Journal Name:
J. Am. Diet Assoc.
Article Title:
The Evidence for Dietary Prevention and Treatment of Cardiovascular Disease.
Date Written:
2008
Volume:
108
Number:
NA
Page:
287
Author(s):
Van Horn, L.; McCoin, M.; Kris-Etherton, P.M; Burke, F.; Carson, J.S.; Champagne, C.M.; Karmally, W.; Sikand, G.
Article:
This extensive review paper presents the American Dietetic Association’s position on the relationship between diet and cardiovascular disease (CVD) risk. Evidence is presented on epidemiologic, experimental, and clinical trial evidence for a number of nutrients and their relationship to blood lipid levels; blood pressure; and coronary heart disease (CHD). Since 2000 research has shifted to other dietary factors, including whole foods and favorable dietary patterns that likewise appear to affect blood lipid levels. As potential nonlipid biomarkers for CVD have also been identified (ie, blood pressure, thrombogenecity, and inflammation) research interest about how diet might influence these factors has increased. Here a summary of the review of research related to alpha linolenic acid (ALA), saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) – of most relevance to canola oil - is presented.
Population studies provide evidence of associations between diets high in SFA and increased total cholesterol (TC) and LDL cholesterol levels, as well as increased risk of both CHD and CVD. Decreasing SFAs, trans fatty acids (TFAs), and cholesterol. SFA, TFA, and dietary cholesterol increase TC and LDL cholesterol levels in a dose-dependent manner, with SFA and TFA having greater cholesterol-raising effects than dietary cholesterol. Polyunsaturated fatty acids (PUFAs) lower TC and LDL cholesterol levels, whereas monounsaturated fatty acids (MUFAs) mainly have a neutral effect. Isocaloric replacement of SFA with PUFA and MUFA decreases TC and LDL cholesterol levels and the TC/HDL cholesterol ratio (sometimes in response to changes in HDL cholesterol level), which collectively reduces CHD/CVD risk.
Three large observational studies examined ALA intake in both men and women at intakes between 1.36 g and 1.5 g/day and reported reduced risk of IHD or acute MI by 45% to 59%. ALA intake was inversely associated with CAD. In the highest three quintiles of ALA intake, the prevalence of CAD was reduced by approximately 50% to 70% for women and about 40% for men. The mean ALA intake was 0.81 g/day for men and 0.68 g/day for women.
For primary prevention of CVD and CHD, the American Heart Association recommends at least two or more servings (approximately 4 oz per serving) of oily fish per week and inclusion of foods and oils rich in ALA, such as walnuts and canola oil. The authors suggest that there are limited intervention studies evaluating the relationship between ALA and risk of CHD. The literature is often confounded by numerous other factors, including fish vs supplement-based studies. In addition, information is needed about the efficacy of marine- and plant-derived n-3 fatty acids in women and in high-risk populations. The effect of plant-based and marine-based n-3 fatty acids on primary prevention of CHD in all population groups is needed. Research to determine the optimal dietary intake of n-3 fatty acids (ie, EPA, DHA, and ALA) and the ratio of n-6:n-3 fatty acids is warranted.
Back to New research paper