Objective: To determine whether healthy males who consumed increased amounts of dietary stearic acid compared with increased dietary palmitic acid exhibited any changes in their platelet aggregability, platelet fatty acid profiles, platelet morphology, or haemostatic factors.
Design: A randomized cross-over dietary intervention.
Subjects and interventions: Thirteen free-living healthy males consumed two experimental diets for 4 weeks with a 7 week washout between the two dietary periods. The diets consisted of approximately 30% of energy as fat (66% of which was the treatment fat) providing approximately 6.6% of energy as stearic acid (diet S) or approximately 7.8% of energy as palmitic acid (diet P). On days 0 and 28 of each dietary period, blood samples were collected and anthropometric and physiological measurements were recorded.
Results: Stearic acid was increased significantly in platelet phospholipids on diet S (by 22%), while on diet P palmitic acid levels in platelet phospholipids also increased significantly (8%). Mean platelet volume, coagulation factor FVII activity and plasma lipid concentrations were significantly decreased on diet S, while platelet aggregation was significantly increased on diet P.
Conclusion: Results from this study indicate that stearic acid (19g/day) in the diet has beneficial effects on thrombogenic and atherogenic risk factors in males. The food industry might wish to consider the enrichment of foods with stearic acid in place of palmitic acid and trans fatty acids.