Maintaining Blood Pressure Stability With Bananas

Blood pressure and hypertension

Epidemiological findings over the years have shown that there is a direct relationship between blood pressure and cardiovascular disease outcomes. This is true with both men and women across all age groups, races, and ethnicities. Classification of blood pressure levels has helped to determine the varying levels of risk, appropriate treatments, and goals of therapy. 

The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) as well as the World Health Organization and the International Society of Hypertension (WHO-ISH) have developed a classification chart for blood pressure readings; Nonhypertensive individuals with a systolic pressure reading of 130 -139 mm Hg or a diastolic blood pressure reading 85 -89 mm Hg are classified as having a high-normal blood pressure.

Subjects whose systolic blood pressure is at least 140 mm Hg and diastolic blood pressure is at least 90 mm Hg or more after repeated readings are considered hypertensive. Hypertension also known as high blood pressure exposes individuals to cardiovascular events and must therefore be treated to reduce the risk of these unwanted complications.

High blood pressure is a medical condition whereby blood flow through the blood vessels occurs with a force higher than normal and tends to strain the heart and injure the blood vessels. Complications may develop from this such as stroke, heart attack, renal function impairment and if left untreated, death.^1,2 

Global prevalence of high blood pressure

In many industrialized countries, about half of the adult population (people older than 55 years) suffers from hypertension. The incidence of hypertension has been shown to increase as people get older and if left unmanaged, the sufferer is predisposed to stroke, congestive heart failure, coronary heart disease, and renal diseases. Indeed the control and management of hypertension have improved particularly since the latter part of the 20^th century, experts warn that the rate of improvement may have reached a plateau.^3,4

In the United States of America, between 2015 and 2016, 29.0% of adults had hypertension. Women (27.7%) and men (30.2%) had similar prevalence rates. This prevalence was found to be slightly higher among men than among women and there was an increase with age from 7.5% in adults between the ages of 18 -39 up to 33.2% in adults between 40 -59 years old. There was a further leap up to 63.1% among adults over 60 years old.

Currently, there are variabilities in available antihypertensive drugs concerning their ability to protect subjects from end-organ damage and fatal cardiovascular events. Most patients need two or more drugs to control their blood pressure. Despite all the available pharmaceutical medications, the associated risk factors remain poorly controlled in most populations. Therefore, the importance of adjuvant methods like lifestyle and dietary modifications cannot be over-emphasized.^5,6

Factors affecting blood pressure

Globally, hypertension is a public health challenge due to its prevalence and predisposition to cardiovascular and renal diseases, especially as the population advances in age. Unfortunately, this is hardly modifiable. There are many other important risk factors that predispose individuals without an underlying medical condition to hypertension (essential hypertension). Some of these include lifestyle factors such as inadequate physical activity, obesity, dietary factors such as high fat, alcohol, and sodium intake, insufficient intake of healthy foods such as whole grains, fruits and vegetables. 

Lifestyle modifications such as moderate exercise, weight loss, reduced alcohol, sodium and fat dietary consumption are effective interventions for individuals with blood pressure above optimal (pre-hypertension) and can even be added as adjunctive therapy for hypertensive subjects using antihypertensive medications. This is effective with minimal risk and a low cost. High sodium significantly increases blood pressure and consequently increases the risk of hypertension.

A balance between potassium and sodium causes a marked decrease in a population. Studies show that an increase in the balance between these is a non-pharmacological means of improving the blood pressure of patients. Intake of potassium through diet has been found to confer a notable degree of protection on the cardiovascular system, reducing blood pressure in hypertensive patients and showing no effects on lipid-blood concentrations or renal function. Natural foods such as fruits and vegetables are an important dietary source of potassium, they have low sodium content in comparison with processed foods which have high sodium and low potassium content.⁷

Bananas and blood pressure

Vegetables and fruits have been shown to have numerous medicinal effects and are considered to be vital dietary components. Many plants are known to be medicinal, and they are popular in traditional medicine in the treatment of diseases all over the world. Bananas, a tropical fruit, is originally native to the Southwestern Pacific.

However, around 600 B.C., it spread to India after which it was cultivated further in many other tropical countries. There are about 300 species of banana across Asia and the Australian tropics. However, India, China, Ecuador, Brazil, Mexico, Indonesia, Thailand, Philippines, and Colombia are some countries popular for their banana cultivation. 

The medicinal benefits of bananas are numerous, ranging from their use in the treatment of diarrhoea and diabetes (using unripe bananas), dysentery, ulcerative colitis, gout, hypertension, and cardiac diseases. The many beneficial components of the fruit are dopamine, vitamin C, and other antioxidants to name only a few. Bananas are one of the many health-beneficial fruits available for consumption and studies have shown that it has high potassium content. A single banana is capable of providing 23% of the daily dietary requirement of potassium (approximately 350 mg of potassium) for an average adult. 

Apart from the benefit of preventing muscle spasms, potassium helps lower the risk of stroke and reduce blood pressure, particularly in individuals who are deficient in potassium and it can improve overall heart function. Bananas are affordable and available all year, and they also provide a variety of delicious options for consumption such as eating it directly, combined in a fruit salad, or consumed as a milkshake or smoothie. 

This claim has been corroborated by the United States of America’s Food and Drug Administration (FDA) which states that “a diet containing high potassium and low sodium may help reduce the risk of high blood pressure and stroke”. Additionally, studies have also found that potassium itself aids electrolyte balance and the maintenance of normal body fluid because it possesses ACE-inhibiting properties (Angiotensin Converting Enzyme inhibitors are a class of antihypertensive drugs) more prominently in ripened bananas. Researchers found that there was a drop in blood pressure among hypertensive patients by 10 % after consuming 2 bananas for a week.⁸

Bananas contain sterol-like components like campesterol, sitosterol, and stigmasterol. These are beneficial for cardiovascular patients because they aid the normal functioning of the heart. Bananas are rich in fibre, and a fibre-rich diet has been shown to reduce the risk of stroke (especially when taken along with magnesium) as well as countering heart diseases and high cholesterol. When an individual is exposed to stress, their potassium level drops. Bananas have been known to restore and regulate this. 

All parts of the bananahave high nutritional value and are therefore a staple food in many cultures. They extract high quantities of micronutrients from the soil which is thereafter made available for human consumption. A 2017 study on the Musa acuminate species of bananas by Shankar et al. observed a nutritional profile pattern as follows: 3.06g of starch, Potassium content of 4.5mg, protein 8.5g, 10g of fiber, reducing sugars of about 80 mg, fat 8.3g, 3.4g of sodium in a 100g of banana.

Banana has the highest content of potassium in comparison with most other fruits, meat, and vegetables. Other species of banana, such as Musa sapientum and Musa paradisiaca, contain 360 g and 487g of potassium, respectively, in 100g of each 9-10. A study suggests that consumption of at least two servings of banana may increase potassium in the body for about an hour after ingestion. Some other studies hypothesize that the diuretic activity resulting from banana intake leads to increased urine excreted. The urine excretion is accompanied by electrolyte removal from the body. This effect has been attributed to the saponin, terpenoids, and flavonoids phytochemical content of the fruit.²

The American Society of Hypertension in 2010 recommended that at least 4.7 g per day of potassium would be beneficial for hypertensive individuals. Another recommendation by the European Society of Hypertension also agrees with increased potassium intake. Similarly, the World Health Organization (WHO) in 2003 suggested that a diet high in fruits, vegetables, and potassium and reduced sodium ingestion has been proven to reduce the incidence of high blood pressure.⁷

Summary

High blood pressure (Hypertension) is a prevalent condition across the world. It is considered a public health challenge by experts. Studies show that it becomes more prevalent as the population advances in age.

A person is considered to be hypertensive where the systolic blood pressure is greater than or equal to 140 mm Hg and a diastolic blood pressure of at least 90 mm Hg. If hypertension is left untreated long-term, it could lead to cardiovascular events such as stroke, heart attack, and renal failure among others. Hypertension is caused by many factors which may include genetic factors, lifestyle, and or dietary factors.

Antihypertensive medications that are currently available are used in twos or threes for their synergistic effects and many of them have been known to vary in their ability to protect the patient from end-organ complications. Therefore, it is essential to adopt adjuvant treatment methods (such as encouraging healthy lifestyle modifications and dietary changes) to complement the existing ones.

Bananas are globally well known and findings have shown that they have medicinal properties that hypertensive patients could benefit from. They have been shown to provide potassium when ingested and regulate the potassium-sodium composition of the body, thereby reducing the blood pressure of the individual. Some studies also suggest that ingestion of bananas induces diuretic effects which help eliminate electrolytes and as a consequence, there is a drop in blood pressure.

Bananas also have phytochemicals and stroll-like components which have been shown to be cardio-protective and known to aid the normal functioning of the heart. More studies need to be carried out to support these findings and introduce these into pharmaceuticals to support currently available therapies.

Conclusion

Studies have shown that bananas can have beneficial effects for individuals with high blood pressure because it helps to eliminate harmful blood pressure- spiking electrolytes, supplies the body with daily required potassium when ingested in sufficient quantities, thereby regulating the blood pressure and exhibit cardio protective properties due to its phytochemical contents.