Blood Type Is Not Associated with Changes in Cardiometabolic Outcomes in Response to a Plant-Based Dietary Intervention

Abstract

BackgroundRisk of cardiovascular disease is lower in individuals with blood type O and increased in individuals with blood type A, compared with those in other blood groups. However, little evidence is available regarding whether individuals with different blood types benefit from different diet recommendations. ObjectiveAs part of a larger intervention trial using a low-fat vegan diet, this study ascertained whether changes in cardiometabolic outcomes were associated with ABO blood type. DesignA secondary analysis among intervention-group participants in a 16-week randomized clinical trial. Participants/settingIn a larger study of overweight individuals randomly assigned to follow a low-fat vegan diet or to make no diet changes for 16 weeks, ABO blood typing was conducted on 68 intervention-group participants. InterventionIntervention-group participants were asked to follow a low-fat vegan diet and attend weekly educational classes to aid in diet adherence. Main outcome measuresBody weight, fat mass, visceral fat volume, blood lipid levels, fasting plasma glucose levels, and glycated hemoglobin concentrations. Statistical analyses performedStudent t tests compared participants with blood type A to all other participants, and individuals with blood type O to all other participants. ResultsThere were no significant differences in any outcome between individuals of blood type A and all other participants, or between individuals of blood type O and all other participants. Mean body weight change was –5.7 kg for blood type A participants and –7.0 kg for all other participants (P = 0.09), and was –7.1 kg for type O participants and –6.2 kg for all other participants (P = 0.33). Mean total cholesterol decreased 17.2 mg/dL in the type A group and 18.3 mg/dL for all other participants (P = 0.90), and decreased 17.4 mg/dL among type O participants and 18.4 mg/dL for all other participants (P = 0.89). ConclusionsBlood type was not associated with the effects of a plant-based diet on body weight, body fat, plasma lipid concentrations, or glycemic control.