There is a surge of interest in the cluster of topics revolving around:
- dietary sugars and carb load, (glycemic load)
- blood sugar levels (glycemia = level of glucose in blood)
- blood insulin levels and insulin resistance,
- general body inflammatory state,
- central obesity
and how these may relate to
- the development and progression of cancer
- the treatment of cancer
This field of study is still early in it’s development. There are many questions versus very few answers. It does seem that all the above factors are related to cancer in many ways.
Some types of cancers tend to be more related to certain metabolic factors than others. When it comes to treatment, there are unique features of the metabolism of certain types of brain tumours that mean that dietary interventions as part of the over-all treatment package may be particularly useful.
Sometimes it is said that all cancers rely on glucose for fuel, so it should be easy to starve them. This statement is “close, but no cigar”. Cancers are highly efficient at pulling glucose from the blood stream. Since you need a certain amount of glucose in your blood stream to be alive, you can not starve the tumour of it’s glucose supply. Further, tumours can use amino acids from your blood supply to generate glucose within their cells – such a l-glutamine, which is an abundant amino acid in the body. In advanced cancer, there is often “cachexia” or wasting of the body tissues, as the tumour sends out chemical signals that cause the body to break down the protein in muscle and tissues to glucose and amino acids.
For these and other reasons, attempts to starve the cancer growth by changes in diet are not really likely to kill or fully stop the cancer progression on their own. Using such dietary changes, though, hold a lot of promise if they can be combined with other treatments.
This is no small subject and there is a lot of opportunity for mis-information and confusion. If you find this topic of interest, it will take some time to get up to speed on the over-all picture.
The situation in term of brain tumours is so specific that it really warrants being a separate topic, so please see also my page on that.
“An overview of the topic of insulin, dietary carbohydrates, and ketogenic diets as it relates to cancer treatment”
Dr. Kieron Rooney, BSc (Hons); (RNutr.); PhD, is a Senior Lecturer in the Faculty of Health Sciences, University of Sydney.
He completed his PhD in Biochemistry in 2004 and for the past 10 years has investigated both human and small animal studies investigating the role of diet and physical activity on parameters of fuel storage and utilisation as they pertain to dysregulated metabolic states such as obesity and type 2 diabetes.
This is a good review presentation, from August 2014.
Research Exploring Insulin/Glycemia Topics in Cancer
(1) Overnight Fasting:
“Prolonged Nightly Fasting and Breast Cancer Risk: Findings from NHANES (2009-2010).” Cancer Epidemiol Biomarkers Prev. 2015 May;24(5):783-9. LINK
- “ BACKGROUND:
A novel line of research has emerged, suggesting that daily feeding-fasting schedules that are synchronized with sleep-wake cycles have metabolic implications that are highly relevant to breast cancer. We examined associations of nighttime fasting duration with biomarkers of breast cancer risk among women in the 2009-2010 U.S. National Health and Nutrition Examination Survey.
A longer nighttime duration was significantly associated with improved glycemic regulation.
Randomized trials are needed to confirm whether prolonged nighttime fasting could improve biomarkers of glucose control, thereby reducing breast cancer risk.
(2) Body Weight and IGF re: Breast Cancer:
Cancer Clin Oncol. 2015;4(2):24-31. LINK to full text
“The Insulin-like Growth Factor Axis, Adipokines, Physical Activity, and Obesity in Relation to Breast Cancer Incidence and Recurrence.”
- “Obesity, a risk factor for the development of postmenopausal breast cancer and certain other cancer types, has also been associated with poorer response to cancer therapy and cancer recurrence”
- “Obesity and physical inactivity are determinants of hyperinsulinema and insulin resistance (Giovannucci & Michaud, 2007), and obesity influences the amount of free insulin-like growth factor (IGF-I) available to cells (Coughlin & Giovanucci, 2012). Hyerinsulinemia may be an underlying factor in chronic conditions such as type 2 diabetes mellitus, obesity, and certain forms of cancer, including breast cancer.”
- “Weight gain and physical inactivity can occur following breast cancer treatment. For breast cancer survivors, cancer-related fatigue is a common symptom (Meneses-Echavez, Gonzalez-Jimenez, & Ramirez-Velez, 2015). Among women who have already been diagnosed with breast cancer, obesity is associated with breast cancer recurrence and poorer survival (Protani, Coory, & Martin, 2010). Maintaining a healthy body weight reduces a woman’s risk of cancer recurrence, diabetes and cardiovascular diseases (Thompson et al., 2012).”
- STUDY RESULTS: “Greater body fatness is associated with a higher risk of postmenopausal breast cancer. The association may be explained, in part, by hyperinsulinemia and alterations in adipokines and estrogens. Nutrition, energy balance, and levels of physical activity are determinants of IGF bioactivity. Alterations in the IGF axis can increase cancer risk and progression. Results from epidemiologic studies indicate that higher circulating levels of IGF-I are associated with an increased risk of breast cancer.”
- STUDY CONCLUSIONS: Intervention studies are needed to determine how to sustain the positive effects of exercise over time and to identify the optimal mode, intensity, frequency, duration, and timing of exercise for breast cancer survivors, including important subgroups of survivors such as African American and Hispanic women …