Apple cider vinegar has been used as a natural remedy for high blood pressure for over 2000 years, and is still popular today. A review of foods used to treat hypertension within the Traditional Chinese Medicine system, for example, lists vinegar among the 38 most frequently recommended foods, alongside celery, tomato, banana, hawthorn, garlic, onion, seaweed, watermelon, mushroom, spinach, soybeans and apples themselves. Despite this traditional and modern use, there is little research into the benefits of apple cider vinegar in people with hypertension.
Apples for high blood pressure
Apples and apple cider vinegar contain antioxidant bioflavonoids which have beneficial effects on the circulation to lower blood pressure and cholesterol levels. Researchers who analysed the diet and health of over 187,450 people found that those who ate the most apples (4 or more per week) had a 9% lower risk of developing hypertension than those who ate less than one per month. Another study involving people with poorly controlled hypertension found that adding dietary flavonoids in the form of dehydrated red apple, dark chocolate and green tea to their treatment significantly reduced their blood pressure by 5/4 mmHg more than the medication alone.
Apple cider vinegar
Apple cider vinegar is made by crushing apples with their skins, and fermenting the resulting cloudy apple juice with yeasts to produce cider. The cider then undergoes a secondary bacterial fermentation which converts the alcohol to acetic acid (acetate).
Apple cider vinegar therefore contains acetate plus other components naturally found in apples, including minerals and antioxidant flavonoids.
Unfiltered apple cider vinegar drinks which include ‘the mother’ contain strands of protein, enzymes and probiotic bacteria that are believed to contribute many of the health benefits of apple cider vinegar, but give the drink a cloudy appearance.
Apple cider vinegar for high blood pressure
Vinegar is a concentrated solution of acetate (acetic acid) which may have the ability to lower blood pressure by reducing the activity of renin.
Renin is both a hormone and an enzyme, which is produced in specialised kidney cells when the pressure of blood flowing through the kidneys is lower than normal. Renin splits a substance called angiotensinogen (which is made in the liver) to release another substance, angiotensin I. This, in turn, is activated by angiotensin converting enzyme (ACE) to form angiotensin II which causes blood vessels to constrict and blood pressure to rise. By reducing the activity of renin, vinegar might help blood vessels to relax (in a similar way to ACE inhibitor drugs) so that blood pressure lowers.
This was tested in the laboratory when vinegar was added to the standard diet of hypertensive subjects, their systolic blood pressure was 21 mmHg lower, after 11 weeks, than a control group who did not have vinegar added to their diet. After 13 weeks, the different in blood pressure between the two groups was a dramatic 30 mmHg. What most natural health sites who quote this study fail to mention, however, is that the ‘subjects’ were hypertensive rats – not people.
So far, the effects of acetate and apple cider vinegar have not been tested in humans, although the researchers did state that it may be useful for people to include vinegar in the diet to prevent hypertension.
Apple cider vinegar for high cholesterol
Taking apple cider vinegar on a daily can lower cholesterol levels. A study carried out by Aston University as part of the BBC progam Trust Me, I’m A Doctor, found that people who took 30ml (two tablespoons) apple cider vinegar (diluted in 200ml water) twice a day, before a meal for 2 months, had an average reduction of 13% in total cholesterol, compared to placebo.
Apple cider vinegar safety
While there are no guarantees, you may find it helpful to add apple cider vinegar to your diet to lower blood pressure and cholesterol, too. Don’t overdo it. There is a case report of a 28 year old woman who ‘overused’ apple cider vinegar and was admitted to hospital with a low blood pressure (100/80 mmHg), a low potassium and a high sodium level. It turned out that she had consumed 250ml vinegar per day, diluted in water, regularly for 6 years, and also had osteoporosis as a result of her generally poor diet.
Although it’s difficult to infer any hard advice from that single case study, it may not be advisable to use apple cider vinegar if you are taking diuretics that deplete potassium levels, include chlorothiazide, chlorthalidone, furosemide, hydrochlorothiazide and others. If in doubt, check with your doctor or a pharmacist.
NB Apple cider vinegar is acidic and can erode teeth. If taking apple cider vinegar regularly, dilute it with water before drinking, and drink the apple cider vinegar through a straw. Rinsing your mouth with water after taking apple cider vinegar also helps to protect against acid erosion of tooth enamel.
If your blood pressure is raised, self-monitoring is key to maintaining good control.
Click here for advice on choosing a blood pressure monitor to use at home.
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