Sugar substitutes and relation to Insulin Index

Do artificial sweeteners affect insulin? Are they safe to consume? Don’t they sound too good to be true? Which is the sweetener that has minimal/no effect on insulin? Which is the best sugar replacement? Answers to these questions will make our lives easier and clear the doubts about what to buy and what to avoid.

The Problem and Reasons to understand the insulin index of sweeteners

The problem in most diabetics, pre-diabetics and insulin resistant people is the reduced ability of their body cells to accept insulin (which carries glucose to generate energy) because of predominantly high levels before (of both glucose and insulin), leading to insulin resistance. Modern diet full of carbohydrates, sugars and processed food and few treatment approaches (such as five meals a day) also keep the insulin levels continuously high, adding to this root problem of low sensitivity to insulin and high glucose intolerance in such people.

The reason why this problem is critical: On the contrary to above, if the body cells’ capacities to uptake glucose by being sensitive to insulin are improved, the condition can be controlled and even reversed in most cases. To do that, we need to cut down the insulin resistance which can be done by not consuming foods that require or raise too much insulin while providing us energy at the same time. Hence it is critical to understand what foods do to our glucose but also our insulin levels when we ingest them.

When both the diabetics and health conscious think about getting healthy, cutting calories is the first thing they generally opt for. And there comes artificial (and some natural) sweeteners or sugar substitutes. While these replacements might have zero or fewer calories, do they really have no effect in the body’s insulin levels? Research says otherwise.

Research on Sugar Substitutes (Both artificial and natural)

Most commonly used zero calorie (or very low calorie) sweeteners are aspartame, sucralose, saccharin and acesulfame potassium and those are the ones covered here.

According to a research at Harvard University, it was found that sucralose (which is said to be of natural origins but is chlorinated) and acesulfame potassium (sometimes used in combination with aspartame and in few products like chewing gums) had negative impacts on insulin on test trials, resulting in higher insulin levels after the tests. (1) Another research in mice showed clear development of glucose intolerance (which is a result of insulin resistance) after the use of saccharides in diet. In the research it was found the mechanism of developing these is via affecting the gut microbes, resulting in disrupted metabolism and essentially raising insulin (further developing intolerance to glucose). (2)

What does this mean? What it means is, almost all of these sweeteners have more insulin secreting effect than table sugar, and even if they do not have any calories, they are messing up the metabolism by secreting more insulin; either by affecting gut health or by affecting hormones/metabolism in the liver. It also means while some sweeteners claim to be of natural origin, they are highly processed by adding chemicals buying a natural sweetener and a sweetener of natural origin could mean two COMPLETELY DIFFERENT things.

Another problem with such sweeteners is because they are extremely sweet than table sugar (hundreds of times more), they are usually required in much smaller doses (1/200 or 1/300). So to make up for the bulk so these sweeteners can be used in measurable quantities (like a teaspoon or a pallet), companies add binders/fillers like maltodextrin. While not a sweetener itself, maltodextrin has a higher glycemic index (=110) and insulin index, so much high than table sugar (sucrose=65) and liquid glucose (=100) and hence, is far worse than those two. In addition to raising the blood sugar and blood insulin more than sugar, it will also stimulate hunger, and users experience increased appetite after the use of aspartame as a side effect. In a research, Aspartame was also found to have a higher insulin index than sucrose and hence will increase glucose intolerance in the long run (3) It was also found that eventually it could lead to development of metabolic syndrome. (4) Similarly, sucralose was also found to mimic insulin like response and increasing glucose intolerance.

What does this mean? It means that most sugar substitutes have a mixer/filler/binder in them. These binders are more often cheap additives like maltodextrin which have a far worse effect on insulin and glucose than sugars, despite having low or no calories. It also means that most sweeteners while having low calories, are not really kind on insulin levels.

So which are the best sweeteners

So which would be the best sugar substitute? Ideally, it should not have any of the complications mentioned above. Hence, the best sweetener should be metabolized in stomach and NOT in liver so it doesn’t affect hormones, has to have a sweet taste, and would be ideal if sourced naturally and has NO maltodextrin (or cheap additives to it). Too much to ask?

We are in luck. The best sugar replacement you could use is Stevia. Stevia is an Indian/South American herb, easily available in powders, dried leaves, and dried leaves powder forms. Or you can buy a plant and grow at home in a flower pot. You can also buy stevia extracted from leaves in white, grain powdered form (make sure by reading the label the brand you are buying does not have additives like maltodextrin). You can also use liquid stevia extract which would be just as safe and effective as the other stevia forms. You can also check out a short video on stevia by Dr. Berg here.

In addition to being safe for consumption and having a zero glycemic index, stevia is found in a research to also increase insulin sensitivity (the opposite of being insulin resistant) and both blood insulin levels and blood glucose levels for test users improved after using stevia. In the same research where it was discovered that aspartame has a higher insulin response than sugar, it was also found that the insulin response of stevia is far lower than that of sugar. (3) Also, because stevia is metabolized in the stomach by stomach acids, it has no negative impact on either insulin or gut health. Hence, it does not hinder/disrupt metabolism in any way.

The other sweeteners which are safe to use, and have no effect on both blood sugar levels and insulin levels are monk fruit (unfortunately currently not available in India) and erythritol. Erythritol being an alcohol sugar, can cause laxation in some users. Because of the bulk it provides, it is a good replacement for sugar where recipes demand bulk and is more relevant for baking purposes. Some companies sell a mix of stevia and erythritol which is also safe to use. Xylitol, sorbitol and mannitol (poly-ols or poly alcohols like erythritol) also have a very low glycemic index (though erythritol has the index of 1, which is the lowest of all poly-ols) and are safe to use. (5) Being poly alcohols, they also might cause laxation or stomach upset in some users.