Recent research has been focusing on ways of lowering blood pressure by dietary interventions.
Previously we considered the role that essential fatty acids may play in controlling hypertension.
Read: Fatty acids lower blood pressure
This week's topic concerns another research approach using fasting as a therapy to lower blood pressure as reported in Issue 156 of the Arbor Clinical Nutrition Updates.
The first study in this series, used the following phases of dietary manipulation to lower blood pressure:
1. 174 hypertensive patients were admitted to hospital and given only vegetables and fruit for 2 days;
2. Thereafter patients were put on a water-only diet, i.e. strict fasting until their blood pressure readings had stabilised;
3. Once blood pressure had stabilised, the hypertensive patients were given a vegan diet consisting of vegetables, fruit and juices, combined with moderate exercise.
- 89% of the patients lost weight (6.9 kg on average) and blood pressure readings decreased (37/13 mm Hg for systolic and diastolic pressure respectively)
- Most of the weight loss and lowering of blood pressure occurred while the patients were on the water-only diet
- The decreases in blood pressure were most significant in patients with very high blood pressure, who started off with an average blood pressure of 194/96 mm Hg, and reduced their blood pressure by 60/17 mm Hg
- In patients who were available for follow-up, the positive effect of this dietary intervention appeared to last for as long as four -five months
The second study made use of the same treatment using patients with borderline hypertension (i.e. patients with moderately increased blood pressure).
Once again the patients lost weight and experienced a drop in both systolic and diastolic blood pressure readings.
Notes on fasting
Fasting or the use of a very restrictive diet based on liquids such as fruit and vegetable juice, have been used for hundreds, if not thousands of years to cleanse or detoxify the body.
The research reported in the Arbor Nutrition Updates indicates that fasting under controlled conditions may also help to lower high blood pressure in hypertensive patients.
The Editors of the Arbor Nutrition Updates do, however, point out that some other aspects of these studies may also have influenced the results.
For example, the enforced rest and isolation in hospital, away from everyday stresses and worries, could also have played a role in lowering blood pressure.
Fasting to lose weight
For those readers who want to use fasting for weight loss, it is important to take careful precautions and to keep the following facts in mind:
- Do not fast for more than 1-2 days at a time
- Make sure that you do not have to work or engage in strenuous physical exercise while you are fasting - it is important to choose the days when you are going to fast carefully - weekends are best, when you can rest and relax and do not have to engage in physical activity or drive a car, or do anything else where you need to be physically and mentally alert
- If you feel faint, or dizzy, or develop any symptoms that indicate that you are overdoing your fast, stop immediately and eat some solid food
- Never combine fasting with exercise as you may develop severe hypoglycaemia
- If in doubt about your health, have a medical checkup and ask your doctor if you can fast. If he/she says “No”, then don’t even try fasting
A word of caution
The research studies and their findings, which were reported recently involving fasting and the use of vegan diets to lower blood pressure are preliminary investigations and readers should note that all these interventions were carried out in hospitals.
If you suffer from high blood pressure and would like to try fasting as a treatment, then you need to discuss this with your physician.
If he/she agrees, then it may be possible for you to check into hospital and use the water-only diet. The important thing is to remember that this type of treatment must be carried out under medical supervision.
It is not a home remedy that you should try on your own. If medical complications should arise, you will not be able to receive the necessary treatment if you are not in hospital. So take great care and always ask your doctor first.
The DASH Diet
Hypertension also reacts well to eating a diet rich in fruit, vegetables, unprocessed grains and cereals and fat-free milk, yoghurt and cottage cheese.
This dietary approach was developed in the USA and is called the DASH Diet. If you visit the Health24 Website and click on ‘Hypertension Centre’ you will find all the information you require concerning the DASH Diet.
You can use the DASH Diet at home and this may well be an easier, less complicated alternative than fasting in hospital.
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Dr Ingrid van Heerden is a registered dietician and holds a doctoral degree in Nutrition and Biochemistry. She believes that "we are what we eat" and offers free nutrition and weight loss advice via her DietDoc service on Health24.com. Read more of her articles.