Diabetics may need to watch the amount of antioxidants they consume as well as their amount of exercise and carbohydrate intake. A recent French review from Avignon University published in the October 2013 issue of Obesity Reviews analyzed 10 randomized controlled trials that examined the effects of antioxidant supplementation on endothelial function of cells along blood vessels among people with type II diabetes mellitus. Dr. Guillaume Walther and colleagues found that non-obese, type II diabetics could benefit from prolonged supplementation of vitamins E and C. However, antioxidant supplementation may not help much among those who are obese and have type II diabetes mellitus.
In the analysis, type II diabetics with a body mass index (BMI) of equal or less than 29.45 kg/m2 seemed to significantly improve from antioxidant supplementation. The benefits seen in this group diminishes among diabetics who weighed more than 29.45 kg/m2. According to the BMI, people who are less than 18.5 kg/m2 are considered underweight, while those who are more than 30 kg/m2 are considered obese. Because BMI does not differentiate between fat weight and non-fat weight (i.e., water, muscle, bone density), this finding may not apply to those have the Terminator or Captain America physique.
While diabetes mellitus management (in type I and type II) has focused mostly on blood sugar control, oxidative stress can contribute to other cardiovascular diseases due to increasing insulin resistance or impairing insulin secretion. According to a 2012 review published in Indian Journal of Endocrinology and Metabolism, researchers Sarita Bajaj and Afreen Khan from MLN Medical College in Allahabad, India, stated that diabetics have a “4-fold increase in the incidence of coronary artery disease” and “a 10-fold increase in peripheral vascular disease.” Both types of diabetes mellitus can increase the mortality rate by three to four times with as much as 75 percent of diabetics dying from cardiovascular disease.
Oxidative stress occurs when there is an imbalance between the amount of free radicals present in the body and the amount of antioxidants that “capture” these free radicals. This process can damage the cell membranes of proteins, lipids, and DNA, which can lead to various diseases, such as cancer, heart disease, various neurological diseases, and autism. Diabetics tend to lose the endothelial functions of the blood vessels that can affect the rate of vasoconstriction and vasodilation, coagulation, immune function, and control the volume of electrolytes within and without of the cells.
Bajaj and Khan mentioned in the review that oxidative stress caused by hyperglycemia can lead to cell death in vivo and in vitro. Type I and type II diabetes mellitus generally have an “increased formation of free radicals and decreased antioxidant capacity” that can lead to further cell damage. Based on the studies they reviewed, they concluded that antioxidants, such as vitamins C and E, N-acetylcysteine, and alpha lipoic acid, may help reduce the complications of diabetes mellitus via food or supplementation.
Foods that are high in such antioxidants include cruciferous vegetables, orange-yellow vegetables like carrots and green peppers, citrus fruits, and various legumes and plant oils. Some animal-based sources of antioxidants, such as cold-water fish and certain organs (i.e. liver, kidney), provide the “good” fats (omega-3’s, alpha lipoic acid) to help maintain cell membrane structure. Even some coffee consumption, which had made health headlines recently, could lower the risk of diabetes mellitus. Based on a study published in April 2014 of Diabetologia among almost 96,000 women and 27,800 men in the U.S., those who increased their coffee intake by about 1.5 cups a day lowered their risk of type II diabetes by 11 percent, while those who cut back more than one cup of coffee a day increased their risk by 17 percent. The participants’ diet was also assessed and taken into consideration with the outcome.
Although antioxidants may seem like the panacea to preventing the complications of diabetes mellitus, diabetics should seek help and consult with their physician and registered dietitian before indulging themselves in the food or self-prescribe to the antioxidant supplement dosage. Too much of a good thing could be just as worse as too little.
By Nick Ng
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