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Background Previous studies of the health effects of low‐fat milk or dairy consumption on the metabolic syndrome have yielded inconsistent results. The present study aimed to investigate the effects of low‐fat milk consumption on traits associated with the metabolic syndrome, as well as inflammatory and atherogenic biomarkers, in Korean adults with the metabolic syndrome. Methods Overweight Koreans with the metabolic syndrome (n = 58) were recruited and randomly assigned to either the low‐fat milk or control group. The low‐fat milk group was instructed to consume two packs of low‐fat milk per day (200 mL twice daily) for 6 weeks, and the control group was instructed to maintain their habitual diet. Clinical investigations were conducted during the screening visit, on study day 0, and after 6 weeks. Results No significant differences in changes in body mass index, blood pressure, lipid profile and adiponectin levels, as well as levels of inflammatory markers, oxidative stress markers and atherogenic markers, were found between the low‐fat milk and control groups. However, compared to the controls, significant favourable decreases in serum soluble vascular adhesion molecule‐1 and endothelin‐1 levels were found in the 12 subjects with high blood pressure and in the 18 subjects with hypertriglyceridaemia in the low‐fat milk group. Conclusions The present study did not demonstrate an overall beneficial effect of low‐fat milk consumption in subjects with the metabolic syndrome. However, low‐fat milk consumption may have a favourable effect on atherogenic markers in subjects with high blood pressure or hypertriglyceridaemia.

It is known that platelet aggregation and blood coagulation are common risk factors for pathologic phenomena in cardiovascular disease. Antiplatelet drugs, such as theophylline and verapamil, decrease the concentration of cytosolic free Ca 2ϩ by elevating the level of cyclic-adenosine monophosphate (cAMP).2) Vasodilators, such as molsidomine, nitroprusside, and nitroglycerine, inhibit the activation of platelets by elevating the cyclic-guanosine monophosphate (cGMP) concentration. 3,4) Egg yolk proteins have been recognized to be beneficial to health for a long time. However, there are adverse reports that the proteins of egg yolk are composed of allergens such as lipovitellenin and livetin. 5,6) Another harmful substance of hen eggs is cholesterol, which affects serum cholesterol levels. Egg cholesterol is known to be contained only in the yolk.7) Interestingly, in our studies, we found that proteins from hen egg yolk (EP) did not contain allergenic proteins and cholesterol (Fig. 1, 2B-5). Accordingly, we investigated whether EP has antiplatelet and anticoagulation effects compared with those of theophylline and molsidomine, which elevate cAMP and cGMP, respectively. MATERIALS AND METHODS Materials Preparation of Protein Extracts from Hen Egg YolksHen eggs were purchased from a local market and the yolks were collected. A total 20 g of egg yolk was homogenized with extraction solvents (chloroform/methanol 2 : 1, v/v) using the method of Folch et al.,8) and then extracted three times with extraction solvents using an extraction mixer (Lab-Line Instruments, Inc.). After centrifugation, the lower layer was collected, frozen at Ϫ80°C, and then lyophilized for 24 h. This dehydrated substance was dissolved and extracted in solvent (chloroform/distilled water 1 : 1, v/v). After centrifugation, the chloroform layer and aqueous layer were separated. The aqueous layer was filtered with a centrifuge filter device (Amicon Centricon YM-10, Millipore, Beford, MA, U.S.A.). The lower layer was frozen at Ϫ80°C and then lyophilized for 24 h. This dehydrated substance was dissolved in distilled water when assayed.Separation and Identification of EP EP containing an equal volume of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) buffer (5% mercaptoethanol, 2% SDS, 10% glycerol, 0.0625 M Tris, 0.01% bromphenol blue, pH 6.8) was boiled for 5 min to denature the proteins completely. The proteins were separated by SDS-PAGE (17%, 1.0 mm gel) according to the method of Laemmli. 9)Separated proteins were stained with silver stain (Silver Stain Plus, Bio-Rad Laboratories) and dried. The relative intensity of protein bands was analyzed using SigmaGel TM Gel Analysis Software (Jandel, Scientific Software, U.S.A.). Molecular weight standards were used as low-range protein size markers in silver stain.Preparation of Human Washed Platelets Blood from healthy human volunteers was anticoagulated by 10% ACD solution (0.8% citric acid, 2.2% sodium citrate, 2.45% glucose). Platelet-rich plasma (PRP) was obtained by centrifugat...