Can Fasting Help Prevent and Manage Chronic Disease?
As mentioned in my article Fasting to Live Longer?, I will now talk to you about the role of fasting in weight loss and weight management, in some chronic illnesses and in cancer.
According to studies done on intermittent fasting for weight loss, it is just as efficient as other strategies. Despite theories from certain studies pointing to other processes, it seems that the principal mechanism for weight loss, including in fasting, is calorie restriction.
In fact, the best strategy for weight loss and maintaining a healthy weight, is the one you are able to maintain for the long-term.
Against Chronic Illnesses
Few studies have evaluated the role of fasting on lipid profile (good and bad cholesterol, triglycerides, etc.) of those at risk of cardiovascular illnesses. In general, fasting seems to have an advantage compared to calorie restriction over a period of several days, by improving certain blood markers such as increasing “good” cholesterol (HDL) and reducing triglycerides (TG). Further studies are however necessary before we can recommend fasting to reduce the risk of cardiovascular illnesses.
Type 2 Diabetes
According to studies on patients living with diabetes, fasting has effects comparable to those obtained by a low-calorie die. Those effects are an improvement in glycated hemoglobin (hbA1c – value that evaluates glycaemia over several weeks) and weight loss. Once again, more studies are necessaries before we can recommend this approach.
Be careful: If you live with diabetes and want to fast, you must do it with your healthcare team to ensure adequate medication control. This is very important to prevent periods of hypoglycemia.
In animal models, fasting seems to have an interesting effect on limiting the toxicity of cancer treatments. Fasting promotes, in health cells, a mechanism of protection that isn’t present in cancerous cells. This mechanism could make treatments more effective against the targeted cells, while sparing some of the healthy cells and reducing the secondary effects of the treatment.
Fasting isn’t recommended for some cancer patients, because of significant weight loss or weakened immune system. What’s more, the lack of data on humans and on different types of cancer prevents us, at least for the moment, to recommend fasting as a complementary measure to cancer treatments.
Note: Pregnant women or breastfeeding mothers, children and teenagers, as well as people suffering from renal and hepatic impairment or failure are advised not to fast. The same goes for people suffering from gout. The reasoning behind this is that, during a fast, uric acid is better reabsorbed by the body and this can therefore increase the risk and frequency of gout attacks.
- Extenso. (July 2017). L’état de la question – L’effet du jeûne sur le poids, le cancer et certaines maladies chroniques. Retrieved from http://www.extenso.org/zone-professionnels-de-la-sante/l-etat-de-la-question/
- O’Flanagan, C. H., Smith, L. A., McDonell, S. B., & Hursting, S. D. (2017). When less may be more: calorie restriction and response to cancer therapy. BMC Medicine, 15, 106. http://doi.org/10.1186/s12916-017-0873-x
- Harvie, M. N., & Howell, T. (2016). Could Intermittent Energy Restriction and Intermittent Fasting Reduce Rates of Cancer in Obese, Overweight, and Normal-Weight Subjects? A Summary of Evidence. Advances in Nutrition, 7(4), 690–705. http://doi.org/10.3945/an.115.011767