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. 2018 Nov 27;2018(11):CD012345. doi: 10.1002/14651858.CD012345.pub3

NDHS Faribault 1968.

Methods National Diet‐Heart Study (NDHS) ‐ Faribault site
RCT, several arms, parallel (n6 LA vs SFA), 1 year
Summary risk of bias: low
Participants Men living in a mental health institute
CVD risk: low
 N: interventions B, C, E combined: randomised 167, analysed 143; control: randomised 57, analysed 52
Mean years in trial: interventions 0.9, control 1.0,
 % male: 100
 Age: unclear
Age range: all 45‐54 years
Smokers: 55%‐59% current smokers in each arm
Hypertension: unclear
Medications taken by ≥ 50% of those in the control group: not reported
Medications taken by 20%‐49% of those in the control group: not reported
Medications taken by some, but < 20% of the control group: not reported
Location: USA
Ethnicty: not reported
Interventions Type: diet provided (residential institution)
Comparison: ↑ PUFA (n‐6) vs usual institutional diet (SFA and MUFA)
Control aims: total fat 40% E, SFA 16%‐18% E, dietary cholesterol 650‐750 mg/d, P/S 0.4 (so PUFA 6.8% E) (whole diet provided)
 Intervention aims: B (C, E) total fat 30% E (40% E, 40% E), SFA < 9% E (< 9% E, not stated), dietary cholesterol 350‐450 mg/d (350‐450 mg/d, not stated), PUFA 15% E (18‐20% E, not stated), P/S 1.5 (2.0, 4.4) (equivalent to Minnesota Coronary Trial diet) (whole diet provided)
Dose aim: increase B 8.2% E, C 12.2% E, E unclear n‐6
Baseline n‐6 (table IX2): 4.4% E LA, 4.8% E PUFA
Compliance by biomarkers: serum TC significantly reduced in intervention compared to control (‐0.91 mmol/L, 95% CI ‐1.17 to ‐0.65). Fatty acid composition of red blood cells suggests that LA was higher in intervention arms (table X6: LA rose by 4 in control, by 5‐7 in other arms, at the expense of MUFA, which rose by 1 in control, fell by 4 or 5 in other arms. Palmitic acid fell by 5 in control, and fell by 4 in intervention arms, stearic did not alter in control, rose by 1 or 2 in intervention arms ‐ no statistical significance or variance info provided, units unclear, probably % of LA+oleic+palmitic+stearic)
Compliance by dietary intake: good. Assessed from 7‐day food records after 28 and 44 weeks combined (tables IX8&9)

  • Energy intake, kcal/d: intervention B 2549, intervention C 2599, intervention E 2560, control D 2593

  • Total fat intake, % E: intervention B 29.0, intervention C 38.5, intervention E 37.1, control 39.5 (decrease B 10.5% E, C 1.0% E, E 2.4 total fat)

  • SFA intake, % E: intervention B 6.1, intervention C 7.0, intervention E 4.6, control D 15.6 (decrease B 9.5% E, C 8.6% E, E 11.0% E SFA)

  • PUFA intake, % E: intervention B 12.1, intervention C 17.8, intervention E 22.3, control D 4.6 (increase B 7.5%E, C 13.2% E, E 17.7% E PUFA)

  • PUFA n‐3 intake: not reported

  • PUFA n‐6 intake, % E LA: intervention B 11.6, intervention C 16.9, intervention E 21.9, control D 4.3 (increase B 7.3% E, C 12.6% E, E 17.6% E LA)

  • Trans fat intake: not reported

  • MUFA intake, % E: intervention B 10.8, intervention C 13.7, intervention E 10.2, control D 19.3 (decrease B 8.5% E, C 5.6% E, E 9.1% E MUFA)

  • CHO intake, % E: intervention B 55.3, intervention C 45.8, intervention E 48.6, control D 45.1 (increase B 10.1% E, C 0.7% E, E 3.5% E CHO)

  • Sugars intake: not reported

  • Protein intake, % E: intervention B 17.0, intervention C 16.7, intervention E 15.7, control D 16.4 (increase B 0.6% E, C 0.3% E, E ‐0.7% E protein)

  • Alcohol intake: not reported


Compliance, other methods: 3.6% of days were lost (diet not eaten)
Inclusion basis: aimed to increase PUFA intake as well as increase PUFA/SFA, reduce SFA slightly and reduce dietary cholesterol.
PUFA dose: B 7.5% E, C 13.2% E, E 17.7% E PUFA
Duration of intervention: 1 year
Outcomes Main trial outcomes: lipid levels and dietary assessment
Dropouts: B 7, C 10, E 7, D (control) 5
Available outcomes: mortality, TC (weight and TG data available but without SDs)
Response to contact: not attempted as trial completed in 1967
Notes Data entered as all interventions combined (B+C+E) vs control (D)
Dose calculations
Interventions: B PUFA 15% E, ↑8.2% E
Control: 17% E SFA, P/S 0.4 so PUFA 6.8% E
C PUFA 19% E, ↑12.2% E
D unclear ↑% E?
Mean for all interventions ↑10.2% E
Trial funding: National Heart Institute
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Stratified randomisation by the statistical centre
Allocation concealment (selection bias) Low risk As above
Blinding of participants and personnel (performance bias) 
 All outcomes Low risk Institution so all participants and trial staff blinded to allocation
Blinding of outcome assessment (detection bias) 
 All outcomes Low risk Outcome assessors were reported as blinded to treatment allocation
Incomplete outcome data (attrition bias) 
 All outcomes Low risk Institution so able to follow‐up all participants through trial.
Selective reporting (reporting bias) Unclear risk No protocol or trials registry entry found
Attention bias Low risk Equivalent, diet provided to both groups
Compliance Low risk TC significantly reduced in intervention compared to control (‐0.91 mmol/L, 95% CI ‐1.17 to ‐0.65). Fatty acid composition of red blood cells suggests LA was higher in intervention arms
Other bias Low risk None found