Increased tendency towards gingival bleeding caused by joint effect of α-tocopherol supplementation and acetylsalicylic acid

α-tocopherol (vitamin E) may play a role in the treatment of arterial thromboembolic disease, possibly by inhibiting platelet aggregation. Thus far, no clinical evidence exists for this effect. The objective of this study was to assess the effect of α-tocopherol supplementation on gingival bleeding either in combination with acetylsalicylic acid (ASA) or without it. This study was an end-point examination of a random sample of male smokers who had participated in a controlled clinical trial, the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study) for 5-7 years. The study included 409 men aged 55-74 years of whom 191 received α-tocopherol supplementation (50 mg/day); 56 used ASA, 30 received both and 132 received neither. Gingival bleeding was examined by probing with a WHO probe and reported as a percentage of bleeding sites adjusted by the logistic regression model. Gingival bleeding was more common in those who received α-tocopherol compared with nonreceivers among subjects with a high prevalence of dental plaque (P < 0.05). ASA alone increased bleeding only slightly. The highest risk of gingival bleeding was among those who took both α-tocopherol and ASA (33.4% of probed sites bleeding vs 25.8% among subjects taking neither α-tocopherol nor ASA, P < 0.001). In the ATBC Study, more deaths from haemorrhagic stroke and fewer from ischaemic heart disease were observed among those participants who received α-tocopherol compared with those who did not. Based on the results of the present study and the ATBC Study, we conclude that α-tocopherol supplementation may increase the risk of clinically important bleedings, particularly when combined with ASA.