食物繊維と大腸がん

＜食物繊維、特に穀物の大量摂取と大腸癌リスク減少との関連が示唆＞

25の前向き（コホート）研究とコホート内症例対照研究のシステマティックレビューの結果です

同じ食物繊維でも、野菜などに比べて、全粒穀物の方が大腸癌のリスクを減少させるようです。
（全粒穀物（3杯/日）で、大腸癌になる確率を0.83倍に減らせる）

糖尿病でも、穀類の食物繊維による血糖降下作用があるし、
もう少し穀類の食物繊維が推奨されてもいいかも・・

原文はこちら

http://www.bmj.com/content/343/bmj.d6617

（BMJ 2011; 343 doi: 10.1136/bmj.d6617 (Published 10 November 2011)

Abstract
Objective
To investigate the association between intake of dietary fibre and whole grains and risk of colorectal cancer.

Design
Systematic review and meta-analysis of prospective observational studies.

Data sources PubMed and several other databases up to December 2010 and the reference lists of studies included in the analysis as well as those listed in published meta-analyses.

Study selection Prospective cohort and nested case-control studies of dietary fibre or whole grain intake and incidence of colorectal cancer.

Results
25 prospective studies were included in the analysis.
The summary relative risk of developing colorectal cancer for 10 g daily of total dietary fibre (16 studies) was 0.90 (95% confidence interval 0.86 to 0.94, I2=0%), for fruit fibre (n=9) was 0.93 (0.82 to 1.05, I2=23%), for vegetable fibre (n=9) was 0.98 (0.91 to 1.06, I2=0%), for legume fibre (n=4) was 0.62 (0.27 to 1.42, I2=58%), and for cereal fibre (n=8) was 0.90 (0.83 to 0.97, I2=0%).
The summary relative risk for an increment of three servings daily of whole grains (n=6) was 0.83 (0.78 to 0.89, I2=18%).

Conclusion
A high intake of dietary fibre, in particular cereal fibre and whole grains, was associated with a reduced risk of colorectal cancer.
Further studies should report more detailed results, including those for subtypes of fibre and be stratified by other risk factors to rule out residual confounding.
Further assessment of the impact of measurement errors on the risk estimates is also warranted.