Beets show genuine biological promise for prostate health, but the evidence is strongest in the laboratory and weakest where it matters most: in living humans. The connection runs primarily through nitric oxide, a molecule your body makes from the nitrate concentrated in beetroot, which plays a documented role in prostate blood flow and urinary function. Several cell-culture studies have also found that beet extracts slow the growth of prostate cancer cells. The gap between these findings and a firm dietary recommendation, however, is wider than most health blogs acknowledge.
How Beets Connect to the Prostate Through Nitric Oxide
Beetroot juice contains unusually high concentrations of inorganic nitrate, which the body converts into nitric oxide after consumption.1PubMed. The benefits and risks of beetroot juice consumption: a systematic review This conversion follows a pathway that researchers have mapped in detail: bacteria on the back of your tongue reduce dietary nitrate to nitrite, which then gets further converted to nitric oxide in the stomach and bloodstream.2PubMed Central. Vascular effects of dietary nitrate (as found in green leafy vegetables and beetroot) via the nitrate-nitrite-nitric oxide pathway Nitric oxide is a signaling molecule that relaxes smooth muscle in blood vessel walls. That relaxation is exactly what makes it relevant to the prostate.
The prostate sits in a dense vascular neighborhood, surrounded by blood vessels that feed the lower urinary tract, the bladder, and the pelvic organs. When nitric oxide levels in this area drop, several things go wrong: blood flow to the pelvic organs decreases, smooth muscle in the prostate and bladder neck tightens, and sympathetic nervous activity ramps up. These changes are thought to contribute to the development and worsening of benign prostatic hyperplasia, the non-cancerous prostate enlargement that causes urinary symptoms in most men as they age.3PubMed. Lower urinary tract symptoms/benign prostatic hypertrophy and vascular function: Role of the nitric oxide-phosphodiesterase type 5-cyclic guanosine 3′,5′-monophosphate pathway Both the body’s own nitric oxide and externally supplied nitric oxide work as vasodilators on the smooth muscle cells involved.3PubMed. Lower urinary tract symptoms/benign prostatic hypertrophy and vascular function: Role of the nitric oxide-phosphodiesterase type 5-cyclic guanosine 3′,5′-monophosphate pathway
This is the same basic pathway that drugs like sildenafil and tadalafil exploit. Those medications block the enzyme that breaks down the downstream signal produced by nitric oxide, effectively amplifying whatever nitric oxide is already present. The logic behind beets is that supplying more raw material (nitrate) upstream should increase nitric oxide production and support the same pathway through diet rather than medication. That logic is pharmacologically sound, but it does not automatically mean that eating beets delivers enough nitric oxide to the right tissues at the right time to make a noticeable difference.
What Lab Studies Show About Prostate Cancer Cells
Separate from the nitric oxide story, beet extracts have been tested directly against prostate cancer cells in laboratory dishes, and the results are consistently encouraging. A study comparing beetroot extract and beet leaf extract against two commonly used prostate cancer cell lines found that both extracts reduced cell proliferation, limited the ability of cancer cells to form colonies, and interfered with growth signaling pathways.4PubMed. Beetroot and leaf extracts present protective effects against prostate cancer cells, inhibiting cell proliferation, migration, and growth signaling pathways The beet leaf extract also slowed cell migration in both cell lines, a property relevant to whether cancer spreads.
An earlier study tested beetroot extract head-to-head with doxorubicin, a standard chemotherapy drug, in prostate cancer cells. The beetroot extract was far less potent than the drug, as you would expect from a food extract versus a pharmaceutical. But it still decreased the growth rate of prostate cancer cells in a dose-dependent manner, and the researchers pointed to betanin, the red pigment that gives beets their color, as a likely active ingredient.5PubMed. Cytotoxic effect of the red beetroot (Beta vulgaris L.) extract compared to doxorubicin (Adriamycin) in the human prostate (PC-3) and breast (MCF-7) cancer cell lines A more recent study explored whether betanin could enhance the effect of radiation therapy in prostate cancer cells and found a synergistic anticancer effect, with the combination triggering cell death and cell cycle arrest more effectively than either treatment alone.6PubMed. The synergistic effects of betanin and radiotherapy in a prostate cancer cell line: an in vitro study
The honest caveat is that cell-culture studies are the earliest stage of cancer research. Killing cancer cells in a dish is not the same as shrinking a tumor in a person. Thousands of compounds show anti-cancer activity in vitro and never pan out in clinical trials, because the human body metabolizes, dilutes, and redirects substances in ways that a petri dish does not. No clinical trial has yet tested whether eating beets or drinking beet juice affects prostate cancer outcomes in real patients. The lab evidence is a reason to keep studying beets, not a reason to treat them as medicine.
Beets, Urinary Symptoms, and Enlarged Prostate
The connection between nitric oxide and benign prostatic hyperplasia is well enough established that researchers have called enhancing the nitric oxide pathway a potential new treatment strategy for lower urinary tract symptoms.7PubMed. The nitric oxide pathway in the human prostate: clinical implications in men with lower urinary tract symptoms This conclusion comes from randomized, placebo-controlled studies of drugs that boost nitric oxide signaling, not from studies of dietary nitrate specifically. But there is a small and intriguing piece of direct evidence.
A study of men with BPH who were given nitrate supplements found a meaningful improvement in peak urinary flow rate (an increase of about 3 ml/s) and a significant decrease in residual urine volume (about 22 ml less urine left in the bladder after voiding). Prostate-specific antigen levels and prostate volume did not change, meaning the nitrate did not shrink the prostate itself but did appear to improve how well urine flowed through the compressed urethra.8PubMed. Nitric oxide based influence of nitrates on micturition in patients with benign prostatic hyperplasia The study used pharmaceutical nitrate, not beetroot, and the sample was small. But it demonstrates that the mechanism linking dietary nitrate to urinary improvement is more than theoretical.
Whether you could get a comparable dose of nitrate from beet juice is an open question. A typical serving of concentrated beet juice delivers roughly 300 to 500 mg of nitrate, which is in the range that exercise-physiology researchers commonly use to study blood-pressure lowering effects. Whether that amount is enough to meaningfully improve pelvic blood flow or urinary function has not been tested in a controlled trial. Men who already take medications for BPH symptoms should not assume beet juice can replace those drugs.
Pelvic Blood Flow and Erectile Function
The prostate does not exist in isolation. The same pelvic blood supply that feeds the prostate also serves the erectile tissue of the penis, which is why drugs that enhance nitric oxide signaling in the prostate also happen to treat erectile dysfunction. Beets fit into this picture because of their nitrate content.
Preliminary research presented at sexual-medicine conferences has examined whether beetroot-based supplements improve erectile function. One study found that combining a nitric oxide-boosting dietary supplement containing beetroot extract with sildenafil improved nighttime erections more than sildenafil alone.9The Journal of Sexual Medicine. Combining a Nitric Oxide Boosting Dietary Supplement With Sildenafil Improves Nighttime Erections More Than Sildenafil Alone Another reported that a supplement containing L-citrulline and beetroot extract improved nighttime erections, with the proposed mechanism being that the high nitrate content dilates blood vessels and improves circulation.10The Journal of Sexual Medicine. L-CITRULLINE AND BEET ROOT SUPPLEMENT IMPROVES NIGHTTIME ERECTIONS
These are conference abstracts of small studies, not large published clinical trials, so they land firmly in the “interesting but preliminary” category. The supplements also combined beetroot with other ingredients, making it hard to isolate the contribution of beets alone. Still, the findings are consistent with what the nitric oxide pathway would predict, and they reinforce the idea that beets affect pelvic vascular health more broadly, not just the prostate in isolation.
The Bioavailability Problem
One of the more deflating findings in beet research concerns betanin, the red pigment that lab studies repeatedly identify as an active anti-cancer compound. A human bioavailability study measured plasma levels of betanin after people consumed either beet juice (containing roughly 194 mg of betanin) or whole beetroot food (containing about 66 mg). Despite these substantial doses, betanin could not be detected in the blood at any time point after ingestion.11PubMed Central. The plasma bioavailability of nitrate and betanin from Beta vulgaris rubra in humans
This is a significant problem for the cancer story. If betanin is the compound killing prostate cancer cells in the lab, but it never reaches measurable concentrations in human blood after you eat beets, then the lab findings may not translate to dietary reality. It is possible that betanin acts locally in the gut, that it breaks down into active metabolites that were not measured, or that the detection methods were not sensitive enough. But until researchers can show that an anti-cancer concentration of betanin or its metabolites actually reaches prostate tissue, the cell-culture results remain suggestive rather than actionable.
The nitrate story is different. Nitrate is absorbed efficiently and reliably increases plasma nitrite levels after beet consumption, which is why beet juice has well-documented effects on blood pressure and exercise performance. The prostate-relevant benefits of beets are therefore more plausible through the nitric oxide route than through the betanin route, at least based on current evidence.
Why Your Mouthwash Might Matter More Than You Think
The conversion of dietary nitrate to nitric oxide depends critically on the bacteria living on the back of your tongue. These bacteria perform the first chemical step, reducing nitrate to nitrite, which then gets swallowed and converted further in the stomach and bloodstream. Without these bacteria, the entire pathway stalls.
Antiseptic mouthwashes wipe out these bacteria, and the consequences are measurable. Research has shown that using mouthwash after consuming dietary nitrate dramatically reduces the resulting increase in plasma and salivary nitrite levels.12Nitric Oxide. A stepwise reduction in plasma and salivary nitrite with increasing strengths of mouthwash following a dietary nitrate load In animal studies, antiseptic mouthwash abolished the blood-pressure-lowering effects of dietary nitrate entirely.13Free Radical Biology and Medicine. Gastroprotective and blood pressure lowering effects of dietary nitrate are abolished by an antiseptic mouthwash A review examining this phenomenon raised concerns that excessive use of antiseptic mouthwash could create nitric-oxide-deficient conditions with potentially serious cardiovascular consequences.14PubMed Central. Antiseptic mouthwash, the nitrate-nitrite-nitric oxide pathway, and hospital mortality: a hypothesis generating review
If you are drinking beet juice specifically for its nitric oxide benefits, using chlorhexidine-based or other strong antibacterial mouthwash regularly could be undermining the very mechanism you are trying to support. This does not mean you should abandon oral hygiene, but it does mean that the timing and type of mouthwash may interact with dietary nitrate in ways worth considering. Brushing your teeth with regular toothpaste does not appear to have the same effect, since toothpaste does not typically eradicate the deep-tongue bacterial communities involved.
Oxalates, Kidney Stones, and Who Should Be Careful
Beets are among a small number of foods that have been shown to increase urinary oxalate excretion, which raises the risk of calcium oxalate kidney stones. The list of confirmed oxalate-boosting foods is short and includes spinach, nuts, chocolate, rhubarb, strawberries, tea, and wheat bran alongside beets.15Journal of the American Dietetic Association. Effect of dietary oxalate and calcium on urinary oxalate and risk of formation of calcium oxalate kidney stones The greatest risk applies to people who absorb oxalate at unusually high rates, including those with certain intestinal conditions.
For most people eating beets a few times a week, the oxalate content is unlikely to cause problems. But men who have a history of kidney stones, particularly calcium oxalate stones, should be thoughtful about consuming large quantities of beet juice, especially the concentrated “shots” marketed for athletic performance. These deliver far more oxalate per serving than a portion of roasted beets on a dinner plate. Drinking plenty of water and pairing beet-heavy meals with calcium-containing foods (which binds oxalate in the gut before it reaches the kidneys) can help offset the risk.
Beeturia and the PSA Scare That Isn’t
About 10 to 14 percent of people experience beeturia, a harmless condition in which urine turns pink or red after eating beets. The pigment responsible is betanin, and whether it shows up in your urine depends on factors like stomach acidity, gut transit time, and individual variation in how you metabolize the pigment. The concern for prostate health is not medical but psychological: red urine can mimic the appearance of blood in the urine, which is a symptom doctors take seriously as a possible sign of urinary tract or prostate cancer.
If you are a man over 50 who has recently started eating beets and notices red-tinged urine, the simplest test is to stop eating beets for a few days and see if the color returns to normal. If it does, you had beeturia. If it does not, or if the discoloration comes and goes independent of beet consumption, that warrants a visit to a doctor. Men undergoing PSA screening or monitoring for prostate conditions should know that beets do not affect PSA levels, as the nitrate study in BPH patients confirmed no change in PSA after nitrate supplementation.8PubMed. Nitric oxide based influence of nitrates on micturition in patients with benign prostatic hyperplasia The scare is cosmetic, not biochemical.
How to Get the Most From Beets if You Are Going to Eat Them
If you want to incorporate beets into your diet with prostate health in mind, the evidence, limited as it is, favors the nitric oxide pathway over the betanin pathway. That means maximizing nitrate delivery and absorption rather than chasing the red pigment specifically.
- Juice over cooked beets: Concentrated beetroot juice delivers more nitrate per serving than roasted or boiled beets, and the nitrate is well-absorbed from liquid form. Cooking does not destroy nitrate, but portion-for-portion, juice is more concentrated.
- Avoid antibacterial mouthwash around consumption: The tongue bacteria that convert nitrate to nitrite need to be intact for the pathway to work. If you use mouthwash, consider separating it from your beet intake by several hours.
- Pair with vitamin C: Acidic environments in the stomach help convert nitrite to nitric oxide. Consuming beet juice alongside citrus or other vitamin-C-rich foods may support this conversion, though this has not been tested specifically for prostate outcomes.
- Watch your kidneys: If you have a history of kidney stones, keep beet juice servings moderate and stay well hydrated. The oxalate load from daily concentrated beet juice adds up.
None of this constitutes medical advice for treating a diagnosed prostate condition. The evidence base for beets and prostate health is a collection of plausible mechanisms, encouraging lab data, and a handful of small human studies that used nitrate rather than beets specifically. What beets offer is a dietary component with a well-characterized vascular mechanism that happens to be relevant to the prostate, sitting inside a vegetable that also supplies folate, potassium, and fiber. For men looking to support prostate health through diet, beets are a reasonable addition to a varied eating pattern, but they are not a substitute for screening, medical follow-up, or prescribed treatment.
What Researchers Still Want to Know
The most glaring absence in this field is a randomized controlled trial testing beet juice or beetroot supplementation against a specific prostate endpoint in humans: urinary symptom scores in men with BPH, PSA trajectories, or cancer recurrence rates. Without that trial, the case for beets remains assembled from adjacent evidence rather than direct proof. The nitric oxide mechanism is established, the lab cancer data are consistent, and the small nitrate-BPH study is suggestive, but no one has connected those dots in a proper clinical study of beets and the prostate.
Researchers also need to solve the betanin bioavailability puzzle. If the red pigment cannot be detected in blood after normal consumption, then either the anti-cancer effects seen in labs are irrelevant to dietary intake, or something more complex is happening with gut metabolism and tissue distribution that current measurement techniques miss. Some groups are investigating whether beetroot compounds reach the colon intact and interact with gut bacteria there, producing metabolites that then enter the bloodstream in different forms. The prostate’s proximity to the pelvic vasculature makes it at least plausible that locally produced metabolites could reach it, but this remains speculative. For now, the most defensible claim is that beets are a nitrate-rich food with established vascular benefits, and those vascular benefits have a demonstrated connection to prostate and pelvic health through a pathway that pharmaceutical research has already validated with drugs. Whether dietary beets deliver enough of the right molecules to the right tissue to produce a meaningful clinical effect is the question that still needs an answer.