Flaxseed supplementation could be useful in people with high cholesterol levels. In particular, it could lower LDL cholesterol in people with high cholesterol.[1][2][3] The effect of flaxseed supplements on other types of cholesterol — like HDL cholesterol and triglycerides — is inconsistent, although some studies do find a decrease in triglycerides and an increase in HDL cholesterol.[3][1][4]
Flaxseed supplements may also lower both systolic and diastolic blood pressure in people with high blood pressure. The effect is most notable when whole or ground flaxseed is used.[5][6][7][8]
Flaxseed has been used in people with high blood glucose. Supplementation with flaxseed seems to lower fasting glucose levels and insulin levels but does not consistently improve HbA1c levels.[9][10][11][12]