In the 21st century, residents of industrialised countries consume at least their entire body weight of sugar per year, with some of them consuming as much as twice their body weight in those 365 days. Most calories we consume daily are sugars. Not only does this differ from previous centuries when we ate more protein, fat, and fibre, but unlike in previous centuries, precious little of our current sugar intake originates from complex sugar sources like fruit and whole grains that contain large percentages of healthy nutrients too.
Types of Sugar
Monosaccharides are simple sugars. These include glucose, dextrose, fructose, and galactose. Disaccharides are complex sugars. These include sucrose and lactose. Polysaccharides are also complex sugars, which include cellulose and starch. With a few exceptions, the health of a sugar is not related to its complexity; they are all basically unhealthy in their pure form. White refined table sugar, for example, is not healthier than the sugar in fruit just because it is complex sucrose while the latter is simple fructose. On the contrary, since the fructose in fruit is included in a unit that contains plenty of healthy nutrients, it is far healthier than a tablespoon of refined white sugar that is almost hundred percent pure sucrose. As a result, when buying groceries, keep your eye out for words like sucrose, maltose, dextrose, fructose, galactose, glucose, arabinose, ribose, xylose, deoxyribose, and lactose and avoid as many of them as you can.
The Mediating Role of Fibre
Most low-carb diets encourage their followers to give up fruit and vegetables like carrots, as these contain fructose. A small South African study, on the contrary, found that people who ate vast quantities of fruit failed to put on weight. The explanation lies in the high amount of fibre that fruit contains in addition to the fructose. If you drink a can of sweetened soda, the large sudden fructose dump demands that your body processes it immediately and quickly. If you eat an apple, your body has to tear through all the fibre before it can separate the fructose that needs to be processed. This takes time, and therefore releases the fructose gradually for slower and more comprehensive processing.
This does not mean you should duplicate the study and binge on fruit. You will see below why this can harm your liver. It does mean, however, that you can safely eat between two and three servings of fruit per day without worrying about your health.
Fructose Can Cause Liver Damage
A high consumption of fructose can cause liver damage. Most modern products, from fruit juice to soda to pasta to salad dressing, contain high-fructose corn syrup because it is much sweeter than sugar cane and thus much cheaper to produce. Sugar cane, or table sugar, also contains fructose, but its fructose is bound to glucose in a way that other organs must help to break it down. Your body processes glucose through complex mechanisms that include numerous organs and hormones like the pancreas, liver, kidneys, adrenal glands, insulin, cortisol, and so forth. Fructose that is not properly bound to glucose, on the other hand, bypasses all these mechanisms and falls straight on the liver to convert into glucose before your body can use it as energy. This unnecessarily and dangerously overloads one of the body's main detoxification organs, which compromises its detoxifying functions and wears it out in the same way alcohol does.
Excessive Fructose Consumption produces Toxic Uric Acid
When the liver struggles to process vast quantities of fructose, it depletes its energy and produces uric acid as a by-product. Even worse, when the cells throughout your body are fed with fructose instead of by the glucose that they expect and need for energy, they burn all their glucose and are then completely depleted of energy. This causes them to die, which also increases the level of uric acid in your body. Uric acid has been found to contribute to gout, kidney disease, high blood pressure, and insulin resistance, which is one of the main symptoms of diabetes. If that is not bad enough, it also causes chronic low-level inflammation that researchers argue contributes to most modern diseases like arthritis, diabetes, cancer, dementia, and cardiovascular disease.
Sugar Causes Obesity
If your body's cells do not need the glucose that is circulating in your bloodstream for energy, it will be converted into fat tissue and deposited around your hips and abdomen. For sake of its survival, your body has evolved to use or store energy, not to excrete it. This gives you two options: either exercise enough to burn all the sugar you eat, or eat less sugar so your body does not receive any more than it will burn for energy.
Fructose also facilitates weight gain due to its failure to stimulate insulin which, in turn, is meant to stimulate production of the hormone leptin, which suppresses hunger. If your diet is high in fructose, you will, therefore, remain hungry long after your body has had enough nutrients and energy.
Sugar Makes You Feel Tired
When you eat protein, fat, or fibre, your body must break it down bit by bit to separate the glucose. It, therefore, slowly releases glucose into the bloodstream from where it can be absorbed by all cells for energy. When you eat clean sugar, your body sends all that glucose straight into your bloodstream and you experience a great energy spike. Since your body must keep blood glucose levels reasonably low, it immediately responds by secreting insulin to remove the glucose from your bloodstream as quickly as possible (to your hips and abdomen, as mentioned above). This sudden drop in glucose from your blood means that there is no more glucose available when your cells demand ready energy. The only way to keep your blood glucose and energy supply constant is to eat fibre and protein-rich food that releases glucose gradually into your bloodstream. Sugar simply spikes it, drops it, and leaves you feeling drained.
Sugar Can Cause Diabetes
Insulin is the hormone that is meant to remove glucose from the blood. If your blood glucose levels are often extremely high due to an excess of sugar in your diet, your body will become resistant to the insulin, in the same way as a heroin addict becomes resistant to the heroin. As a result, your body will need ever larger amounts of insulin to keep your blood glucose level reasonably low. This insulin resistance is the chief symptom of type 2 diabetes which, in turn, causes obesity and cardiovascular disease.
Sugar Can Cause Cardiovascular Disease
People who consume a lot of sugar are more than twice as likely to die of heart disease than those who do not. If your blood sugar level often soars because of excessive sugar in your diet, and your body becomes so resistant to insulin that it can no longer keep your blood glucose at a reasonable level, the sugar that circulates unabsorbed in your blood stream starts to stick to the inner linings of your arteries. This increases your blood pressure, which is a known risk for cardiovascular disease. A high-sugar diet may also stimulate the liver to dump more fats into the bloodstream, which increases cholesterol and thereby the risk of developing serious cardiovascular complications.
Sugar Can Impair Your Brain Function
Sugar causes something researchers call brain metabolic disorder. If you suffer from this disorder, your brain is incapable of using energy properly. By engaging certain molecules in the brain, sugar causes your brain to become insulin resistant, which ruins its ability to extract the available glucose which it needs to use as energy. Moreover, it apparently inhibits the molecules that help to stimulate synaptic plasticity, which then slows down the speed at which nerves can communicate with each other. While this research is still preliminary, it does show that rats on high-sugar diets struggle to memorise mazes. To the extent that this can be generalised to humans, sugar may, thus, sabotage your ability to think and remember.
Ultimately Remove All Sugar
To really improve your health, or prevent developing some serious conditions, gradually remove most sugar from your diet. You will be surprised how easy it is to retrain your taste buds to appreciate the subtle tastes of unsweetened foods.