Vega-Lopez 2006 To assess the effect of consuming palm oil versus partially hydrogenated soybean, canola oil or soybean oil on lipids and indicators of glucose homeostasis Non-smoking adults aged over 50 years, with LDL>3.36 BMI: 26.0 No sample size calculations given All food provided by researchers; same food in all phases, prepared with different oils giving 20% energy Test diet composition determined by chemical analysis Total-C: CCX, Spectrum; Incstar, Stillwater, MN LDL-C: calculated from total-C, HDL-C and VLDC-C 3 blood samples averaged Controlled by design Energy intake adjusted to maintain stable body weight Adverse/other effects: TG, lipoproteins, indicators of glucose homeostasis and HDL metabolism Total-C, LDL-C Diet 1: 6.2, 4.3 Diet 2:5.4, 3.6 P<0.05 Lichtenstein 1999 To assess the effect of various commercially available margarines & a vegetable shortening with a wide range of TFA to butter on lipids Non-smoking adults aged over 50 years, with LDL>3.36 BMI: 27.4 No sample size calculations given All food provided by researcher; additional water and non-energy beverages allowed; Step 2 diet with soybean oil or semiliquid margarine used to prepare foods Test diet composition determined by chemical analysis Total-C: with a biochromatic analyzer (model CCX, Spectrum, Incstar, Stillwater, Minn.) with enzymatic reagents LDL-C: not stated 3 blood samples averaged Controlled by design Weight assessed 4xweek Adverse/other effects: HDL, TG, lipoproteins, Total-C, LDL-C Diet 1: 5.8, 4.0 Diet 2: 5.9,4.0 P: NS
Lovejoy 2002 To assess the effect of diets enriched in SFA, TFA and MUFA on measures of insulin sensitivity Non-smoking adults with LDL and TG between centile BMI: 23.5 A priori power analysis: 22 subjects would provide >85% power to detect a difference in SI of 0.45 units between diets, which would be clinically meaningful in subjects with average insulin sensitivity. All food provided by researchers; alcohol prohibited; specially formulated blends developed to achieve isolated exchange for oleic acid for SFA used in baking etc Test diet composition determined by chemical analysis Total-C: Beckman Synchron CX7 LDL-C: Friedewald (SI reflects the effect of an incremental change in plasma insulin to increase fractional glucose clearance independent of glycaemia.) Controlled by design Energy adjusted to maintain stable body weight if weight varied more than 2 kg/wk Adverse/other effects: HDL, TG, glucose, insulin sensitivity Total-C, LDL-C Diet 1: 3.8, 2.2 Diet 2: 3.9, 2.2 P: NS Berglund 2007 To assess the effect of the Step 1 diet, a MUFA-containing diet and an average American diet on overall risk factor profile Healthy individuals with one or more of the following: low HDL-cholesterol, high triacylglycerol, or high insulin concentrations BMI: 27.6 No sample size calculations given All food provided by researchers except Saturday evening meal (although a Step 1-type meal was advised). Test diet composition determined by chemical analysis Total-C: enzymatic assay (not further described) LDL-C: Friedewald 3 blood samples averaged Controlled by design Fibre 7.5 g higher on CHO diet Weight assessed 2/week Adverse/other effects: HDL, TG, lipoproteins uric acid, glucose, insulin Total-C, LDL-C Diet 1: 5.2, 3.3 Diet 2: 4.9, 3.1 Diet 3: 4.9, 3.1 P<0.01 for Diets 2 and 3 vs Diet 1 on pairwise tests Statistical analysis adjusted for seasonal variation
Nielsen 2002 To compare the effects of two oleic acid rich diets (from olive oil or rapeseed oil) to sunflower-seed oil lipids Non-smokers Total-C: 4.71 BMI: 22.9 Power calculations: 18 subjects would have power 0·85, at alpha=0.05 to detect a difference of 0·2 mmol/l in total -C. All foods provided by researchers; additional water, and in small amounts, plain coffee, and tea allowed Base diet of 30% energy with 50 g/10 MJ of rapeseed oil, extra virgin olive oil or sunflower seed oil incorporated into bread, cakes, etc. Test diet composition based on chemical analysis of the food Total-C: B-M CHODPAP 236-691 LDL-C: calculated as the difference between HDL-C concentration and the cholesterol concentration in the LDL+HDL fraction Controlled by design Weight assessed every second day; energy intake adjusted if weight varied more than 1 kg Adverse/other effects: HDL, TG, tocopherol, carotenes Total-C, LDL-C Diet 1: 3.5, 2.2 Diet 2: 4.1, 2.7 Diet 3: 3.6, 2.3 P<0.001 by ANOVA No period or effects were detected Poppitt 2002 To compare the effect of a natural butter-fat, modified to replace a proportion of saturates with MUFAs and PUFAs to regular butter could improve risk factors including lipids Men with normal weight Weight: 69 kg No sample size calculations given Residential study providing all food and beverages Pasture-fed cows given encapsulated unsaturated fat to alter butter fat composition. Test and regular butter with similar colour and hardness, used in meals and snacks, food preparation for subjects. Test diet composition based on chemical analysis of the food Total-C: method not stated LDL-C: method not stated 2 blood samples averaged Controlled by design Weighed daily; weight remained within 2 kg. Adverse/other effects: HDL, TG, glucose, insulin, lipoproteins, clotting factors Total-C, LDL-C Diet 1: 4.3, 2.9 Diet 2: 4.2, 2.7 P<0.05 (total-C); <0.01 (LDL-C) by ANOVA
2008 To compare the effect of ruminant versus industrial TFA on total-C and LDL-CA on plasma and other risk factors. Non-smoking young men, 18-30 No sample size calculations given Cows given safflower oil to alter composition butter derived from their milk. This butter or oils used to vary TFA content while limiting variation in SFA content of diet. All food provided by researchers; unlimited additional water, caffeine-free diet beverages permitted; tea and coffee restricted to 500 mL/day. Fatty acid profile of test fats determined by chromatography; diet composition calculated using food tables. Total-C: not specified (references given) LDL-C: not specified (references given) Controlled by design Weight assessed 5/week; energy intake altered to keep weight constant Adverse/other effects: HDL, TG, CRP, lipoprotein Total-C, LDL-C Diet 1: 4.8, 3.3 Diet 2: 4.7, 3.2 P: NS Carry-over effects were tested for Rajaram 2009 To compare the effect of walnuts or fatty fish versus a healthy diet on serum lipids Non-smoking /mildly hyperlididaemic adults LDL-C: 3.53 BMI: 24.8 Sample size : 18 subjects needed in a crossover design to detect a mean difference in serum LDL-C of 0.26 mmol/L, alpha=0.05, power>0.9 All food provided by researchers Control diet consistent with dietary guidelines but without omega-3 rich food (nuts or seafood) versus 42.5 g walnuts substituted for meat/dairy food 6 days/week. Nuts eaten alone or in salads etc. Test diet composition calculated using food tables. Total-C: enzymatic colorimetric assays with the Bayer 550 Express Chemistry Analyser LDL-C: as above 2 blood samples averaged Controlled by design Weight assessed 2/week Adverse/other effects: HDL, TG, lipoprotein Total-C, LDL-C Diet 1: 5.1, 3.1 Diet 2: 4.9, 2.8 P<0.05