Can sugar really weaken your immune system?

Slashing your sugar intake has become a popular trend, but is it really necessary?
Slashing your sugar intake has become a popular trend, but is it really necessary?

Reducing your sugar intake is a major struggle – and quitting it altogether is even harder. Most of us wouldn't be able to go even a day without sugar, one of the reasons being that 74% of processed foods contain hidden sugars.

Brands that claim their products contain "zero refined sugar" are simply referring to the absence of white sugar. We need to know that ingredients ending in "-ose", like glucose, fructose and sucrose are also sugar units and only have subtle differences in the way they’re digested and absorbed.  

There are, however, ways to reduce your daily intake without going cold turkey.

Read: I gave up sugar for 14 days and this is what happened

Sugar in its different forms

A previous Health24 article explains that sugar is a simple carbohydrate and comes in many different forms. In its simplest form, it is called a monosaccharide, which includes:

  • Glucose (occurs naturally in fruits and plant juices)
  • Fructose (occurs naturally in fruits, some root vegetables, cane sugar and honey)
  • Galactose (combines with glucose to form lactose) 

While consuming a small amount of sugar every day isn’t going to kill you, consuming too much added sugar puts you at risk for some deadly diseases. The World Health Organization (WHO) recommends that a person's added sugar consumption per day should be no more than 10% of their total daily caloric intake. 

Can a sugar-overload crash your immune system?

But, apart from leading to, among other things, weight gain, blood sugar problems and an increased risk of heart disease, could the "root of all (nutritional) evil" also have an effect on your immunity? 

There is a widespread belief that sugar weakens the immune system, mainly based on a 1970s study where people donated blood before and after consuming large amounts of sugar. The researchers found that after a large dose of sugar, certain white blood cells (neutrophils) were less aggressive in destroying bacteria.

However, this belief is built on a shaky foundation as the study was never replicated or expounded. Nutritionist Monica Reinagel notes that while eating sugar may put your white blood cells into a temporary coma, it’s a little more complicated than that:

“To look at a petri dish full of neutrophils in a sugar-induced coma and say that ‘eating sugar suppresses immune response’ is a bit of an over-simplification,” she said.

A more recent study done on mice showed that an overconsumption of sugar and its effects on your immune system is dependent on the type of bug you’re fighting. While the consumption of sugar seemed to aid the mice in recovering from viral infections, it was unsuccessful in fighting bacterial infections.

Is it really worth it?

The bottom line is that, apart from the above risks, we are already aware of so many other downsides of consuming excessive sugar. According to Men’s Health, sugar can:

  • Double your risk of heart disease
  • Lead to obesity
  • Cause kidney stones
  • Cause tooth decay

The best advice is therefore to severely limit your added sugar intake. We also need to beware of "healthy" sugar substitutes such as honey and maple syrup, as the calories they contain are essentially the same as in sugar.

Image: iStock

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