The Sourdough School

BALM – Proven as one of the healthiest approaches to bread in the world.

Based in the walled gardens of Dr. Vanessa Kimbell's beautiful Victorian home in rural Northamptonshire, UK, we tutor individuals and train bakers and healthcare professionals in Baking as Lifestyle Medicine (BALM). Personalising bread to your lifestyle, gut microbiome, and unique genetics for optimal health—tailoring fermentation, fibre, and diversity so that your daily bread becomes the foundation of your health.

+44(0)7813308301
[email protected]
Follow on Instagram
  • Facebook
  • Instagram
  • Pinterest
  • Twitter

Student Login

Schedule a Call to Learn More

Navigation
  • Home
    • About The Sourdough School
    • Contact Us & FAQ
    • Request a Callback
    • Practical Information
    • The Team
    • A Social Enterprise
    • General FAQ’s about The School
    • Contributors & Guest Tutors
    • What Our Students Say
    • Login
  • Courses
    • Priority Access: Join the Waiting List
    • Workshops
    • Bake For Health Retreat
    • Tuscan Retreat
    • Diploma
  • Assessments
    • Bread & Health Assessment
    • Gut Health Assessment
    • Nutrigenomic Assessment
  • Our Approach
    • Baking as Lifestyle Medicine (BALM)
    • 12 Week Student Support Pack
    • Bread as Preventative Health
    • Personalising Bread Using Nutrigenetics
    • Training Bakers & Healthcare Professionals
    • Diversity Bread™
    • Prove it – The Case Studies
    • BALM & Bread in The Blue Zone
    • Proven: Bread Podcast
  • Admissions
    • Request a callback
    • Location, Opening Hours & Course Days & Times
    • Reviews
  • Shop
    • Our Flour and Ingredients
    • Our Books
    • Equipment
    • Flours From Farmers Directory
    • Add Farmer to the Directory

606 - ‘Whole Grains, Refined Grains, and Cancer Risk: A Systematic Review of Meta-Analyses of Observational Studies’. Nutrients. 12(12), 3756

Reference Number: 606

Year: 2020

Authors: Glenn A Gaesser

Link: Link to original paper

Health: Cancer

Nutrition: Fibre | Whole grain

Summary

Abstract

PubMed, Web of Science, and the Cochrane Database of Systematic Reviews were searched for meta-analyses that provided risk estimates (±95% confidence intervals) for associations between intakes of whole and refined grains and risk of total and site-specific cancer. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Only meta-analyses that included whole grains and refined grains as separate food groups, and not as part of dietary patterns, were included. A total of 17 publications were identified that met inclusion criteria. Within these, results from a total of 54 distinct meta-analyses were reported for whole grains and 5 meta-analyses for refined grains. For total cancer mortality, 7 meta-analyses of cohort studies indicated that whole grain intake was associated with 6% to 12% lower risk in comparison of highest vs. lowest intake groups, and 3% to 20% lower risk for doses ranging from 15 to 90 g/day. For site-specific cancers, meta-analyses indicated that whole grain intake was consistently associated with lower risks of colorectal, colon, gastric, pancreatic, and esophageal cancers. Limited data were available for refined grains, with only 4 publications providing risk estimates, and only 1 of the meta-analyses included more than 3 studies. High intake of refined grains was associated with increased risk of colon and gastric cancer. By contrast, in the only dose-response meta-analysis, each 90 g/day consumption of refined grains was associated with a 6% lower risk of total cancer. In addition to the limited number of published meta-analyses on refined grains, results were also weakened due to the fact that refined grains were frequently defined to include both staple grain foods and indulgent grain foods, and the majority of studies included in the meta-analyses provided no specific definition of refined grains. Overall, meta-analyses of cohort and case-control studies consistently demonstrate that whole grain intake is associated with lower risk of total and site-specific cancer, and support current dietary recommendations to increase whole grain consumption. By contrast, the relationship between refined grain intake and cancer risk is inconclusive.

Take a look at our courses at The Sourdough School

All reasonable care is taken when advising about health aspects of bread, but the information that we share is not intended to take the place of treatment by a qualified medical practitioner. You must seek professional advice if you are in any doubt about any medical condition. Any application of the ideas and information contained on this website is at the reader's sole discretion and risk.

  • Facebook
  • Instagram
  • Pinterest
  • Twitter

Email Sign Up

BANT Member
Lifecode GX

Terms and Conditions | Privacy Policy
Copyright © 2025 Vanessa Kimbell
Call +44 (0)7813308301 | Email [email protected]
Registered in England & Wales: 08412236
Website by Callia Web