According to a new study from Dana-Farber Cancer Institute, colon cancer survivors whose diet is heavy in sugar and starchy carbohydrates are far more likely to have a recurrence of the disease than are patients who eat a better balance of foods. And the connection is even stronger in patients who are overweight or obese.
Recent studies have shown that colorectal cancer survivors whose diet and activity patterns lead to excess amounts of insulin in the blood have a higher risk of cancer recurrence and death from the disease. High insulin levels can be produced by eating too many starchy and sugar-laden foods.
The study involved 1,011 stage III colon cancer patients who had undergone surgery and participated in a clinical trial of follow-up chemotherapy for their disease. Participants reported their dietary intake during and six months after the trial.
Researchers tracked the patients' total carbohydrates, as well as their glycemic index (a measure of how quickly blood sugar levels rise after eating a particular food), and glycemic load (which takes into account the amount of a carbohydrate actually consumed), and looked for a statistical connection between these measures and the recurrence of colon cancer.
They found that participants with the highest dietary levels of glycemic load and carbohydrate intake had an 80 percent increased risk of colon cancer recurrence or death compared with those who had the lowest levels. Among patients who were overweight or obese, the increase was even greater.
The researchers theorize that a high glycemic load may stimulate the body's production of insulin which, in turn, may increase the proliferation of cells and prevent the natural cell-death process in cancer cells that have metastasized from their original site.
While the study doesn't prove that diets high in glycemic load and carbohydrate intake cause recurrence of colon cancer, the results strongly suggest that it plays a role.
Low glycemic foods include beans, lentils, nuts, pasta, brown rice, quinoa, sweet potatoes, steel-cut or large flake oats, oat bran, Red River cereal, bran cereal and most fruit. In contrast, foods such as white potatoes, white bread, instant rice, refined breakfast cereals, cereal bars, and sweets have a high glycemic index and cause sharp rises in blood sugar and insulin.
Use the following tips to help you adopt a low glycemic diet:
- Use common sense. Unprocessed fresh foods such as whole grains, legumes, nuts, fruits and vegetables will have a low GI value. High glycemic foods are usually highly processed and may have a concentrated amount of sugar.
- Include at least one low GI food per meal, or base two of your meals on low GI choices.
- Pay attention to breads and breakfast cereals since these foods contribute the most to the high glycemic load of our North American diet.
- Avoid eating high GI snacks like pretzels, corn chips and rice cakes as these can trigger hunger and overeating. Opt for fresh fruit, low fat dairy products, nuts or plain popcorn.
- Choose fruits that are more acidic (e.g. oranges, grapefruit, cherries) as these have a low GI and will lower the glycemic load of a meal.
- Use salad dressings made from vinegar or lemon juice - the acidity will result in a further reduction in the GI of your meal.
- Watch portion size. When it comes to weight control, excess calories add up regardless of how they impact your blood glucose and insulin.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.