Effects of Palm Oil Consumption on Lipidic and Lipidoproteinic Profiles in Patients Suffering from Ischemic Heart Pathologies

Because of its content of saturated fatty acids, palm oil is often considered as being atherogenic nutritionally, and would therefore purveyor of certain diseases including cardiovascular disease. The present study was conducted to assess changes in the lipid profile and lipoprotein of patients with ischemic heart, consumers versus non-consumers of palm oil. The study involved 120 patients enrolled at the Cardiology Institute of Abidjan, divided into 3 groups. Group 1 consisted of 50 patients consumers of refined palm oil, group 2, of 40 patients taking the two forms of oil (refined and raw red), and group 3 comprised 30 patients not consuming palm oil (control group). The lipid parameters and lipoprotein measured were total cholesterol, triglycerides, HDL and LDL cholesterol, and the atherogenic index. In patient’s consumers of refined palm oil, after 04 weeks of diet, 58% had normal cholesterol rate, 14% hypercholesterolemia and 28% with low cholesterol rate. As for patients taking both types of palm oil, 57.50% had normal cholesterol rate, 15% hypercholesterolemia and 27.50% with low cholesterol rate. Patients, non-consumers of palm oil had low cholesterol rate at 26.67%. The difference was not significant. Whatever the form of consumption, we notice a variation in the cholesterol rate as well as a tendency of low cholesterol rate after four weeks of dieting, with no significant difference. The same pattern was observed with the dosages of triglycerides, LDL cholesterol, HDL cholesterol and atherogenic index, for which changes were also not significant in the 03 groups. The consumption or not of palm oil, whatever the form and the duration of consumption, had no significant influence on serum lipid and lipoprotein parameters and the atherogenic index of patients carriers of ischemic heart disease. This study, although preliminary, has allowed determining that palm oil is harmless in patients with ischemic heart disease, consumers or non consumers of that oil.


Introduction
The ischemic heart disease or coronary artery disease is a major cause of death worldwide [1], which is expanding in developing countries [2,3] namely in Côte d'Ivoire, where its occurrence has been pointed out for several years [4]. Many factors may be responsible for the decrease in the oxygen supply, including organic obstructions [5], caused by cholesterol deposits build up (atherosclerotic plaque), calcium and other substances carried by the blood. These deposits gradually narrow the coronary arteries depriving some parts of the heart with blood and oxygen, which therefore results in an ischemia [6]. In order to prevent the occurrence of cardiovascular disease, or limit their growth, some patients are recommended not to consume food that can increase the cholesterol content, so the atherogenic risk. Among these fatty foods, palm oil is the most often mentioned because of its saturated fatty acids content, said to be source of atherogenic and therefore would purveyor certain diseases, including cardiovascular disease [7][8][9][10]. Works on the assessment of knowledge on the nutritional values of palm oil have shown that this oil was advised against by medical as well as paramedical staffs for hypertensive patients with ischemic heart disease, respectively 56% and 43 13% [11,12], because it is said to be responsible for hypercholesterolemia. Several studies have shown the beneficial effects of the consumption of palm oil on health [13][14][15][16], and particularly in Côte d'Ivoire. Although these studies have shown the benefits of the consumption of this oil, as well as its antioxidant properties [17][18][19], no work has focused on the changes in the lipid profile and lipoprotein among patient's consumers of palm oil, whereas this country is, after Nigeria, Africa's second largest producer of palm oil and the largest exporter of this commodity. [20] This work thus intends to study the changes in the lipid parameters and lipoprotein in patients with ischemic heart disease, consumers or non consumers of palm oil, in order to establish the relationship between the consumption of palm oil and the occurrence of cardiovascular risk within the studied population.

Methodology
Adult patients of both sexes, with ischemic heart disease, enrolled in the Cardiology Institute of Abidjan, were divided into 3 groups. Group 1 consisted of 50 patients consumers of refined palm oil; group 2, of 40 patients taking the two types of oil (refined and raw red); and, group 3 comprised 30 patients non consumers of palm oil (control group). Regarding the oil consumption, the recommended intakes were calculated based on the weight of each patient, while explaining to those accompanied by their wives (for men in couples), the oil quantity equivalence: 25 g of oil corresponded roughly to 2 tablespoons. [21,22]. The lipid needs are 1g/ kg of body weight / day (1 gram of fat contains 9 calories), and these fats represent 20 to 30% of the 2,500 Kcal. According to the nutritional recommendations, the average adult (total metabolism of 2,500 kcal) should consume about 100 grams of fat per day (i.e. 20% to 30% of the total daily intake). A total of 120 known patients under treatment were asked to follow the usual diet for a total of 4 weeks. The diet included refined palm oil, commonly consumed in the area of Abidjan, the two types of palm oil (refined and raw red in daily equal amounts), and another vegetable oil for non consumers of palm oil. The alcoholsmoking patients as well as those with liver disease were not included.

Biological Parameters Analyzed
The total cholesterol, triglycerides, HDL-cholesterol were measured in the 3 groups by conventional enzymatic methods in patients during the admission time and after 04 weeks of diet, that after 10 to 12 hours of fasting. The LDLcholesterol were calculated using the Friedwald formula. The relationship total cholesterol-HDL was used to assess the risk of atherogenesis. These dosages were performed in the laboratory of Biochemistry of the Institute of Cardiology of in Abidjan using Roche's automated random "COBAS INTEGRA 400". The parameters were interpreted taking into account the reference values in healthy Ivorian [23], where normal cholesterol ranges from 1.5 to 2.2 g/l; normal triglyceride: 0,4 to 1.4 g; normal HDL (high): >0.4 g/l; LDL cholesterol: normal: <1.7 g/l.

Consent
We had had a clear and free consent of each patient before starting the study

Statistical Tests
The statistical tests utilized were the Fisher and Khi-deux Tests at a threshold of 5%. The variations in the lipid and lipoprotein parameters were not significant in both palm oil consumers (refined and the 2 types) and non palm oil consumers, in the initial assessment of the patients. The variations in the lipid and lipoprotein parameters were not significant in both palm oil consumers and non consumers after 04 weeks of dieting. Nota Bene: atherogenesis index: normal: <5; Abnormal : >5 The consumption or not of palm oil has no significant influence on the atherogenesis index in the initial assessment after 04 weeks of dieting.

At the Socio-Epidemiolocal Level
Patients had an average age of 57.34 years with a sex ratio of 1.13. Our results are similar to those of Bertrand et al [24] in which the mean ages were 55 and 56 years respectively. The average age generally corresponds to the age range of onset of major chronic diseases, including diabetes and hypertension. Most of the patients had a hypertension history either personally or at the family level. This could be explained by the Framingham study quoted by Froment [25], which showed that the risk of hypertensive subjects compared to subjects with normal blood pressure was tripled for ischemic heart disease, doubled to arteritis, and multiplied by five for congestive heart failure. Hypertension is a major risk factor for the onset of ischemic heart disease. It would make sense to support these patients.

Concerning the Consumption or Non Consumption of Palm Oil
In Côte d'Ivoire, palm oil is the primary oil used in households, which would explain its high consumption. The refined palm oil mainly consumed, mostly sold, and easily accessible has emerged as cooking and frying oil in all types of food preparation in the tropics in particular [16,20,26]. Patients who do not consume palm oil would probably have received advice to stop it as reported by other studies [11,12,27,28], claiming that palm oil would deteriorate or aggravate their condition.

Lipid and Lipoprotein Parameters Variations
Relationship between total cholesterolemia and consumption or non consumption of palm oil: Among those patients with refined palm oil, 62% had normal cholesterol, 20% hypocholesterolemia and 18% hypercholesterolemia. In patients who consume both forms of palm oil, the cholesterol was normal in 60% of cases, decreased in 20% and was high in 20% of cases. In patient's non consumers of palm oil, the cholesterol was normal in 60% of cases, 23.33% had hypercholesterolemia and 16.67% hypocholesterolemia. The difference was not significant. After 04 weeks of dieting, 58% of patient's consumers of refined palm oil had normal cholesterol, 14% hypercholesterolemia and 28% lower in cholesterol. As for patients taking both forms of palm oil, 57.50% had normal cholesterol, 15% hypercholesterolemia and 27.50% hypocholesterolemia. Non-consumers of palm oil patients had hypocholesterolemia at 26.67%. The difference here also was not significant. Whatever the form of consumption, we see a variation of cholesterol in the same direction with a tendency to hypocholesterolemia after four weeks of dieting, with no significant difference. Our results are consistent with those of Pacetti et al. [14] who showed stabilization or even a decrease in the total cholesterol among patient's consumers of palm oil. Similarly, Ebong [16] demonstrated the influence of palm oil in lowering the total cholesterol. This change was similar to those of patients who consumed refined palm oil and both forms, without a significant difference. Thus, no matter whether patients consume refined palm oil, both forms of palm oil that did not influence their serum cholesterol levels. Our results are in line with those of Onyeali et al. [29], which had shown the beneficial effects of the consumption of palm oil on the plasma lipid profile in Wistar rats. They showed that the consumption of palm oil had led to a significant reduction in the total cholesterol compared with control groups. Ladeia et al. [30] also demonstrated in subjects fed on palm oil, a significant reduction in blood cholesterol levels. Zhang et al. [31] had assessed the effect of palm oil used in the Chinese diets compared to soybean oil, peanut oil and lard. They demonstrated that diets containing palm oil had reduced significantly the serum cholesterol levels of subjects as opposed to the lard, but comparable to soybean oil effect mainly polyunsaturated. Basu et al. [32] in India had also shown the role of palm oil in lowering the total cholesterol.

Relationship Between Triglyceridemia and Consumption or Non Consumption of Palm Oil
Triglycerides were normal: 92.5%, 95% and 86.66% respectively in patients who consume refined palm oil, the two forms of oil in non-consumers, this during admission before the diet. After 04 weeks of dieting, the triglyceride level was also normal: 86%, 87.5% and 90% respectively in patients who consume refined palm oil, both forms of palm oil and non-consumers. Thus, triglycerides were normal in consumers of refined palm oil as well as in the two forms of consumption, with no significant difference. Onyeali et al. [29] pointed out a significant reduction in triglycerides, as well as Zhang et al. [31], Arenceta et al [33] who demonstrated the influence of palm oil consumption in the reduction or normalization of serum triglycerides. The work of Sundram [14] and Ebong [16] had also shown that palm oil consumption does not significantly influenced triglycerides subjects.

Relationship Between HDL Cholesterol and Consumption or Non Consumption of Palm Oil
During admission, 70% of both patient's consumers of refined palm oil and the two forms of oil had high HDL cholesterol levels. After 04 weeks of dieting, the HDL cholesterol levels were even higher, respectively 82%, 80% and 76.67% in patients who consumed refined palm oil, both forms of oil and non palm oil consumers. Patients with normal HDL cholesterol that is to say high, up almost 70% in the 3 groups, with no significant difference led us to say that the consumption or not of palm oil did not influence significantly the HDL cholesterol levels. In addition, Onyeali et al. [29] showed that diet containing palm oil had no significant effect on serum HDL cholesterol levels. Similarly, Boon et al [36] had reported a rise in HDL cholesterol in Patients Suffering from Ischemic Heart Pathologies patient's consumers of palm oil. This suggests the beneficial effect of the consumption of palm oil. The HDL cholesterol, conventionally called "good cholesterol", vehicles the cholesterol from tissues to the liver for elimination. Thus, a low level of HDL cholesterol is a risk factor, but on the contrary a higher or normal rate is viewed as cardioprotective [33,35,36].

Relationship Between LDL Cholesterol and Consumption or Non Consumption of Palm Oil
During admission, the LDL cholesterol was normal in 96%, 90% and 83.33% of consumers (refined palm oil and both forms) and non consumers, respectively. After 04 weeks of dieting, 98% and 97.5% of consumers of refined palm oil and the two forms had normal levels of LDL cholesterol, without significant difference. In non consumers of palm oil, the LDL cholesterol did not varied significantly, as well. Thus, the LDL cholesterol was lowered or normal among in the refined palm oil consumers as well as in the two forms, with no significant difference. Onyeali et al. [29] had also showed that the consumption of palm oil had led to a significant reduction in LDL cholesterol, which decrease is also reported by other studies [33][34][35].

Relationship Between Palm Oil and the Atherogenesis Index
The atherogenic index, defined as the ratio between the total cholesterol and the HDL should be less than 5 [23,37]. This report was varied in both directions, both for consumers regardless of the form of oil consumption and non consumers of palm oil, with no significant difference. Other parameters, in addition to lipid parameters such as sex, BMI, deserve to be explored to better objectify the impact of palm oil on the ratio total cholesterol / HDL [38]. Zhang et al. [34] reported that even among those who were hyper-cholesterolemic, the palm oil significantly reduced the ratio total cholesterol/HDL. After 04 weeks of dieting with palm oil, there was no significant change in the atherogenic index. Thus, whether patients consumed palm oil or not, that did not change significantly the atherogenic index. This could suggest, in accordance with other studies, that the consumption of palm oil does not influence significantly the cardiovascular risk [38,39].
Most of the benefits of palm oil on the lipid and lipoprotein profile is said to be linked to the high content of antioxidants, carotenoids, and vitamin E. In fact, tocotrienols and tocopherols represent respectively 70% and 30% of vitamin E found in palm oil [13,16]. The tocotrienols are well known in the inhibition of HMG-CoA reductase, a key enzyme in cholesterol biosynthesis. Thus, the palm oil is beneficial in reducing cholesterol thereby controlling serum cholesterol levels in the consumer. Sulli et al. [40] demonstrated that supplementation of the diet in tocopherol and β-carotene had reduced plasma cholesterol levels in hypercholesterolemic rabbits after 08 weeks of diet. This study confirms previous studies about the benefits of the consumption of palm oil, particularly its protective effects as far as cardiovascular diseases are concerned.

Conclusion
The Consumption or not of palm oil, as well as the form of consumption after 04 weeks of dieting, had no significant influence on the serum lipid and lipoprotein parameters, and the atherogenic index of patients with ischemic heart disease. The palm oil has helped to lower cholesterol after 04 weeks of dieting (28% of patient's consumers of refined palm oil and 27.50% of patient's consumers of the two forms of palm oil). In patient's non consumers of palm oil, 26.67% had hypocholesterolemia with no significant difference. It would not therefore make any sense to consider palm oil responsible for the occurrence of cardiovascular diseases namely ischemic heart diseases; this because palm oil has rather beneficial effects on the cardiovascular system. The study, although preliminary, has allowed showing the harmfulness of palm oil in patients with ischemic heart disease, consumers or non consumers.