Fructose: The Simple Sugar that Complicated my Life
Sugars are made from combinations of three Monosaccharides (single-molecule sugars): Glucose, Galactose, and Fructose. Glucose is the substance that our bodies use to produce energy. Galactose is also known as Milk Sugar and occurs mostly in dairy products. Fructose, also known as Fruit Sugar, occurs mostly in plants.
All three Monosaccharides have the same chemical formula: C6H12O6. They differ in the way the various atoms are arranged. Glucose and Galactose have a hexagonal structure, while Fructose is pentagonal (see above).
Humans do not need Fructose to survive. We could live our entire lives without ever being exposed to it and never know the difference. However, it enters our diets mainly through plants and plant products. Over the last 50 years, food manufacturers have been using High Fructose Corn Syrup instead of regular sugar because it costs less and tastes sweeter. This additional Fructose in our diets has changed the state of national health.
One of my good friends steered me to a lecture called “Sugar: The Bitter Truth” by Dr. Robert Lustig of UCSF (https://www.youtube.com/watch?v=dBnniua6-oM). It gets a bit scientific, but his bottom line is “Fructose is like alcohol but without the buzz.” Basically, an excessive intake of Fructose does as much damage to the Liver (if not more) than drinking alcohol. Dr. Lustig’s belief is that the overabundance of High Fructose Corn Syrup into the American diet has been the main culprit for the sharp rise in obesity and Type 2 Diabetes.
In simple terms, we can metabolize only a certain amount of Fructose at a time in our Liver. Just to make matters worse, the Liver is the only organ in the body that processes Fructose. If too much accumulates and cannot be processed, it can be turned into fat (by a process known as De Novo Lipogenesis) and stored in the Liver, displacing normal-functioning cells, which leads to Fatty Liver, Fibrosis, and Cirrhosis. Excess Fructose can also become Triglycerides, leading to elevated levels of that substance in the blood. These two alternatives cause problems for the body in different ways (to be addressed later).
It seems our family genetic defect reduces the amount of Fructose that can be metabolized by the Liver at any one time, and most of the ingested sugar turns to fat or Triglycerides. The accumulating Liver damage further diminishes its ability to process Fructose as time goes on, and eventually (without any intervening dietary alteration) it can no longer metabolize the sugar properly. The fat retained in the Liver causes fibrosis and the development of scar tissue, eventually replacing all functioning cells.
I have attempted to reduce the amount of Fructose I eat in order to preserve what’s left of my Liver. However, it is so pervasive in our food supply that it makes eating difficult. The worst part is that wheat has a significant Fructose content, and I have attempted to minimize my intake. That means giving up bread, pizza, pasta, and bagels (among other common foods). Even certain vegetables have too high a level of Fructose: asparagus, cabbage, cauliflower, Brussel sprouts. Fortunately, potatoes, rice, and corn have little of it (High Fructose Corn Syrup is processed from Sweet Corn). Most of the Gluten-Free products are also Fructose free (but usually taste free as well). Some fruits have high levels of Fructose (apples and pears) but four categories are low on the scale: Citrus, Drupes (fruits with pits), Berries, and Melons. Avocado is probably the best example of a low-Fructose fruit.
My experiments with producing a palatable wheat-free bread have begun. Details later on.