There has been a worrying increase in non-communicable diseases like hypertension and diabetes in Zimbabwe and also globally over the past two decades. Experts largely attribute this to changes in lifestyle and diet. It is, therefore, more crucial than ever that people have knowledge of ways they adopt to prevent and manage these non-communicable diseases. This article focuses on how diet can manage and prevent hypertension or high blood pressure. One great philosopher once said, “We are what we eat.”

What is blood pressure?

Specialists define blood pressure as the force that is exerted on blood vessels as blood moves through the body. They record blood pressure as two numbers, namely the systolic and diastolic pressure. They measure blood pressure in units called millimeters of mercury (mm Hg).

The systolic pressure is measured when the heart is pumping blood, and the diastolic pressure is measured between heartbeats when blood is flowing back to the heart.

What is hypertension or high blood pressure?

High blood pressure is diagnosed when the systolic pressure is above 140 mm Hg and the diastolic pressure is above 90 mm Hg after several readings. Normal blood pressure is a systolic reading between 110 and 130 mm Hg and a diastolic between 85 and 60 mm Hg.

The dangers of hypertension

Hypertension is a silent killer because it rarely has symptoms. It can cause heart attack, stroke, impaired vision, and kidney failure if left untreated for a long time. The risk of hypertension increases with age because one can go for years without being detected until a stroke or heart attack occurs. Hypertension has to be treated early after diagnosis.

Dietary approaches to managing hypertension

Balanced diet
Figure 1: Balanced diet

What people eat influences their chances of developing high blood pressure. Healthy eating is very important in reducing the risk of hypertension and lowering high blood pressure.

The DASH (Dietary Approaches to Stop Hypertension) diet is recommended for reducing high blood pressure. It basically comprises food that is low in fat (trans and saturated fat) and cholesterol. In addition, it comprises more foods that are high in roughage or dietary fibre for example vegetables, whole grains, and fruits. Also, the diet should be low in salt, processed foods, sugary beverages, alcohol, and red meat.

Important dietary changes to lower high blood pressure

1. Eat more fruits and vegetables

Fruits and vegetables
Figure 2: Health food-Fruits and vegetables

Fruits and vegetables contain magnesium, potassium, and dietary fibre proven to lower hypertension. About 4 to 5 portions of fruits should be consumed each day to lower hypertension. One portion of fruit is equivalent to a medium apple, banana, and orange or 2 smaller sized fruits (peaches, plums), or 1 handful of tiny fruits (wild loquat, snot apples, smellyberry fingerleaf fruits, grapes, strawberries) or 150 ml of pure fruit juice.

About 4-5 portions of vegetables should be consumed each day to lower high blood pressure. One portion of vegetables is equal to one small bowl (75-80g) of cabbage, leaf cabbage (rugare), indian kale (tsunga), jute (derere), spider flower (nyevhe), cow pea leaves (munyemba), or 3 tablespoons of peas or beans or 150 ml of tinned vegetables. Tinned vegetables are discouraged because they usually contain a lot of sodium because of preservatives they contain, for example, MSG.

2. Consume low fat dairy foods

Only 2-3 portions of dairy foods that are low in fat should be consumed each day, for example, low-fat milk, yoghurt, and cheese. This is because low-fat milk products contain potassium, calcium, protein, and magnesium, which help in lowering blood pressure. One portion of milk and yoghurt is equal to 150ml. One portion of cheese is 125g.

low-fat milk
Figure 3: low fat food

3. Reduce salt intake to lower than 6g per day

Iodised salt
Figure 4: Table salt

Most of the salt or sodium that we consume is in processed or manufactured foods and takeaways. Therefore, it is advisable to avoid canned, fried, and salted foods for example sardines, potato crisps, pizza, and dried kapenta. It is very important that foods that are low in salt/sodium should be used because this keeps blood pressure at healthy levels. Strategies that can lower the salt in the diet are using spices and herbs instead of salt for seasoning during the cooking process. In addition, reading food labels and avoiding foods with sodium preservatives like MSG is highly advisable.

4. Eat foods containing unsaturated fats in the diet

Figure 5: Food with unsaturated fats

Unsaturated fats help to maintain cholesterol-free arteries, which lowers blood pressure. Examples of foods that are rich in mono-and polyunsaturated fats are peanuts, avocados, soya beans, and fish such as tilapia and mackerel. Saturated and trans fats should be avoided in the diet because they help build up cholesterol in the arteries and this will eventually contribute to increased blood pressure. Foods like french fries, doughnuts, butter, and lard should be avoided as they contain the previously mentioned unhealthy fats. In addition, all meat should be lean and all fat should be trimmed.

5. Reduce alcohol intake

Alcohol should be consumed in moderation because drinking excess amounts can raise blood pressure. The recommended quantities per day are 1-2 units for women and 2-3 units for men. One unit is equal to half a pint of beer, a tot of spirits, or half a glass of wine. In addition, there should be at least two days without drinking alcoholic beverages per week.

Alcoholic beaverage
Figure 6: Alcoholic beverage

6. Other factors for consideration

  • Carbohydrates that are high in fibre, for example, wholemeal bread, unrefined maize meal and wholemeal rice should be included in the diet at least 3 servings a day because the fibre helps in lowering blood pressure.
whole meal bread
Figure 7: Whole-wheat bread
  • Drinks that contain a lot of caffeine, for example, coffee, red bull, coca-cola and energy drinks should be avoided. This is because caffeine can increase blood pressure. Dietary supplements of potassium, calcium and magnesium are not recommended for reducing blood pressure because the meal plan explained above will contain enough of these nutrients.
  • Patients who take medication for hypertension should continue taking it according to their doctor’s prescription. Stress can contribute to hypertension, so it is important to manage it.
  • Physical activity and losing weight also help in managing hypertension.