Table 1.
Studies outlining the effects of decreasing dietary linoleic acid levels (% energy) from baseline on changes in plasma/serum phospholipid arachidonic acid level
| Author, (reference) | Study design | Subjects | Diet length | Diet comparison | LA (% change) Baseline to intervention | ΔAA (%) change | Comments |
|---|---|---|---|---|---|---|---|
| Lasserre [17] | Randomized crossover | N = 24 | 5 months | Peanut oil diet (baseline) compared to milk fat diet | -90 (6.5%-0.6% ) | 9.99 N.S. | Used peanut oil group b/c close to DRI for LA. Subjects were nuns in monastery. |
| Peanut oil diet (baseline) compared to low erucic acid rapeseed oil (canola oil) diet | -30 (6.5%-4.5%) | -5.49 N.S. | Used peanut oil group b/c close to DRI for LA. Subjects were nuns in monastery. | ||||
| Lichtenstein [35] | Randomized double-blind crossover | N = 30 | 35 days | Soybean oil diet (baseline) compared to high oleic acid soybean oil diet | -82 (11%-1.9%) | -2.58 N.S. | Pooled data of men and women. Baseline diet of 10.96% energy closest to DRI for LA. AA did not differ among remaining groups tested either |
| Liou [37] | Randomized crossover | N = 24 | 4 weeks | High linoleic acid sunflower oil (diet) compared to high oleic acid safflower oil (diet) | -63 (10.5%-3.8%) | -5.55 N.S. | Incorporated test oils into baked foods (cookies, breads), mayonnaise, salad dressing. AA data presented in graphs, not tables. Fish intake was avoided for all groups. AA PL content did not differ between sequence of diets going from high LA to low LA or vice versa. Study address low or high LA with constant ALA at 1%. |
| Goyens [38] | Double-blind intervention | N = 19 | 6 weeks | Reduced LA in food items (margarines, pastries, baked goods) | -57 (7%-3%) | 5.26 N.S. | Test oils consumed in margarine and pastries. Prohibited consumption of fish or marine foods in all groups. |
| Vega-Lopez [36] | Randomized crossover | N = 15 | 35 days | Canola oil diet compared to palm oil diet | -50 (6.5%-3.3%) | -8.06 N.S. | Canola oil in mixed foods was replaced by palm oil in mixed foods. AA did not change among all three dietary groups. Canola oil diet is baseline because closest to DRI LA intake. |
| Li [39] | Parallel intervention | N = 17 | 28 days | High LA diet to moderate LA diet using canola oil/canola margarine | -48 (13.5%-7%) | -3.80 N.S | Subjects were given diet more than twice DRI for LA and then given diet resembling the DRI for LA. All groups were asked to not consume fish. |
| High LA diet to normal LA diet using canola oil/canola margarine | -39 (11.9%-7.3%) | -16.5 N.S. | |||||
| Mantzioris [40] | Parallel intervention | N = 15 | 4 weeks | Control diet (sunflower oil) group compared to intervention diet (flaxseed oil) | -57 (7.8%-3.3%) | -4.5 N.S. | Control group consumed relatively close to DRI for LA while intervention group reduced LA by more than half. |
| King [16] | Randomized parallel | N = 66 | 6 weeks | Baseline diet compared to low fat diet | -29 (10%-7.1%) | 4.1 (p < 0.05) | Used modified food items for diets containing different amounts of fat. Reported AA PL in % change. |
| Geppert [41] | Randomized double- blind intervention | N = 54 | 8 weeks | Baseline diet compared to LA reduced diet (using olive oil capsules) | -12 (5.8%-5.1%) | 1.12 N.S. | Used olive oil capsules with vegetarians. |
Percent change (±) from baseline in AA that is significant is identified with (p < 0.05). Percent change (±) from baseline in AA that is not significant is denotedby N.S.
Abbreviations: AA, arachidonic acid; DRI, Dietary Reference Intake; LA, linoleic acid; PL, phospholipid