Abstract
In response to Dr. Klement's comments, Drs. Simone and Champ agree that a ketogenic diet (KD) may be added as a dietary intervention in cancer treatment. They suggest that patients with certain cancers that put them at risk for cachexia may respond best to a KD, whereas patients with cancers that do worse with weight gain might benefit more from calorie restriction or intermittent fasting.
We appreciate Dr. Klement's insightful comments. The authors agree that a ketogenic diet (KD) can be added as a type of dietary intervention in cancer treatment. We believe the umbrella term “nutrient restriction” should be used to describe all types of dietary modification, including caloric restriction (CR), intermittent fasting (IF), and a KD [1]. Whereas various types of nutrient restriction may alter key molecular pathways in the same manner, they may alter others differently. It also may be determined that, clinically, certain cancer types benefit most from a specific type of dietary intervention. For example, as Dr. Klement states, it may be found that patients with cancers that are prone to cachexia, such as pancreatic cancer, may benefit most from a KD, whereas patients with cancers known to do worse with weight gain, such as breast cancer, may benefit most from CR or IF [2]. This should be evaluated thoroughly for each cancer and subtype.
A KD should be evaluated thoroughly. We pointed out the potential benefit of carbohydrate restriction in our report, as some of the historical CR studies noted the largest benefit solely with carbohydrate reduction [3]. It is unknown whether this was accomplished by reducing circulating glucose or from downregulation of the insulin growth factor pathway through a reduction in circulating insulin, although both may be reasonable assumptions. Recent data from a pilot trial in patients with cancer receiving a ketogenic diet revealed such effects on the insulin pathway [4].
We also agree that micronutrients are vital and their content must be addressed when discussing and evaluating nutrient restriction. Dietary interventions are often thought of as reductions of macronutrients, more specifically carbohydrates, fats, or protein; however, caloric restriction is often a restriction of overall calories and may overlook micronutrient content, which can be significantly altered with various dietary interventions.
Finally, the authors agree that with any dietary intervention during cancer treatment, a multidisciplinary approach is vital, with both dietary counseling from a trained professional and counseling in behavioral modification to ensure adherence to the intervention.
Disclosures
The authors indicated no financial relationships.
References
- 1.Simone B, Champ CE, Rosenberg AL, et al. Selectively starving cancer cells through dietary manipulation: Methods and clinical implications. Future Oncol. 2013;9:959–976. doi: 10.2217/fon.13.31. [DOI] [PubMed] [Google Scholar]
- 2.Champ CE, Volek JS, Siglin J, et al. Weight gain, metabolic syndrome, and breast cancer recurrence: Are dietary recommendations supported by the data? Int J Breast Cancer. 2012 doi: 10.1155/2012/506868. [Epub ahead of print] [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Champ CE, Baserga R, Mishra MV, et al. Nutrient Restriction and Radiation Therapy for Cancer Treatment: When Less Is More. The Oncologist. 2013;18:97–103. doi: 10.1634/theoncologist.2012-0164. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Fine E, Segal-Isaacson C, Herzkopf S, et al. A pilot safety-feasibility dietary trial targeting insulin inhibition in ten patients with advanced cancer. BMC Proc. 2012;6(suppl 3):60. doi: 10.1016/j.nut.2012.05.001. [DOI] [PubMed] [Google Scholar]