The problem with high blood glucose levels

By The Low Carb Clinic, 22 January 2019 - 410 words (2 minutes)

High blood glucose levels are extremely harmful. They cause significant damage in both small and large blood vessels throughout the body. [1]   

Glycation is a reaction between sugar (glucose) and proteins or lipids, which forms advanced glycation end-products (AGEs). AGEs accumulate in the body as part of normal aging, but higher levels can cause trouble.  AGEs cause damage by ‘cross-linking’ (forming bonds) with parts of different cells in the body, altering the cell’s structure, affecting the proteins inside the cells, and so negatively impacting its ability to function. AGEs also damage proteins found in the blood, increasing inflammation.[2]

No matter how old you are, higher levels of AGEs are linked to higher levels of oxidative stress and inflammation – increasing the risk of a broad range of complications to health, including cardiovascular disease, kidney disease, Alzheimer’s, and premature ageing.[3] The more glucose in the blood, the more AGEs are formed – so people with diabetes have much higher levels of AGEs, and so more blood vessel damage.[4]

Small blood vessel damage can lead to severe vision loss and blindness (diabetic retinopathy), which affects up to 35% of people with diabetes[5] and is the leading cause of blindness in Australia.[6] Damage to the small blood vessels in the kidneys (diabetic nephropathy) means that diabetes is the leading cause of kidney failure in Australia.[7] Damage to the peripheral nerves (diabetic neuropathy) can cause severe pain and non-healing wounds (for example, foot ulcers) – leading to amputations, which are 15 times more common in people with diabetes. [8] About 10,000 amputations occur annually in Australia.[9]

AGEs also damage large blood vessels. They disrupt the inner lining of blood vessels, hardening and narrowing them, which prevents the vessels from properly relaxing (atherosclerosis).[10] This contributes to heart and peripheral vascular disease because it impairs blood flow, preventing adequate oxygenation as well as the disposal of waste products throughout the body. Glycation also makes the platelets in the blood ‘sticker’ – which means blood clots are more likely, contributing to strokes.[11] In Australia, people with diabetes are up to four times more likely to have a heart attack or stroke.[12]

Carbohydrates are the main dietary source of glucose, and so are the biggest contributor to increased blood glucose levels. In this way, diabetes can be seen as a condition of carbohydrate intolerance, with carbohydrate consumption likened to ‘glucose toxicity.’ With so much extra glucose in the blood stream, increased levels of AGEs are formed, causing life-threatening damage all around the body.

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