Calorie restriction and Cancer

[Paul McGlothin]

Recently an email list thread started that included questions from a CR Society member who is fighting cancer. Lots of people with cancer consider calorie restriction, since research suggests that CR may prevent and help fight cancer. To learn the basics of calorie restriction and cancer, see articles like this one from Hursting, who publishes regularly on the subject:

Calorie restriction and cancer prevention: a mechanistic perspective

 

 

Stephen D Hursting*, Sarah M Dunlap, Nikki A Ford, Marcie J Hursting and Laura M Lashinger

 

Review Cancer & Metabolism 2013, 1:10 doi:10.1186/2049-3002-1-10

 

The electronic version of this article is the complete one and can be found online at: http://www.cancerand.../content/1/1/10

 

© 2013 Hursting et al; licensee BioMed Central Ltd.

 

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommo...licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 

 

 

Abstract

 

Calorie restriction (CR) is one of the most potent broadly acting dietary interventions for inducing weight loss and for inhibiting cancer in experimental models. Translation of the mechanistic lessons learned from research on CR to cancer prevention strategies in human beings is important given the high prevalence of excess energy intake, obesity, and metabolic syndrome in many parts of the world and the established links between obesity-associated metabolic perturbations and increased risk or progression of many types of cancer. This review synthesizes findings on the biological mechanisms underlying many of the anticancer effects of CR, with emphasis on the impact of CR on growth factor signaling pathways, inflammation, cellular and systemic energy homeostasis pathways, vascular perturbations, and the tumor microenvironment. These CR-responsive pathways and processes represent targets for translating CR research into effective cancer prevention strategies in human beings.

 

 

 

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I decided to start this post in this easily accessible forum, whose format encourages development over time. Hopefully, it will be a helpful resource for those who want to learn more about calorie restriction and cancer.

 

One of our members asked me to describe my CR diet/lifestyle particularly as it pertains to cancer. My personal approach activates longevity signaling. I downregulate cell signals that drive growth and provide easily available energy. For me. that turns out to be a very complex carbohydrate diet with a moderate intake of fat and protein. I try to keep glucose levels on the low side. That doesn’t mean I recommend the exact same diet for other people. With longevity signaling as a foundation, I try to help people find a diet that fits their needs and personality. If I had cancer, I would tweak my dietary intake until I reached the metabolic state recommended by the cancer expert, Dr. Tom Seyfried. Basically that means keeping calories , glucose, and protein low enough to make it difficult for cancer cells to survive.

 

This is an excerpt from my list response:

 

Dr. Tom Seyfried is a scientist whose work is of immense practical value to many cancer patients. He has a lot of experience with doctors who treat cancer. Dr. Seyfried recently released "Cancer as a Metabolic Disease, " a best-selling book, which recommends treating cancer with ketogenic calorie restriction.I am friends with Dr. Seyfried, who is a member of the Society's scientific advisory council.

 

 

Here's a video of Dr. Seyfried discussing his approach to cancer :

 

This 2010 paper by the same name as Dr Seyfried's book, is an excellent introduction to Dr. Seyfried's work:http://www.nutrition...m/content/7/1/7. A main point of the ketogenic approach is that cancer cells need voracious amounts of energy to continue their rapid growth and, unlike normal cells, they cannot use ketones for energy. So a state of ketosis deprives them of energy and either kills them or makes them more vulnerable to chemotherapy.

 

Here is the conclusion from the 2010 paper:

 

"Evidence is reviewed supporting a general hypothesis that cancer is primarily a disease of energy metabolism. All of the major hallmarks of the disease can be linked to impaired mitochondrial function. In order to maintain viability, tumor cells gradually transition to substrate level phosphorylation using glucose and glutamine as energy substrates.

 

While cancer causing germline mutations are rare, the abundance of somatic genomic abnormalities found in the majority of cancers can arise as a secondary consequence of mitochondrial dysfunction. Once established, somatic genomic instability can contribute to further mitochondrial defects and to the metabolic inflexibility of the tumor cells. Systemic metastasis is the predicted outcome following protracted mitochondrial damage to cells of myeloid origin. Tumor cells of myeloid origin would naturally embody the capacity to exit and enter tissues.

 

Two major conclusions emerge from the hypothesis; first that many cancers can regress if energy intake is restricted and, second, that many cancers can be prevented if energy intake is restricted. Consequently, energy restricted diets combined with drugs targeting glucose and glutamine can provide a rational strategy for the longer-term management and prevention of most cancers."

 

Although I do not have cancer, I too practice ketogenic CR with a low protein, moderate fat, and very complex carbohydrate approach. Dr. Seyfried is interested in this, since many patients have difficulty following standard ketogenic dietary regimens.

 

I hope my comments are helpful.

 

Paul

[Jedrzej]

Hi Paul,

 

Thank you for this post. Would you like to share a bit about your very complex carbohydrate diet? I'm very interested to know what kind of carbs you eat and how many grams of them on a daily basis.

 

Right now I'm trying to decide what approach would be better for me. Lower carbohydrates and higher fat intake or maybe opposite. I'm quite active so will keep my protein intake at 1.5g per 1 kg of lean body mass while doing lower crab. If I decide to go for lower fat and higher carbs, then I will have around 1g of proteins per 1 kg of lean mass.

 

I guess very complex carbs might keep hunger away better than fat.

[Paul McGlothin]

Hi Paul,

 

Thank you for this post. Would you like to share a bit about your very complex carbohydrate diet? I'm very interested to know what kind of carbs you eat and how many grams of them on a daily basis.

 

Right now I'm trying to decide what approach would be better for me. Lower carbohydrates and higher fat intake or maybe opposite. I'm quite active so will keep my protein intake at 1.5g per 1 kg of lean body mass while doing lower crab. If I decide to go for lower fat and higher carbs, then I will have around 1g of proteins per 1 kg of lean mass.

 

I guess very complex carbs might keep hunger away better than fat.

 

Hi Jedrzej,

 

Thanks for taking an interest in my post. The "very" complex carbs I enjoy often include barley and all kinds of lightly cook, low GI veggies -- broccoli, kale, cabbage, etc.Here is a picture of several CR recipes I enjoy as written up in this blog: A Calorie Restriction Diet: What that Really Means. One change since the photo was taken: we no longer eat eggs.

 

Using calorie restriction to describe this wonderful lifestyle is somewhat inaccurate these days. Although CR practitioners should still limit calories ( unless they have let their BMI drop too low), the main focus should be on activating longevity signaling in their cells. Discovering what those signals are has been a major accomplishment of calorie restriction scientists over the past 20 years. Now we know that results from blood tests such as fasting insulin and IGF-1 should guide dietary choices, if you hope to slow aging.

 

That is why I would be careful about eating so much protein. Excess protein often raises IGF-1 levels quite significantly, the very opposite of what you want.

 

One more suggestion, you mentioned avoiding hunger. Another approach is to welcome a little hunger into every day. The hunger hormone ghrelin, downregulates anabolic pathways-- an action associated with a host of benefits, such as improved cardiovascular health For example:

 

Ghrelin and the cardiovascular system.

 

Endocr Dev. 2013;25:83-90. doi: 10.1159/000346056. Epub 2013 Apr 25.

 

Isgaard J.

 

Snip: experimental and a limited number of clinical studies suggest a potential role for ghrelin in the treatment of congestive heart failure. So far, reported cardiovascular effects of growth hormone secretagogues and/or ghrelin include lowering of peripheral resistance, either direct at the vascular level and/or by modulating sympathetic nervous activity. Other observed effects indicate possible improvement of contractility and cardioprotective and anti-inflammatory effects both in vivo and in vitro. Copyright © 2013 S. Karger AG, Basel.

 

PMID:2365239

 

 

I wish you great good luck with your calorie restriction diet and much happiness.

 

Paul