Nigeria, yesterday, joined the rest of the globe to celebrate World Hypertension Day (WHD). May 17 every year is set aside by the World Hypertension League (WHL), an affiliated section of the International Society for Hypertension (ISH), since 2005 to promote public awareness of the menace and to encourage citizens of all countries to prevent and control this silent killer, the modern epidemic. The theme for WHD 2017 is Know Your Numbers with a goal of increasing high blood pressure (HBP) awareness in all populations worldwide. CHUKWUMA MUANYA, Assistant Editor, examines tested natural remedies for the treatment of hypertension or HBP.
HYPERTENSION (HTN) is the medical term for high blood pressure. Studies have shown that it is dangerous because it makes the heart work too hard and contributes to atherosclerosis (hardening of arteries), besides increasing the risk of heart disease and stroke. HTN can also lead to other conditions such as congestive heart failure, kidney disease, and blindness.
According to the World Health Organization (WHO), hypertension is a global health issue that affects more than one billion people worldwide and it is estimated that hypertension is responsible for at least 51 percent of deaths due to stroke and 45 percent of deaths due to heart disease.Several studies have shown that many people have high blood pressure, but most do not know, as it does not usually have its own symptoms.
Blood pressure readings are in two sets of numbers. The top number, systolic pressure indicates pressure on the artery walls when the heart beats. The lower number, diastolic pressure, and shows the pressure on artery walls between heartbeats.
A normal reading is 120/80. Above those numbers up to 140/90 is considered pre-hypertension while above 140/90 is hypertension. But people with normal health in the pre-hypertension zone are not considered at risk for strokes, heart, or kidney failure.
Those who are overweight or diabetic are more at risk with higher than normal BP. Over half of the high BP population is diabetic. Men are more likely to have high BP, and those who smoke and drink alcohol excessively are more likely to have high BP.
Five healthy lifestyle modifications that lower hypertension risk by two-thirds
A research team from Finland reporting to the European Society of Cardiology Congress has found that healthy behaviours regarding alcohol, physical activity, vegetable intake and body weight reduce the risk of hypertension by two-thirds. They note that prevention of hypertension is essential to improving health and preventing morbidity and mortality.
Follow healthy lifestyle parameters to slash the risk of high blood pressure
The team identified five major cardiovascular disease-related lifestyle factors: smoking, alcohol consumption, physical activity, obesity and consumption of vegetables. Their task was to determine if correcting abnormalities in these factors could help predict the future increase of blood pressure and development of clinical hypertension. They developed a large cohort study including 9,637 men and 11,430 women, aged 25 to 74 who were free of hypertension during baseline measurements. The study lasted for 20 years.
The researchers set parameters for healthy lifestyle factors as follows: not smoking; alcohol consumption less than 50g per week; leisure time physical activity at least three times per week; daily consumption of vegetables; and normal body weight of Body Mass Index (BMI) lower than 25.BMI is a measure of weight in kilogrammes divided by height in metres squared that is kg/m2.
Fruits and vegetables: Dietary potassium linked with lower blood pressure
Eating potassium-rich foods like sweet potatoes, avocados, spinach, beans, bananas — and even coffee — could be key to lowering blood pressure.Professor of cell and neurobiology at the Keck School of Medicine of the University of Southern California (USC), United States (US), Alicia McDonough, said: “Decreasing sodium intake is a well-established way to lower blood pressure. But evidence suggests that increasing dietary potassium may have an equally important effect on hypertension.”
McDonough explored the link between blood pressure and dietary sodium, potassium and the sodium-potassium ratio in a review article published in the April 2017 issue of the American Journal of Physiology — Endocrinology and Metabolism. The review looked at population, interventional and molecular mechanism studies that investigated the effects of dietary sodium and potassium on hypertension.
Increasing dietary potassium will take a conscious effort, however. McDonough explains that our early ancestors ate primitive diets that were high in fruits, roots, vegetables, beans and grains (all higher in potassium) and very low in sodium. As a result, humans evolved to crave sodium — but not potassium. Modern diets, however, have changed drastically since then: processed food companies add salt to satisfy our cravings, and processed foods are usually low in potassium.
“If you eat a typical Western diet,” McDonough says, “your sodium intake is high and your potassium intake is low. This significantly increases your chances of developing high blood pressure.” When dietary potassium is low, the balancing act uses sodium retention to hold onto the limited potassium, which is like eating a higher sodium diet, she says.
McDonough recommends developing public policies to increase intake of dietary potassium from plant-based sources. She also advocates adding potassium content to nutrition labels to help raise consumers’ awareness of economical sources of potassium.
Football is medicine for women with high blood pressure
The Danish concept Football Fitness has proved to be just as effective as tablets for countering high blood pressure. Furthermore, women participating in the project have also benefited from improved physical fitness, decreased body fat percentage and stronger bones.
Professor Peter Krustrup of the University of Southern Denmark calls this “a 4-0 health victory for Football Fitness, with the ball hitting every corner of the net”. This is the first time he has demonstrated a long-term effect for female patients participating in Football Fitness.
In a randomised trial involving 31 women aged 35-50 with mildly high blood pressure, one hour of football training two to three times a week over one year proved to be an effective broad-spectrum medicine, with positive effects on blood pressure, body fat percentage, bone density and physical fitness.
According to Professor Krustrup, the results of the project, backed by 14 years of football research, show that football can be used for effective prevention and treatment of a number of lifestyle diseases, including cardiovascular disease and type 2 diabetes. The results also support the growing evidence that physical activity can lead to a more broad-spectrum reduction in risk factors for cardiovascular disease than traditional pharmacological treatment. The study was published in the acclaimed Scandinavian Journal of Medicine and Science in Sports.
Banana (Musa sapientum)
Researchers have found that banana contains phytochemicals, thus its intake reduces blood pressure significantly among hypertensive individuals.The study published in the journal Medical Science is titled “Effect of banana on blood pressure of hypertensive individuals: a cross sectional study from Pokhara, Nepal.”
Medicinal use of banana is well known. Musa paradisiaca (plantain) and Musa sapientum is used in diarrhoea (unripe), dysentery, intestinal lesions in ulcerative colitis, diabetes (unripe), in sprue, uremia, nephritis, gout, hypertension, cardiac disease.
Apart from effect in blood pressure, banana inhibits atherosclerosis and gallstones in vivo. Musa paradisiaca inhibits cholesterol crystallization, showing this effect. Banana contains large amounts of potassium. Approximately, 300mg/100g fresh weight. Experimental evidences suggest that potassium is an important regulator of blood pressure. Altered vascular sensitivity to vasoactive hormones and alterations in divalent cation metabolism playing a key role mediating blood pressure. After extensive review of literature relatively fewer documents found enlighten the blood pressure lowering effect of banana on human subjects.
Avocado (Persea americana)
A new review of studies looking at the health effects of avocados finds that there is “satisfactory clinical evidence” that the fruit can help to treat metabolic syndrome.
Metabolic syndrome is defined as a cluster of risk factors that can raise the risk of other health conditions, such as type 2 diabetes, heart disease, and stroke.
Risk factors include abdominal obesity, low levels of high-density lipoprotein (HDL) cholesterol – or “good” cholesterol – high triglyceride levels, high blood pressure, and high fasting blood sugar.The presence of at least three of these risk factors warrants a diagnosis of metabolic syndrome.
Adopting a healthful diet is considered one of the best ways to prevent or treat metabolic syndrome. The new review – recently published in the journal Phytotherapy Research – suggests that avocados should form a part of this diet.
Eating watermelons can help reduce blood pressure
Food scientists from the Florida State University, United States, have discovered that consuming 6 grams of L-citrulline contained in watermelon extract for a period of six weeks helped normalize the blood pressure of all the participants in the study (nine adults) who were previously observed to have raised blood pressure. This recent activity was reported in The News.
The lead researcher of the group that conducted the new study, Dr. Arturo Figueroa, claimed that the team is the first to document the significant improvements in aortic hemodynamics in middle-aged people (both men and women) who have been diagnosed to be pre-hypertensive, but is otherwise healthy, and regularly receiving therapeutic watermelon doses.
To put it simply, the findings imply that the common watermelon, sometimes called the “functional food” possesses a vasodilatory effect. Dr. Figueroa further adds that watermelon consumption can actually keep pre-hypertension at bay, and prevent it from advancing into a full-blown case of hypertension; and as previously mentioned, hypertension is the precursor to more serious health conditions such as strokes and heart attacks.The study discussed above was recently included in the pages of the American Journal of Hypertension.
Drinking beet juice daily lowers high blood pressure
A new study just published in the American Heart Association journal Hypertension has found there is a substance that lowers high blood pressure significantly.
Researchers found that people with hypertension, the medical term for high blood pressure, who drank about eight ounces of beet juice daily, had a decrease in blood pressure of about 10 mm Hg. The scientists explained in their paper that the amount of juice from beets (known as beetroots in Europe) consumed contains 0.2g of dietary nitrate — that’s about the same amount of nitrate that’s found in a large bowl of lettuce or approximately two beets.
The study involved eight women and seven men who had a systolic blood pressure between 140 to 159 millimeters of mercury (mm Hg), a measurement indicating they had high blood pressure. Other than hypertension, none had other medical complications and they weren’t taking blood pressure medication. The research subjects drank 250 mL of beet juice or water containing a low amount of nitrate. Then their blood pressure was monitored over the next 24 hours.
Compared with the group drinking water with just a bit of nitrate, the research subjects who drank beet juice were found to have reduced systolic and diastolic blood pressure. This impact on blood pressure continued even after nitrite circulating in the blood had returned to their previous levels before the juice was consumed. In fact, the positive effect was most pronounced three to six hours after drinking the juice – but it was still present even a day later.
Natural herbs in the treatment of hypertension
A study published in Pharmacognosy Review has validated some local herbs for the treatment of hypertension. The study is titled “Role of natural herbs in the treatment of hypertension.”This review provides an introduction of the naturally occurring medicinal plants that have so far been scientifically studied and reported to have hypotensive or antihypertensive effects.
Garlic (Allium sativum)
Garlic has long been used for a variety of cardiovascular conditions, especially hyperlipidemia. It has also been reported to have hypotensive action. It is thought to increase nitric oxide production, resulting in smooth muscle relaxation and vasodilatation. One of the primary active compounds that gives garlic its characteristic odor and many of its healing benefits is called allicin. Meta-analysis of randomly chosen literary data has demonstrated that garlic is related to decrease of Blood Pressure (BP) in patients with increased systolic pressure, but not in patients without increased systolic pressure.
Garlic preparations have been found to be superior to placebo in reducing BP in individuals with HTN. The antioxidative and antihypertensive effect of garlic has been observed in 20 patients with HTN compared to 20 patients with normal pressure, who have been receiving garlic pearls preparation for a period of two months. The results have revealed decreased BP, significant reduction of 8-hydroxy-2-deoxyguanosin, level of nitric oxide, and lipid peroxidation, and an increased level of antioxidative vitamins (C and E). This study points to the beneficial cardioprotective action of garlic in essential HTN.
Soursop (Annona muricata)
Annona muricata is a member of the family of custard apple trees called Annonaceae and a species of the genus Annona, known mostly for its edible fruits Annona. The tree grows natively in the Caribbean and Central America. The leaf extract of the plant has been reported to lower an elevated BP by decreasing the peripheral vascular resistance.
Oat (Avena sativa)
A diet containing soluble fibre-rich whole oats can significantly reduce the need for antihypertensive medication and improve BP control. Considering the lipid and glucose improvements as well, increased consumption of whole oats may significantly reduce cardiovascular disease risk. The addition of oat cereals to the normal diet of patients with HTN has been found to significantly reduce both systolic and diastolic BP. Soluble fiber-rich whole oats may be an effective dietary therapy in the prevention and adjunct treatment of HTN.
Tea plant (Camellia sinensis)
There are many potential health benefits from drinking tea. There is lots of interest among researchers on the effect of tea on cardiovascular disease. Research on tea and HTN is contradictory. Research on black tea (fermented tea) (Camellia sinensis) shows no effect on BP in people with HTN. Population research links consumption of green tea (unfermented) (Camellia sinensis) and oolong tea (partially fermented) (Camellia sinensis) with a decreased risk of developing HTN.
Carrot (Daucus carota)
It has been used in traditional medicine to treat HTN. Activity-directed fractionation of aerial parts of D. carota resulted in the isolation of two coumarin glycosides coded as DC-2 and DC-3. Intravenous administration of these compounds caused a dose-dependent (1–10 mg/kg) fall in arterial BP in NMT anesthetized rats. In the in vitro studies, both compounds caused a dose-dependent (10–200 μg/ml) inhibitory effect on spontaneously beating guinea pig atria as well as on the K+ (potassium ion) -induced contractions of rabbit aorta at similar concentrations. These results indicate that DC-2 and DC-3 may be acting through blockade of calcium channels, and this effect may be responsible for the BP-lowering effect of the compounds observed in the in vivo studies. Two new guaiane-type sesquiterpene terpenoids containing an interesting epoxy unit, daucuside and daucusol, have been isolated from fruits of D. carota.
Soybean (Glycine max)
Soybean has been found to be effective as a hypotensive agent. One study has shown a very modest reduction in BP, whereas other study shows no benefit.
Zobo/Roselle (Hibiscus sabdariffa)
This happens to be one of the most extensively studied plants for antihypertensive properties. The leaves, calyx, and corolla of this plant are used traditionally in many West African countries for various medicinal purposes and as edibles. The antihypertensive effect of this plant extract has been variously studied. One study reported the antihypertensive effect of calyx of HS.
Adegunloye et al independently produced a similar result in Lagos, Nigeria. An intravenous administration of 20 mg/kg of a water extract of dry HS calyx produced a fall in the BP of experimentally induced hypertensive rats. The antihypertensive effects of the crude extract of the HS have been attributed to mediation through acetylcholine and histamine like dependent mechanism through direct vasorelaxant effects. Earlier report showed that the petal crude extract of same plant had a direct relaxant effect on the aortic smooth muscle of rats. The chronic administration of aqueous extract of HS has been reported to reverse cardiac hypertrophy in renovascular hypertensive rats.
Clinical trials of the plant extract in human being have shown reliable evidence of antihypertensive effects. A standardized dose of HS (9.6 mg per day) given to 39 patients and captopril, 50 mg per day, given to the same number of patients did not show significant difference relative to hypotensive effects, antihypertensive effectiveness and tolerability.
Tomato (Lycopersicon esculentum)
Tomato extract contains carotenoids, such as lycopene, beta-carotene, and vitamin E, which are known as effective antioxidants, to inactivate free radicals and to slow the progress of atherosclerosis. A study showed that extract of tomato (Lyc-O-Mato) modestly reduces BP in patients with mild, untreated HTN. A significant correlation has been observed between systolic BP and lycopene levels. Tomato extract when added to patients treated with low doses of ACE inhibition, calcium channel blockers, or their combination with low-dose diuretics had a clinically significant effect-reduction of BP by more than 10 mmHg systolic and more than 5 mmHg diastolic pressure. No side effects to treatment were recorded and the compliance with treatment was high.
In anesthetized rats, the crude extract of the leaves of M. oleifera caused a fall in systolic, diastolic, and mean BP in a dose-dependent manner. The antihypertensive effect was brief, returning to normal within two minutes. Heart Rate (HR) was not affected significantly, except at high doses (3 and 10 mg/kg), which produced a small degree of bradycardia. It was also established that thiocarbamate and isothiocyanate fractions of the crude extract were responsible for the antihypertensive activity.
Scent leaf/Basil (Ocimum basilicum)
It has been reported that a crude extract of O. basilicum causes a fall in systolic, diastolic, and mean BP in a dose-dependent manner with median effective dose of 30 mg/kg. The antihypertensive effect is brief and returns to normal within two minutes. This cardiovascular effect of the extract has been attributed to eugenol, which exerts its effect by blocking the calcium channels.
Phyllanthus amarus belongs to the plant family Euphorbiaceae. To the Efik it is called oyomokeso amanke edem; geeron-tsuntsaayee (birds millet) in Hausa; Ibo (Asaba) buchi oro, Ibo (Umuahia) ngwu; iyeke in Urhobo; and ehin olobe or eyin olobe in Yoruba.
This plant is used as a diuretic and to lower BP in traditional medicine practice. Amaechina and Omogbai reported that intravenous administration of the aqueous extract of the leaves of this plant (5-80 mg/kg) to anesthetized NMT male rabbits produced a significant fall in mean diastolic, systolic, and mean arterial pressures in a graded dose-response manner. The dose of 5 mg/kg produced the least hypotensive effect, causing a fall in mean diastolic, systolic, and mean arterial pressure of 13.3 ± 3.1, 19.7 ± 5.4, and 14.3 ± 3.4 mmHg, respectively, whereas the dose of 80 mg/kg produced the greatest fall in mean diastolic, systolic, and mean arterial pressure of 49.7 ± 7.9, 45.5 ± 9.5, and 48.00 ± 6.5 mmHg, respectively. The extract produced greater depressant effect on the diastolic BP than the systolic BP.
Sesame (Sesamum indicum)
Alcoholic extract of seeds (1–30 mg/kg) caused hypotension in anesthetized rats. A fall in systolic as well as diastolic BP in dose-dependent manner was observed. HR was found to decrease at slightly higher doses (10-30 mg/kg). Atropine (2 mg/kg) was reported to abolish the cardiovascular responses, indicating the presence of acetylcholine-like substance in the seeds. Sesamin and sesaminol are the major phenolic constituents of sesame oil. A study in hypertensive patients indicated that sesame oil consumption remarkably reduced oxidative stress and simultaneously increased glutathione peroxidase, superoxidase dismutase, and catalase activities. These results support the hypothesis that sesame oil consumption may help to enhance antioxidant defense system in human beings. The investigators suggested that sesamin is a useful prophylactic treatment in HTN and cardiovascular hypertrophy.
Cocoa (Theobroma cacao)
Cocoa powder, enriched with flavonoid constituents, is used for preventing cardiovascular disease. Flavonoids, contained in chocolate, stimulate formation of nitric oxide, increase vasodilatation, and reduce endothelial dysfunction. A growing body of clinical research also shows that daily consumption of dark or milk chocolate (T. cacao), 46 to 105 g daily, providing 213 to 500 mg of cocoa polyphenols, can lower systolic BP by about 5 mmHg and diastolic by about 3 mmHg.
Wheat bran (Triticum aestivum)
It has been reported that increasing dietary wheat bran intake by 3 to 6 g/day modestly reduces systolic and diastolic BP.
Ginger (Zingiber officinale)
Ginger root is commonly used in Asian cooking. It acts to improve blood circulation and relaxes muscles surrounding blood vessels. The crude extract of ginger (Zo.Cr) induced a dose-dependent (0.3-3 mg/kg) fall in the arterial BP of anesthetized rats. In guinea pig paired atria, Zo.Cr exhibited a cardiodepressant activity on the rate and force of spontaneous contractions. In rabbit thoracic aorta preparation, Zo.Cr relaxed the phenyl ephrine-induced vascular contraction at a dose ten times higher than that required against K+ (80 mM)-induced contraction. Ca2+ channel-blocking activity was confirmed when Zo.Cr shifted the Ca2+ dose-response curves to the right, similar to the effect of verapamil. These data indicate that the BP-lowering effect of ginger is mediated through blockade of voltage-dependent calcium channels. Chronic administration of Pet ether extract (PE) (50 mg/kg/day; po), toluene fraction (10 mg/kg/day; po) of ginger rhizome, and Korean ginseng extract (KGE) (30 mg/kg/day; po) significantly reduced the BP in deoxycorticosterone acetate salt-induced hypertensive rats, whereas PE (50 mg/kg/day; po) and KGE (30 mg/kg/day; po) reduced the BP in fructose-induced hypertensive rats. The mechanism of action may partly involve the serotonergic antagonistic property. Human trials for hypotensive effect of ginger have been few and generally used a low dose with inconclusive results.