Eating Well

Are you a health professional?

This section does not replicate the other information on this page but provides additional details or context most relevant to professionals.

Counseling patients

Do you have concerns about introducing lifestyle changes to your patients? 

• I don’t know if there’s evidence that this really will make a difference.
• Will I make my patients feel guilty for eating poorly, being overweight, and so on?
• If I bring this up, I won’t have time to adequately counsel them.
• I don’t have the knowledge and resources to support them through making lifestyle changes.

You’re not alone in these concerns,¹Stump TK, Robinson JK et al. Physicians’ perspectives on medication adherence and health promotion among cancer survivors. Cancer. 2019 Dec 1;125(23):4319-4328. and you don’t have to do this alone. Of greatest importance is that you assess your patient’s lifestyle, sensitively introduce the topic of making lifestyle changes and why it’s important, then refer them to resources to support them in making lifestyle changes.

Even a short, focused conversation can lead to changes. Nutritional and dietary advice can help your patients, especially regarding quality of life.²Zhang F, Jin Y, Qiang W. The effects of dietary advice on malnutrition in Cancer patients: a systematic review and meta-analysis. Supportive Care in Cancer. 2020 Apr;28(4):1579-1585. Many practitioners have found that patients who feel better tend to tolerate and complete difficult treatments and may be more compliant with other therapies.

We’ve gathered the clinical evidence for you in How can Eating Well help you? What the research says › plus notable preclinical evidence on this page. And we’ve started a list of recommendations and resources for you to share with your patients in Making changes › You may want to expand on that with a list of good local resources to refer your patients to.

We provide some resources to help you get started engaging your patients in conversations about lifestyle changes in general and specifically Eating Well.

Guidance on engaging your patients in lifestyle conversations

Print materials to display or share with patients

Counseling for safety

In general, a plant-based, whole-foods diet can be individually tailored to the patient to be optimally nutritious and safe. Refer patients to a clinician such as a registered dietician certified in oncology nutrition or a naturopathic oncologist for diet individualization and monitoring, especially if patients are interested in or prescribed metabolic diets such as ketogenic or intermittent fasting. Patients are advised not to try specialized diets without expert guidance. See reviews of diets in which we discuss cautions, contraindications and monitoring for various diets and approaches: Diets and Metabolic Therapies: Introduction ›

Reimbursement

Intervention support and success

Evidence regarding dietary-change interventions:

• Behavior changes among people with cancer with an online diet intervention, and the mode of delivery did not influence the amount of dietary behavior change in a meta-analysisa statistical analysis that combines the results of two or more research studies; the results of smaller research studies addressing the same or similar questions can be analyzed as though they are one bigger, more powerful study of RCTsrandomized controlled trial, a study design in which people are randomly assigned to either an experimental group or a control group to compare the outcomes from different treatments; an RCT is considered a strong design for determining a therapy’s effects³Furness K, Sarkies MN, Huggins CE, Croagh D, Haines TP. Impact of the method of delivering electronic health behavior change interventions in survivors of cancer on engagement, health behaviors, and health outcomes: systematic review and meta-analysis. Journal of Medical Internet Research. 2020 Jun 23;22(6):e16112.
• Strong evidenceconsistent, significant effects in several large (or at least one very large) well designed clinical studies or at least two meta-analyses of clinical studies of moderate or better quality (or one large meta-analysis) finding similar results (this is the CancerChoices definition; other researchers and studies may define this differently) that behavioral incentives may encourage healthier eating behaviors in adolescents in a meta-analysis of controlled trialsa study design in which people are assigned to either an experimental group or a control group to compare the outcomes from different treatment; assignment is not random, and so this is not as strong a study design as a randomized controlled trial, but still stronger than an uncontrolled trial⁴Corepal R, Tully MA, Kee F, Miller SJ, Hunter RF. Behavioural incentive interventions for health behaviour change in young people (5-18 years old): a systematic review and meta-analysis. Preventive Medicine. 2018 May;110:55-66. 
• No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. on time to progression or progression-free rates at 2 years among people with early stage prostate cancer participating in a counseling behavioral intervention by telephone promoting consumption of 7 or more daily vegetable servings compared to those receiving written information about diet and prostate cancer in a mid-sized RCT⁵Parsons JK, Zahrieh D et al. Effect of a behavioral intervention to increase vegetable consumption on cancer progression among men with early-stage prostate cancer: the MEAL randomized clinical trial. JAMA. 2020 Jan 14;323(2):140-148.
• Better adherence to a more Mediterranean-style, anti-inflammatory dietary pattern among breast cancer survivors with overweight or obesity who participated in an education and culinary-based dietary intervention including monthly nutrition and cooking workshops, motivational interviewing telephone calls and individualized newsletters compared to monthly informational brochures in a mid-sized RCT⁶Zuniga KE, Parma DL et al. Dietary intervention among breast cancer survivors increased adherence to a Mediterranean-style, anti-inflammatory dietary pattern: the Rx for Better Breast Health Randomized Controlled Trial. Breast Cancer Research and Treatment. 2019 Jan;173(1):145-154.
• A meta-analysis of interventions found no consistent trends in physical activity and/or nutrition behavior change related to social cognitive theory-based interventions among cancer survivors as to delivery method or whether the intervention targeted single or multiple behaviors.⁷Stacey FG, James EL, Chapman K, Courneya KS, Lubans DR. A systematic review and meta-analysis of social cognitive theory-based physical activity and/or nutrition behavior change interventions for cancer survivors. Journal of Cancer Survivorship. 2015 Jun;9(2):305-38.
• Participation in lifestyle interventions is valued by palliative cancer patients and may strengthen their coping abilities. However, some of the participants also expressed feelings of guilt and inadequacy.⁸Mikkelsen HE, Brovold KV, Berntsen S, Kersten C, Fegran L. Palliative cancer patients’ experiences of participating in a lifestyle intervention study while receiving chemotherapy. Cancer Nursing. 2015 Nov-Dec;38(6):E52-8.

Clinical practice guidelines

Recommends a nutrition consultation for treating cancer-related fatigue

Mode of action: diet and hormones

Lower risk of breast cancer recurrence among people following a reduced-fat diet may be due to metabolic hormones and factors associated with decreased fat tissue.⁹Dieli-Conwright CM, Lee K, Kiwata JL Reducing the risk of breast cancer recurrence: an evaluation of the effects and mechanisms of diet and exercise. Current Breast Cancer Reports. 2016;8(3):139-150.

Further evidence

Notable preclinical evidence is presented here. Clinical evidence is summarized in How can Eating Well help you? What the research says ›

Optimizing your body terrain: preclinical evidence

Inflammation

• Blueberries reduce inflammation and cell damage from oxidation in animal studies.¹⁰Zhao F, Yan S, Tian M. Blueberry polyphenol extracts enhance the intestinal antioxidant capacity in weaned rats by modulating the Nrf2-Keap1 signal pathway. Frontiers in Physiology. 2021 Feb 4;12:640737; Land Lail H, Feresin RG et al. Berries as a treatment for obesity-induced inflammation: evidence from preclinical models. Nutrients. 2021 Jan 23;13(2):334.

Immune function

• Edible mushrooms may regulate the immune system.¹¹Jayachandran M, Xiao J, Xu B. A critical review on health promoting benefits of edible mushrooms through gut microbiota. International Journal of Molecular Sciences. 2017 Sep 8;18(9).

Your microbiome

• Shifting from a Mediterranean diet to a standard Western diet high in heavily processed foods and meats negatively altered the microbiota in 1 day, and a diet high in sugar decreased necessary microbial diversity within 1 week in animal studies¹²Turnbaugh PJ, Ridaura VK et al. The effect of diet on the human gut microbiome: a metagenomic analysis in humanized gnotobiotic mice. Science Translational Medicine. 2009 Nov 11; 1(6):6ra14; Sen T, Cawthon CR et al. Diet-driven microbiota dysbiosis is associated with vagal remodeling and obesity. Physiology and Behavior. 2017 May 1;173:305-317.
• A high-sugar diet, irrespective of the amount of fat, led to increases in body weight and body fat and gut microbiota dysbiosis characterized by an overall decrease in bacterial diversity and an increase in Firmicutes/Bacteriodetes ratio in mice.¹³Sen T, Cawthon CR et al. Diet-driven microbiota dysbiosis is associated with vagal remodeling and obesity. Physiology & Behavior. 2017 May 1;173:305-317.
• Altered gut bacteria and fewer colon tumors among mice eating walnuts¹⁴Nakanishi M, Chen Y et al. Effects of walnut consumption on colon carcinogenesis and microbial community structure. Cancer Prevention Research (Philadelphia). 2016 Aug;9(8):692-703.

Commentary

Helpful links for professionals

Ho ZC. Principles of diet therapy in ancient Chinese medicine: ‘Huang Di Nei Jing’. Asia Pacific Journal of Clinical Nutrition. 1993 Jun;2(2):91-5.

Ligabel J, Meyerhardt JA. The roles of diet, physical activity, and body weight in cancer survivorship. UpToDate.

Fortmann SP, Burda BU et al., editors. Vitamin, mineral, and multivitamin supplements for the primary prevention of cardiovascular disease and cancer: a systematic evidence review for the US Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2013 Nov. Report No.: 14-05199-EF-1.

Wedlake LJ, Shaw C, Whelan K, Andreyev HJ. Systematic review: the efficacy of nutritional interventions to counteract acute gastrointestinal toxicity during therapeutic pelvic radiotherapy. Alimentary Pharmacology and Therapeutics. 2013 Jun;37(11):1046-56.