New research shows that antioxidant supplements are vital for diabetics and pre-diabetics.

(Scientific references are at the bottom of the page) 

Recent research has shown that even well controlled diabetics need to take antioxidant supplements. Medical scientists have described a new pathological process called “metabolic memory”. Metabolic Memory is a code that becomes imbedded in the cells of diabetics and sustains the release of pre-treatment levels of harmful free radicals. High levels of unopposed free radicals cause oxidative stress and most of the circulatory and other problems experienced by diabetics.

 For a number of years we have known that diabetic patients suffer from free radical overload and oxidative stress. Scientific evidence shows that oxidative stress is the underlying cause of the blood vessel damage so characteristic of diabetes; and most complications of diabetes are caused by diseased blood vessels. High blood pressure, poor circulation, kidney disease and nerve damage are primarily the result of damage to both small and large blood vessels in diabetic patients. 

Damage to blood vessels is caused by the action of free radicals on the endothelium (or lining) of the blood vessels. Even though it is a layer only one cell deep, the endothelium plays a very important role in the normal and abnormal functioning of arteries and veins. It has many vital functions; not only does it control vascular dilatation and constriction,  but it also regulates the release of various hormones and controls the formation of clots in the arteries in response to injury. Endothelial dysfunction leads to arterial constriction atherosclerosis and irreversible arterial damage thereby increasing the risk of heart attack, stroke, peripheral arterial disease, kidney failure and other problems.

 Hyperglycemia (high blood sugar) is the prime cause of free radical overload in diabetics and those with metabolic syndrome. Until recently, it was thought that once the blood sugar was under control the harmful effects of oxidative stress would be halted. However this has been shown not to be the case and a mechanism called “metabolic memory” has been described that accounts for this phenomenon. It appears that, during periods when an individual’s blood sugar is not controlled, proteins are glycated (attached to a glucose molecule). These glycated proteins retain a ‘memory’ which compels them to continue to sending out stress signals. This stress signaling sustains the production of excess free radicals and oxidative stress even after treatment has returned the blood sugar levels to normal. Unless countered by dietary antioxidants, the persistent release of free radicals maintains the unhealthy state of oxidative stress and vascular damage.

 A recent clinical trial has shown conclusively that those insulin dependent diabetics who took antioxidants in addition to insulin reduced oxidative stress considerably compared to those who were using insulin without an antioxidant.

This and other studies have also discovered further interesting information regarding the type of antioxidants used to treat oxidative stress in diabetics. Vitamin E (usually an effective antioxidant) was found to be of no use at all in this context. Vitamin C, although far more effective than vitamin E, did not completely control oxidative stress – even in those diabetics whose blood sugar levels were very well controlled and did not have any other conditions that may have caused oxidative stress.

 This observation should not come as too much of a surprise when we appreciate the fact that there are many different types of free radicals and that no single antioxidant can access all parts of the cell or neutralize all free radical species.

This ground breaking research tells us two important things:

1. Diabetics need to ensure that they are very aggressive in controlling their blood sugar levels at all times.
2. By far the majority of people are diagnosed with diabetes months or years after the disease process has started. This means that the high blood-sugar levels put them under oxidative stress for months or years prior to receiving treatment and harmful “metabolic memories” become encoded into their cellular proteins. Even if diabetics, once they receive treatment, then go on to sustain normal blood sugar levels, the embedded cellular metabolic memory will continue to stimulate free radical release and sustain damaging oxidative stress.

 
Accumulated research to date tells us that not only do all diabetics need to take adequate amounts and variety of antioxidants but non-diabetics need to do so too. Apart from having regular check-ups for diabetes and related conditions like metabolic syndrome, everyone should eat a diet with significant quantities of antioxidant-rich foods.

However it is vitally important that those at risk for diabetes, metabolic syndrome or any other disease associated with oxidative stress take an antioxidant supplement too.

 Spices have the highest antioxidant activity of all food groups (American Journal of Clinical Nutrition 2006). A balanced spice-based antioxidant supplement provides over 100 protective antioxidant compounds as well as spices like cinnamon, coriander, fenugreek, ginger and others that help to lower blood sugar levels.

 References:

1.Hypothesis: the 'metabolic memory', the new challenge of diabetes.
Diabet Med. 2007 Jun;24(6):582-6. Epub 2007 May 8.
Ihnat MA, Thorpe JE, Ceriello A.
2.Endothelial dysfunction: a comprehensive appraisal
Cardiovasc Diabetol. 2006 Feb 23;5:4.
 Esper RJ, Nordaby RA, Vilariño JO, Paragano A, Cacharrón JL, Machado RA.
3.Simultaneous Control of Hyperglycemia and Oxidative Stress Normalizes Endothelial Function in Type 1 Diabetes
Diabetes Care 30:649-654, 2007
Antonio Ceriello,Sudhesh Kumar,Ludovica Piconi Katerine Esposito,and Dario Giugliano
4.Biochemistry and molecular cell biology of diabetic complications.
 Nature. 2001 Dec 13;414(6865):813-20.
  Brownlee M.
5.Advanced glycation end products and antioxidant status in type 2 diabetic patients with and without peripheral artery disease.
Diabetes Care. 2007 Mar;30(3):670-6.
 Lapolla A, Piarulli F, Sartore G, Ceriello A, Ragazzi E, Reitano R, Baccarin L, Laverda B, Fedele D.
6.The effects of diet on inflammation: emphasis on the metabolic syndrome.
J Am Coll Cardiol. 2006 Aug 15;48(4):677-85. Epub 2006 Jul 24.
Giugliano D, Ceriello A, Esposito K
7.Oxidative stress and diabetes-associated complications
Endocr Pract. 2006 Jan-Feb;12 Suppl 1:60-2.
Ceriello A
8.New insights on oxidative stress and diabetic complications may lead to a "causal" antioxidant therapy.
Diabetes Care. 2003 May;26(5):1589-96
Ceriello A