Vitamins E and C lower risk for heart disease and vitamin K improves insulin sensitivity
In diabetics, vitamins E and C lowered risk for heart disease and extended life after a heart attack, and vitamin K increased insulin sensitivity in men, in three new studies.
In a diabetes study, doctors explained that type 2 diabetics have a higher risk for heart and blood vessel disease because of chemical changes that can clog and stiffen blood vessels and thought that the antioxidant vitamin E may reduce or prevent these effects. About 40 men and women with type 2 diabetes and no other disease or diabetic complications took 500 IU of vitamin E per day. After 10 weeks, levels of three blood-clotting molecules that had been abnormally high at the start of the study had decreased by an average of 21 percent and a chemical that relaxes the muscles around blood vessels—boosting blood flow and lowering the risk of clotting—had increased by 50 percent. Scientists followed up for another 10 weeks while participants stopped taking vitamin E and found that one of the blood-clotting molecules had returned to the same unhealthy level as before taking vitamin E. Researchers concluded that vitamin E may be a “new tool” for protecting against blood vessel damage in type 2 diabetes.
In a vitamin C and E study, researchers noted that diabetics who have a heart attack produce abnormally high levels of unstable oxygen molecules that damage cells and theorized that the antioxidant vitamins C and E could help diabetics live longer after a heart attack. Doctors gave 122 diabetics who just had a heart attack 1,000 mg of vitamin C intravenously over 12 hours, followed by 400 mg of vitamin C plus 200 mg of vitamin E orally three times per day or a placebo. After 30 days, diabetics who had taken vitamins C and E were 68 percent less likely to have died than those who did not take vitamins C and E.
In an insulin study, researchers thought that vitamin K would increase insulin sensitivity in older adults who were not diabetic. Doctors followed 355 non-diabetic men and women, aged 60 to 80, who were taking 500 mcg of vitamin K (phylloquinone) per day as part of a study on bone loss. After 36 months, men who had taken vitamin K had significantly better insulin sensitivity than men who had taken a placebo. There was no effect for women. Insulin helps the body convert blood sugar (glucose) into energy. In diabetes, the body mishandles insulin, leading to chronically high blood sugar levels.