Format

Send to

Choose Destination
JAMA Oncol. 2016 Sep 1;2(9):1146-53. doi: 10.1001/jamaoncol.2016.0740.

Association of Physical Activity by Type and Intensity With Digestive System Cancer Risk.

Author information

1
Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, Massachusetts.
2
Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
3
Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, Massachusetts3Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts.
4
Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, Massachusetts5Department of Medicine, Harvard Medical School, Boston, Massachusetts.
5
Department of Medicine, Harvard Medical School, Boston, Massachusetts6Department of Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.
6
Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, Massachusetts2Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts3Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts5Department of Medicine, Harvard Medical School, Boston, Massachusetts.

Abstract

IMPORTANCE:

Accumulating evidence indicates that common carcinogenic pathways may underlie digestive system cancers. Physical activity may influence these pathways. Yet, to our knowledge, no previous study has evaluated the role of physical activity in overall digestive system cancer risk.

OBJECTIVE:

To examine the association between physical activity and digestive system cancer risk, accounting for amount, type (aerobic vs resistance), and intensity of physical activity.

DESIGN, SETTING, AND PARTICIPANTS:

A prospective cohort study followed 43 479 men from the Health Professionals Follow-up Study from 1986 to 2012. At enrollment, the eligible participants were 40 years or older, were free of cancer, and reported physical activity. Follow-up rates exceeded 90% in each 2-year cycle.

EXPOSURES:

The amount of total physical activity expressed in metabolic equivalent of task (MET)-hours/week.

MAIN OUTCOMES AND MEASURES:

Incident cancer of the digestive system encompassing the digestive tract (mouth, throat, esophagus, stomach, small intestine, and colorectum) and digestive accessory organs (pancreas, gallbladder, and liver).

RESULTS:

Over 686 924 person-years, we documented 1370 incident digestive system cancers. Higher levels of physical activity were associated with lower digestive system cancer risk (hazard ratio [HR], 0.74 for ≥63.0 vs ≤8.9 MET-hours/week; 95% CI, 0.59-0.93; P value for trend = .003). The inverse association was more evident with digestive tract cancers (HR, 0.66 for ≥63.0 vs ≤8.9 MET-hours/week; 95% CI, 0.51-0.87) than with digestive accessary organ cancers. Aerobic exercise was particularly beneficial against digestive system cancers, with the optimal benefit observed at approximately 30 MET-hours/week (HR, 0.68; 95% CI, 0.56-0.83; P value for nonlinearity = .02). Moreover, as long as the same level of MET-hour score was achieved from aerobic exercise, the magnitude of risk reduction was similar regardless of intensity of aerobic exercise.

CONCLUSIONS AND RELEVANCE:

Physical activity, as indicated by MET-hours/week, was inversely associated with the risk of digestive system cancers, particularly digestive tract cancers, in men. The optimal benefit was observed through aerobic exercise of any intensity at the equivalent of energy expenditure of approximately 10 hours/week of walking at average pace. Future studies are warranted to confirm our findings and to translate them into clinical and public health recommendation.

PMID:
27196375
PMCID:
PMC5846204
DOI:
10.1001/jamaoncol.2016.0740
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center