Coronary heart disease (CHD) is the term that describes what happens when your heart’s blood supply is blocked or interrupted by a build-up of fatty substances in the coronary arteries. Although CHD mortality has been falling during the past 30 years, it is still the commonest cause of death in most developed countries. For instance, in the UK, CHD accounts for about 114000 deaths a year and approximately 1.3 million people have had a heart and around 2 million people are suffering from angina. Primary prevention of CHD is therefore a major public health priority. An increase in the consumption of fruit and vegetables has been advocated for the prevention of CHD, stroke and some cancers.
First of all, i think the first step in treatment for CHD is reducing risk factor. Recommended focusing on life style strategies, such as getting regular moderate to intense exercise and adopting a healthful diet. Individuals who eat more fruit and vegetables are likely to have lower rates of smoking, a lower intake of salt and saturated fat, higher levels of physical exercise and are less likely to be overweight. Such healthier diet and lifestyles have been shown to reduce the risk of CHD. In my opinion consuming fruits and vegetables is needed to a reduced risk of CHD, because fruit and vegetables are rich sources of potassium, folate, fiber, antioxidants and bioactive phytochemicals.
Based on journals published by Journal of Human Hypertension, As the studies included in this meta-analysis reported fruit and vegetable consumption using different measurement units and serving sizes also varied between studies, therefore standardized and grouped fruit and vegetable consumption into three categories: <3servings/day, 3–5 servings/day and 4-5 servings/day for each study (equivalent to 0-235 g/day, 235–391 g/day, 4391 g/day for fruit and vegetables combined). This was performed by an experienced nutritionist (CA Nowson) with assistance from M Lucas. We estimated the average weight of a range of commonly consumed fruit and vegetables using serving size weights for a 0.5 cup standard serving, as indicated in the Composition of Foods Raw, Processed, Prepared, USDA Nutrient Database for Standard Reference, Release. From this database, the average serving was calculated as 80 g for fruits and 77 g for vegetables. Dietary folate is a determinant of plasma homocysteine level, and there have been several studies relating plasma homocysteine levels with the risk of CHD. Dietary fibre may contribute to the reduction in CHD risk by lowering blood pressure and cholesterol. Phytochemicals (plant sterols, flavonoids and sulphur-containing compounds) found in fruits and vegetables may be important in reducing risk of atherosclerosis. Antioxidants have been shown, in experimental models, to reduce atherosclerosis, mainly through a reduction of the amount of oxidized low-density lipoprotein available to be incorporated into lesions. Increasing fruit and vegetable consumption causes a rise in plasma antioxidants in randomized trials. However, longterm intervention studies of folate, vitamins B, C and Eandb-carotene have failed to show any beneficial effect on CHD. Therefore, the contributions of folate, fibre, antioxidants and phytochemicals to a reduced risk of CHD with a higher fruit and vegetable intake are speculative.
In conclusion, I believe meta-analysis of prospective cohort studies demonstrates that increased consumption of fruit and vegetables from less than 3 to more than 5 servings/day is related to a 17% reduction in CHD risk, whereas increased intake to 3–5 servings/day is associated with a smaller and borderline significant reduction in CHD risk. These results provide strong support for the recommendations to consume more than 5 servings/day of fruit and vegetables.