Test of effect of lipid lowering by diet on cardiovascular risk. The Minnesota Coronary Survey.

Abstract

The Minnesota Coronary Survey was a 4.5-year, open enrollment, single end-time, double-blind, randomized clinical trial that was conducted In six Minnesota state mental hospitals and one nursing home. It Involved 4393 Institutionalized men and 4664 Institutionalized women. The trial compared the effects of a 39% fat control diet (18% saturated fat, 5% polyunsaturated fat, 16% monounsaturated fat, 446 mg dietary cholesterol per day) with a 38% fat treatment diet (9% saturated fat, 15% polyunsaturated fat, 14% monounsaturated fat, 166 mg dietary cholesterol per day) on serum cholesterol levels and the Incidence of myocardlal Infarctions, sudden deaths, and all-cause mortality. The mean duration of time on the diets was 384 days, with 1568 subjects consuming the diet for over 2 years. The mean serum cholesterol level In the pre-admission period was 207 mg/dl, falling to 175 mg/dl in the treatment group and 203 mg/dl In the control group. For the entire study population, no differences between the treatment and control groups were observed for cardiovascular events, cardiovascular deaths, or total mortality. A favorable trend for all these end-points occurred In some younger age groups. (Arteriosclerosis 9:129-135, January/February 1989) T he institutions chosen for the trial were the Minnesota state mental hospitals at Anoka, Fergus Falls, Hastings, Moose Lake, St. Peter, and Willmar and the nursing home at Oak Terrace. Before initiation of the experimental phase, the populations were observed for a 3-year period, during which their suitability for a long-term dietary trial was studied. The feeding program began in the Willmar State Hospital in November, 1968. The program was phased in to the other institutions in succession over the following 15 months. The trial was an outgrowth of the National Diet-Heart Feasibility Study. 1 Methods Ethical ConsiderationsThe project was approved by the Clinical Research Committee of the University and, after extensive discussion with the relevant institutional committees, by each of the collaborating hospitals. No consent forms were required on the grounds that the two diets were both acceptable as house diets and the tests all contributed to better patient care. Before initiation of the study in each hospital, all the residents and staff were invited to a meeting at which the investigators explained the project. Samples of the foods were served at these meetings. There was a question and Received March 25,1987; revision accepted August 30,1988. answer period, and the residents were invited to make appointments for one-to-one further explanations if they wished. They were allowed to decline to participate or to discontinue their participation at any time. Nonparticipants were served the control diet, which was similar to the pre-study institutional diets. Blood was not drawn from nonparticipants, and electrocardiograms were not recorded. Participation was nearly 100% with fewer than a dozen refusals throughout the trial. Experimental PlanThe original population was initially ...

Dietary fats and coronary heart disease

“…CHD rates were reduced on the modified diet: 51% lower for CHD deaths alone (P = 0.10) and 67% lower for CHD deaths or major electrocardiogram change (P = 0.001). In a later US study of similar design, little evidence was seen for a reduction in CHD amongst the group with modified fat intake [27]; however, the mean follow-up of 1 year was likely too short to observe an effect.…”

Effect of reducing total fat intake on body weight: systematic review and meta-analysis of randomised controlled trials and cohort studies

“…8 Of 48 included randomised controlled trials in the other review, 24 were included in the current review. Of the remaining 24 randomised controlled trials, 10 did not compare reduced fat intake with usual fat intake (they were included as they modified fat), [53][54][55][56][57][58][59][60][61][62][63] and 13 aimed to reduce weight in some or all participants so were ineligible for the current review. [64][65][66][67][68][69][70][71][72][73][74][75][76] Only one trial was eligible for this review but was not included as no data were provided on body weight, body mass index, or waist circumference.…”

Effects of Dietary Macronutrients on Plasma Lipid Levels and the Consequence for Cardiovascular Disease

“…Despite accumulating findings that suggest a relationship between saturated fat intake and CVD risk, a meta-analysis of 21 prospective cohort studies with 5-23 years of follow-up found no significant association between saturated fat intake and risk of stroke or CVD when the data were pooled together, even though individual studies had reported significant associations [42]. Similarly, no significant differences in the number and frequency of cardiovascular events and deaths between diets differing in fat composition were reported following periods of over 2 years [43]. It, therefore, remains unclear whether saturated fats are more dangerous in promoting CVD compared to unsaturated fats.…”