What is the best strategy to lower the level of the cancer-promoting growth hormone IGF-1?
Caloric Restriction vs. Plant-Based Diets
4.7/5 - (53 votes)
Hundreds of thousands of deaths in the United States every year are attributed to obesity, now overtaking smoking as perhaps the main preventable cause of illness and premature death. In particular, excess body fatness is an important cause of most cancers, according to a meta-analysis of studies done to date. For some cancers, about half of cases may be attributable to just being overweight or obese.
What’s the connection, though? Why do individuals who are obese have increased cancer risk? To answer this question we must consider the biochemical consequences of obesity, like IGF-1, insulin like growth factor one is a cancer-promoting growth hormone associated with a variety of common cancers in adults, as well as children. Kids who got cancer had about four times the levels of IGF-1 circulating in their bloodstream, whereas people growing up with abnormally low levels of IGF-1 don’t seem to get cancer at all. Zero cases of cancer out of 300 people.
I’ve talked about this cancer-proofing mutation, the role animal protein intake plays in boosting IGF-1 production from our liver, which may explain plant-based protection from cancer, and how plant-based one has to eat, but our liver is not the only tissue that produced IGF-1, fat cells produce IGF-1 too. That may help explain this 21st century cancer epidemic caused by obesity.
So of course drug companies have come up with a variety of IGF-1 blocking chemo agents, with cute names like figitumamab, but with not-so-cute side effects such as early fatal toxicities. So perhaps better to lower IGF-1 the natural way, by eating a plant-based diet, as vegan women and men have lower IGF-1 levels. Maybe, though, it’s just because they’re so skinny. The only dietary group that comes close to the recommended BMI of 21 to 23 were those eating strictly plant based diets, but so maybe it’s the weight loss that did it. Maybe we can eat whatever we want as long as we’re skinny.
To put that to the test, we’d have to find a group of people that eat meat—but are still as slim as vegans. Long-distance endurance runners, running an average of 48 miles a week for 21 years. If you run 50,000 miles you too can maintain a BMI of even a raw vegan. So what did they find?
If you look at blood concentrations of cancer risk factors among the groups of study subjects, you see that only the vegans had significantly lower levels of IGF-1. That makes sense given the role animal protein plays in boosting IGF-1 levels.
But the vegan group didn’t just eat less animal protein, they ate fewer calories. And in rodents at least, caloric restriction alone reduces IGF-1 levels. So OK, maybe low IGF-1 among vegans isn’t due to their slim figures, but maybe the drop in IGF-1 in vegans is effectively due to their unintentional calorie restriction. OK, so let’s compare vegans to people practicing severe calorie restriction.
They recruited vegans from the St. Louis Vegetarian Society, and went to the Calorie Restriction Society to find folks practicing severe caloric restriction. What did they find?
Only the vegan group got a significant drop in IGF-1. These findings demonstrate that, unlike in rodents, long-term severe caloric restriction in humans does not reduce the level of this cancer-promoting hormone. It’s not how many calories we eat, Protein intake may be the key determinant of circulating IGF-1 levels in humans, and so reduced protein intake may become an important component of anticancer and anti-aging dietary interventions.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.
- D L Katz. Facing the facelessness of public health: what's the public got to do with it? Am J Health Promot. 2011 Jul-Aug;25(6):361-2.
- G De Pergola, F Silverstris. Obesity as a major risk factor for cancer. J Obes. 2013;2013:291546.
- M Badr, T Hassan, S E Tarhony, W Metwally. Insulin-like growth factor-1 and childhood cancer risk. Oncol Lett. 2010 Nov;1(6):1055-1059.
- G K Reeves, K Pirie, V Beral, J Green, E Spencer, D Bull, Million Women Study Collaboration. Cancer incidence and mortality in relation to body mass index in the Million Women Study: cohort study. BMJ. 2007 Dec 1;335(7630):1134.
- A G Renehan, M Tyson, M Egger, R F Heller, M Zwahlen. Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. Lancet. 2008 Feb 16;371(9612):569-78.
- A G Renehan, M Zwahlen, C Minder, S T O’Dwyer, S M Shalet, M Egger. Insulin-like growth factor (IGF)-I, IGF binding protein-3, and cancer risk: systematic review and meta-regression analysis. Lancet. 2004 Apr 24;363(9418):1346-53.
- S C Larsson, A Wolk. Excess body fatness: an important cause of most cancers. Lancet. 2008 Feb 16;371(9612):536-7.
- O Shevah, Z Laron. Patients with congenital deficiency of IGF-I seem protected from the development of malignancies: a preliminary report. Growth Horm IGF Res. 2007 Feb;17(1):54-7.
- U N Das, When less is adequate: protein and calorie restriction boosts immunity and possibly, longevity--but how and why? Nutrition. 2009 Sep;25(9):892-5.
- L Fontana, S Klein, J O Holloszy. Long-term low-protein, low-calorie diet and endurance exercise modulate metabolic factors associated with cancer risk. Am J Clin Nutr. 2006 Dec;84(6):1456-62.
- M F McCarty. A low-fat, whole-food vegan diet, as well as other strategies that down-regulate IGF-I activity, may slow the human aging process. Med Hypotheses. 2003 Jun;60(6):784-92.
- N E Allen, P N Appleby, G K Davey, R Kasks, S Rinaldi, T J Key. The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans. Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1441-8.
- R L Westley, F E May. A twenty-first century cancer epidemic caused by obesity: the involvement of insulin, diabetes, and insulin-like growth factors. Int J Endocrinol. 2013;2013:632461.
- Y Goto, I Sekine, M Tanioka, T Shibata, C Tanai, H Asahina, H Nokihara, N Yomamoto, H Kunitoh, Y Che, H Kikkawa, E Ohki, T Tamura. Figitumumab combined with carboplatin and paclitaxel in treatment-naïve Japanese patients with advanced non-small cell lung cancer. Invest New Drugs. 2012 Aug;30(4):1548-56.
- M Honhai, Z Tiehong, S Hongchang, C Honxin, D Jiajun. The adverse events profile of anti-IGF-1R monoclonal antibodies in cancer therapy. British Journal of Clinical Pharmacology. 2014 June;77(6):917–928.
- S E Dunn, F W Kari, J French, J R Leininger, G Travlos, R Wilson, J C Barrett. Dietary restriction reduces insulin-like growth factor I levels, which modulates apoptosis, cell proliferation, and tumor progression in p53-deficient mice. Cancer Res. 1997 Nov 1;57(21):4667-72.
- L Fontana, E P Weiss, D T Villareal, S Klein, and J O Holloszy. Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans. Aging Cell. Oct 2008; 7(5): 681–687.
- L Fontana, E P Weiss, D T Villareal, S Klein, and J O Holloszy. Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans. Aging Cell. Oct 2008; 7(5): 681–687.
Images thanks to Marcelo Nava, Paul Boxley, and Jennifer via Flickr.
Hundreds of thousands of deaths in the United States every year are attributed to obesity, now overtaking smoking as perhaps the main preventable cause of illness and premature death. In particular, excess body fatness is an important cause of most cancers, according to a meta-analysis of studies done to date. For some cancers, about half of cases may be attributable to just being overweight or obese.
What’s the connection, though? Why do individuals who are obese have increased cancer risk? To answer this question we must consider the biochemical consequences of obesity, like IGF-1, insulin like growth factor one is a cancer-promoting growth hormone associated with a variety of common cancers in adults, as well as children. Kids who got cancer had about four times the levels of IGF-1 circulating in their bloodstream, whereas people growing up with abnormally low levels of IGF-1 don’t seem to get cancer at all. Zero cases of cancer out of 300 people.
I’ve talked about this cancer-proofing mutation, the role animal protein intake plays in boosting IGF-1 production from our liver, which may explain plant-based protection from cancer, and how plant-based one has to eat, but our liver is not the only tissue that produced IGF-1, fat cells produce IGF-1 too. That may help explain this 21st century cancer epidemic caused by obesity.
So of course drug companies have come up with a variety of IGF-1 blocking chemo agents, with cute names like figitumamab, but with not-so-cute side effects such as early fatal toxicities. So perhaps better to lower IGF-1 the natural way, by eating a plant-based diet, as vegan women and men have lower IGF-1 levels. Maybe, though, it’s just because they’re so skinny. The only dietary group that comes close to the recommended BMI of 21 to 23 were those eating strictly plant based diets, but so maybe it’s the weight loss that did it. Maybe we can eat whatever we want as long as we’re skinny.
To put that to the test, we’d have to find a group of people that eat meat—but are still as slim as vegans. Long-distance endurance runners, running an average of 48 miles a week for 21 years. If you run 50,000 miles you too can maintain a BMI of even a raw vegan. So what did they find?
If you look at blood concentrations of cancer risk factors among the groups of study subjects, you see that only the vegans had significantly lower levels of IGF-1. That makes sense given the role animal protein plays in boosting IGF-1 levels.
But the vegan group didn’t just eat less animal protein, they ate fewer calories. And in rodents at least, caloric restriction alone reduces IGF-1 levels. So OK, maybe low IGF-1 among vegans isn’t due to their slim figures, but maybe the drop in IGF-1 in vegans is effectively due to their unintentional calorie restriction. OK, so let’s compare vegans to people practicing severe calorie restriction.
They recruited vegans from the St. Louis Vegetarian Society, and went to the Calorie Restriction Society to find folks practicing severe caloric restriction. What did they find?
Only the vegan group got a significant drop in IGF-1. These findings demonstrate that, unlike in rodents, long-term severe caloric restriction in humans does not reduce the level of this cancer-promoting hormone. It’s not how many calories we eat, Protein intake may be the key determinant of circulating IGF-1 levels in humans, and so reduced protein intake may become an important component of anticancer and anti-aging dietary interventions.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.
- D L Katz. Facing the facelessness of public health: what's the public got to do with it? Am J Health Promot. 2011 Jul-Aug;25(6):361-2.
- G De Pergola, F Silverstris. Obesity as a major risk factor for cancer. J Obes. 2013;2013:291546.
- M Badr, T Hassan, S E Tarhony, W Metwally. Insulin-like growth factor-1 and childhood cancer risk. Oncol Lett. 2010 Nov;1(6):1055-1059.
- G K Reeves, K Pirie, V Beral, J Green, E Spencer, D Bull, Million Women Study Collaboration. Cancer incidence and mortality in relation to body mass index in the Million Women Study: cohort study. BMJ. 2007 Dec 1;335(7630):1134.
- A G Renehan, M Tyson, M Egger, R F Heller, M Zwahlen. Body-mass index and incidence of cancer: a systematic review and meta-analysis of prospective observational studies. Lancet. 2008 Feb 16;371(9612):569-78.
- A G Renehan, M Zwahlen, C Minder, S T O’Dwyer, S M Shalet, M Egger. Insulin-like growth factor (IGF)-I, IGF binding protein-3, and cancer risk: systematic review and meta-regression analysis. Lancet. 2004 Apr 24;363(9418):1346-53.
- S C Larsson, A Wolk. Excess body fatness: an important cause of most cancers. Lancet. 2008 Feb 16;371(9612):536-7.
- O Shevah, Z Laron. Patients with congenital deficiency of IGF-I seem protected from the development of malignancies: a preliminary report. Growth Horm IGF Res. 2007 Feb;17(1):54-7.
- U N Das, When less is adequate: protein and calorie restriction boosts immunity and possibly, longevity--but how and why? Nutrition. 2009 Sep;25(9):892-5.
- L Fontana, S Klein, J O Holloszy. Long-term low-protein, low-calorie diet and endurance exercise modulate metabolic factors associated with cancer risk. Am J Clin Nutr. 2006 Dec;84(6):1456-62.
- M F McCarty. A low-fat, whole-food vegan diet, as well as other strategies that down-regulate IGF-I activity, may slow the human aging process. Med Hypotheses. 2003 Jun;60(6):784-92.
- N E Allen, P N Appleby, G K Davey, R Kasks, S Rinaldi, T J Key. The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans. Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1441-8.
- R L Westley, F E May. A twenty-first century cancer epidemic caused by obesity: the involvement of insulin, diabetes, and insulin-like growth factors. Int J Endocrinol. 2013;2013:632461.
- Y Goto, I Sekine, M Tanioka, T Shibata, C Tanai, H Asahina, H Nokihara, N Yomamoto, H Kunitoh, Y Che, H Kikkawa, E Ohki, T Tamura. Figitumumab combined with carboplatin and paclitaxel in treatment-naïve Japanese patients with advanced non-small cell lung cancer. Invest New Drugs. 2012 Aug;30(4):1548-56.
- M Honhai, Z Tiehong, S Hongchang, C Honxin, D Jiajun. The adverse events profile of anti-IGF-1R monoclonal antibodies in cancer therapy. British Journal of Clinical Pharmacology. 2014 June;77(6):917–928.
- S E Dunn, F W Kari, J French, J R Leininger, G Travlos, R Wilson, J C Barrett. Dietary restriction reduces insulin-like growth factor I levels, which modulates apoptosis, cell proliferation, and tumor progression in p53-deficient mice. Cancer Res. 1997 Nov 1;57(21):4667-72.
- L Fontana, E P Weiss, D T Villareal, S Klein, and J O Holloszy. Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans. Aging Cell. Oct 2008; 7(5): 681–687.
- L Fontana, E P Weiss, D T Villareal, S Klein, and J O Holloszy. Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans. Aging Cell. Oct 2008; 7(5): 681–687.
Images thanks to Marcelo Nava, Paul Boxley, and Jennifer via Flickr.
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Title
Caloric Restriction vs. Plant-Based Diets
LicenseCreative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Content URLDoctor's Note
That same data set that compared plant eaters to marathon runners was also featured in Hibiscus Tea vs. Plant-Based Diets for Hypertension and Arteries of Vegans vs. Runners.
More on the caloric consumption and longevity:
- Why Do We Age?
- Caloric Restriction vs. Animal Protein Restriction
- Prevent Cancer From Going on TOR
- Saving Lives by Treating Acne with Diet
What exactly is IGF-1 and what is the relationship to animal protein consumption? View my 9-part video series:
- IGF-1 as One-Stop Cancer Shop
- Cancer-Proofing Mutation
- The Answer to the Pritikin Puzzle
- How Plant-Based to Lower IGF-1?
- Protein Intake & IGF-1 Production
- Animalistic Plant Proteins
- Too Much Soy May Neutralize Benefits
- How Much Soy Is Too Much?
- Plant-Based Bodybuilding
Update: I have a couple of newer videos on caloric restriction. See:
- The Benefits of Calorie Restriction for Longevity
- Potential Pitfalls of Calorie Restriction
-
Diet and Caloric Restriction for Longevity—The Monkey Trials
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