education · heart ·
A Supervised Water Fast Dropped Blood Pressure 37 Points. Read The Fine Print First
174 inpatients, 10 to 11 days, an average 37/13 mmHg drop. No control group, and every study in this literature comes from the same clinic.
The number is extraordinary enough that most people stop reading at the number, which is exactly the problem.
A supervised water-only fast dropped average blood pressure by 37 over 13 mmHg. That is roughly three times what a typical blood pressure drug delivers. It is also a figure that comes with more qualifications than almost anything else we have published, and the qualifications are the useful part.
What was actually done
174 consecutive hypertensive patients, with blood pressure above 140 systolic, 90 diastolic, or both, were treated as inpatients under medical supervision (Goldhamer et al., Journal of Manipulative and Physiological Therapeutics, 2001).
The protocol had three parts, and people who repeat the headline usually only mention the middle one:
- A prefast of 2 to 3 days eating only fruits and vegetables
- Water-only fasting, 10 to 11 days on average
- A refeeding period of 6 to 7 days introducing a low-fat, low-sodium, vegan diet
Results: almost 90% finished below 140/90. Average reduction 37/13 mmHg. In those with stage 3 hypertension, systolic above 180 or diastolic above 110, the average reduction was 60/17 mmHg.
A newer single-arm trial at the same kind of centre enrolled 29 participants with stage 1 and 2 hypertension and no type 2 diabetes. Median fast 11 days, median refeed 5 days. By the end, median blood pressure had normalised to below 130/80, body weight fell by more than 5%, and antihypertensive medication was completely discontinued. Retention was 100% to the end of refeeding and 93% at six weeks (Zeiler et al., Nutrients, 2024).
Now the fine print, and there is a lot of it
There is no control group. Anywhere. Not in the 2001 series, not in the 2024 trial, which describes itself as single-arm. Nobody was randomised to anything. So we cannot separate the fast from the two weeks of rest, the removal of salt, alcohol and processed food, the daily medical attention, or the simple fact of being somewhere residential with nothing else to do.
The medication headline is smaller than it sounds. In the 2001 series, all patients taking antihypertensive medication at entry successfully discontinued it, which reads enormously. Then you find the denominator: that was 6.3% of the sample. Around eleven people. True, and not the same claim as “174 people came off their medication.”
Every study here comes from the same place. The 2001 series, the 2024 trial and the safety review below all originate with TrueNorth, the organisation that operates the residential fasting centre. We said the same thing about the grounding literature being written by its own proponents, and the rule does not change because this result is more exciting. It does not make the data false. It means independent replication does not yet exist.
And the 2001 comparison to drug averages is the authors’ own. That paper contrasts its result with published antihypertensive drug averages drawn from the literature. That is a comparison of this cohort against other people in other studies, not a trial of fasting against a drug. No such trial exists.
A result this large from an uncontrolled series is a reason to run the trial, not a reason to skip it.
How safe is it, precisely
This is where we think the honest reading is less reassuring than the usual summary.
A chart review covered visits to a residential facility from 2006 to 2011. Of 2,539 charts, 768 visits met the criteria: at least 21 years old, water-only fasting for two or more consecutive days, with a refeeding period at least half the fast length (Finnell et al., BMC Complementary and Alternative Medicine, 2018).
The highest-grade adverse event per visit:
| Severity | Visits |
|---|---|
| Grade 2 or lower (mild to moderate) | 555 |
| Grade 3 (severe) | 212 |
| Grade 4 (life-threatening) | 1 |
| Grade 5 (death) | 0 |
| Serious adverse events | 2 visits (0.002%) |
Serious adverse events were genuinely rare, and the authors’ conclusion that the protocol can be safely implemented in a medical setting is supported.
But 212 of 768 visits, about 28%, had a severe event as their worst. Three quarters of all recorded events were mild, and the picture is still of an intervention where roughly one visit in four produces something severe enough to be graded that way. That is not a wellness retreat. That is a clinical procedure with a monitoring requirement.
Why you cannot do this at home
We would normally put a safety note at the end. This one goes in the body, because the gap between what was studied and what a reader might try is wider here than anywhere else on this site.
The fast was the middle of a supervised protocol, not the whole thing. The structured refeeding is a medical step with real risks of its own, and it was half the length of the fast.
Blood pressure medication plus a dropping blood pressure is the specific danger. If pressure falls 37 points while the drugs that were lowering it are still on board, the result is not a better number. In these studies, medication was managed and withdrawn by clinicians watching daily.
Ten days without food is not a scaled-up version of skipping breakfast. Electrolytes, kidney function and cardiac rhythm are the reasons there is daily monitoring, and they are not things you can feel going wrong in time.
Anyone with diabetes, kidney disease, a heart condition, an eating disorder history, who is pregnant or breastfeeding, or who takes any regular medication, should treat this as information about a clinical programme and not as a protocol.
What we are and are not saying
| Claim | Our line |
|---|---|
| Fasting treats, cures or prevents hypertension | Never |
| Supervised water fasting was followed by large BP drops | Yes. 37/13 mmHg average in 174 inpatients |
| It beats medication | Untested. No controlled comparison exists |
| The effect is proven to be the fasting | No. No control group separates it from rest, diet and attention |
| 174 people came off blood pressure drugs | No. Only 6.3% were on any at entry |
| It is low risk | In a clinic, serious events were rare. 28% of visits still had a severe event |
| You can try this at home | No. Every study was inpatient with daily supervision |
| The research is independent | No. It comes from the organisation running the centre |
Where the design shows up
Something in these numbers is worth sitting with even after all the caveats.
Pressure that high is usually described as a chronic condition, meaning a thing you have, permanently, that gets managed. And then a body is put in a room, given water, rested for two weeks, and the number moves further than pharmacology moves it.
That does not prove fasting is the mechanism. It does suggest that a good deal of what gets called chronic is being actively produced, every day, by inputs that are still arriving. Take enough of them away at once and the body shows you what it was doing underneath.
Which is an argument for the unglamorous version far more than for the dramatic one. The salt, the alcohol, the processed food and the weight were all in that room too, and all of them are addressable on a Tuesday without a clinic.
“Is this not the fast which I choose, to loosen the bonds of wickedness, to undo the bands of the yoke, and to let the oppressed go free?” Isaiah 58:6, NASB
The verse carries the conviction. One hundred and seventy-four inpatients and no control group carry the evidence.
What to do this week
Do not fast. Take the parts of the protocol that are not the fast.
Every one of these programmes included removing salt, alcohol, and processed food, and finished by introducing a low-fat, low-sodium, plant-based diet. Those components have randomised evidence of their own, and none of them require supervision.
That is not a consolation prize. It is the part of the intervention you can actually keep, and keeping it is what the fasting programmes themselves were trying to launch people into.
If the dramatic version genuinely interests you, the honest route is a medically supervised programme with your own prescriber involved from the start, not a long weekend of willpower.
Read this next: what the DiRECT trial did about medication, with a control group: the rebound effect and coming off medication. The mineral with real blood pressure data on the plate: higher potassium intake tracked with 24% lower stroke risk. And how we weigh a literature with this much conflict in it: two of medicine’s top editors say you can’t believe much of it.
Sources
- Goldhamer A, Lisle D, Parpia B, Anderson SV, Campbell TC. “Medically supervised water-only fasting in the treatment of hypertension.” Journal of Manipulative and Physiological Therapeutics, 2001;24(5):335-339. https://pubmed.ncbi.nlm.nih.gov/11416824/
- Zeiler E, Gabriel S, Ncube M, et al. “Prolonged Water-Only Fasting Followed by a Whole-Plant-Food Diet Is a Potential Long-Term Management Strategy for Hypertension and Obesity.” Nutrients, 2024;16(22):3959. https://pubmed.ncbi.nlm.nih.gov/39599745/
- Finnell JS, Saul BC, Goldhamer AC, Myers TR. “Is fasting safe? A chart review of adverse events during medically supervised, water-only fasting.” BMC Complementary and Alternative Medicine, 2018;18(1):67. https://pubmed.ncbi.nlm.nih.gov/29458369/
Article metadata retrieved from PubMed. Photograph from Pexels. Scripture quoted from the New American Standard Bible.
Educational content from True Health Solutions. We do not diagnose or prescribe, and nothing here is a substitute for care from someone who knows your history. The body heals. We write about what supports that design.
Questions people ask
- How much did blood pressure drop?
- In 174 consecutive hypertensive inpatients on a medically supervised water-only fast averaging 10 to 11 days, the average reduction was 37/13 mmHg, and almost 90% finished below 140/90. In those with stage 3 hypertension the average drop was 60/17 mmHg.
- Is that better than medication?
- Nobody has run that comparison. There was no control group and no drug arm in any of these studies, so the honest answer is that this has never been tested head to head against anything.
- Is it safe?
- Under medical supervision, serious events were rare. In a chart review of 768 supervised fasting visits, two visits involved a serious adverse event. But 212 of those 768 visits involved a grade 3 event, which is severe, so this is not a gentle intervention.
- Can I do this at home?
- No. Every study here was inpatient, under daily medical supervision, with a structured refeeding period. Water-only fasting for ten days without supervision is genuinely dangerous, particularly for anyone on blood pressure medication, and refeeding has its own risks.
- Who ran these studies?
- Essentially all of them come from one organisation, TrueNorth, which also operates the residential fasting centre where the fasting takes place. That does not make the data wrong and it belongs on the table.
