By Dr Suman S Karanth
World Cancer Day: One out of three patients who walk into my clinic ask me "Doctor I have been told by our relatives that sugar is bad for my cancer. Hence I have cut it out of my diet completely." I, like most of my colleagues, are often intrigued by how easily people fall prey to such myths. In the internet era, where information is overflowing, you will find a lot of misleading information about how sugar causes cancer cells to grow quickly and how if you cut out sugar from your diet you could defeat cancer.
Does sugar feed cancer cells?
Been wondering whether cancer cells feed on sugar? All cells, normal and cancer cells, depend on blood sugar (glucose) to generate energy.
The idea that cancer cells thrive on and are addicted to excessive sugar started long ago when a German scientist Otto Warburg noticed cancer cells consuming massive amounts of sugar in a dish. He also noticed that these cancer cells did not have an efficient way of harvesting this energy that could be generated from glucose and instead converting it to lactate. Thus, it would seem logical to deprive the cancer cell from glucose. However multiple research clearly shows this is in fact incorrect and there remains no association of sugar-free diets lowering the risk of cancer.
When people cut sugar from their diet, are they "starving" cancer cells?
Human body has an in-built mechanism to sustain a certain range of glucose levels especially when it falls to dangerously low levels. Even if sugar is cut out from diet, the body will use other stores to sustain blood glucose levels. So, you don't really "starve" cancer cells by cutting out sugar from the diet.
Depriving cancer cells of sugar will neither slow its growth, nor will giving more sugar speed up its growth.
If sugar doesn't cause cancer, why bother?
Should cancer patients avoid sugar? We should bother about this as there is an indirect link between sugar and cancer. Eating lots of refined carbohydrates or food with added sugars, leads to weight gain ultimately leading to obesity.
Obesity is linked to nearly more than 13 different cancers. The reason for this is the increased body fat that promotes inflammation, which over time damages the DNA and leads to cancer. Obesity is one of the most important modifiable risk factors for cancer after smoking.
Which are the right kinds of sugar to take?
There are many sources of refined sugars such as:
- sweetened beverages
- salad dressing and
- many more to the list.
Avoid or reduce consumption of such products.
You can replace them with more natural sugars such as honey, jaggery or maple syrup which possesses antioxidants which are protective to your body.
Having said this, it remains important to limit the daily intake of sugar to acceptable levels. Even though studies have not shown a link between artificial sweeteners and cancer, until we have more robust information, it is better to limit their consumption.
Final take-home message on sugar consumption?
I tell all my patients the following: Sugar must be consumed in amounts that complement a balanced diet. Too much sugar can cause unhealthy weight gain, obesity and increase in cancer risk. Curb that sweet tooth and find a way to include more natural sugars and less processed food in your diet.
The author is Consultant, Medical Oncology, FMRI. Views expressed are the author's own.