Finding Glycemic Load’s Role in Cancer Risk
AICR/WCRF’s new Continuous Update Project (CUP) report found that eating a diet high in glycemic load increases the risk of endometrial cancer. It’s the first time the accumulated research has been strong enough for a CUP report to find a link between glycemic load and cancer risk.
So what is glycemic load and how does it fit into your dinner plans? And can it really prevent metabolic havoc? AICR’s Nutrition Communication Manager Alice Bender, MS, RD, explains.
Q: What’s the difference between glycemic load and glycemic index?
A: Glycemic index is a measure of how much a food that has 50 grams of carbohydrates increases your blood sugar. Glycemic load takes into account a typical serving size of food, the actual amount a person would eat. A great example of a food high in glycemic load is a sugary soda, that’s pretty much pure sugar and water; the body digests it quickly and it increase the sugar in your blood relatively quickly compared to a piece of fruit that has fiber and takes longer to digest.
Q: And blood sugar affects insulin levels?
A: Yes. When blood sugar goes up quickly then your body produces a lot of insulin to try and bring it down. What insulin does is it helps move sugar out of your blood and into your cells for energy. Many people have a problem with insulin resistance, which means the insulin is not as effective as it should be in moving the sugar out of the blood and into the cells. Eating a diet that produces lots of sugar quickly leads to your body continuing to pump out insulin to handle that blood sugar.
Q: For cancer risk, can you talk about why excess insulin a big deal?
A: High insulin can create metabolic havoc in your body. One thing we know about insulin is that it can be a growth promoter. It’s a hormone and it can lead to other hormones that can cause cancer cells to grow more quickly. Over time, having high insulin levels produces a metabolic environment that can encourage cancer cell growth.
"It’s not about what specific foods should I eat and which should I stay away from; it’s looking at your overall diet."
Q: There seem to be more studies recently looking at glycemic load and cancer risk. Does that means anything?
A: Glycemic load is a good research tool to look at the kinds of foods people are eating over time, such as if a certain population is eating lots of high sugary beverages and foods. It’s interesting to look at how GL might affect endometrial and other cancers for research purposes, but a diet high in glycemic load is one we already know is not a healthy cancer protective diet.
Q: Would you recommend focusing on glycemic load and looking at those GL charts to eat healthier?
A: Glycemic load and glycemic index are not tools that I would recommend you use to choose your foods. You can choose low GL foods and not have a healthy diet. And GL says nothing about protein, which is important. The GI for a food also changes depending upon how that food is prepared, the type, and what you eat it with. Protein is digested more slowly than carbohydrates, for example, so eating nuts or beans with a high GL food will help blunt the glycemic response.
Q: So what do you want people to take away from this finding?
A: It’s not about, ‘what specific foods should I eat and which should I stay away from’; it’s looking at your overall diet. A healthy diet is low in many of the foods high in glycemic load, but also can include a few high glycemic load foods in small amounts. Focus on a diet high in whole foods that have fiber and filling your plate with colorful fruits and vegetables; it’s a diet that includes legumes, nuts and only some lean animal protein. It’s limiting sugary, processed foods. Overall this diet will also be a low glycemic load diet, and lowers risk for cancer, heart disease and other chronic diseases.
Bottom line: It’s the New American Plate way of really looking at what’s on your plate and following AICR’s recommendations. That’s really the key.