Understanding Cancer: Causes, Treatment & Prevention | Drs. Urvi Shah & Neil Iyengar

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Different dietary camps often make bold claims regarding the impact of lifestyle on cancer prevention and treatment. Many people diagnosed with cancer will ask themselves whether it is their “fault”, too. We’ve touched on cancer many times on The Proof, but in Episode #254, I sit down with Dr Urvi Shah and Dr Neil Iyengar for the show’s first conversation dedicated to understanding cancer.

“Nutrition is, indeed, a powerful tool. How we use it depends on what the goals are and what the current status [of the patient] is.” – Dr Neil Iyengar

Dr Iyengar and Dr Shah both have a keen interest in the role of lifestyle in cancer development and treatment, having recently published a review titled Plant-Based and Ketogenic Diets As Diverging Paths to Address Cancer. In today’s conversation, we take a closer look at what cancer is, how it develops, and how lifestyle factors come into the picture.

“A lot of the large population studies from the US, UK, and France show that plant-forward diets or plant-based diets are associated with reduced risk of developing cancer overall and also specific cancers… it’s not just the direct effect, but the indirect effect of being able to tolerate treatments well.” – Dr Urvi Shah

Drs Urvi Shah and Neil Iyengar are board-certified oncologists at Memorial Sloan Kettering Cancer Center in New York. They are both actively involved in nutrition research, looking at how lifestyle interventions can affect cancer-related outcomes. Dr Shah specialises in treating patients with multiple myeloma, and Dr Iyengar specialises in treating patients with breast cancer. Together, Dr Shah and Dr Iyengar hold a wealth of knowledge on cancer, with both hands-on experience treating patients and as researchers.

“We also know that weight changes and shifting into excess adiposity or obesity can unfortunately decrease the efficacy of some of our cancer treatments. It has been estimated that about 1 in 6 female cancer deaths are related to obesity, and 1 in 7 male cancer deaths are related to obesity.” – Dr Neil Iyengar

In Episode #254, you will learn about pre-cancerous cells, our bodies’ surveillance systems to prevent cancer, and the hallmark features of cancer. This episode is packed with practical information on the intersection between lifestyle factors and cancer: we identify the lifestyle habits that can reduce cancer, treat it, and prevent its recurrence. We also weigh up plant-based and ketogenic diets for cancer treatment and prevention, and the clinical trials currently underway looking at nutrition and cancer.

Specifically, we discuss:

  • Intro (00:00)
  • Cancer and precancerous cells (06:51)
  • Genetics and cancer risk (20:58)
  • Obesity and cancer risk (24:30)
  • Modifiable factors and reducing recurrence risk (36:44)
  • The role of nutrition in cancer treatment (47:34)
  • Plant-based diet vs ketogenic diet (51:50)
  • Dr. Neil investigates the effects of plant-based diets and exercise on breast cancer  (1:13:12)
  • Soy, dairy, protein, and cancer risk (1:17:04)
  • Unprocessed red meat and colorectal cancer (1:30:52)
  • Organic foods vs conventional produce (1:37:10)
  • Ultra-processed food and cancer risk (1:40:52)
  • Alcohol intake and exercise recommendation (1:43:11)
  • Strong predictors of breast cancer (1:49:33)
  • Stress and sleep  (1:51:56)
  • Importance of screening (1:52:46)
  • Outro (2:01:54)

I hope you find this episode’s focus on cancer illuminating. Drs Shah and Iyengar bring an evidence-based yet practical lens to this complex topic, and you will no doubt finish this episode with a better understanding of how to reduce your risk of cancer in the future.

You can connect with Dr Neil Iyengar on Twitter, and learn more about him here. Connect with Dr Urvi Shah on InstagramTwitter, and LinkedIn, and learn more about her here.

The best way to support the show is to use the products and services offered by our sponsors. To check them out, and enjoy great savings, visit theproof.com/friends.

Enjoy, friends.


More about Dr Neil Iyengar

Dr. Neil Iyengar is a board-certified Medical Oncologist and clinical-translational researcher at Memorial Sloan Kettering Cancer Center (MSKCC) where he specializes in the care of patients with breast cancer. He also holds joint research appointments at the Rockefeller University Center for Clinical and Translational Science and Weill Cornell Medicine in New York. Dr. Iyengar received his undergraduate and medical degrees from the University of Illinois at Chicago accelerated degree program where he graduated with the College’s highest honours (University Scholar). He completed residency training in Internal Medicine at the University of Chicago Medical Center followed by a fellowship in medical oncology and haematology at MSKCC. He now holds a faculty position as an Associate Attending the Breast Medicine Service at MSKCC.

Dr. Iyengar’s research program investigates interventions to improve metabolic health as a strategy to reduce breast cancer risk and mortality. His group is testing the anti-cancer effects of structured exercise and nutritional interventions in people at high risk or diagnosed with breast cancer. Dr. Iyengar’s research is also investigating the use of drugs that treat metabolic disorders, such as diabetes and obesity, to improve the effectiveness of cancer therapies. In an effort to rapidly translate this work, Dr. Iyengar also leads the Healthy Living Program, a novel cancer care model that aims to translate research findings from lifestyle intervention trials into clinical practice during and after cancer therapy. His work has been recognized and awarded by several organizations, including research grants from the National Cancer Institute, the American Cancer Society, the Breast Cancer Research Foundation, Conquer Cancer the ASCO Foundation, and others. He has published numerous original research articles and has been an invited speaker at several international conferences.

More about Dr Urvi Shah

Dr. Urvi Shah is a haematologist, oncologist, and physician-scientist. She holds faculty positions as an Assistant Attending on the Myeloma Service at Memorial Sloan Kettering Cancer Center (MSK) and Assistant Professor of Medicine at Weill Cornell Medicine. She completed fellowships in haematology/oncology at Montefiore Medical Center, and in cancer immunotherapy by MSK and the Parker Institute for Cancer Immunotherapy in New York. She is board certified in Internal Medicine, Hematology and Medical Oncology. She is also a member of the Junior Faculty Council.

Her own personal experience being treated for Hodgkin lymphoma as an oncology fellow in 2016 led to her interest in studying the role of modifiable risk factors in cancer. She is studying the link between nutrition and cancer most specifically myeloma via its effect on metabolic markers, immune system, and the microbiome. Her research program includes clinical retrospective projects, clinical prospective trials, and translational collaborative research. She is the principal investigator (PI) of several investigator-initiated trials. She opened the first pilot nutrition trial in plasma cell disorders to date (NUTRIVENTION; NCT04920084) in 2021 that completed enrollment. She has 2 other NUTRIVENTION studies currently enrolling (NCT05640843, NCT04497961).

Dr. Shah has been supported by career development awards from the National Cancer Institute Paul Calabresi K12, International Myeloma Society and American Society of Hematology. Her research is also funded by the Health Tree Foundation, Paula and Rodger Riney Foundation and Allen Foundation. Additionally, she received the American Society of Hematology Clinical Research Training Institute Award, ECOG ACRIN Young Investigator Translational Research Award, Henry Moses Prize and Celgene Future Leaders in Hematology Award. She is currently pursuing a Master’s in Science degree through the Gerstner Sloan Kettering Graduate School of Biomedical Sciences. Dr. Shah has published first author papers prominent journals such as Blood and Clinical Cancer Research amongst others and has been an invited speaker internationally.

Supporting studies

  • Association of Frequency of Organic Food Consumption With Cancer Risk: Findings From the NutriNet-Santé Prospective Cohort Study PMID: 30422212
  • Estimation of cancer risks and benefits associated with a potential increased consumption of fruits and vegetables • PMID: 22981907
  • Nutrition Interventions in Rheumatoid Arthritis: The Potential Use of Plant-Based Diets. A Review • PMID: 31552259
  • Plant-Based and Ketogenic Diets As Diverging Paths to Address Cancer: A Review • PMID: 35797039
  • Sustained Minimal Residual Disease Negativity in Multiple Myeloma is Associated with Stool Butyrate and Healthier Plant-Based Diets • PMID: 36170461
  • Nutrition perceptions, needs and practices among patients with plasma cell disorders • PMID: 35443718
  • Dietary and microbiome evidence in multiple myeloma and other plasma cell disorders • PMID: 36997677
  • Association of Frequency of Organic Food Consumption With Cancer Risk: Findings From the NutriNet-Santé Prospective Cohort Study • PMID: 30422212
  • Body Fatness and Cancer–Viewpoint of the IARC Working Group • PMID: 27557308
  • Dietary fiber and probiotics influence the gut microbiome and melanoma immunotherapy response • PMID: 34941392
  • Carcinogenicity of consumption of red and processed meat • PMID: 26514947

Additional resources

  • A Study of the Body’s Response to Exercise and a Plant-Based Diet in Overweight Postmenopausal Women with Breast Cancer • MSKCC
  • Cancer Prevention Recommendations • World Cancer Research Fund International
  • Meat, fish, dairy and cancer risk • World Cancer Research Fund International
  • New Dimensions in Cancer Biology: Updated Hallmarks of Cancer Published • AACR
  • Preventing High Blood Sugar with Ketogenic or Low Carbohydrate Diets or Medication in People Being Treated for Metastatic Breast Cancer • MSKCC
  • A Study Comparing a Plant-Based Diet with Supplements and Placebo in People with Monoclonal Gammopathy of Undetermined Significance or Smoldering Multiple Myeloma • MSKCC
  • A Pilot Plant Based Dietary Intervention in MGUS and SMM Patients with Elevated BMI Is Feasible and Associated with Improvements in Metabolic and Microbiome Biomarkers of Progression • Ash Publications
  • How to Prevent Cancer: 10 Recommendations • AICR

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