More local foods to beat heart diseases validated
Nigeria on September 29 joined the rest of the globe to celebrate the World Heart Day (WHD), which is part of an international campaign to spread awareness about heart disease and stroke prevention.
The World Heart Federation (WHF) found that heart disease and strokes are the world’s leading cause of death, killing 17.1 million people every year – that’s more than victims of cancer, Human Immuno-deficiency Virus (HIV) and Acquired Immune Deficiency Syndrome (AIDS) and malaria.
Several studies have shown that heart diseases are the major cause of morbidity and mortality in adult Nigerians. In recent times, diabetes, hypertension, high cholesterol and heart diseases with its attendant complications including stroke, heart attack and kidney damage have been on the increase.
Overeating, lack of exercise, unhealthy diets and high blood pressure, cholesterol and glucose levels have been identified as factors that can trigger heart disease and threaten human lives.
However, Nigerian researchers have identified and validated more local foods and plants for prevention, treatment and management of heart diseases.Top on the list are garlic, Zobo and scent leaf. Researchers have found that eating functional foods like coconut oil, banana, various beverages, different fruits, specific vegetables, grains, legumes, herbs and spices also helps in fighting these chronic diseases.
Previous studies had shown that a combination of daily intake of coconut oil, local spices, banana, local bitters such as bitter leaf, scent leaf as well as exercise training would reduce the risk of developing chronic and non communicable diseases like blood pressure, blood sugar (diabetes) and heart diseases.
Earlier studies suggest that a combination of bitter leaf (Vernonia amygdalina) and scent leaf (Ocimum gratissimum) extracts could not only reduce the blood glucose level, but protects the heart and testes against impairment and complete destruction due to diabetes.
A study by researchers at the University of Calabar published in February 2012 edition of The Internet Journal of Tropical Medicine concluded, “we therefore conclude that extracts of Vernonia amygdalina and Ocimum gratissimum apart from their hypoglycemic actions could protect the heart against impairment and complete destruction due to diabetes.”
A recent review of medicinal plants with hypotensive or antihypertensive effects published in Journal of Medical Sciences identified medicinal plants that has been scientifically studied and reported to have hypotensive or antihypertensive effects.
Allium sativum (garlic)
A plant that is indigenous to Asia but has been introduced to Africa especially the savannah areas. It is used locally in Nigeria for the treatment of respiratory infections, worms and sometimes applied topically for the treatment of skin diseases. Garlic has been used as both food and medicine in many cultures for thousands of years. One of the primary active compounds that give garlic its characteristic odour and many of its healing benefits is called Allicin.
Studies suggest that raw garlic may have beneficial cardiovascular effects, including lowered blood pressure. The same study concluded that since garlic is relatively safe and has a number of other healthful benefits, a professional herbalist may recommend 5 to 10 minced raw garlic doves per day or 300 mg of dried garlic extract three times a day for those at risk of hypertension and heart disease.
According to Prof. Maurice Iwu, it has been established that, extracts of garlic possessed a demonstrable cholesterol lowering and antihypertensive properties. In a feeding experiment with rabbits, the animals given garlic had very less marked increase in blood cholesterol than those given the same diet but without garlic. The oil extracted from garlic prevents fat induced hypercholesterolemia and sucrose induced hyperlipidaemia and enhances fibrinolytic activity. The extract has been shown in five consecutive cases of hypertension to reduce the blood pressure to satisfactory levels.
Hibiscus sabdarifa (HS)/Zobo
This happens to be one of the most extensively studied plants for antihypertensive properties. The plant belongs to the botanical family malvacae. The leaves; calyx and corolla of this plant are use traditionally in many West African countries for various medicinal purposes and edibles. The calyx is used for making beverage soup, drink (Zobo) and sauces. The antihypertensive effect of this plant extract has been variously studied. Iwuanyawu and Ayani reported from Jos, Nigeria that, the extract of HS at doses of 500 and 1000 mg kg-1 per oral produced a dose dependent reduction of blood pressure in spontaneously hypertensive rats. Adegunloye et al independently produced a similar result in Lagos, Nigeria. An intravenous administration of 20 mg kg-1 of a water extract of dry HS calyx produced a fall in the blood pressure of experimentally induced hypertensive rats.
The anti hypertensive effects of the crude extract of HS have been attributed to mediation through acetylcholine and histamine like dependent mechanisms via direct vaso-relaxant 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 aortic relaxant effect of the plant was recently found to be mediated through chronic nitric oxide synthetase inhibition.
Apart from attenuating hypertension, the chronic administration of aqueous extract of HS has been reported to reverse cardiac hypertrophy in renovascular hypertensive rats. Chen et al also reported that, HS extract inhibits the development of atherosclerosis in cholesterol fed rabbits. At a dose of 500-1000 mg kg-1 it lowers both systolic and diastolic blood pressure. Aqueous extract of HS given intravenously to cats, lowered blood pressure dose dependently. It relaxed rabbit aorta, uterus and diaphragm.
Clinical trials of the plant extract in human 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.
The evidence for efficacy of Hibiscus sabdariffa extract in human hypertension was provided by Haji-Faraji and Tarkhani when 31 patients with moderate essential hypertension were given HS extract for 12 days; 11.2 per cent decrease in systolic blood pressure and 10.7 per cent reduction in diastolic blood pressure was recorded. Another human trial was conducted by Kirdpon to buttress the therapeutic efficacy of HS extract against high blood pressure. It was observed that, the urinary excretion of creatinine, uric acid, citrate, tartrate, calcium and sodium increased when 36 men consumed HS regularly with a corresponding fall in blood pressure. Odigie and Adigun reported about the blood pressure lowering effect of HS extract in normotensive volunteers.
Is a rapidly growing plant belonging to the Cecropaicea family, ubiquitous to the tropical rain forests particularly of West Africa. It is known as the umbrella three or corkwood in English, parasoiler in French; Aga or Agbawo in Yoruba; Onru in Igbo and Uno in Efik. Traditionally, preparations from various parts of the plant such as leaves, latex, stem bark and roots are used as remedy for various illnesses especially hypertension, typanosomiasis, leprosy, chest infections and rheumatism.
Several workers have demonstrated the scientific efficacy of the latex and the leaves extract as a vaso-relaxant and therefore hypotensive agent. Ayinde et al reported about the hypotensive effect of Musanga cecropioides stem bark extract in rabbits. The water extract of the stem bark produced a dose-related reduction in mean arterial blood pressure.
The mean arterial blood pressure fell by 4.51±0.5 mm Hg at 10 mg kg-1 and 65.23±6.28 mm Hg at 40 mg kg-1. The hypotensive effect of the extract was not affected by prior administration of either atropine (0.5 mg kg-1) or promethazine (0.25 mg kg-1). In a similar, studies on the stem bark extract of the plant. Adeneye reported that, a graded doses of the extract (0.5 to 5 mg kg-1 body weight) produced a dose dependent fall in the mean arterial pressure of Sprague-Drawley rats.