The Science Nook on Prevention

The mounting body of cancer research is compelling as it relates to prevention.  Research is showing that proactively following healthy daily behaviors will significantly work to reduce the risk of cancer. The American Institute of Cancer Research (AICR) estimates that approximately 1/3 of the most common cancers in the US are preventable through a healthy diet, physical activity, and weight management [i]. While there are many factors that affect cancer risk, such as genetics, age related factors and biological factors, following the recommended healthy lifestyle guidelines is an important piece of the puzzle to achieving and maintaining a cancer-fighting lifestyle.  

Here we look at two recent studies that provide useful information on the impact of nutrition and exercise on cancer prevention.  The impact of regular exercise and consistent consumption of a high fiber diet in reducing the risk for cancer while enhancing overall longevity are discussed.

 

Study 1

Association of Leisure-Time Physical Activity With Risk of 26 Types of Cancer in 1.44 Million Adults

 

Journal: JAMA Internal Medicine

 

Higher amounts of moderately intense physical activity, even those activities incorporated into daily activities, like chores, reduces the incidence of 13 of the 26 cancers and promotes a 7% reduction in risk for total cancer.  This finding was established in a very large 2016 meta-analysis of 12 prospective cohort studies incorporating 1.44 million cancer-free participants   Physical activity has long been established with lower risk of heart disease and premature death within the general population. Moderate intensity exercise may also reduce several different cancers [ii][iii].

In the study, each participant filled out self-reporting questionnaires specifying the amount and type of their weekly leisure-time physical activity, which is defined as any activity that is done by an individual which improves or maintains fitness.  After being followed for a median of 11 years, the relationship between the amount and intensity of weekly leisure time activity to the incidence of 26 different cancer types was examined [iv][v].

It was found that those exercising the most out of the group reaped the greatest benefits.  This highly active group showed a 20% reduction in the risk of 7 cancers (esophageal, liver, lung, kidney, gastric, endometrial and leukemia) and a 10-20% reduction in the risk of 6 additional cancers (myeloma, colon, head and neck, rectal, bladder, and breast).

 

For the patient and caregiver

Taking part in consistent exercise can surely help to prevent cancer.  For those who have been diagnosed, exercise is also a potent tool.  It helps to prevent recurrences later on into survivorship, may reduce the side effects of treatment like fatigue, and can improve treatment outcomes.  When working to fit movement into the daily routine, keep a log or mental checklist to determine when you are feeling motivated to move around.  Modify exercises to work around your treatment plan; a certified trainer can be huge help in this process.  There are many ways to sneak physical activity into your journey to help reap the benefits seen in this study.

Try these out:

  • walking the stairs instead of taking the elevator or escalator
  • parking further away in the parking lot
  • using a standing desk
  • suggesting and scheduling walk meetings during the work day
  • having fun while cleaning and cooking.  Dancing is a joyful way to get the heart rate up.
  • trying out free exercise videos on YouTube. Choose one to suit your mood.

 

For the healthcare team

Support your patient mentally and physically by encouraging physical activity throughout their treatment process. If the patient is new to exercise, start slow (even 10 minutes per day) and gradually work up to a goal of 30 minutes per day, all the while personalizing the approach to their treatment schedules and their medical history and motivation.

 

Study 2

Association Between Dietary Fiber and Lower Risk of All-Cause Mortality: A Meta-Analysis of Cohort Studies

 

Journal: American Journal of Epidemiology

 

Higher fiber diets can equate to significant risk reductions for the most common cancers, according to this meta-analysis of 17 prospective cohort studies incorporating 982,411 participants [vi].  Dietary fiber has long been established as an important component of a healthy diet. Fiber’s main role is often seen to improve digestive health and reduce constipation. The newer main role?  Preventing cancer.  

Findings suggest that fiber intake may significantly reduce the risk of death by 10% for every 10 gram/day increase. These results are consistent with previous studies showing that every 10-g/day increase in dietary fiber intake was associated with 5%, 10%, and 44% decreases in the risks of cancers of breast, colorectum, and stomach, respectively [vii][viii][ix].

 

For the patient and caregiver

Being mindful about incorporating fiber rich foods with each meal is important and may be protective against cancer.  Some excellent options are whole grains, fruits and vegetables (preferably with the peel), legumes, and nuts and seeds.  For ideas, look for delicious recipe ideas on our website.  For foods with packaging, read the nutrition label. Good sources of fiber contain at least 2.5 grams per serving and excellent sources contain 5 or more grams per serving.  Make gradual increases to avoid indigestion and stay hydrated to ensure adequate breakdown of the fiber to avoid gut discomfort.  Aim for a minimum of 25-30 grams of fiber/day  and gradually increase to 35-40 grams/day if tolerated. Talk to your RD if you are experiencing diarrhea or constipation and to get advice on the best type of high fiber foods appropriate for you during your cancer journey.

 

For the healthcare team

Ensure your patient is meeting their dietary fiber needs. A 24-hour dietary recall will help to give direction.  Provide a list of high fiber food sources and brainstorm strategies to incorporate more in their meals, such as oatmeal instead of raisin bran during the breakfast meal.  Always work around treatment side effects, and make sure to realize that, based on the side effects of the disease, there may be times when higher fiber intake is not recommended.

 
 
References
[i] In brief: preventing cancer by the numbers. American Institute for Cancer Research (AICR). Accessed at: http://www.aicr.org/cancer-research-update/2012/may_16_2012/cru-in-brief-preventing.html?referrer=https://www.google.com/
[ii] Arem H, Moore SC, Patel A, et al. Leisure time physical activity and mortality: a detailed pooled analysis of the dose-response relationship.JAMA Intern Med. 2015;175(6):959-967.
[iii] World Cancer Research Fund, American Institute for Cancer Research. Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective. Washington, DC: American Institute for Cancer Research; 2007.
[iv] Moore SC, et al. Leisure-time physical activity and risk of 26 types of cancer in 1.44 million adults. JAMA Internal Medicine. May 16, 2016.
[v] Kushi LH Doyle, C Mcullough M et al. American Cancer Society Guidelines on nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity. CA Cancer J Clin. 2012; 62 (1) : 30-67.
[vi] Yang Yang, Long-Gang Zhao, Qi-Jun Wu, Xiao Ma, Yong-Bing Xiang; Association Between Dietary Fiber and Lower Risk of All-Cause Mortality: A Meta-Analysis of Cohort Studies.American Journal of Epidemiology. Volume 181, Issue 2, 15 January 2015, Pages 83–91
[vii] Aune D Chan DS Greenwood DC et al.   Dietary fiber and breast cancer risk: a systematic review and meta-analysis of prospective studies. Ann Oncol.  2012; 23 (6): 1394-1402.
[viii] Aune D Chan DS Lau R et al.   Dietary fibre, whole grains, and risk of colorectal cancer: systematic review and dose-response meta-analysis of prospective studies. BMJ.  2011;343: d6617
[iv] Zhang Z Xu G Ma M et al.   Dietary fiber intake reduces risk for gastric cancer: a meta-analysis. Gastroenterology.  2013 ;145 (1): 113-120.e3
Tasha Feilke MS, RD, CSO, LDN

Clinical Operations

Tasha is a registered dietitian as well as a Massachusetts licensed dietitian. She obtained her Master’s of Science in Nutrition at Bastyr University in Washington state and completed her dietetic internship at San Francisco State University. She has worked in various inpatient, outpatient,and community settings in Seattle and the Bay Area since 2005. Prior to her move to Boston in 2014 she worked exclusively at the Alta Bates Comprehensive Cancer Center in Berkeley, CA. Tasha is passionate about motivating people to reach their fitness and nutrition goals throughout all stages and conditions of life and believes food can truly serve as medicine.

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