In 2015 the average total sugar consumption for adults in Canada was 85 grams per day (20 teaspoons). Of this total, 46 grams per day (12 teaspoons) contains free sugars. Free sugars are those added to foods and beverages by the manufacturer, cook or consumer, and sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates. Other sugars that come from dietary fiber are not refined and come from vegetables, fruits and whole grain sources. Excess free sugar consumption is associated with heart disease, stroke, obesity, diabetes, high blood cholesterol, cancer and dental caries (cavities). The Canadian Heart and Stroke Foundation position statement on Sugar recommends reducing added sugar intake to less than 10% and ideally to less than 5% of the total energy consumption. For a 2,000 calorie diet, a 10% energy consumption is equivalent to 48 grams of sugar daily (12 teaspoon) and 5% energy consumption is equivalent to 24 grams of sugar (6 teaspoon). Drinking two 8 ounces cans a day of sugar sweetened beverages increases the risk of depression by 5%, and drinking 3 cans per day increases the risk of depression by 25%. Also pre-diabetic status and diabetes are associated with increased cognitive decline in the elderly.
Relevant to current times are the effects of excess sugar intake to our immune system. Early evidence in the 70’s indicated that 100 grams of ingestion of free sugar reduced the capacity of neutrophils (a type of white blood cell that helps during bacterial infections) to function during a bacterial infection for up to 5 hrs after ingestion. More recent research has shown that this may not apply to viral infections where glucose ingestion (a type of sugar) was shown to be protective. Now these effects are related to a single dose, not to prolonged exposure to excess sugar intake. Other research has shown that sugars and particularly fructose (the type of sugar in high quantity in high fructose corn syrup and used as a sweetener in beverages) inhibits MBL, a component of the immune system, in recognizing Staphylococcus aureus bacteria and Influenza A virus both common human pathogens.
Fructose has also been found to affect the balance in the gut bacteria. Gut bacteria has been shown to interact with the host immune system influencing immune responses and disease risks. Gut bacteria is also know to modulate the gut-brain signals in health and stress-related conditions such as anxiety and depression.
The presented research shows the many ways that excess free sugar consumption can negatively affect your health. It seems reasonable to conclude that reducing your intake of free sugar will help to reduce risks of metabolic and cardiovascular disease, improve your immune function, help your gut bacteria and reduce depression and anxiety risks.
In our next blog article we will look at how to boost your immune system and help improve your gut bacteria.
References:
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- Wang A, Huen S C , Luan H H, et. al. Opposing Effects of Fasting Metabolism on Tissue Tolerance in Bacterial and Viral Inflammation. Cell (2016) 166, pp. 1512–1525 September 8, 2016.
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