Sugar, Carbohydrates, and Cancer

Glycemic Index

Carbohydrates turn into sugar (or glucose) in our bodies, in part due to the enzymes that we secrete that break down carbohydrates into sugar. This is why when we let white bread or a cracker soak for a long time in our mouth; it begins to taste sweet like sugar. This scientific description of how much glucose is formed from in the body various foods is called the glycemic index.

Glycemic Load

Some types of carbohydrates turn more quickly into sugars in our bodies. What is equally important is how fast particular foods turn into sugars, or glucose. This can be referred to as the glycemic load. Glycemic load has more to do with other properties of the food than simply the amount of carbohydrate, or sugar that it is made up of. Glycemic load takes into account the amount of fat, protein and fiber that is in any particular food. This is why apple juice turns more quickly into sugar in the body than eating an apple – the fiber in the apple slows down how fast the sugar from the apple is absorbed in the gut, leading to slower rise in blood glucose levels. Therefore apple juice has a higher glycemic load than an apple.

For this reason, you can’t rely solely on carbohydrate or sugar levels in a particular food in order to determine how healthy the food is. Of course, the amount of sugar in any particular food is important, but it is just as important to consider the other components of the food such as the fiber, fat, or protein content.

Cancer & Sugar Links

The link between cancer and high sugar foods (or foods with a high glycemic index) is indirect, but meaningful. There are known associations with diets high in carbohydrates and sugars, and the development of prostate, colorectal, ovarian and pancreatic cancers. Additionally, research has demonstrated a link between eating fewer carbohydrates and improvements in breast cancer and colon cancer survival.

Reduce Carbohydrates Wisely

If you are trying to cut carbohydrates, do so wisely. Begin with reducing ‘nutrient empty’ foods such as soda, sweets, and foods with added sugar. Instead, eat complex carbohydrates such as sweet potatoes, quinoa, other whole grains, beans and lentils. These foods have other nutritional benefits and are considered ‘dietary keepers’.

Artificial sweeteners are not a good replacement for sugar in the diet for several reasons. Although they don’t raise blood sugars directly, they don’t support the health of the body either. They disrupt the gut microbiome, which has important implications for the immune system, among other concerns. Additionally, artificial sweeteners have not been shown to aid in weight loss. This is in part because artificial sweeteners are very sweet in their flavor, thereby fooling the brain into thinking that you are eating sugar. When we eat sweet foods, the reward center in our brain is activated, thus leading us to want to eat more sugary or sweet foods, more frequently.

The best strategy for reducing sugar in your diet, especially if you have a ‘sweet tooth’, is to work towards changing your taste and habits. It may take a few weeks, but for most people, once they have minimized sweets and sugar-rich foods, the sweet cravings lessen or stop. This may be because the reward center in the brain stops getting activated and the desire for sugar is reduced.

It is also important not to deprive yourself of sugar, as this can lead to sugar binging. Sugar and sweets often symbolize comfort and celebration. They should be considered rare treats to be thoroughly savored, not as a routine or daily part of the diet. If you are craving sweet treats during cancer treatment, you may choose to keep healthier options around such as dark chocolate, unsweetened dried fruits, homemade energy nut/seed balls, or choose to make fruit smoothies with ingredients like banana, nut butters, almond milk and cocoa powder to fulfill the sweet cravings (though more often, when you can, choose fruits like berries instead of bananas for their lower sugar content and glycemic load).

You can also visit the Comfort Foods section in this Toolbox for healthier dessert recipes.