Hypertension is normally treated with drugs which typically need to be continued for life. But is there anything else you can do?
Foods that Help
The most well-known diet for hypertension is the DASH diet (Dietary Approaches to Stop Hypertension). This diet emphasises healthy foods such as fruit vegetables, nuts, seeds and fish with less red meat, sugar and refined carbohydrates. It has been shown a number of studies to lower blood pressure and reduce the risk of heart attacks and stroke. It is similar to the Mediterranean diet.
However what is less widely known about that the DASH diet is based on the work of a Dr Frank Sacks. He was well aware that research studies had found that the more plant-based the diet, the greater the reduction in blood pressure and the more meat, fish and dairy in the diet the lower the benefit. However he did not think he could “sell” a purely plant-based diet to the public so it was watered down.
A good diet for hypertension should be high in potassium (most fruit and vegetables) and magnesium (green leafy vegetables, seeds). Organic produce has higher levels of vitamins and minerals. Recommended foods include apples, asparagus, aubergine, broccoli, cabbage, cantaloupe, grapefruit, all green leafy vegetables, melons, peas, prunes, raisins, squash and sweet potatoes. Garlic has a definite beneficial effect in hypertension as do celery, blueberries, onions and cayenne pepper.
Flaxseed deserves a special mention as 3 tablespoons of ground flaxseed daily has been found to reduce blood pressure as much as the most effective blood pressure tablets (calcium antagonists) and more than other blood pressure drugs.
Foods that Harm
Probably the most important change in the diet is to reduce or stop sugar and refined carbohydrates. These can create a condition called insulin resistance and this can lead to hypertension, heart disease or diabetes. It affects 25% of the population. Sugar is in lots of foods, especially processed foods. Read labels: these give sugars per 100grams and remember that 1 teaspoonful of sugar is 4 grams. It is the hidden sugars which catch people out and high levels can be found in cereals, soups, yoghurts, sauces and particularly foods labelled as low fat. Refined carbohydrates include most bread (except wholemeal) most cereals (which are also high in sugar and salt), pasta, cooked potatoes, chips and white rice. Sugar and refined carbohydrates make up 50% of the British diet and have no nutritional value but they are addictive. Most wholemeal or wholegrain products are okay (though even these often have added sugar).
A likely mechanism here is that carbohydrates cause spikes of high sugar with a later sharp fall in sugar (hypoglycaemia). As blood sugar falls adrenaline is released causing blood pressure to rise.
Keep levels of meat and dairy products low. In particular avoid milk on cereals (use alternatives such as unsweetened soya, almond or rice milk). Milk has a strongly association with heart disease.
Hydrogenated fats are particularly harmful. These occur whenever fats are heated such as in margarines, fried foods and supermarket vegetable oils. They are also in most processed foods. Increase essential fats which are found in oily fish (herring, mackerel, sardines, anchovies), seeds (linseed, sunflower seeds, pumpkin seeds), some nuts eg. almonds, and cool-pressed seed oils (eg sunflower oil). These must not be heated. Cook with olive oil, butter or coconut oil.
The longer the interval between the last food you eat in the evening meal (and this includes alcohol) and breakfast the better. After 6 hours without food the body starts burning fat which is beneficial. Ideally make this interval at least 12 hours (optimum 16 hours). Making this interval longer has been shown to improve blood pressure.
There is a low salt version of the Dash diet. However a lot of the data linking salt with hypertension is unconvincing. Table salt and sea salt are largely refined products and a better alternative is salts which contain other healthy minerals. Celtic sea salt is one of the healthiest but Solo or Losalt are useful alternatives.
Exercise for 20 minutes three times weekly has been shown to reduce blood pressure.
Weight loss alone can help blood pressure.
Alcohol typically worsens blood pressure, so keep this low.
Sunlight has an important effect in lowering blood pressure. Being outdoors on a cloudy day is quite adequate for the health benefits.
Mental Techniques can also be helpful. Blood pressure can respond to biofeedback. Listening to a good relaxation tape can be a very enjoyable way of improving your health.
Some people have food allergies and are sensitive to specific foods and their blood pressure can drop markedly after an exclusion diet. Clues that you may react this way are other allergic symptoms such as catarrh, irritable bowel, migraine or asthma. It is easy to find out if you have this problem because your blood pressure will be much lower after one week on an exclusion diet. (See separate leaflet).