The glycemic index and your eyes

One way to safeguard the long-term health of your eyes, among other things, is to understand the differences between carbohydrate foods and their rating on the glycemic index. 

• Low GI foods trickle-feed our body systems, producing only small fluctuations in blood sugar and insulin levels. These help to promote weight loss and reduce obesity.
• High GI foods cause rapidly fluctuating blood sugar levels — a sharp rise after eating, shortly followed by a plummet. That's because the blood sugar surge prompts a corresponding steep rise in insulin, the hormone that enables the body to metabolize sugar.
• Too much insulin, in turn, causes the sharp drop in blood sugar levels over the next few hours — prompting more carbohydrate cravings. Like sugar, all processed carbohydrates have a high GI, while most fruits have a low GI, causing only a gentle rise and keeping levels more stable.

• A high intake of refined carbohydrates is already known to increase the risk of diabetes, because repeated demands for insulin, from eating lots of high GI foods, put a strain on the pancreas where insulin is produced. Both diabetes and obesity can damage your eyesight, but a simple change of diet, that reduces your intake of processed foods, could reduce the risk.
• Diets high in refined starches, such as breads and cereals, may also be linked to dramatic increases in nearsightedness. Bread has been eaten for thousands of years — but not bread as we know it today. Modern refining techniques have hugely increased the rate of starch digestion and, in response, the body pumps out more insulin.
• Researchers from Colorado State University and the University of Sydney in Australia suggest that this could affect children's eye development. If the coordination of eyeball lengthening and lens growth is disturbed during crucial periods, the eyeball may lengthen too much, causing nearsightedness in children.
• This theory could also help to explain why people who are obese or have adult diabetes are also more likely to become nearsighted.