Food Lipids: Chemistry, Nutrition, and Biotechnology

Recently, well-controlled studies investigating effects of specific saturated fatty
acids have been published. Tholstrup et al. [86] reported that diets rich in lauric plus
myristic acids or palmitic acid increased factor VII coagulant activity as compared
with a diet rich in stearic acid. It was also suggested that the turnover of prothrombin
was increased on the lauric plus myristic acids diet as fragment 1�2 concentrations
were higher on such a diet than on a stearic acid diet [87] (Fig. 15). However, stearic
acid increased fibrinogen concentrations compared with the lauric plus myristic acid
diet [87]. In a second study, Tholstrup et al. [13] investigated diets rich in myristic
acid or palmitic acid. On the myristic acid diet, subjects showed an increase in factor
VII coagulant activity. Thus, these studies [13,86] suggest that saturated fatty acids,
except for stearic acid and probably MCFA, increase factor VII coagulant activity.
However, stearic acid may have an unbeneficial effect on fibrinogen concentrations.
C. Fibrinolysis
The process involved in thrombus dissolution, and thus the conversion of fibrin into
fibrin degradation products, is called fibrinolysis. A simplified scheme of the fibrinolytic
pathway is given in Figure 16. The central reaction in the fibrinolytic process
is the conversion of plasminogen into plasmin, which is regulated by the action of
tissue plasminogen activator (t-PA). The fibrinolytic capacity of blood is regulated
by inhibiting t-PA activity by the action of plasminogen activator inhibitor type-1
(PAI-1), while plasmin is inhibited mainly by �2-antiplasmin [88].
1. Measurement of Fibrinolytic Capacity of Plasma
The fibrinolytic capacity of plasma can be measured by global tests or more specific
assays. The global tests include the dilute clot lysis time, the euglobulin clot lysis
Figure 15 Effects of lauric plus myristic acid, myristic acid, and stearic acid on factor VII
coagulant activity relative to those of palmitic acid. Healthy young men consumed diets
enriched in lauric plus myristic acids (C12:0 and C14:0; 14% of energy), myristic acid
(C14:0; 14% of energy), palmitic acid (C16: 15–16% of energy), or stearic acid (C18:0;
14% of energy) for 3 weeks [13,86].
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