A sweet killer
Consuming too much sugar can have bad, and even potentially fatal, effects on our health.
SUGAR is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food.
Ingestion of sugars immediately stimulates neural and behavioural responses that are distinct from those evoked by compounds with salty, sour, bitter and/or umami tastes.
In humans, sugars generate the distinctive taste quality of “sweetness”.
It is highly palatable and nutritive (to a certain extent), therefore it is part of our diet and is consumed in both complex and simple forms.
Sugary sources
Sugar is obtained from grains, vegetables, nuts, seeds and legumes.
These naturally-occurring carbohydrates contain starch as the main energy source.
They also contain fibre, which is essential to maintain bowel health.
As per dietary guidelines, carbohydrates from the above food sources should constitute 40-55% of the total calorie intake in a balanced diet.
In addition to complex carbohydrates, we also consume simple carbohydrates (free sugar), which is obtained from fruit, milk and added sugars.
The sugar in milk (lactose) and fruit (fructose) are natural and come along with vitamins, minerals and antioxidants.
They are considered healthy, whereas added sugars contain only calories and lack these essential vitamins and minerals.
The common source of added sugars are table sugar, candy, pastries, cakes, desserts, cookies, soft drinks and fruit drinks.
Chemically, added sugars are rich in sucrose and fructose (high fructose corn syrup).
As these food products are delicious and easily available, their consumption is enhanced in all age groups throughout the world.
Studies have shown that excessive added sugar can trigger overeating due to brain adaptations, which in turn can cause several health problems, including obesity.
Considering the harmful effects of additional sugars, the World Health Organization (WHO) recommends that sugar comprise less than 10% of the total calories eaten in a day (i.e. 12 teaspoons of sugar or less in a day for a normal diet).
The organisation even recommends reducing sugar intake to less than 5% (six teaspoons of sugar) if possible for added health benefits.
Metabolising sugar
Carbohydrates consumed in the diet undergo digestion, get converted into glucose and are absorbed.
The body’s cells either use the glucose immediately for energy or it is stored in the liver or muscles (glycogen) for future use.
Vital organs in our body like the brain, red blood cells and kidneys, need glucose as a primary source of energy for optimal function.
Both dietary and stored carbohydrates (glycogen) regularly supply glucose to these organs.
This is aided by the balanced action of hormones named insulin and glucagon.
Any imbalance in the levels of insulin will result in a metabolic disorder known as diabetes mellitus.
Lack of glucose supply to the brain or excess insulin (in diabetic patients) can cause giddiness, coma, and even death if untreated.
Added sugars are generally rich in sucrose or fructose.
Sucrose gets broken down in the body into glucose and fructose.
Fructose that is not needed immediately for the body’s needs is converted straight to fat in the liver and stored there.
The excess fat thus produced either gets accumulated in the liver, eventually resulting in a fatty liver, or is released from the liver via a lipid carrier (very low density lipoprotein, VLDL, cholesterol).
This lipid carrier is metabolised in our blood vessels to become LDL (low density lipoprotein) or “bad” cholesterol, which is the major culprit for cardiovascular (heart) complications related to high sugar intake.
Several studies have shown that excess sugar can cause health problems such as obesity and metabolic syndrome (which includes high blood pressure, high triglycerides and high fasting glucose), which in turn enhances the risk of cardiovascular disease and non-alcoholic fatty liver disease.
Excess refined sugar intake can cause the impairment of the natural mechanisms that prevent us from eating when we are full.
This will trigger overeating and obesity in the long run, leading to high blood glucose, increased blood pressure and increased fat levels, and resulting in serious effects on the heart and liver, like a heart attack or liver failure.
Decreasing excess sugar
How then can we prevent ourselves from consuming excess sugar and facing its bad health effects?
Here are some of the ways: > Consume complex carbohydrates that are rich in nutrients, fibre and vitamins.
> Avoid highly refined grains and flours as they are absorbed quickly, and lack vitamins and fibre. > Restrict the consumption of added sugar to less than 5% of your total calories consumed in a day (i.e. approximately only six or less teaspoons of sugar per day). > Avoid highly-sugared or fortified soft drinks and commercially-available food items with added sugars (read the food label for calories per serving).
> Keep an eye on the sugar content of anything and everything you buy (read the ingredients list – the ingredients are listed in descending order of amount in the food).
> Exercise and a healthy lifestyle, along with a balanced diet with the right amount of sugars, will help you stay healthy. Remember, prevention is better than cure, so do consume added sugars in moderation.
Associate Professor Dr Jeevan Kumar Kenchanoor Shetty and Assoc Prof Dr Venkatesh R. Naik are the academic leads in biochemistry and pathology respectively at the Perdana University-Royal College of Surgeons in Ireland School of Medicine. This article is courtesy of Perdana University. For more information, email starhealth@ thestar.com.my. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.