Fish oils and cardiovascular disease

BMJ 1995;310:1604 (17 June)

Letters

Fish oils and cardiovascular disease

EDITOR,--In their editorial B N C Pritchard and colleagues concludedthat fish oils have beneficial effects on lipids and the haemostaticsystem, but they pressed for more studies in diseases relatedto atherosclerosis.¹ We wish to reinforce this recommendation,particularly in relation to diabetes.

Two studies in which we have been involved have suggested possibleadverse effects on the coagulation system. In the case of patientswith insulin dependent diabetes a randomised trial showed significantincreases in fibrinogen and clotting factor X concentrationsin the group that took a fish oil supplement.² In a separatetrial in patients with non-insulin dependent diabetes factorVII concentration increased significantly in the group receivingthe fish oil preparation; this group also showed worsening glycaemiccontrol.³ Fibrinogen and factor VII may be risk factors forischaemic heart disease.⁴ Thus these apparently adverse effectson the coagulation system may outweigh other potentially beneficialeffects on . . . [Full text of this article]