 3-4 mmHg net advantage over a control diet is modest, but in the range that population-wide dietary shifts can meaningfully affect cardiovascular risk over years.

A separate trial tested whether adding potatoes to a DASH-style diet (rich in fruits, vegetables, and low-fat dairy) would change blood pressure in adults with and without type 2 diabetes. After six weeks, there was no significant difference in blood pressure between the groups eating potatoes and those on a standard DASH diet without them. The researchers noted a positive trend in the potato groups, but the numbers did not clear the statistical bar.² The practical takeaway is that potatoes did not undermine an otherwise blood-pressure-friendly diet, but they did not add a detectable boost either.

These trials are small, and neither one lasted longer than a few weeks. The evidence is suggestive, not definitive. Still, the direction is consistent: plain potatoes do not raise blood pressure, and they may produce a mild benefit in people whose blood pressure is already elevated.

Why Cooking Method Changes the Answer

If there is one finding that runs through nearly every potato-and-blood-pressure study, it is that frying undoes whatever benefit the potato might offer. The INTERMAP study, which looked at dietary patterns and blood pressure across thousands of adults, found no association between total potato intake and blood pressure, and no association for boiled, mashed, or baked potatoes specifically. But in U.S. women, higher fried-potato intake was linked to about 2.3 mmHg higher systolic and 1.1 mmHg higher diastolic blood pressure, independent of body weight. When fried-potato meals also had poor overall nutritional quality, the association with systolic blood pressure climbed to nearly 4 mmHg.³

Large prospective cohort data tell a similar story. In three major U.S. cohorts followed for years, eating four or more servings of French fries per week was associated with a 17% higher risk of developing hypertension compared with eating less than one serving per month. Baked, boiled, or mashed potatoes showed a weaker and statistically borderline association. Potato chips, interestingly, showed no link at all.⁴ The chip finding is surprising until you consider that a typical chip serving is smaller in weight than a typical French fry serving, and the cohort data could not fully untangle serving-size effects.

These observational results do not prove frying causes higher blood pressure. People who eat a lot of fried potatoes tend to eat differently in general, and separating the potato from the rest of the dietary pattern is difficult. But the consistency across studies makes it reasonable to say that if you are eating potatoes hoping for a blood-pressure benefit, frying them is the wrong approach. Baking, boiling, roasting, or microwaving preserves whatever helpful compounds the potato carries, without layering on the oil, salt, and excess calories that come with deep frying.

How Potassium and Sodium Balance Fit In

A medium baked potato with skin delivers roughly 900 mg of potassium, which puts it among the most potassium-dense common foods. Potassium is the mineral most consistently linked to blood pressure reduction in dietary research, mainly because it helps the kidneys excrete sodium and relaxes blood vessel walls. The question is whether getting that potassium from a whole potato works differently than getting it from a supplement pill.

The randomized trial that compared potatoes to potassium gluconate supplements found something notable on this point. Even though both the potato phase and the supplement phase delivered similar amounts of extra potassium, only the potato phase produced a significant drop in systolic blood pressure. And the potato phase had one other measurable advantage: participants retained significantly less sodium during the weeks they ate potatoes compared with the control phase, the French fry phase, and even the supplement phase. Sodium retention during the potato weeks averaged about 490 mg per day, versus roughly 890 mg during the control and nearly 1,020 mg during the supplement period.¹

That sodium finding is striking. It suggests that potatoes may help the body shed sodium more effectively than an equivalent dose of potassium delivered in pill form. One plausible explanation is that the potato’s package of other compounds, including fiber, phenolic acids, and organic acids, works alongside potassium in ways a purified supplement cannot replicate. This is a single trial, so it needs replication, but it aligns with the broader nutritional principle that whole foods often outperform isolated nutrients.

Purple Potatoes and the Pigment Advantage

Not all potatoes are nutritionally interchangeable, and the most compelling blood pressure data come from a variety most people rarely eat: purple potatoes. In a crossover study of 18 adults with hypertension (most already on blood pressure medication), eating six to eight small microwaved purple potatoes twice daily for four weeks lowered diastolic blood pressure by about 4 mmHg and systolic by about 5 mmHg. Importantly, participants did not gain weight during the potato phase.⁵ A 4-5 mmHg reduction may sound small, but for context, that is in the range of some single blood pressure medications, and it occurred on top of existing drug therapy.

Purple and blue potatoes get their color from anthocyanins, the same class of pigments found in blueberries and red cabbage. These compounds have antioxidant and anti-inflammatory properties, and there is growing evidence they interact with the cardiovascular system in specific ways. Animal research using anthocyanin-enriched purple potato flour found that it lowered serum angiotensin II (a hormone that constricts blood vessels and raises blood pressure) by about a third in hypertensive rats, and increased gut microbial diversity with a more favorable bacterial balance.⁶ Molecular docking in that same study suggested that potato anthocyanins bind strongly to endothelin-1 and angiotensin II, two proteins central to blood pressure regulation.

The human trial was small and the animal data is preliminary, so purple potatoes are not a proven treatment. But if you are choosing between white and purple potatoes at the farmers’ market, the purple variety brings additional bioactive compounds that white varieties lack, on top of the potassium and fiber they share.

Other Compounds in Potatoes That May Matter

The blood pressure story is not just about potassium and anthocyanins. Potatoes contain several other classes of compounds under active investigation.

Chlorogenic acid, a phenolic compound abundant in potatoes (especially near the skin), has been studied for a range of metabolic effects including anti-inflammatory and antihypertensive activity.⁷ Most of that research involves chlorogenic acid in isolation or in coffee, so it is difficult to say how much the amount in a serving of potatoes contributes on its own. But it is part of the matrix of compounds that may explain why whole potatoes behave differently from potassium supplements.

Potato proteins, particularly a family called patatins, break down during digestion into smaller peptides. Laboratory studies have found that these peptides inhibit angiotensin-converting enzyme (ACE) in test-tube assays.⁸ ACE inhibitors are among the most widely prescribed classes of blood pressure drugs, so the idea that potato-derived peptides could mimic a weak version of that effect is intriguing. That said, demonstrating ACE inhibition in a test tube is a long way from proving it happens at meaningful levels in the human body after eating a potato. This is basic science pointing toward a mechanism, not clinical evidence of benefit.

Resistant starch, which forms when potatoes are cooked and then cooled, has been reviewed as a potential contributor to cardiometabolic health, including blood pressure improvement, through its effects on gut bacteria and fiber-like properties.⁹ Cold potato salad, in other words, delivers a different nutritional profile than a hot baked potato, and the resistant starch in the cooled version may offer a modest additional pathway to cardiovascular benefit. How much resistant starch survives reheating varies, but some persists even after warming a previously cooled potato.

The Replacement Question

One detail that often gets lost in the “are potatoes good or bad” debate is what potatoes are replacing in the diet. In the large cohort study of three U.S. populations, replacing one daily serving of baked, boiled, or mashed potatoes with one serving of a non-starchy vegetable was associated with a 7% lower risk of developing hypertension.⁴ That substitution analysis matters because it reframes the question. Potatoes are not inherently harmful for blood pressure, but they are not the most effective vegetable choice if your primary goal is keeping blood pressure low. A plate of broccoli, spinach, or green beans is going to deliver potassium and other minerals alongside more fiber and fewer rapidly digestible carbohydrates.

On the other hand, potatoes are often not replacing a leafy green. They are replacing refined grains, white bread, or white rice. In that substitution, the potato is likely the better choice for blood pressure, given its potassium density and the fact that it pairs with meals in ways that other high-potassium foods (like bananas or beans) might not. Nutritional advice that treats potatoes as equivalent to white bread, as some older dietary frameworks did, does not hold up well against the trial and observational evidence now available.

When High Potassium in Potatoes Becomes a Problem

The very thing that makes potatoes potentially helpful for blood pressure, their high potassium content, becomes a concern for people with advanced kidney disease. Healthy kidneys regulate blood potassium levels efficiently, but when kidney function declines past a certain point, excess potassium can accumulate and cause dangerous heart rhythm disturbances. People on potassium-restricted diets, particularly those with stage 4 or 5 chronic kidney disease or those on dialysis, are typically advised to limit high-potassium foods.

This does not mean kidney patients must avoid potatoes entirely. Research on leaching techniques has shown that cutting potatoes into small pieces and soaking or double-cooking them can substantially reduce potassium content. One study established an optimized double-cooking method (brief first cook followed by rinsing) that maintained the potato’s texture while maximizing potassium reduction, creating a version that may be suitable for kidney patients who want broader dietary options.¹⁰ Earlier work on leaching potassium from tubers confirmed that while these methods reduce potassium, the remaining content varies and should still be tracked carefully by anyone on strict restrictions.¹¹

For the general population without kidney issues, the potassium in potatoes is a feature, not a bug. Most adults in Western countries consume well below the recommended daily intake of potassium, and potatoes are one of the cheapest and most accessible ways to close that gap.

What Potatoes Cannot Do

Even if every optimistic finding in the potato research holds up, the effect sizes are small. A 4-6 mmHg drop in systolic blood pressure is meaningful at the population level but is unlikely to replace medication for someone with stage 2 hypertension (readings consistently above 140/90). Potatoes are a dietary component, not a treatment. They fit into a blood-pressure-friendly eating pattern alongside other potassium-rich foods, sodium reduction, physical activity, and weight management.

The research also has significant gaps. Most trials have been short (four to six weeks), included small numbers of participants, and studied specific preparations like microwaved purple potatoes or carefully portioned baked potatoes. Whether the same effects appear in a typical home-cooking setting, with butter and sour cream and salt, remains an open question. The answer almost certainly depends on what goes on top. A plain baked potato with skin intact is a different nutritional proposition from one loaded with cheese, bacon bits, and a generous pour of ranch dressing. The clinical trials stripped away those additions, and real-world eating rarely does. Anyone hoping to get a blood-pressure benefit from potatoes should pay at least as much attention to what accompanies the potato as to the potato itself.