IS SUGAR POISON? LISTEN TO EXPERTS
There is an urgent need to change the way we look at fructose and its impact on our body
Fructose, a once-beneficial but-now-deadly type of sugar, is seen as the common link in high blood pressure, insulin resistance, Type 2 Diabetes and obesity |
Sugar has been demonised in recent years. But how can such a sweet thing wreak so much havoc in our lives? Fructose, a type of sugar in particular, has been at the receiving end of virulent attacks by diabetes experts. Numerous books had been written about its ill effects, denigrating sugar, and its half-sibling, fructose.
And it’s for a good reason. Fructose has been labelled as the equivalent of a “dietary sleeper terrorist cell” of our times. Fructose intake appears to drive excessive food intake. Here’s why:
What is fructose?
It’s a type of simple sugar from fruits. Fructose is one of the three dietary monosaccharides, along with glucose and galactose, absorbed directly into blood during digestion. Fructose is mainly supplied in the diet through fruits and honey. Eating lots of fruit — especially before winter or a drought — was a matter of survival for many species. Fructose is a simple monosaccharide found in many plants, where it is often bonded to glucose to form the disaccharide sucrose.
What are the benefits of fructose?
Fructose is simply a fat-storage agent that was necessary for the survival of most species, especially humans. It’s credited for being a “key survival factor” in evolution, according to research led by Dr Richard J. Johnson, a nephrologist at the University of Colorado in a 2019 study published in the Journal of Internal Medicine. “Fructose metabolism is a common evolutionary pathway of survival associated with climate change, food shortage and droughts,” Dr Johnson and his co-authors wrote. They described fructose as a “survival pathway” used by many species as a means for providing adequate fuel and water, while also providing protection from a decrease in oxygen availability.
What is the main function of fructose?
Simply put, it’s a fat-storage agent. It preferentially shifts the organism towards the storage of fat and glycogen that can be used to provide energy and water at a later date — such as long winters/ droughts or cataclysmic events that threaten the extinction of a species, researchers explained.
Specifically, what does fructose do?
The actions of fructose are driven in part by what’s known as “vasopressin” and the generation of uric acid. Fructose: Causes sodium retention Raises blood pressure Helps reduce oxygen demands to aid survival, especially in situations where oxygen availability is low.
Shifts energy production from the mitochondria to glycolysis.
It enhances Vitamin C metabolism.
How does fructose control energy production?
Mitochondria are membranebound cell organelles that generate most of the chemical energy needed to power the cell’s biochemical reactions. Chemical energy produced by the mitochondria is stored in a small molecule called adenosine triphosphate (ATP). Fructose shifts the energy provided in nutrients towards fuel storage and away from ATP production by downregulating mitochondrial metabolism and the favouring of glycolysis.
How does fructose drive excessive food intake?
In a 2017 study published in the journal Advances in Nutrition, Dr Richard Johnson and fellow researchers offered insights into the mechanisms driving obesity and diabetes, specifically focussing on the role of leptin. They found that obesity is associated with leptin resistance that would result in an impaired satiety (sense of being full) response. They also found that obesity is associated with reduced dopamine receptors in the brain (nucleus accumbens) linked to an impaired control related to food intake.
They pointed out that one potential mechanism for causing fatigue (which leads to less exercise and more sedentary life) relates to mitochondrial function and/or ATP concentrations. Fructose is known to reduce ATP concentrations in the liver, even after oral ingestion of an amount of fructose equivalent to that in a soft drink. Fructose intake also induces oxidative stress that inactivates certain enzyme that then leads to an impairment in fat oxidation, which then reduces ATP concentrations.
Why is leptin called the satiety hormone?
Leptin is a hormone made by small intestine cells that helps regulate energy balance by inhibiting hunger. That’s why it’s also known as the “satiety hormone”. making it directly connected to body fat and obesity. This hormone released from the fat cells located in adipose tissues, which sends signals to the hypothalamus in the brain.
It helps regulate and alter long-term food intake and energy expenditure, not just from one meal to the next. The primary function of leptin is to help the body maintain its weight.
Because it comes from fat cells, leptin amounts are directly connected to an individual’s amount of body fat. If the individual adds body fat, leptin levels will increase. If an individual lowers body fat percentages, the leptin will decrease as well.
It helps inhibit hunger and regulate energy balance, so the body does not trigger hunger responses when it does not need energy. However, when levels of the hormone fall, which happens when an individual loses weight, the lower levels can trigger huge increases in appetite and food cravings. This, in turn, can make weight loss more difficult.
What’s the role of fructose in the survival of humans and other species?
Researchers point out that mutations have occurred during at least two periods of mass extinction — that enhanced the activity of fructose to generate fat.
So from the point of view of paleontology, fructose is the agent that enhances fat generation, which was useful during periods of cataclysms such as during the Cretaceous– Paleogene extinction (65 million years ago) and the Middle Miocene disruption (12–14 million years ago), which led to the extinction of many species. These properties of fructose, researchers argued, likely helped survival in the setting of extreme dehydration or salt deprivation.
What exactly is ATP?
Adenosine triphosphate (ATP) is the energy-carrying molecule found in the cells of all living things. A compound consisting of an adenosine molecule bonded to three phosphate groups, and is present in all living tissue. The breakage of one phosphate linkage (to form adenosine diphosphate, ADP ) provides energy for physiological processes such as muscular contraction.
So in today’s world, is fructose intake necessary?
No. The long and short of fructose is that it helps the body store fat for a food-less winter. In prehistoric times, when there’s no industrial food production, having no source of fructose was an existential threat. But in today’s word, when sugar is widely available and you have supply of fruits all year round (watermelon from Hunduras, Iran, China at different times of the year!) thank to transcontinental travel, this is problematic. And this is a growing health issue both in rich and developing countries. That’s why many governments, including the UAE, are now implementing a “sugar tax”. Why? fructose intake is seen as the biggest driver for the global diabetes bulge, now considered a “silent pandemic”.
Fructose has been labelled as the equivalent of a ‘dietary sleeper terrorist cell’ of our times. Fructose intake appears to drive excessive food intake across almost all age groups.
How does glycolysis compare against glyconeogenesis?
Sugar is so important in the normal function of our body that when we don’t get it, the body generates it. Glycolysis the breakdown of a carbohydrate by way of phosphate derivatives with the production of pyruvic or lactic acid and energy stored in high-energy phosphate bonds of ATP. Glyconeogenesis turns fats to glucose. It’s the process of fatburning, via the synthesis of sugars (such as glucose and glycogen) from substances other than sugars. It’s the production in our body of carbohydrates (glycogen), from amino acids, fats, and other non-carbohydrates.
In prehistoric times, having no source of fructose was an existential threat. But in today’s word, when sugar is widely available thank to global supply chains, this is problematic.
What are the ill-effects of excessive fructose intake?
Fructose overload (from softdrinks, for example) leads to mechanisms that are better understood by today’s medical science. Today, fructose plays a big role in the high incidence of diabetes and obesity. If nothing is done, say experts, the disease burden wrought by diabetes and heart disease will explode around the world.