Blood Glucose and Mood Swings:
When sugar is digested, our blood glucose level rises and this puts us in a good mood. We feel alert and happy. But when blood glucose rises too quickly and too sharply, the makes us feel depressed and irritable. We start to crave sugar and once we have eaten some, pancreas tends to over-produce insulin, sending the blood glucose level plunging. This we feel good again.
This fluctuation in the blood glucose level is the basis of mood swings. The effect is worsened when we eat refined carbohydrates that are easily and quickly digested. Sugar, being highly refined, is the greatest culprit.
Hyperactivity and sugar intake
Children who take too much sugar often become hyperactive. One reason is that high blood glucose boosts the level of adrenaline - the hormone associated with the "fight or flight" response to stress. The boost is five-fold and the effect can last up to five hours.
Elevated adrenaline levels can make a person hyperactive, anxious and irritable. As a result, hyperactive children cannot keep physically still. They move about in a chaotic manner and this often leads their parents to label them as "naughty". Mentally, they cannot keep still either. They are constantly distracted and cannot concentrate during school lessons. Such children are diagnosed as having ADHD, or Attention Deficit Hyperactivity Disorder.
During the upswing of blood glucose, the child becomes aggressive, anxious, hyperactive and inattentive. The IQ level of the child drops as much as 25 points and the child is unable to focus on his or her studies. During the blood glucose downswing after the pancreas secretes insulin, the child becomes tired, irritable and depressed. The child may also feel dizzy. At night, the child is unable to sleep and may experience night sweating.
While hyperactivity is normally associated with children, adults suffer from it too. Some adults constantly feel an urge to do things. They cannot keep still and cannot relax. They, too, have difficulty paying attention. When you speak with them, you can sense their minds wandering all over.
Nerve damage and inflammation
Excess glucose also has an inflammatory effect, which damages nerve cells and obstructs their function. In brain cells, excess glucose binds with proteins and they become oxidised in a process called glycation. This results in the formation of advanced glycation end-products (AGES) that swell the cell membranes and cause cell damage. They interfere with the movement of brain nutrients that are critical for cell communications.
Both inflammation and glycation lead to Alzheimer's disease. The first symptom is usually an inability to remember recent events. As the disease advances, the sufferer may show signs of confusion, irritability, aggression, difficulty with language and long-term memory loss.
Madness linked to excessive sugar consumption
Excessive sugar and glucose is the single most important cause of mental health problems, including "madness". Sugar has been linked to anti-social and criminal behaviour as well.
One reason is that the digestion of carbohydrates requires B vitamins, which are also essential for mental performance. Carbohydrate foods naturally come with adequate B vitamins, but refined carbohydrates like sugar, white rice and refined flour products have had most of their B vitamins removed. When we eat these products, we don't get enough B vitamins and our mental performance is greatly affected.
In his book Sugar Blues, American journalist William Dufty points out that the first mental institutions were established in Western society only after sugar became part of the common diet. He documents several cases of people who committed violent and irrational acts - such as a teenager shooting and killing his grandmother for no apparent reason - after consuming large amounts of sugary foods like chocolate.
Last Meals is an exhibition by photographer Jonathan Kambouris featuring murderers on death row, with their last meals superimposed onto their mug shots. The majority of these murderers had asked for last meals comprising high-sugar foods like soda drinks, sweets, chocolates and other "junk" foods. Only a few chose healthy meals, or not to eat anything.
Aldolf Hitler is probably the most famous "sugarholic." Hitler always had chocolates inside his desk drawer and he would add sugar to wine. He was known for his bad temper and some historians have attributed it to pain from his rotten teeth. But Hitler's rotten teeth are yet another sign of high sugar consumption and this is a more plausible explanation for his mood swings and bad temper.
Criminologist Alexander Schauss, who wrote Diet, Crime and Delinquency, has conducted controlled scientific experiments where he showed that changing the diet of prisoners - particularly reducing their sugar intake - can greatly improve their behaviour, with fewer incidents of fights, use of vulgar language and attempted escapes. Excessive sugar not only damages your brain; it can ruin your life!
This content is adapted, with permission, from Book 1 of 2 : The Wonders of Nutrition by Dr Ang Poon Liat. MBBS, M.MED (PAED), MRCP (UK PAED), FAMS, MD.