Maintaining Healthy Blood Pressure
27th August, 2021
The cardiovascular system, also commonly known as the circulatory system, consists of the heart, veins, arteries, capillaries and blood. These structures work together in circulating blood throughout the body while transporting oxygen, nutrients, hormones and waste products. The circulatory system has the vital role of maintaining blood homeostasis and the mechanisms which regulate this process are closely related to blood pressure.
Blood pressure is determined by two factors: 1) the amount of blood your heart pumps, and 2) the amount of resistance to blood flow in the arteries. This results with a blood pressure reading of two numbers: the systolic and diastolic, in a measurement of millimetres of mercury (mmHg). The systolic (top) number shows the pressure in the arteries during heart beats while pumping out blood; and the diastolic (bottom) number shows the pressure in arteries during the rests in-between heart beats. Healthy blood pressure is less than 120/80 mmHg.
Blood pressure naturally rises and falls throughout the day, however a consistently high force of blood flowing against arteries, causing circulatory resistance can result in high blood pressure. Prolonged high blood pressure may lead to a clinical diagnosis of hypertension, a common circulatory system condition and leading risk factor of cardiovascular disease.
The National Health Survey of 2017-2018 indicated that 4.3 million people had high blood pressure and 2.6 million adults reported hypertension. Hypertension and high blood pressure are often termed ‘silent conditions’, as they can be present for many years without any signs or symptoms. When uncontrolled, further complications may arise and for this reason, it is important to regularly monitor blood pressure.
There are five categories of hypertension: healthy, elevated, stage 1, stage 2 and hypertensive crisis. The progression of this condition can be caused by primary or secondary factors. Primary or essential hypertension is the most common type which develops gradually over many years with no direct cause, however it can be influenced by genetics, environmental factors, diet and lifestyle. Secondary hypertension has a rapid onset and tends to be more severe, occurring as a result of underlying health conditions.
Risk factors of hypertension include age, gender, ethnicity, family history and pregnancy. The proportion of Australians with high blood pressure and hypertension shows a trend which increases with age. The prevalence also varies with gender, with 25% of men and 20% of women reporting high blood pressure. Additional contributing factors in the development of hypertension include: insufficient physical activity, being overweight, poor sleep quality, stress, smoking, excessive alcohol consumption and an unhealthy diet.
So what are some ways to support healthy blood pressure?
- The DASH diet, short for ‘Dietary Approaches to Stop Hypertension’ is a nutritional program which aims to support healthy blood pressure. The DASH diet recommends a reduction of sodium, saturated fats, sugars and alcohol, while encouraging more vegetables, fruits, nuts, beans, wholegrains, poultry, fish and low-fat dairy products.
- According to the Australian Institute of Health and Welfare, in 2015, 5.8% of Australia’s total burden of disease was attributed to high blood pressure and of this, 21% was due to diets high in sodium. Sodium can directly increase the risk of hypertension and based on national guidelines, it is recommended to restrict daily intake to 1,500mg – 2,300mg.
- Potassium has dual actions in hypertension, it helps to reduce the effects of sodium and also supports blood vessel health. The recommended intake of potassium is 2,800mg – 3,800mg daily and can be found in foods including: apricots, avocados, bananas, beans, raisins, prunes, spinach, mushrooms and potato.
- Calcium is a mineral required for healthy functioning of the cardiovascular system and heart. The recommended intake of calcium is 1,000mg – 1,300mg daily and food sources include low-fat dairy, seafood, collard greens, legumes, white beans, tofu and dried fruit.
- Magnesium supports cardiovascular system health and functions. The recommended daily intake is 255mg – 420mg and dietary sources include: pumpkin seeds, almond, spinach, cashew, and black beans.
- Other heart healthy foods: antioxidants and flavonoids i.e. berries; polyphenols i.e. dark cocoa chocolate; nitrates i.e. beetroot juice; fibre i.e. oatmeal; and omega-3 i.e. salmon.
- Other foods to avoid: sugars and fructose, refined carbohydrates, red meats, caffeine and processed foods. An unhealthy diet has been associated with high blood pressure and reports indicate Australians don’t consume enough from the five food groups.
- Statistics show that four in five Australian adults do not meet the national guidelines for physical activity and that 67% of adults are classified as overweight or obese. Being overweight places extra stress on the cardiovascular system, with studies linking excessive body fat to increased risk of high blood pressure. A healthy weight range as indicated by the Body Mass Index (BMI) scale, supports a healthy blood pressure. Weekly recommendations include 150 minutes of moderate physical activity.
- Stress is a contributing factor to elevated blood pressure, particularly when faced by a stressful situation. The release of hormones activates the body’s “fight or flight” response, causing blood vessels to constrict and the heart rate to increase. Stress management techniques such as mediation, deep breathing or yoga can help to manage stress and shield against the short-term onset of high blood pressure.
- Sleep regulates various function in the body, including blood pressure. During sleep, blood pressure usually decreases and having deprived or disturbed sleeping patterns may negatively impact the cardiovascular system health and increase the risk of high blood pressure. It is recommended to sleep 7-9 hours per night and to promote good sleep quality, bedtime routines are encouraged.
- A clean lifestyle can help to maintain healthy blood pressure and also general wellbeing. Studies show that excessive alcohol consumption and smoking can have a damaging effect on the cardiovascular system and increase the risk of hypertension. Reports from 2019 indicate that of Australians aged 14 and over, 11% are daily smokers and 5.4% are daily consumers of alcohol. Reducing to a moderate intake, or ideally cessation of smoking and alcohol consumption habits can help to support healthy blood pressure.
To maintain a healthy blood pressure level, consider these modifiable risk factors of diet and lifestyle for a proactive approach towards supporting overall cardiovascular system health.