Sugar - Sweet Poison

 

“A spoonful of sugar helps the medicine go down in a most delightful way”, sang Mary Poppins in reference to sugar’s long reputation for making our lives happier. 

In fact, our language is rife with positive sugar associations to sugar: we call our significant other ‘Honey’, we refer to a nice person as a ‘sweet’ person, grumpy people are told to ‘sweeten’ their characters, and when something pleases us, we exclaim ‘sweet!’. 

Culturally, we associate sugar with happiness, and sweets are never far from celebrations. Birthday parties are crowned with cake, juice and sodas. Soft drink ads are splashed with happy faces, and candy packaging advertise its ‘happy-inducing’ properties with loud flashy colors and childish cartoons.

But beyond mere cultural references, there is an evolutionary reason for this positive association.

Glucose is the fuel for our muscles, and the brain is its main consumer. As such, we are biologically programmed to reach out for sweet foods - we have even evolved to find it the pleasurable of all tastes. 

However, while this evolutionary trait helped our ancestors to favor calorie-rich foods at a time when nourishment was scarce, the same stimulus has led us to a veritable epidemic of obesity and obesity-related diseases.

For centuries, the only sources of sweet products were found in fruits and honey. Refined sugar extracted from beets and sugar canes made their appearance along the Industrial Revolution, but it was not until the second half of the 20th century when the production increased enough to make it cheap and accessible for all consumers.

In the 1990's, the food industry shifted from sugar to high fructose corn syrup, a cheaper source of sugar but also one far more addictive than refined sugar.

And our appetite for sweets hasn’t but increased over the decades.

Two parallel phenomena have taken place: at the same time that we have lowered our physical activity to historical minimums, the quantity of sugar we consume has increased. 

Our sedentary lifestyle makes it impossible to burn out the amount of sugar we ingest, opening the door to all sorts of health problems, the most visible of which is obesity. 

The link between excess of sugar consumption and obesity is now well-established, but for decades it was a fact obscured by the food industry.

Beyond a mere issue of appearance, sugar-linked obesity is a serious health issue with multiple ramifications, including important social and economic impacts.  

According to a 2013 research carried out by the Credit Suisse Research Institute, the global cost of obesity (in terms of medical care and work leaves associated to obesity and related health-issues) was calculated in $700 billion. 

However, the actual numbers may be even greater, and it is estimated to augment as obesity-related diseases appear in workers at a younger age.

Despite its undeniable capacity to boost our mood, sugar has another, darker face, one that scientists have studied for over five decades and that the food industry has often tried to hide.

Learn here more about the positive and not-so-positive aspects of sugar, a compound that is as indispensable for our lives as it is dangerous in excess.

What is sugar?

According to the Merriam-Webster dictionary, sugar is “a sweet crystallizable material that consists wholly or essentially of sucrose, is colorless or white when pure tending to brown when less refined, is obtained commercially from sugarcane or sugar beet and less extensively from sorghum, maples, and palms, and is important as a source of dietary carbohydrate and as a sweetener and preservative of other foods.”

The regular table sugar we put in our coffee is a refined version of sucrose, one of the six types of simple carbohydrates: glucose, fructose, galactose, sucrose, lactose, and maltose.

However, not all sugars are equal.

Carbohydrates are divided into four types, based on their molecular structure: monosaccharides, disaccharides (simple carbs), oligosaccharides, and polysaccharides (complex carbs.)

Simple carbs can be found in fruits, sugar cane, beets, carrots, honey, maple syrup, candies, etc.

Complex carbohydrates are very common in animals, plants, and bacteria. They are constituents of cell membranes, as well as subcellular materials of cells. They are also found in physiological fluids such as blood, tears, and milk. 

Glycoproteins are one of the most important types of complex carbohydrates in our bodies, and include collagen, mucins, immunoglobulins, and human plasma proteins such as fetuin, transferrin, and ceruloplasmin, among many others. 

Some examples of complex carbs include the oligosaccharides of milk, the cellulose of plant cell walls, and storage forms such as starch and glycogen. When it comes to food, we find complex carbs in vegetables, unrefined cereals, milk, potatoes, peas and beans, among others. 

Carbohydrates are essential for our lives, and although sugar is only a simple carb, it has a role in making us feel better.

When we eat sugar the brain produces dopamine, our ‘reward’ neurotransmitter, and serotonin, the neurotransmitter responsible for our feelings of well-being, and the most susceptible to dietary influences. 

In addition to this, sugar suppresses the hypothalamic pituitary adrenal axis in our brains, weakening our body’s response to stress. 

In fact, an ancient home remedy for nerves was drinking water with a bit of sugar.

The combination of these, along with the textures and additional qualities of the sugary products we eat - crunchiness, chewiness, softness, caffeine high - makes us feel relaxed and ‘happy’.

Unlike complex carbs, simple carbs have a smaller molecular composition, entering the bloodstream much faster than complex carbs. This makes them a source of quick energy and a mood booster. 

However, this sugar rush has a steep cost. 

High glucose levels in the bloodstream trigger insulin secretion, which in turn causes a sudden shortage in glucose (hypoglycemia). This is the cause behind that tired feeling we experience after we binge on a simple carb meal (a.k.a ‘food coma’.)

Unfortunately, tiredness is not sugar’s only or worst side effect. 

Excess of sugar makes you more prone to serious health conditions. 

You are probably aware that excess of sugar consumption can lead to type 2 diabetes, contributes to infections, has a direct influence on diabetic retinopathy that may lead to blindness, and it may contribute to pancreatic cancer. 

But these are only some of the severe health problems related to sustained excess of sugar consumption.

The oxidative stress caused by sustained excess of sugar damages our cells, and is linked to a long list of illnesses, which include neurodegenerative diseases, mental illnesses, cancer, and autoimmune disorders such as rheumatoid arthritis.

According to a 2014 study published by Dr. Frank Hu from the Harvard T.H. Chan School of Public Health, there is a link between a diet high in sugars and the risk of dying from cardiovascular disease. 

High glucose levels overload the liver, which converts the simple carbs to fat, and over time may turn into fatty liver disease, a contributor to diabetes. Also, high glucose levels are linked to high blood pressure and is known to increase chronic inflammation, a contributor to heart disease, cancer, and type 2 diabetes.

Diets high in Advanced Glycation Endproducts (AGEs) have been demonstrated to interfere with many cell functions, such as antioxidant defenses, mitochondrial metabolism, and cellular inflammation. These alterations may contribute to liver damage, impair skeletal development, and cause heart and brain damage.  

AGEs are not only found in sugary confections, but also in red meat, cream cheese, nuts, oils, mayonnaise, butter, margarine, and fried eggs among other products. 

A Bomb of Sugar and AGEs

Sugar ages you. 

A 2012 study by researchers at the University of California found a relationship between the consumption of fructose and the aging of cells. This cellular ageing affects our entire body, including our brain.

The mitochondria within our cells are responsible to produce energy. They use glucose and exude free radicals as a natural byproduct of this process, called ‘oxidation’. The more sugar we consume, the more free radicals are produced. 

According to Dr. Vera Novak from the Beth Israel Deaconess Medical Center, type 2 diabetes accelerates brain aging, which in turn accelerates the progression of functional decline, casting a direct link to Alzheimer’s and dementia. 

All of these means that sugar not only ages how you look, but also ages your brain.

Want to stop the clock? Cut off the sugar!

Sugar is as addictive as cocaine. 

A 2019 study at the Department of Clinical Medicine at Aarhus University found that sugar influences the brain’s dopamine and opiod systems in a similar way as hard drugs do. 

The dopamine and opiod system - also called the reward system-, is the area of the brain where neurotransmitters are released, and is responsible for our feelings of ecstasy and dependence. 

In the experiment carried out by his team, Dr. Michael Winterdahl found that sugar intake caused changes in the brain’s reward system in only 12 days, and that it was activated from the very first sugar intake.

In fact, brain scans reveal that a brain addicted to sugar is not too different from a brain addicted to cocaine in its response capacity to dopamine.

Other studies have found that sustained sugar intake diminishes the activity of neurons synthesizing oxytocin (the “love” neurotransmitter), and blocks the autophagy process in the hypothalamus, impairing our feeling of satiety. 

This not only induces us to eat more sugar in order to achieve the same level of satisfaction, but it also fosters the accumulation of toxic molecules in the cells, which can lead to serious diseases such as Parkinson’s, Alzheimer, or cancer.

What’s worse is that foods that cause a higher elevation in blood glucose produce a greater addictive drive in the brain, which is another good reason to keep them out of our diets.

Excess of sugar can impair your cognition. 

A study published by Neuroscience revealed that a diet high in added sugar reduces the production of brain-derived neurotropic factor (BDNF), an essential brain chemical for learning and the formation of new memories, and that frequent exposure to high glucose (HbA1c) levels are associated with brain shrinkage and diminished mental capacity.  

Other studies have confirmed these findings, demonstrating that high glucose levels in the blood can impair the brain’s functional connectivity and affect the brain matter, which can cause the brain to shrink. 

Since a continuous excess of sugar damages the blood vessels, the brain’s blood irrigation may also result affected, causing cognitive difficulties and even the development of vascular dementia in severe cases.

A 2016 study published in Behavioral Brain Research suggests that high levels of glucose in the bloodstream can be harmful to the brain, resulting in slowed cognitive function, and deficits in memory and attention. 

Other studies indicate that excess of sugar may cause inflammation in the brain, leading to memory difficulties. And while this inflammatory damage may be reversed by changing to a low-sugar diet complemented with omega-3 fatty acids, if repeated over time the damage may become permanent. 

Studies of long-term diabetics show progressive brain damage, showing deficits in learning, memory, and other cognitive functions.

However, high levels of sugar impair the brain’s ability to process emotions even in healthy young people, as revealed by a brain imaging study, and these individuals also score lower in tests of cognitive function. 

Protect your brain - stay away from excess of sugar.

Sugar can make you feel sad. 

For all its promotion of inducing happiness, excess of sugar can have the exact opposite effect.

After the initial sugar rush produced by sweets, there’s a drop in glucose levels (hypoglycemia). This slump not only makes us feel tired, but if the brain doesn’t have enough glucose to function, neurotransmitters are not produced, impairing neuronal communication. 

Several studies have found a direct link between excess of sugar and mental illnesses.

According to Dr. Adrian Raine from the University of Southern California in Los Angeles, the hypoglycemia caused by a sudden sugar rush can lead to nervousness and irritability, and may provoke a full-blown aggressive outburst (see next point). 

However, the opposite also causes adverse effects: people with type 2 diabetes report increased anxiety and depression during events of acute hyperglycemia (elevated blood sugar).

Since excess of sugar causes both hyperglycemia and hypoglycemia, people who reach out to sugar for a mood boost end caught up in a vicious circle from which is very hard to break.

According to a 2017 research published by the journal Scientific Reports, people with the highest level of sugar consumption were a 23% more likely to be diagnosed with a mental disorder than those with the lowest sugar intakes.

According to Dr. Michael Winterdahl, due to its addictive power, sugar can replace natural stimuli (such as learning or social interaction), in the brain’s reward system, thus giving preference to sugar over meaningful social contact or other pleasant activities.

Sugar can make you more violent. 

Excess of sugar has always been on the suspicion line for causing hyperactivity, attention deficit, and aggressive behavior, and scientists are finally finding concrete evidence of this.

Researchers from Cardiff University found that children who regularly ate candy and sugary confections well into adulthood had committed at least one violent offense by age 34-38. 

The doctors in charge of the research suggest that, due to the regular consumption of treats, these children failed to learn to delay gratification, carrying their impulsive behavior into adulthood. 

The researchers also pointed that children who eat a lot of sweets also tend to have a predilection for junk food in general. 

Scientists have found an association between a tendency to develop low blood glucose and aggression. 

Several other studies point at a clear link between fluctuations in blood glucose and consuming large amounts of dietary Trans Fatty acids (dTFAs) with aggressive behavior. 

A study from the University of California, San Diego School of Medicine, concluded that a higher trans fat intake was significantly associated with aggression, a result independent from conditions such as sex, ethnicity and age. 

Since excess of sugar also impairs cognitive functions and self-control, it is not unlikely to suspect a relationship between excess of sugar, junk foods, and violent behavior.

How much Sugar should we consume?

Unfortunately, unlike other nutrients, there is no set dietary regulation for sugar. 

Our sugar consumption varies depending on our lifestyle habits, body mass index, age, and metabolism. 

However, as a general guideline, the American Heart Association recommends that women should not consume more than 6 teaspoons (24 grs) a day, and men no more than 9 teaspoons (36 grs.) a day.

This is a lot less than the average daily consumption of most adults and children in most Western countries: 24 teaspoons a day, according to the National Cancer Institute.

What to do?

Cutting off sugar is not an easy task. Nearly all the foods we buy in the supermarket contain some level of added sugars, even those foods that aren’t sweet at all. 

Sugar is normally used as a food preserver, and as such can be found as hidden added sugar in a wide range of products, whether sweet or savory, labeled as ‘healthy’ or not. 

Some foods which you probably didn’t know contain added sugar are: processed meats (beef patties, sausages, cured meats, jerky, etc.), canned beans, canned soups, instant noodles, microwave popcorn, mayonnaise, salad dressings, coleslaw, instant oatmeal, packaged cereals, bread, protein powder, protein bars, non-dairy milk, peanut butter, cream liquors, tomato sauce, and more.  

In addition, sugar is listed under various different names in food labels, making it harder to spot. Some of the names used are: brown sugar, corn syrup, corn sweetener, fruit juice concentrates, high-fructose corn syrup (HFCS), invert sugar, malt sugar, molasses, syrup sugar, and derivates ending in ‘ose’: dextrose, fructose, maltose, maltodextrose, sucrose, etc.  

Our hectic lifestyle often leads us to consume processed and packaged foods due to their convenience and accessibility; but these foods are often loaded with sugar, fats and artificial additives. 

Due to its addictive power, quitting sugar is extremely hard. Moreover, social pressure makes it harder to cut off from settled habits. 

Although some articles advice to satisfy your sweet tooth with fruits, not only certain fruits have as much sugar as junk foods, but some ‘healthy snacks’ are also simple sugar traps. 

Banana - 12 grams of sugar per 100 grs.

Grapes - 16 grams of sugar per 100 grs.

Raisins - 59 grams of sugar per 100 grs.

Canned peach - 21 grams of sugar per ½ cup

Canned pineapple - 25,8 grams of sugar per cup

Prune juice - 24 grams of sugar per 1/2 cup 

Coca cola - 10,8 grams of sugar per 100 ml.

Iced Tea - 8 grams of sugar per 100 grs

Red Bull - 10 grams of sugar per 100 ml.

Some of the sweet products we crave have unique characteristics not found in fruits (crispiness, gumminess, caffeine, etc.). Thus, replacing them is not so easy.

In addition, shunning off sugary products is socially unpopular, as anyone who has tried giving ‘healthy treats’ to children on Halloween knows.

Hard, but not impossible, specially if the idea is not to avoid sugar altogether but restrict its intake to a healthy minimum. 

Here’s a few suggestions on how to change your sugar habits:

1- Don’t cut your sugar intake cold-turkey. This move shifts your brain into deprivation mode and reinforces its need. Instead, try to progressively reduce your sugar consumption. For instance, if you take your tea with two lumps of sugar, try using 1 ½ for a few days, and then reduce it to 1. Retraining your tastebuds is the surest way to reduce your sugar consumption.   

2- Don’t shift to replacements - You may have heard that substituting sugar for artificial sweeteners or other ‘natural’ sugars is a good alternative to satisfy your sweet tooth. But these chemicals are not exempt from side-effects, some linked to cancer, or still unknown. It’s safer to stick to the old natural sugars (honey, brown sugar, maple syrup, etc.) and retrain yourself to eat smaller, less frequent servings.

3- Avoid packaged, refined, and processed foods in favor of home-made food - Usually, the ingredients used at home are more natural and you’ll be in control of the amounts used. If you must consume processed foods -at the office, social gatherings, parties, etc.- moderate your servings and establish exchanges (i.e. eat that donut but skip the sugar in your coffee.) 

4- If you consume it, burn it! - A big part of the global obesity problem stems from our sedentary lifestyle. The clue is to spend the energy we put into our bodies. If you eat sugar, make sure you burn it! In addition, regular exercise helps our body control the glucose level, regulates our appetite, reduces anxiety and depression, and keeps our system running in optimal condition.

5- Use measure - Craving for chocolate? Don’t deprive yourself, as this will only make you want it more and you’ll end up bingeing. Instead, control your servings: instead of eating a whole chocolate bar, eat a few pieces, just enough to indulge without the guilt. This will also train your tastebuds to eat less sugar. 

6- Time it - Try satisfying your sweet tooth early in the morning; that way, you’ll have the rest of the day to burn it off. Also, set an hour limit to eat simple carbs, some 5 - 6 hours before going to bed, so as to give yourself enough time to burn it. 

7- Don’t use sugar as a reward - specially with children. A treat every now and then is fine, but making it a regular occurrence installs habits that will later be extremely hard to break.

8.- Is it really a sweet craving? Among several other functions, the hypothalamus sends signals to your brain to control thirst, appetite, and body temperature, and sometimes we are so overwhelmed by stress and other factors, that we can be easily confused. If you have a sweet craving, try having a glass of water first - you may be surprised!

9.-Try alternatives. Sometimes we reach out for sugars for the sensations associated to them, not for the sweetness in itself. For instance, when we crave for gummies - is it the flavor or the chewiness we crave? Try chewing a sugarless gum instead. Try swapping a chocolate bar for a glass of home-made chocolate milk, or a serving of almonds in the case of nut chocolate bars. Get creative! You may be surprised at how satisfying the low-sugar alternatives can be.

10.-Don’t rely on sugar for your dopamine and serotonin. Engage in activities that may bring you enjoyment and satisfaction: gardening, playing music, doing sports, taking a walk. All of these will trigger the feel-good neurotransmitters that sugar tries to mimic at such a hefty cost.

 

Sugar is a necessary element in our diets and a sweet companion to our moments of happiness, but from our teeth to our heart and brain, the entire body suffers from its over-consumption. 

Given all the accrued evidence of its negative side effects, it is not entirely illogical to think that the excess of sugar in our diets (along with high trans fatty acids and AGEs) is a key contributing factor in the raising levels of depression and mental health issues, lack of self-control, and the spread of aggressiveness and violence worldwide, particularly in young people.

Bad habits are hard to break - the best is to develop good habits from the start.  

Training your taste buds to get the most of every bite, and moderating its daily intake are the best way to enjoy the sweetness of sugar and its benefits without regrets.

To Learn More:

Interested in learning more about the side effects of sugar? Then you will probably enjoy reading the book “Fat Chance: The Hidden Truth About Sugar”, by American pediatric endocrinologist Robert Lustig, a fervent anti-sugar advocate.

Sources: Harvard Health, National Center for Biotechnology Information, Pew Research, Science News, Science.org, University of Michigan, NPR, The Atlantic, Integrative Medicine, New Scientist, La Tercera.