Interaction of physical activity and diet: implications for haemostatic factors.

Regular moderate intensity physical activity and habitual diet providing no more than one third of energy from fats have been recommended for the prevention of atherosclerotic diseases. The background for these guidelines is the key role of plasma lipids. However, the importance of thrombogenesis in acute myocardial infarction has become obvious during the last decade. Hyperlipidaemia and excess of adipose tissue increase platelet aggregability and blood coagulation, and decrease fibrinolysis. Both regular physical activity and dietary fat reduction decrease blood lipids and body fat thereby diminishing the risk of thrombosis. Currently, data on interactions between physical activity and diet on haemostasis are scarce, and the few studies available have not demonstrated additional effects when these two lifestyle modifications have been combined. This paper is restricted only to studies using controlled randomized design. Regular moderate intensity physical activity as well as diet rich in omega-3 fatty acids decrease platelet aggregability. The effects of regular physical activity on plasma fibrinogen remain contradictory, while the impact of diet is even less clear. Plasminogen activator inhibitor-1, a possible link between insulin resistance syndrome and coronary heart disease, may decrease due to physical training or low fat diet. It can be hypothesized that moderation in physical activity and diet carries a more powerful impact on blood coagulation and fibrinolysis than either lifestyle modification alone. Studies focusing on the interactions of regular moderate physical activity and fat-modified diet are needed in efforts to optimize the preventive actions by lifestyle changes.