Eau-Coulee Seventh Day Adventist Church-Diabetes and Antioxidants

Diabetes and Antioxidants

The War on Free Radicals

You remember to check your blood sugar every day, but do you think to take your daily dose of vitamin E? Recent studies show that antioxidants such as vitamins C and E may help prevent vascular complications in diabetics, such as blindness, kidney failure, peripheral neuropathy -- damage to the feet, legs, fingers and hands -- and amputation.

What Do Antioxidants Do?

Antioxidants help neutralise the effects of free radicals, formed when the body’s cells burn oxygen. This toxic byproducts cause damage to tissues through oxidative stress, which has been linked to conditions such as cancer, heart disease and cataracts as well as the natural aging process. Free radicals are highly reactive; they start chain reactions that produce more free radicals.

“Diabetes is considered premature aging,” says Dr. Bob Eckel, an endocrinologist at the University of Colorado’s Health Sciences Center in Denver. “Damage to a wide variety of tissues, including the heart and blood vessels, eyes, nerves and kidneys, is associated with the production of free radicals.”

The body’s natural metabolism is only one of many sources for free radicals.

Others include:

Unfortunately, for diabetics, increased levels of glucose can also be a source.

“Oxidative stress and inflammation increase in diabetes due to high blood sugar, which produces a lot of free radicals,” states Dr. Kenny Jialal, endocrinologist at UT Southwestern Medical Center in Dallas.

Our bodies produce natural antioxidants, but diabetics have depleted antioxidant reserves and their levels of vitamin C are especially low, a deficiency which has been linked to peripheral artery disease -- a circulatory condition in which the leg blood vessels become blocked. A survey by the American Heart Association shows that 63 percent of all diabetic patients suffer from some form of heart disease, including circulatory problems, high blood pressure and congestive heart failure.

“Diabetics face increased risk for heart attack and stroke,” notes Dr. Sridevi Devaraj, a clinical pathologist at UT Southwestern. “Antioxidants provide secondary prevention by reducing inflammation.”

Recent animal studies have demonstrated that oxidative stress can damage insulin-producing cells in the pancreas, which can worsen diabetes. Rats fed with 500 milligrams of vitamin E showed a significant increase in insulin levels as well as a decrease in sugar levels. They also exhibited better blood sugar control.

In the past, studies on humans have been limited, but last year, Jialal -- along with other researchers at UT Southwestern -- studied the effects of vitamin E on diabetes. Study participants were given 1200 international units -- more than 160 times the recommended dietary allowance of 10 milligrams -- of vitamin E for three months.

“Vitamin E in high doses has an effect on complications,” Jialal says. Participants showed a reduction in oxidised levels of LDL (“bad”) cholesterol, a leading cause of arterial disease. “You also see improved blood flow in the eyes and kidneys. Other parts of the world already routinely prescribe vitamin E.”

Jialal notes, however, that more study needs to be done to determine the long-term impact of antioxidants on diabetes.

Adding Antioxidants to Your Diet Most antioxidants, including vitamins A and C along with folic acid, naturally occur in foods. Vitamin supplements should not be considered an alternative to healthy eating. “Fruits, vegetables and whole grains are all good sources for antioxidants,” says Eckel. “They’re preferable to using supplements.”

High doses of vitamin C, in particular, can cause DNA breaks and may have pro-oxidative effects in certain conditions and diseases, meaning that it could actually promote the production of free radicals.

Eckel recommends following dietary guidelines from the American Heart and Diabetes Associations. Eat at least five servings of fruits and vegetables a day, although nine is optimal. Pick those that are dark green or orange in color.

Vitamin E is much harder to get from your diet. A natural supplement of at least 500 milligrams is recommended. “Vitamin E is a fat-soluble vitamin found in oils,” explains Devaraj. “You definitely don’t want to add oil to your diet because it adds to your risk [for heart disease].”

It’s important to always talk to your doctor first before taking supplements. Devaraj notes that diabetics with clotting disorders who are on anticoagulants should not take vitamin E supplements, which can cause excessive bleeding. Herbal supplements such as gingko, which are purported to be antioxidant rich, are also not recommended.

“There hasn’t been enough study done [on herbals]. We don’t know how they metabolise in the body,” she says. “The first line of treatment for diabetes should be anti-hypertensive medication, weight loss and a good diet. Try this first before adding supplements.”

“The use of antioxidants is very promising,” adds Eckel. “It’s something we need to understand better. Antioxidant vitamins won’t completely prevent complications, but they may reduce the overall severity.”