Why Is Sugar Toxic?

The sugar industry would like us to think that the calories we get from sugar are harmless. But that is an enormous—and deliberate—lie. Calories from sugar are the most likely to make us gain weight. Excess sugar causes insulin resistance. Insulin resistance is at the root of many of our most serious diseases, including type 2 diabetes, heart disease, stroke, Alzheimer’s dementia, and even cancer.

Sugar is the nutritional equivalent of cigarettes and should be avoided.

As if that’s not enough, for many people, eating sugar also makes them hungrier and causes cravings for more sugar. As one member put it, eating sugar when you’re hungry is “like pouring gasoline on a fire.”

What Makes Calories from Sugar Different and So Harmful?

The most common types of sugar we eat are table sugar (sucrose) and high-fructose corn syrup (HFCS). Both table sugar and HFCS consist of roughly 50/50 blends of two other types of sugar: glucose and fructose.

Glucose spikes our levels of insulin, which is a hormone that tells our bodies to store extra calories as fat and to hold on to the calories that we’ve already stored. Therefore, the more glucose you eat—whether from sugar or starch—the more likely you are to gain weight. (Fat, on the other hand, does not spike insulin levels, which means that—contrary to popular belief—it is actually less likely to be stored as fat.)

Ironically, eating lots of glucose can lead to a feeling of hunger even as you’re gaining weight, since calories that should be available to you to burn are instead getting tucked away into fat cells.

When we consume excess amounts of protein, our bodies turn this excess protein into glucose. That is why in addition to carbohydrate restriction, JumpstartMD calls for moderate protein consumption.

But weight gain isn’t the only negative consequence of glucose.

Once glucose leaves our bloodstream, it is either immediately burned by our brains and muscles or stored as glycogen (little starch-like molecules) in muscle cells and the liver.

However, there are limitations as to how much glycogen our muscles and liver can store. So what happens when our finite glycogen stores are full? The extra glucose gets sent to the liver, where it is turned into fat.

Once glucose has been turned into fat, it cannot be converted back to glucose. It either stays in the liver (causing issues such as non-alcoholic fatty liver disease) or is sent into the bloodstream as triglycerides (fat). This increases your circulating levels of triglycerides as well as the most dangerous form of LDL cholesterol, both of which raise the risk of heart attacks and strokes and are linked to the inter-related formation of diabetes, metabolic syndrome, and obesity among other conditions.

Note that glucose doesn’t always taste sweet. Simple starches, such as those in bread, pasta and crackers, are just long chains of glucose molecules, so the impacts of glucose that we’re talking about apply to starchy foods as well.

Fructose creates a condition called insulin resistance, which in turn increases our risks for conditions such as type 2 diabetes, obesity, and high blood pressure. Insulin resistance is the root cause behind “hardening of the arteries” (AKA “atherosclerosis”), which leads to cardiovascular diseases like heart attacks and strokes.

Unlike glucose, which can be absorbed directly into our blood, fructose can only be broken down by the liver, where it gets turned into fat (triglycerides). There is virtually no limit to how much fructose the liver can convert into fat, and once fructose has been turned into fat, it can’t be converted back.

Once the liver has converted fructose into triglycerides (i.e. fat), it raises risks for heart disease, diabetes and weight gain in the same ways that glucose-derived triglycerides do. How? It releases some of them into the bloodstream, which causes weight gain when the triglycerides are taken up by fat cells. What’s more, it increases circulating levels of triglycerides as well as the most dangerous form of LDL cholesterol, both of which raise the risk of heart attacks, strokes, and diabetes among other conditions.

Some of these newly formed fats (triglycerides) are also taken up by the liver itself, which can lead to non-alcoholic fatty liver disease. They also are likely to be stored in the adipose (fat) tissues surrounding your organs within your abdomen. This abdominal fat (“visceral adiposity”) is a defining feature of metabolic syndrome, and is widely recognized to be the most dangerous type of body fat because it releases substances that are associated with increased risks for diabetes, heart attacks, strokes, Alzheimer’s disease and various cancers.

And as if all that isn’t enough, fructose is caloric but it does not suppress the production of ghrelin, which is a hormone that increases appetite. (When ghrelin levels go down, we feel satiated). To boot, fructose fails to stimulate leptin, a hunger hormone that suppresses appetite. All sound diabolical? It is. Simply put, the more fructose you eat, the more likely you are to overeat.

Put this all together and, contrary to what we’ve been told for years, the calories from sugar actually do act differently in our bodies than those from protein and fat.

Calories from sugar make us gain weight and increase our risks for disease. Sugar, in all its forms, should be avoided whenever possible.

Recommended Reading

The Case Against Sugar, by Gary Taubes (available for sale in JumpstartMD clinics)