Cardiovascular diseases including heart attack and hypertension have been shown to be the leading causes of death worldwide. But recent researches suggest that eating meals rich in chilli pepper, tomatoes, olive oil, garlic, ginger could reverse the trend. CHUKWUMA MUANYA reports.
CAN extracts of chilli pepper, tomatoes, olive oil, garlic and ginger prevent heart attack? New research from the University of Cincinnati, United States, shows that a common, over-the-counter pain salve made with a component of chili pepper rubbed on the skin during a heart attack could serve as a cardiac-protectant, preventing or reducing damage to the heart while interventions are administered.
These findings are published in the September 14 edition of the journal Circulation. Chili peppers are also called African Pepper, Devil's Tongue, Red Bird Pepper and Hot Flame peppers. Chilli pepper is called isie, ekie, or asie in Edo, Efik/Ibibio - ntokon, aman-ntuen, ntueen, Igbo - ose, ose-oyibo, ose etore, ose nukwu, ose nwamkpi, or ose mkpe; Yoruba - ata-jije, ata-eiy, or ata sisebe.
Dr. Keith Jones, a researcher in the Department of Pharmacology and Cell Biophysics, and scientists in his lab have found that applying capsaicin to specific skin locations in mice caused sensory nerves in the skin to trigger signals in the nervous system. These signals activate cellular "pro-survival" pathways in the heart, which protect the muscle.
Capsaicin is the main component of chili peppers and produces a hot sensation. It is also the active ingredient in several topical medications used for temporary pain relief.
Capsaicin is approved for use by Germany as a topical treatment for muscle spasms, both United States Pharmacopeia (USP) and National Formuary (NF) have validated its use as a carminative, stimulant and rubefacient and the United States Food and Drug Administration (FDA) has recognised capsaicin (a compound found inherently in Cayenne) as an Over-The Counter (OTC) topical analgesic.
Researchers have also established the effect of specific dietary constituents on coronary heart disease risk factors.
K. Ahuja of the University of Tasmania, Australia, in his Ph.D thesis has shown that diet influences the coronary heart disease (CHD) risk factors including lipids and lipoproteins, glucose, insulin, and endothelial function.
This research thesis examined the effects of the three different (tomato-olive oil combination and chilli) but widely consumed dietary components, on a range of metabolic and vascular parameters of CHD risk. They found that a meal of chilli pepper, tomatoes and olive oil decrease the risk of CHD, especially in people with increased Body Mass Index (BMI) for whom the risk of cardiovascular morbidity and mortality is higher than in lean individuals.
BMI is a measure of weight in kilogrammes/ height in metres squared. A BMI of between 20 to 24.9 is considered healthy/ideal; 25 to 29.9 is overweight, 30 to 40 is obese, while less than 20 is underweight.
The effect of four-week chilli supplementation on metabolic and arterial function in humans showed no obvious beneficial or harmful effects on metabolic parameters but may reduce resting heart rate and increase effective myocardial perfusion pressure time in men.
The study was published the European Journal of Clinical Nutrition by Ahuja K. D., Robertson I. K., Geraghty D. P., and Ball M. J. at the School of Human Life Sciences, University of Tasmania, Launceston, TAS, Australia.
Also, Nigerian researchers have successfully used fresh leaves of lemon grass and dried banana pulp to treat hypercholesterolaemia in animal models. Hypercholesterolaemia is a condition in which levels of cholesterol in the blood are higher than normal.
The researchers claim this hypocholesterolaemic effect (lowering of the blood cholesterol levels) can be replicated in human.
High cholesterol in the blood is associated with an increased risk of various disorders, such as coronary heart disease and stroke. These disorders are caused by blood vessels becoming narrowed with fatty deposits (which cholesterol is part of), leading to reduced blood flow (or total blockage of blood flow) to vital organs, like brain. Atherosclerosis is caused by hardening and narrowing of arteries.
Factors that facilitate development of the disorders of hypercholesterolaemia include smoking, lack of proper exercise, emotional stress, diets rich in saturated fatty acids, coffee drinking, diabetes and heredity.
Garlic (Allium sativum) has also been shown to help prevent heart disease (including atherosclerosis, high cholesterol, and high blood pressure) and cancer. Animal studies and some early investigational studies in humans, have suggested possible cardiovascular benefits of garlic.
A Czech study found that garlic supplementation reduced accumulation of cholesterol on the vascular walls of animals. Another study had similar results, with garlic supplementation significantly reducing aortic plaque deposits of cholesterol-fed rabbits.
Another study showed that supplementation with garlic extract inhibited vascular calcification in human patients with high blood cholesterol. The known vasodilative effect of garlic is possibly caused by catabolism of garlic-derived polysulfides to hydrogen sulfide in red blood cells, a reaction that is dependent on reduced thiols in or on the Red Blood Cell (RBC) membrane. Hydrogen sulfide is an endogenous cardioprotective vascular cell-signaling molecule.
Although these studies showed protective vascular changes in garlic-fed subjects, a randomised clinical trial funded by the National Institutes of Health (NIH) in the United States and published in the Archives of Internal Medicine in 2007 found that the consumption of garlic in any form did not reduce blood cholesterol levels in patients with moderately high baseline cholesterol levels.
Scientists have shown that a natural supplement made from tomatoes, taken daily, can stave off heart disease and strokes. The tomato pill contains an active ingredient from the Mediterranean diet - lycopene - that blocks "bad" low density lipoprotein (LDL) cholesterol that can clog the arteries.
Ateronon, made by a biotechnology spin-out company of Cambridge University, is being launched as a dietary supplement and will be sold on the high street. Experts said that more trials were needed to see how effective the treatment is.
Preliminary trials involving around 150 people with heart disease indicate that Ateronon can reduce the oxidation of harmful fats in the blood to almost zero within eight weeks.
Israeli researchers have found that ginger extract can have dramatic effects of cardiovascular health, including preventing atherosclerosis, lowering cholesterol levels, and preventing the oxidation of LDL.
Researchers studied the effects of a standardised ginger extract on the development of atherosclerosis in mice genetically predisposed to develop the condition prematurely. In addition plasma cholesterol levels and the resistance of their LDL to oxidation and aggregation were evaluated.
The researchers note that oxidative damage of LDL is thought to play a key role in the development of atherosclerosis and that consumption of nutrients rich in phenolic antioxidants has been shown to be associated with slowing down the development of atherosclerosis.
The authors conclude that "dietary consumption of ginger extract ... significantly attenuates the development of atherosclerotic lesions. This antiatherogenic effect is associated with a significant reduction in plasma and LDL cholesterol levels and a significant reduction in the LDL basal oxidative state, as well as their susceptibility to oxidation and aggregation."
Meanwhile, Jones is working with Neal Weintraub, a University of California Health cardiologist and director of UC's cardiovascular diseases division, and other clinicians to construct a translational plan to test capsaicin in a human population.
"Topical capsaicin has no known serious adverse effects and could be easily applied in an ambulance or emergency room setting well in advance of coronary tissue death," Jones says. "If proven effective in humans, this therapy has the potential to reduce injury and/or death in the event of a coronary blockage, thereby reducing the extent and consequences of heart attack."
Researchers observed an 85 per cent reduction in cardiac cell death when capsaicin was used. They also found that a small incision made on the abdomen triggered an 81 per cent reduction.
"Both this and the capsaicin effect are shown to work through similar neurological mechanisms," Jones says. "These are the most powerful cardioprotective effects recorded to date. This is a form of remote cardioprotection, using a skin stimulus that activates cardioprotection long before the blocked coronary artery is opened."
Weintraub adds that this finding offers an important distinction between existing therapies.
"All of the current interventions require the vessel to be opened before doctors can act and since it takes time to elicit protection, tissue dies," he says. "This treatment will protect the heart before the vessel is opened while producing a strong protective effect that is already active when we open the vessel."
Jones and Weintraub think that skin-the main sensor and largest human body organ-has evolved to protect animals, including humans, in a variety of ways.
"By activating these sensors in the nervous system, via skin, we think that a response to preserve and protect the heart is triggered," Weintraub says.
"We think that this technique is fooling the body into sending out protective signals," Jones adds.
"This may be similar to the way certain acupuncture treatments work; there may be a neurological basis. In a broad sense, this work may provide a 'Rosetta stone' for translating alternative medicine techniques-like acupuncture-to Western medicine. Perhaps we can understand the biological mechanisms of how alternative treatments may be successful for patients."
Now, researchers will further explore this concept by investigating which sensors are associated with certain aspects of organ protection-and how much of specific stimuli are needed to produce the desired responses.
"This could help create favourable outcomes for those who are experiencing stroke, shock or are in need of an organ transplant, and the best part is that it is done non-invasively and is relatively inexpensive," Jones says.
But he warns against rubbing capsaicin on your belly if you feel like you are having a heart attack.
"We don't know if it will work for all indications, for all patients, and we don't know if it will work over an extended amount of time," he says. "A major goal is testing this therapy in clinical trials, but we still need to study more about dosage and application-where we put it on the body for the best results. However, this has tremendous clinical potential and could eventually save lives."
This study was funded by the National Institutes of Health and by the University of Cincinnati. Jones and Weintraub have filed a patent for this funding but have received no honoraria from the makers of capsaicin.
The aims of the Australian study were to investigate the effects of: o a lycopene (tomato)-rich high monounsaturated fat (light olive oil) diet and a lycopene-rich high carbohydrate diet (each diet of 10 days duration) on serum lycopene, lipid profile and serum oxidation in 21 men and women aged between 22 and 70 years with a BMI of 18 - 30kg/m2. A chilli blend (30g/day) supplemented diet and a bland (chilli free) diet (each diet of four week duration) on a range of metabolic and vascular parameters in 36 men and women aged between 22 and 70 years with a BMI of 18 - 35kg/m2.
The measured parameters included serum lipids and lipoproteins, lipid oxidation, glucose, insulin, basal metabolic rate (BMR), heart rate (HR), peripheral and aortic blood pressure, augmentation index (AIx; a measure of arterial stiffness) and subendocardial viability ratio (SEVR, an indicator of myocardial perfusion). o single meals containing chilli blend (30g) with or without the background of a chilli-containing diet on a range of postprandial metabolic and vascular parameters (n = 36). o a chilli blend supplemented diet (of three weeks duration) on endothelial-independent and-dependent vasodilation (assessed after administration of glyceryl trinitrate (GTN) and salbutamol, respectively) compared to the effects of a bland diet (n = 15). o the active ingredient of spices (in different concentrations) including chilli (capsaicin and its analogue dihydrocapsaicin), turmeric (curcumin), piprine (black pepper) and the colour pigment of tomatoes (lycopene) on the in vitro copper-induced oxidation of serum lipids.
The dietary intervention studies were conducted using a randomised crossover design on a weight maintenance regime. Two different groups of people volunteered to take part in the tomato-olive oil and the chilli studies. All participants from the four week chilli study also took part in the meal studies. Ten days of a high lycopene monounsaturated fat rich and high lycopene carbohydrate rich diets presented similar increase in serum lycopene concentration and a similar reduction in serum total and LDL cholesterol.
The AIx after three weeks of regular chilli consumption was lower on the chilli diet compared to the bland diet, but there was no significant difference in the overall effects of GTN and salbutamol on endothelium-independent and -dependent vasodilation between the two diets. Four weeks of iso-energetic weight maintenance chilli and bland diets produced no significant differences in serum lipids, glucose, insulin, peripheral and central blood pressure, AIx, SEVR or BMR. HR was lower after four weeks of chilli-supplemented diet in men, but not in women.
Serum collected after the chilli-supplemented diet exhibited a lower rate of copper-induced oxidation compared to the serum after the bland diet. Women, but not men, also showed a longer lag phase after the chilli-supplemented diet compared to the bland diet. This was probably due to the higher chilli/capsaicin and dihydrocapsaicin intake (per kg body weight) in women.
In vitro studies with capsaicin, dihydrocapsaicin (and curcumin) also exhibited a concentration effect for the resistance to copper-induced serum lipid oxidation.
The researchers wrote: "Results of the meal tests were surprising and exciting. The CAB meal (chilli-containing meal after the bland diet, eaten on day 29 of the bland diet) and the CAC meal (chilli-containing meal after the chilli diet, eaten on day 29 of the chilli diet) showed a lower maximum increase in postprandial serum insulin and overall postprandial serum insulin response compared to the BAB meal (bland meal after the bland diet, eaten on day 22 of the bland diet). The probable reason for this ameliorated insulin profile was a small reduction in insulin secretion and a large increase in the hepatic insulin clearance.
"The correlation between insulin and SEVR indicated an increase in the myocardial perfusion after the CAC meal compared to the BAB meal. All these results were more pronounced after the CAC meal and in people with BMI greater than 26kg/m2. Contrary to popular belief and some previously published data, we did not observe a significantly higher energy expenditure (EE) after the CAB meal or the CAC meal compared to the BAB meal.
"In fact, a lower EE was observed in people with increased BMI on the CAC meal compared to the BAB meal. This effect was possibly the consequence of improved postprandial insulin profile and reduced sympathetic nervous system activity after the CAC meal.
"The results from these investigations may have significance in improving serum lycopene concentrations, lipid profile (tomatoes and olive oil), postprandial insulin response (chilli) and increased resistance of serum to copper induced oxidation (chilli) and hence decreasing the risk of CHD, especially in people with increased BMI for whom the risk of cardiovascular morbidity and mortality is higher than in lean individuals.
"Together, the results from these studies not only advance our knowledge relating to the relationship between some foods and the CHD risk factors but provide an opportunity to combine olive oil, tomatoes and chillies with other foods and spices (as often used in curries) in an attempt to further investigate foods and cuisines that will minimise the various risk factors for CHD
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