This study is the first one to show the effect of dietary intervention in the secondary prevention of CHD. It is meal pattern study even if very often labelled as sole fat modification study

1. 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

2. 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
2

3. 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
Page 3

4. 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
Page 4

5. Methods (schematic)
Leren et al. . Bull N Y Acad Med. 1968 August; 44(8):
1012–1020
Page 5
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→

6. 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
Page 6
Note! This data on diets is only available in
Acta Med Scan publication (original paper
version)

7. 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)

8. Methods, diet (3/3)
Leren et al. . Acta Med Scand. 1966; Suppl 466; 1-9 (only in the paper version of the
study)
Page 8

9. Results (myocardial infarctions)
Leren et al. . Bull N Y Acad Med. 1968 August; 44(8):
1012–1020
Page 9
Absolute number
of outcomes P=0.022
Δ - 33 %
P=0.029
Δ - 56 %
Difference in MI’s was driven by younger patients

10. Results (total cholesterol)
Leren et al. . Bull N Y Acad Med. 1968 August; 44(8):
1012–1020
Page 10
Total cholesterol change from baseline (%)
Multifactorial
cholesterol
lowering
diet
Baseline in both groups 7,6 mmol/L (296 mg/dl)

11. 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
Page 11
Dietary intakes (based on a sub-group representing
4 % of all subjects)

12. 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
Page 12

13. 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 study
Encouraged
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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utritionist
Leren et al. . Bull N Y Acad Med. 1968 August; 44(8):
1012–1020
Page 13

14. 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
Page 14

15. Read also about
Finnish Mental Hospital Study
Click for slides here
15

16. Welcome aboard!
14/02/1516
http://twitter.com/pronutritionist
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http://www.pronutritionist.net (Finnish)
http://www.pronutritionistblog.com (English)
Reijo Laatikainen, Authorized Nutritionist, MBA