Sugar, my friend sugar, why are you so delicious and so harmful at the same time? And now, in Christmas time, I think I couldn’t choose a better time to write it. So, sit down, relax and keep reading 🙂
What are carbs?
Carbohydrates are the sugars, starches and fibers found in fruits, grains, vegetables and milk products. Though often maligned in trendy diets, carbohydrates — one of the basic food groups — are important to a healthy life.
Carbs are stored in the liver (around 100 grams) and muscles tissue (around 400 grams, depending on our carbs intake), in form of glycogen. When we need energy, glycogen is transformed, through glycogenesis, into glucose and releases to the bloodstream, where there are around 140 mg/dl (if we are not diabetics).
There are two types of carbs:
Also known as refined carbs. Their main characteristics are:
- Easy and fast digestion.
- Fast absorbed.
They also contain a high glycemic index. It means that there is a quick hormonal response right after their consumption through the pancreas, releasing insulin and all the effects that this hormone has on the body.
Examples of these sources are:
- Fruits drinks
- Sugary drinks
- Maple syrup
- Jams, jellies
*Although veggies, honey (non-processed one) and fruits are part of the simple carbs set, they are considered a healthy source of carbs due to the amount of fiber and vitamins that they contain.
They refer to as dietary starch and are made of sugar molecules strung together like a necklace or branched like a coil. They are often rich in fiber, thus satisfying and health promoting. Whole plant foods are a good source of complex carbs and, therefore, are also often high in vitamins and minerals.
Examples of these sources are:
- Whole grains and foods made from them, such as oatmeal, pasta, and whole-grain bread.
- Starchy vegetables such as potatoes, sweet potatoes, corn, and pumpkin.
- Beans, lentils, and peas.
The division between simple and complex carbs is made based on the glycemic index (or the speed that food is absorbed). Simple carbs are absorbed quicker, which means that glycemia (or the amount of free glucose in the bloodstream) raises up quickly. Once it happens, the pancreas releases insulin in order to keep a normal glucose level. However, it has a few problems:
- Too much insulin provokes that glucose goes down too much. It means that the liver has to quickly release more glucose into the bloodstream, which provokes again that the pancreas releases more insulin.
- If this loop described above is continuously happening, we start to become insulin resistant and our body has to release each time more and more quantity of insulin in order to keep the normal blood’s glucose levels. This is the previous step to a type II diabetes.
- Also, exceed glucose intake activates another reaction called: lipogenesis. Lipogenesis is a biochemical reaction, where fatty acids are synthesized and joined to glycerol in order to create triglycerides or fat. Triglycerides are then released to the bloodstream as a lipoprotein called VLDL. When it reaches fat cells (or adipose tissue), it shrinks them. Once it is big enough, it is transformed into another lipoprotein: “LDL” or normally called “bad cholesterol”. If more insulin is released, more times lipogenesis will be activated (4). This problem also occurs with an excess in complex carbs.
Complex carbs also play a very important role within sport. Our body absorbs them slower, which means that blood glucose is easily controlled. Complex carbs are very useful when we want to replenish the hepatic and muscular glycogen after a workout session but we have to keep in mind that we can absorb only around 1500 kcals. Athletes can get an advantage of it after workouts and during long sessions by delaying fatigue and enhancing lactate removal, endurance time and heart rate response (3).
What is sugar?
Sugar is the generalized name for sucrose (50% glucose/50% fructose molecule). Sweet, short-chain, soluble carbohydrates, many of which are used in food. They are composed of carbon, hydrogen, and oxygen. There are various types of sugar derived from different sources. Simple sugars are called monosaccharides and include glucose (also known as dextrose), fructose, galactose (1), etc…
Glucose is the primary source of energy for every cell in the body. Because the brain is so rich in nerve cells, or neurons, it is the most energy-demanding organ, using one-half of all the sugar energy in the body (2).
Sugar and Obesity
I’m pretty sure you have heard that eating sugar is not good because you put weight on. Well, I have to be clear with this point: NO, IT DOES NOT. You don’t become obese by eating sugar. You become obese because we live in an obesogenic environment where unhealthy and ultra-processed food is everywhere. Of course, if sugar excess is an important part of your diet, therefore, you have more possibilities of becoming obese and suffer metabolism syndrome (6, 7, 10) ( is the name for a group of risk factors that raises your risk for heart disease and other health problems, such as diabetes, stroke, hypertension, heart disease…). Having a healthy and balanced diet will improve that situation, but we cannot only blame sugar in this case (5, 11).
Sugar and Diabetes
382 million of people suffered of diabetes in 2014. It stands for a 8.4% of the total world population. But more serious is that during the next 2 decades, it will grow a 55%, reaching a total of 585 million of people.
Only in Spain, more than 5 millions of people have been diagnosed with type II diabetes and the annual cost of this sickness reaches the impressive number of 23.077 millions of euros (8). Pretty important numbers keeping in mind that they are still growing and we are doing little or nothing (13) to improve them.
Refined sugar has been related to type II diabetes in multiples studies (9, 10, 11, 14). And it does not occurs only in adults. Children are also exposed to develop premature diabetes due to the amount of processed sugary food available for them (12).
One example that I can’t avoid mentioning is the new “Colacao para niños” (Colacao for children, in Spanish). This new meal, especially done for children, contains 21g of sugar per mug. Keeping in mind that a child must not overpass 30 grams per day, it means that one mug of Colacao contains the 70% of the maximum sugar intake recommended by the OMS (15). UNBELIEVABLE!
Sugar and Addiction
This topic is a bit controversial. Some research show that sugar is not addictive for humans (16). However, we can find others that show that sugar might be addictive (17, 18, 19), showing withdrawal symptoms. These phenomena were demonstrated by studying the circadian rhythm of body temperature, as recorded by telemetry, by analyzing metabolic data and by observing behavioral responses.
Sugar and Cancer
The evidence shows that sugar is related to cancer. These studies (20, 21) shows how the consumption of added sugar, soft drinks, and sweetened fruit soups or stewed fruit was positively associated with the risk of pancreatic cancer.
This one (22) also shows how high levels of triglycerides, glucose, and insulin are associated with risk of colon cancer and those diets high in simple sugars increase the risk of colon cancer because of their impact on these factors.
There are also studies (23, 24) that show how a sugar-free or ketogenic diet or low carbs is related to cancer cells dead. This study (25) shows how glycolytic inhibition by way of pharmacologic agents plus dietary manipulation has promise in the metabolic approach to cancer control.
The majority of studies mentioned above show how an excess or a daily processed sugar intake is harmful in many different ways. We MUST try to reduce this sugar intake and substitute processed sugar sources by natural one such as fruits and vegetables, which provide us plenty of vitamins, water and energy.
Does it mean that we must cut off processed sources? No, it doesn’t. Sugar is another nutrient and we have to eat it but in the proper way. We can still, sporadically, eat an ice cream but not on daily basis and, of course, it must not be a substitute of any of our meals.
My recommendation is: eat plenty of micronutrient. Fruits, veggies, eggs, meat and fish will give you everything that you need. Remember, always eat real food and your body and health will thank you.