Oslo Diet Heart Study

Leren et al. The effect of plasma cholesterol lowering diet in male survivors of myocardial infarction. Bull N Y Acad Med. 1968

August; 44(8): 1012–1020.

(does NOT contain detailed diet instrcutions)

Published also as doctoral thesis in

Acta Med Scand. 1966; Suppl 466; 1-9

(comprehensive version containing the detailed dietary instructions )

[Updated February 2015]

Page 1

Important note:

Detailed dietary instructions can only be found in the long and

original paper version from 1966, not in the electronically available

version from 1968

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Pronutritionist’s background

• In meta-analyses, saturated fat intake is not independently linked to coronary heart disease (CHD) incidence (Siri-Tarino et al. 2010, Skeaff  & Miller J. 2009 and Mente et al. 2009)

• Another meta-analysis based on the randomized outcome trials, demonstrated a lower incidence of CHD if saturated fat was replaced by polyunsaturated fat (Mozaffarian et al. 2010)

• The results of Mozaffarian’s meta-analysis were heavily driven by two studies: a) Finnish Mental Hospital Study (FMHS) and b) Oslo Diet Heart Study

• Oslo Diet Heart Study is often perceived as a fat modification trial but this has been questioned by Ramsden et al. 2010

• Oslo Diet Heart Study is still a landmark trial, but how does it stand the test of time?

Leren et al. . Bull N Y Acad Med. 1968 August; 44(8): 1012–1020

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Methods (patients)• Parallel randomized trial • Secondary prevention of CHD among myocardial infarction (MI)

survivors• Primary outcomes: Reinfarctions and serum total cholesterol• N=412, males, age 30-64 years• Active treatment was started 1-2 years after MI • Total cholesterol levels at baseline in both groups 7,6 mmol/L (296

mg/dl)• Subjects were free living• Length: 5 years per arm• Era: 1956 → (60 months follow up)

• “Dieters” = active treatment group”

Leren et al. . Bull N Y Acad Med. 1968 August; 44(8): 1012–1020

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Methods (schematic)

Leren et al. . Bull N Y Acad Med. 1968 August; 44(8): 1012–1020

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Randomization of patients (MI survivors, n = 412)

Comprehensive “cholesterol lowering diet” (“Dieters”) (see details next page) n=206

Dairy fat diet = control (normal Norwegian diet) n=206

5 yearsy. 1956→

Methods, diet (1/3)

Cholesterol lowering diet• Soybean oil was provided for free

(from “15-30 g /day as medicine” OR 0,5 L/week for cooking)

• Sardines canned in cod liver oil “which proved to be a popular as a bread spread”. Provided for free.

• Fish and shell fish recommended instead of all types of meat

• All consumed meat to be lean (visible fat should be removed)

• Use of “brown bread” encouraged instead of “whole milk loaf”

• Increased vegetable, nuts, beans, peas & fruit consumption encouraged

• Margarine use was “entirely restricted”• Only 1 egg yolk per week• Multivitamin provided

Normal diet (control)• No restrictions• No free foods were provided for

controls • Multivitamin provided

Leren et al. . Acta Med Scand. 1966; Suppl 466; 1-9

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Note! This data on diets is only available in Acta Med Scan publication (original paper

version)

Methods, diet (2/3)

Leren et al. . Acta Med Scand. 1966; Suppl 466; 1-9 (only in the paper version of the study)

Page 7

Note! This data on diets is only available in Acta Med Scan publication (original paper

version)

Methods, diet (3/3)

Leren et al. . Acta Med Scand. 1966; Suppl 466; 1-9 (only in the paper version of the study)

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Results (myocardial infarctions)

Leren et al. . Bull N Y Acad Med. 1968 August; 44(8): 1012–1020

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Absolute number of outcomes P=0.022

Δ - 33 %

P=0.029

Δ - 56 %

Difference in MI’s was driven by younger patients

Results (total cholesterol)

Leren et al. . Bull N Y Acad Med. 1968 August; 44(8): 1012–1020

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Total cholesterol change from baseline (%)

Multifactorial cholesterol

lowering diet

Baseline in both groups 7,6 mmol/L (296 mg/dl)

Results (diet)

Multifactorial diet Normal diet

Total fat 104 g (39 E %) N/A

Soy bean oil 72 % of total fat N/A

Fish fat 11,6 % of total fat N/A

Animal fat 8.8 % of total fat N/A

Cereal fat 5.0 % of total fat N/A

Other fat sources 2.6 % of total fat N/A

Cholesterol 264 mg N/A

Carbohydrates 269 g N/A

Protein 92 g N/A

Leren et al. . Bull N Y Acad Med. 1968 August; 44(8): 1012–1020

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Dietary intakes (based on a sub-group representing 4 % of all subjects)

Pronutritionist’s discussion (1/3) • Oslo Diet-Heart delivered robust results in secondary prevention of

coronary heart disease (CHD -33 % & fatal MI -54 %)

• Oslo Diet Heart Study is not a sheer SFA/PUFA modification trial but a dietary pattern studysuch as Lyon Diet Heart or Predimed studies

• Oslo Diet Heart dietary intakes were poorly reported. Only 4 % of participants provided any dietary data. In controls none provided dietary data.

• “Dieters” possibly received 5 grams of marine omega-3 fatty acids, 15 mcg vitamin D extra, and controls received 7 grams more of TFA due to different dietary patterns (Ramsden et al. 2010)

Leren et al. . Bull N Y Acad Med. 1968 August; 44(8): 1012–1020

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Pronutritionist’s discussion (2/3)Pursued dietary changes in Oslo Diet-Heart

Means Method of support

Increase in omega-6 fatty acids (linoleic acid)

Soybean Oil for cooking or “as medicine”Nuts

Free soybean oil

Encouraged

Increase in omega-3 fatty acids

Canned sardines in cod liver oil Nuts

Free canned sardine delivery twice during the studyEncouraged

Increase in Vitamin D Canned sardines in cod liver oil

Free canned sardine delivery twice during the study

Decrease in SFA intake Skim milk ↑, butter/margarine and meat restricted

Encouraged/banned

Decrease in trans fat intake

Margarine restricted Banned

Increase fiber and indigestible carbs

Increase in brown bread & vegetable, fruit, beans intake

Encouraged

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Leren et al. . Bull N Y Acad Med. 1968 August; 44(8): 1012–1020

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Pronutritionist’s discussion (3/3)

• Oslo Diet Heart Study produced very similar results to Lyon Diet Heart Study in which TFA-low margarine was the vehicle of n-3 and n-6 fatty acids in the context of Mediterranean dietary pattern

• Dietary pattern used in Oslo Diet Heart Study is very similar to what is recommended in many official dietary guidelines globally

– Higher than usual intake of both n-6 and n-3 FAs– High fiber intake – Low refined carbohydrate intake– Low intake of saturated fat and cholesterol– High consumption of vegetables, fruits, berries, whole grains, nuts and beans – More fish and seafood and possibly poultry instead of of red and processed meat– More vegetable oils or margarines low in TFA instead of butter and old-fashioned

margarines high in TFA

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Read also about Finnish Mental Hospital Study

Click for slides here

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Welcome aboard!

11/04/2316

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http://www.pronutritionistblog.com (English)

Reijo Laatikainen, Authorized Nutritionist, MBA