Chandrasekharan N
Palm Oil Research Institute of Malaysia, Kuala Lumpur.
Med J Malaysia. 1999 Sep;54(3):408-27; quiz 428.
Fat remains a hot topic because of concerns over associations between consumption of fats and the incidence of some chronic conditions including coronary artery disease, diabetes, cancer and obesity. Dietary fats serve multiple purposes. The effects of dietary fats generally reflect the collective influences of multiple fatty acids in the diet or food. This presentation highlights some recent developments on the role of dietary fats and oils in health and disease. Debate continues over the role of dietary modification in coronary prevention by lipid lowering. The degree to which a recommended diet will result in health benefits for an individual is difficult to predict, because the outcome will depend on the influence of other factors such as a person's genetic constitution, level of physical activity and total diet composition. There can now be little doubt about the importance of genetic factors in the etiology of cardiovascular disease, diabetes, obesity and cancer. The importance of antioxidant status in the prevention of cardiovascular disease as well as many cancers is being increasingly recognised. It is now evident that not all saturated fatty acids are equally cholesterolemic. Recent accounts evaluating palm oil's effects on blood lipids and lipoproteins suggest that diets incorporating palm oil as the major dietary fat do not raise plasma total and LDL cholesterol levels to the extent expected from its fatty acid composition. Palm oil is endowed with a good mixture of natural antioxidants and together with its balanced composition of the different classes of fatty acids, makes it a safe, stable and versatile edible oil with many positive health and nutritional attributes. In recent times, adverse health concerns from the consumption of trans fatty acids arising from hydrogenation of oils and fats have been the subject of much discussion and controversy. Trans fatty acids when compared with cis fatty acids or unhydrogenated fats have been shown to lower serum HDL cholesterol, raise serum LDL cholesterol and when substituted for saturated fatty acids, increase lipoprotein Lp (a) level, an independent risk factor for the development of coronary heart disease. The idea of which foods, nutrients and supplements are "healthy" is often being amended as new scientific data is presented and then simplified for the consumers. What was once perceived as a healthy diet is often no longer considered as such and vice versa. Dietary recommendations have to change with time and the evidence available. Nutritional recommendations should encourage eating a great variety of nutrient sources within our food supply in moderation. Various lifestyle options to improve health should also be promoted.
由于担心脂肪摄入与某些慢性疾病（包括冠状动脉疾病、糖尿病、癌症和肥胖症）的发病率之间存在关联，脂肪仍然是一个热门话题。膳食脂肪有多种作用。膳食脂肪的作用通常反映了饮食或食物中多种脂肪酸的综合影响。本报告重点介绍了膳食油脂在健康与疾病方面作用的一些最新进展。关于通过降低血脂来进行饮食调整在预防冠心病中的作用，争论仍在继续。难以预测推荐的饮食对个人健康能带来多大益处，因为结果将取决于其他因素的影响，如一个人的基因构成、身体活动水平和总体饮食构成。现在，基因因素在心血管疾病、糖尿病、肥胖症和癌症病因中的重要性几乎毋庸置疑。抗氧化状态在预防心血管疾病以及许多癌症中的重要性正日益得到认可。现在很明显，并非所有饱和脂肪酸对胆固醇的影响都是相同的。最近评估棕榈油对血脂和脂蛋白影响的报告表明，以棕榈油作为主要膳食脂肪的饮食，其血浆总胆固醇和低密度脂蛋白胆固醇水平升高的幅度并不如其脂肪酸组成所预期的那样大。棕榈油含有多种天然抗氧化剂，再加上其不同类别脂肪酸的平衡组成，使其成为一种安全、稳定且用途广泛的食用油，具有许多积极的健康和营养特性。近年来，油脂氢化产生的反式脂肪酸对健康的不良影响一直是许多讨论和争议的主题。与顺式脂肪酸或未氢化脂肪相比，反式脂肪酸已被证明会降低血清高密度脂蛋白胆固醇水平，升高血清低密度脂蛋白胆固醇水平，并且当替代饱和脂肪酸时，会增加脂蛋白Lp(a)水平，而脂蛋白Lp(a)是冠心病发生的一个独立危险因素。随着新的科学数据的呈现，哪些食物、营养素和补充剂是“健康的”这一观念常常被修正，然后再为消费者进行简化。曾经被视为健康的饮食现在往往不再被这样认为，反之亦然。饮食建议必须随着时间和现有证据而改变。营养建议应鼓励适度食用我们食物供应中的各种营养来源。还应推广各种改善健康的生活方式选择。
