The link between insulin resistance and cancer has been of growing interest to health care professionals and researchers in recent years. Limiting insulin resistance, which leads to obesity (amongst other major health concerns) is now believed to be a key step in avoiding cancer.
Rescu. spoke to naturopathic oncologist Dr Lise Alschuler for her top tips on how to avoid insulin resistance and prevent cancer.
RESCU: Tell us a little about your background in medicine and with cancer research specifically
I am a naturopathic doctor with board certification in naturopathic oncology and I have been practicing since 1994. I also work as an independent consultant in the area of practitioner and consumer health education. I maintain a naturopathic oncology part-time practice out of Naturopathic Specialists, based in Scottsdale AZ. I have co-authored The Definitive Guide to Cancer: An Integrative Approach to Prevention, Treatment and Healing, and The Definitive Guide to Thriving After Cancer: A Five-Step Integrative Plan to Reduce the Risk of Recurrence and Build Lifelong Health. I also co-created, along with Karolyn Gazella, FiveToThrivePlan.com, and we co-host a radio show, Five To Thrive Live! on the Cancer Support Network about living more healthfully in the face of cancer. I am a five-year breast cancer survivor, or thriver, as I like to say.
RESCU: The research linking cancer to insulin resistance is still fairly recent — can you tell us a little about when it started and what sort of research has been conducted thus far?
I am not exactly sure when the research began, but I suspect that the connection between insulin resistance and cancer was firmly established with the discovery of the peroxisome proliferator-activated receptors (PPARs) in the 1990’s. These receptors comprise an important subfamily of the nuclear hormone receptors that play a central role in maintaining insulin sensitivity. PPARs were also discovered to have a tumour suppressor function. This discovery opened up significant curiosity about the linkage between insulin resistance and cancer. In addition to this, the alarming increase in the global rates of obesity, a condition often influenced by insulin resistance, coupled with the fact that obesity is considered responsible for one out of every five deaths due to cancer, has fuelled the discovery process to better understand the connection between insulin resistance and cancer. One of the hottest areas of research in this area is the study of the impact of PPAR agonists such as metformin in controlling various cancers.
RESCU: How does one go about getting tested for insulin resistance?
Insulin resistance is a physiological condition rather than a diagnosis per se. It occurs when there is a systemic cellular resistance to insulin. This results in a deficiency of glucose intracellularly. In response to this deficit, the pancreas attempts to compensate by secreting more insulin (in a blind attempt to drive more glucose into the cells). Thus, in insulin resistance, fasting blood levels of glucose, insulin and its companion insulin growth factor-1 (IGF-1) elevate. These can all be measured in laboratory evaluation. Clinicians can also calculate a ratio, The Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) to generate a score that can define IR. Anyone with abdominal obesity, a sedentary lifestyle and sleep deprivation is at high risk of insulin resistance and should be evaluated.
RESCU: Is insulin resistance reversible?
Insulin resistance is most definitely reversible. Having said that, it is not necessarily an easy process as reversal requires significant lifestyle changes. An adult who is insulin resistant can temporarily reverse their condition within weeks, and if the lifestyle changes remain, can more permanently revert from insulin resistance within months.
RESCU: And what’s the best way to reverse insulin resistance?
There are numerous strategies to reverse insulin resistance. Probably the most important one is exercise. Exercise decreases insulin resistance, improves mood, lessens fatigue, improves sleep, manages weight, reduces hot flashes, improves immunity, and prevents osteoporosis. In addition, a low glycaemic load diet (essentially a diet with minimal processed foods and refined sugar, adequate fibre, protein and essential fats) is a very effective strategy. Diet and exercise together may be even more powerful than metformin in preventing diabetes. If one adds to this increased sleep and a targeted dietary supplement program, insulin resistance will retreat.
RESCU: How can we prevent insulin resistance?
Prevention of insulin resistance is of key importance. A lifestyle-based prevention program emphasises:
- Daily, moderately vigorous exercise for at least 45 minutes
- A plant-based diet devoid of processed foods and refined sugar.
- Adequate sleep (at least 7 hours nightly; preferably 8 hours nightly).
RESCU: What other simple lifestyle changes can we take to prevent cancer?
One of my favourite strategies to prevent both insulin resistance and cancer is to consume the polyphenolic compounds found in plants. These polyphenolics include pigmented flavonoids – giving plant foods their wonderful colours, and providing cellular protection against cancerous transformation. This is why it is so important to eat a colourful diet (the “rainbow diet”), to include spices (highly concentrated in polyphenols), and to use dietary supplements (nutrients and herbs) that contain these polyphenols.
RESCU: Prevention aside, has this research changed the way cancer patients are treated at all?
Insulin resistance is now a recognised contributor to worse prognosis for those diagnosed with cancer. Several key clinical trials have demonstrated the effects of eating a high glycaemic load diet, of diabetes and of insulin resistance on worsening cancer outcomes. This knowledge has stimulated some oncologists to recommend weight loss, lower glycaemic load diets, exercise and drugs such as metformin as a part of their treatment program. As the research continues, this is likely to become even more widely incorporated into cancer care.
Dr Lise Alschuler will be a speaker at the forthcoming 2nd Annual BioCeuticals Research Symposium in Sydney April 11-12, 2014.
