Starting a low-carb or keto diet with high blood pressure

bloodpressure-man

So you have high blood pressure and you want to try a low-carb or keto diet? Congratulations! It may be the most effective thing for lowering your blood pressure naturally.1 In some cases it may even normalize your blood pressure completely.2

However, there are two minor potential problems.

1. Blood-pressure medication

If you’re on blood-pressure medication and start a low-carb diet there’s a risk of getting low blood pressure. You may relatively quickly become too healthy for your current dosage of medication.3

This blood-pressure lowering effect on low carb can happen within days, but it may also take months or even a year to reach full effect.

If you feel weak, tired, dizzy etc. you should check your blood pressure. If it’s low, e.g. below 120/80, you should contact your doctor to discuss lowering or stopping your medication.

This is something most doctors should be able to handle. But if you need to find a doctor with good knowledge about the handling of medication on a low-carb diet, check out our low-carb doctors map and directory.

2. Salt and bouillon Cup of bouillon

When starting a low-carb diet we often recommend getting extra fluid and salt, perhaps in the form of bouillon – especially during the first two weeks. The reason is to minimize early side effects that can otherwise be troublesome during the first week on low carb, e.g. headache.

You should only take this bouillon if your blood pressure is well controlled, as it may increase blood pressure marginally.4

If your blood pressure is high despite medication you should not take extra salt or bouillon. Doing so could raise the blood pressure even higher, and it is not wise to risk that.

Any side effects will usually pass within a few days anyway, as your body switches from using glucose to fat as its main fuel.

Learn more

How to normalize your blood pressure

Find a low-carb doctor

A low-carb diet for beginners

A keto diet for beginners

Low carb for doctors

Are you a doctor or do you know one? Here’s our low carb for doctors resource, with information on how to safely handle medications on a low-carb diet:

Low carb for doctors
 

Disclaimer: Discuss any changes in medication and relevant lifestyle changes with your doctor. Full disclaimer
  1. The research to date shows that blood pressure often declines in people following carbohydrate-restricted diets:

    Obesity Reviews 2012: Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors [strong evidence]

    Archives of Internal Medicine 2010: A randomized trial of a low-carbohydrate diet vs orlistat plus a low-fat diet for weight loss [moderate evidence]

    Cardiovascular Diabetology 2018: Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study [weak evidence]

    South African Journal of Critical Care 2013: Low-carbohydrate and high-fat intake can manage obesity and associated conditions: occasional survey [very weak evidence]

  2. In a small study, people with metabolic syndrome who followed a ketogenic diet for 12 weeks experienced significant reductions in blood pressure, going from an average of 141/89 to 123/76, along with weight loss and other health improvements. In fact, by the end of the study, many of them no longer met the criteria for a diagnosis of metabolic syndrome:

    Journal of Medicinal Food 2011: A pilot study of the Spanish ketogenic Mediterranean diet: an effective therapy for the metabolic syndrome [weak evidence]

  3. In a recent very-low-carb diet study, researchers had to discontinue blood pressure medications in 11% of participants due to reductions in blood pressure:

    Cardiovascular Diabetology 2018: Cardiovascular disease risk factor responses to a type 2 diabetes care model including nutritional ketosis induced by sustained carbohydrate restriction at 1 year: an open label, non-randomized, controlled study [weak evidence]

  4. This effect occurs in individuals with “salt-sensitive” hypertension, who respond to higher salt intakes with an increase in blood pressure:

    Current Opinion in Nephrology and Hypertension 2012: Mechanisms and consequences of salt sensitivity and dietary salt intake [overview article]