Sugar may be downright irresistible but it can be easily named as one of the most damaging ingredients for our health. Of course all sugars are not created equal. As part of well-balanced diet, specific sugar - for example derived from fruits, grains and whole fresh foods - is not worrisome. But added sugars from processed foods and beverages are nothing but extra calories providing little or no nutritional value. When it comes to understanding the side-effects of consuming too much sugar, weight gain is considered the number one factor along with the increased risk of diabetes. But extra calories, weight gain and diabetes risks are just the tip of the iceberg.
A substantial body of research has suggested that excessive intake of added sugars triggers inflammation and makes the body highly susceptible to chronic diseases such as metabolic syndrome, type 2 diabetes, heart disease, Alzheimer’s disease, depression, high blood pressure, increased cholesterol and triglyceride levels, premature aging and cancer. Sugar also causes minerals deficiency, impairs the immune functions, promotes fungal growth and drives hyperactivity, anxiety and poor concentration in children. Simply put, excessive sugar intake has the potential to damage our body in many ways.
In addition, sugar is highly addictive. It arrests the brain chemistry, floods our brain with dopamine – a neurotransmitter that controls the brain’s reward and pleasure centre – making us feel instantly happy and energetic. In fact, studies have shown that sugar is even more addictive than cocaine.
Let’s look at some major reasons why sugar is so bad for you after all.
Metabolic disorders and Type 2 Diabetes
Insulin is an important hormone released by the beta cells of the pancreas. It allows the cells to efficiently utilize sugar or glucose from the bloodstream. Excessive sugar in the blood stimulates the pancreas to pump out high amounts of insulin. Over a period of time:
- Cells become resistance to the effects of insulin and stop responding normally to the hormone
- This leaves high levels of glucose floating in the bloodstream.
This is called insulin resistance, a condition that primes the body for developing many diseases such as metabolic syndrome, pre-diabetes and eventually full force type 2 diabetes.
Weight gain and obesity
Sugar works in many ways to bring abnormal weight gain. The way sugar interferes with the brain chemistry and impacts the hormones is a clear recipe for excessive fat gain. Elevated sugar levels result in insulin spikes. Insulin blocks the production of leptin, a hormone that regulates appetite by telling your brain you have eaten enough and you are full. Without leptin to signal your brain, you feel hungry even when you have just eaten and you crave for more food. Read our blog on how Jiaogulan tea can be an effective natural remedy for weight loss.
If you are leading a sedentary lifestyle and eating a diet that has too much of added sugars, there are high chances of getting liver damage. Added sugar is rich in fructose. Excess fructose is converted into fat in the liver and as more and more fat starts to build-up around the liver it can lead to non-alcoholic fatty liver disease.
A paper published in the journal Nature showed that the pathways involved in the metabolism of alcohol are similar to those involved in fructose and glucose metabolism . The paper also highlighted that excessive consumption of fructose triggers the same health problems as alcohol. And if you believe that having a slim body is a guarantee against liver damage caused by too much of fructose, you are mistaken. A 2013 study found that the fructose induced liver damage is possible even when there is no obesity or extra calories .
A sugar rich diet is one sure-fire way to increase your risk of developing heart disease. According to a study published in the Journal of the American Medical Association, people who consumed 17 to 21 percent of calories from added sugar had a 38 percent higher risk of dying from cardiovascular disease compared to people who consumed 8 percent of their calories from added sugar. 
- Sugar promotes inflammation in the arteries. This can cause excessive build-up of plaque (atherosclerosis), the leading driver of heart attack and stroke.
- Sugar can lead to weight gain, insulin resistance and type 2 diabetes, all these inter-related factors contributing further to overall risk of heart disease.
- Sugar increases the levels of LDL cholesterol and triglycerides while lowering HDL cholesterol levels. .
- Sugar increases blood pressure. A study found that sugar may be worse for your blood pressure than salt .
When our body develops insulin resistance, too much insulin circulates in the bloodstream, causing reduced carriage of insulin to the brain. Reduced levels in the brain insulin are responsible for cognitive decline and the onset of Alzheimer’s disease. For example, insulin resistance causes brain lesions and also hinders the delivery of glucose to the brain cells. Without much glucose, which the brain burns as fuel to get energy, the brain will not be able to function and remember things very well. It is not surprising that experts call Alzheimer's disease "Type 3 Diabetes."
While previous research has suggested that diabetes increases the risk of developing Alzheimer’s disease, a recent study showed that high blood glucose directly contributes to the development of amyloid protein plaques in the brain . Accumulation of beta-amyloid plaques are one of the early drivers of the complex changes associated with Alzheimer’s disease. These plaques are clusters of faulty proteins that gradually destroys healthy brain cells. The lead author of the study Shannon Macauley said, “Our results suggest that diabetes, or other conditions that make it hard to control blood sugar levels, can have harmful effects on brain function and exacerbate neurological conditions such as Alzheimer’s disease.” 
Overconsumption of sugar has also been linked with other brain disorders. High glucose levels have been associated with an increased risk of dementia . In fact, a 2013 study published in the New England Journal of Medicine showed that high blood sugar appears to be a contributing risk factor for developing dementia even in people who don’t have diabetes .
Research suggests that a diet high in added sugars reduce the synthesis of brain-derived neurotrophic factor (BDNF) . BDNF is a brain chemical that plays an important role in memory formation and learning. It helps the brain to make new connections and repair damaged brain cells. All in all, BDNF sounds a pretty important chemical for overall brain health. Decreased levels of BDNF have also been implicated in the development of Alzheimer's disease and depression.
Research also shows that levels of BDNF are predominantly low in those who have impaired glucose metabolism. A study reported that “decreased BDNF may be a pathogenetic factor involved not only in dementia and depression, but also in type 2 diabetes, potentially explaining the clustering of these conditions in epidemiological studies” . There appears to be a vicious cycle as overloading the body with added sugars leads to low BDNF, which worsens the glucose metabolism and contributes to the risk of insulin resistance, type 2 diabetes and metabolic syndrome.
That Bad Sugar Crash
Have you experienced that brief burst of energy when you bite into a delicious cookie? And how it transforms into fatigue and an energy slump soon after. Studies show that it only takes 30 minutes to go from a sugar high to complete sugar crash. When too much sugar is consumed, the body often finds itself struggling to get the balance right. Excessive sugar floods the bloodstream and triggers the body to quickly produce insulin, creating sudden spikes and downs in blood sugar levels. All of this causes “sugar crash” with blood sugar levels dropping too low too quickly, with symptoms like headaches, dizziness, exhaustion, sleepiness, irritability, difficulty in concentrating, anxiety, and extreme mood swings. In addition, this sudden crash also makes you hungry, and you then crave even more sugar.
Studies show that eating lots of added sugars puts you at a higher risk of developing cancer. Findings of one study suggests that “cancer cells can readily metabolize fructose to increase proliferation" .
Sugar triggers inflammation in the body, which is considered a root cause of cancer formation. A study reported that “abundance of inflammatory cells in adipose tissue of obese and diabetic patients may promote systemic inflammation which can result in a protumorigenic environment .” In addition, people with insulin-resistance may be at an increased risk of cancer due to the excessive production of free radicals known to cause damage to the DNA.
Excessive sugar in the blood cross-links to vital proteins, thereby creating a new breed of harmful molecules called advanced glycation end products or AGEs. AGEs are particularly damaging to collagen and elastin, proteins that maintain our skin’s elasticity which keeps it firm. Too much of sugar destroys the fibres of these proteins and also promotes the growth of brittle and weak collagen, an effect that manifests in the form of wrinkles, fine lines and saggy skin. AGEs also deactivate our body’s internal supply of anti-oxidant enzymes, which makes our skin vulnerable to damage inflicted by sun’s UV radiations. In short, sugar wrecks our skin.
- Robert H. Lustig, Laura A. Schmidt & Claire D. Brindis. Public health: The toxic truth about sugar. Nature International weekly journal of science.
- Kylie Kavanagh, Ashley T Wylie, Kelly L Tucker, Timothy J Hamp, Raad Z Gharaibeh, Anthony A Fodor, and John M Cullen. Dietary fructose induces endotoxemia and hepatic injury in calorically controlled primates. The American journal of clinical nutrition.
- Quanhe Yang, PhD; Zefeng Zhang, MD, PhD; Edward W. Gregg, PhD; W. Dana Flanders, MD, ScD; Robert Merritt, MA; Frank B. Hu, MD, PhD. Added Sugar Intake and Cardiovascular Diseases Mortality Among US Adults. JAMA Internal Medicine.
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