Functional medicine and cancer

The emphasis functional medicine places on the whole body system is especially important in cancer care. Nutrition, gut health, the microbiome, sleep, stress reduction and supportive care can all help relieve symptoms of cancer treatment, help survivors thrive and avoid recurrence, and may help cancer treatment or speed recovery.

A functional medicine practitioner can help you support and strengthen your body and boost your mental health. Functional medicine does not treat cancer directly, but an integrative oncologist can help you choose functional medicine approaches to coping with cancer. Visit www.cancerchoices.org to learn more.

Is there evidence that functional medicine works?

In the last 30 years, as health care providers and patients focus more on whole health, more research has been done to explore how lifestyle changes can affect health. Some examples are:

• Women with fatigue, stress and digestive disorders who engaged in a functional medicine approach called the Kalish method for 28 weeks experienced a 38% average decrease in fatigue, a 27% average decrease in stress, and a 22 percent average decrease in confusion. ⁷
• A meta-analysis of adults with a high risk of developing diabetes found that lifestyle interventions similar to but not identical with functional medicine approaches (such as diet changes and exercise) successfully reduced diabetes incidence, and this effect was seen years after the intervention had ended. ⁸
• Research studies have found that lifestyle interventions, including diet modifications and exercise, are an effective strategy for pregnant women suffering from gestational diabetes. ⁹ People with anxiety and/or depression who received a lifestyle intervention focused on diet modification and increasing physical activity saw their anxiety, depression and stress related symptoms decrease. ¹⁰ Patients in a 12-week study of inflammatory arthritis reported less pain and better physical and mental health after using a functional medicine treatment approach than patients who did not use functional medicine. ¹¹
• Intensive functional medicine-based lifestyle changes improved cognitive function in one study of people with early Alzheimer dementia or mild cognitive impairment. ¹²

Information for patients and clinicians

Websites

If you or your health care provider would like to explore more research on functional medicine’s impact on a particular health concern, visit www.ifm.org/health-topics

If you are interested in functional medicine for cancer treatment, visit Functional Medicine in Cancer Care at Cancer Choices. The Body Terrain handbooks can also be helpful.

Medical and Nursing Journal Articles

A review of functional medicine’s history and principles can be found in these articles:

• Bland JS. Functional Medicine Past, Present, and Future. Integr Med (Encinitas). 2022 May;21(2):22-26. PMID: 35698609; PMCID: PMC9173848.
• Sager, Brigitte DNP, FNP-C, NC-BC, AFMC, CNE. Functional Medicine in Nursing. AJN, American Journal of Nursing 124(10):p 32-40, October 2024. | DOI: 10.1097/01. NAJ.0001063812.69063.b1

Are there precautions, side effects or safety concerns I should be aware of before I pursue functional medicine?

Functional medicine is widely considered a safe way of addressing physical and mental conditions when delivered by a certified functional medicine practitioner.

As when you work with any physician, you may experience side effects from a specific treatment plan. Talk to your functional medicine doctor if this happens.

It is common for a functional medicine doctor or dietician to make suggest changes to your diet. You may have some digestive issues while your body adjusts.

You may also experience discomfort or anxiety with the number of diagnostic tests recommended, such as blood tests.

How often should I seek treatment from a functional medicine practitioner? How long is each session?

How often and for how long you see your functional medicine doctor depends on why you need and want their help. Besides doctor’s appointments, you will probably also have tests, including blood tests. Your functional medicine specialist may also refer you to a registered dietician, nutrition counselor, or exercise specialist who can help you adjust your diet and current level of physical activity.

What training and certifications do functional medicine clinicians need?

To be certified as a functional medicine clinician, you must be a licensed medical, naturopathic, osteopathic or chiropractic doctor. Certification is open to doctors of all disciplines. Other health care providers can also qualify for certification, including dentists, nurse practitioners, physician assistants, registered nurses, registered dieticians, acupuncturists, and pharmacists.

There are extensive educational requirements to be certified as a functional medicine physician, including taking and passing an Applying Functional Medicine in Clinical Practice (AFMCP) course and classes in six additional modules.

How do I find a functional medicine practitioner near me?

• The Institute for Functional Medicine

How much will seeing a functional medicine practitioner cost me?

The cost depends on location, provider and services needed. How much you will pay out of pocket to see a functional medicine practitioner will depend on your insurance coverage. The first visit can cost several hundred dollars in addition to the cost of blood and lab work, which can add up quickly. Follow-up visits are less costly.

Will my insurance company cover the cost of seeing a functional medicine practitioner?

Whether your insurance company covers functional medicine, and how much, depends on your individual policy. Most companies will cover the cost of seeing a functional medicine practitioner if they are a licensed practitioner in that state – but not always.

Some of the blood and other tests may be covered, but many may not be. This is because functional medicine physicians often order tests that go beyond usual medical coverage. The best way to find out whether your insurance company covers functional medicine is to contact them and ask about both the provider and the tests they plan to order.

Additionally, it is common for a functional medicine practitioner to refer you to specialists such as a dietician or health coach.

These may not be covered. Again, contact your insurance company to learn what they will cover.

Should I tell my primary care physician that I am seeing a functional medicine clinician?

Yes. It is important to let your primary care physician and any other health care providers know that you would like to use functional medicine for your medical condition or concern. You may need to have some of your medications or other treatments adjusted, and all your doctors and health care providers should know what the others are doing or prescribing. This helps you stay as safe and healthy as possible. Open communication helps you avoid complications and allows all your health care providers to work together to address your condition.

References

1. US Centers for Disease Control. Preventing Chronic Diseases: What You Can Do Now. May 15, 2024. Available at www.cdc.gov/chronic-disease/prevention/index.html. Accessed January 18, 2025.
2. Bland, J. (2015) Functional Medicine: An Operating System for Integrative Medicine. Integrative Medicine, 14(5): pp. 18-20.
3. Bland, J. (2017). Defining Function in the Functional Medicine Model. Integrative Medicine, 16(1): pp. 22-25.
4. Riegel, B., Moser, D.K., Buck, H.G., et al. American Heart Association Council on Cardiovascular and Stroke Nursing; Council on Peripheral Vascular Disease; and Council on Quality of Care and Outcomes Research. (2017). Self-Care for the Prevention and Management of Cardiovascular Disease and Stroke: A Scientific Statement for Healthcare Professionals From the American Heart Association. Journal of the American Heart Association, 6(9): pp. 1-27.
5. US Centers for Disease Control. Fast Facts: Health and Economic Costs of Chronic Conditions. July 12, 2024. Available at www.cdc.gov/chronic-disease/data-research/facts-stats/index.html. Accessed January 18, 2025. The Institute for Functional Medicine. Healthy Function by Treating the Root Causes of Disease. 2025. Available at www.ifm.org/functional-medicine. Accessed January 18, 2025.
6. Cutshall, S.M., Bergstrom, L.R., & Kalish, D.J. (2016). Evaluation of a functional medicine approach to treating fatigue, stress, and digestive issues in women. Complement Ther Clin Pract, 23: pp. 75-81.
7. Haw, J.S., Galaviz, K.I., Straus, A.N., Kowalski, A.J., Magee, M.J., Weber, M.B., Wei, J., Narayan, K.M.V., & Ali, M.K. (2017). Long-term Sustainability of Diabetes Prevention Approaches: A Systematic Review and Meta-analysis of Randomized Clinical Trials. JAMA Internal Medicine, 10.
8. Brown, J., Alwan, N.A., West, J., Brown, S., McKinlay, C.J., Farrar, D., & Crowther, C.A. (2017). Lifestyle interventions for the treatment of women with gestational diabetes. Cochrane Database of Systematic Reviews, 5.
9. Forsyth, A., Deane, F.P., & Williams, P. (2015). A lifestyle intervention for primary care patients with depression and anxiety: A randomised controlled trial. Psychiatry Research, 230(2): pp. 537-544.
10. Droz N, Hanaway P, Hyman M, Jin Y, Beidelschies M, Husni ME. The impact of functional medicine on patient-reported outcomes in inflammatory arthritis: A retrospective study. PLoS One. 2020 Oct 8;15(10):e0240416.
11. Droz N, Hanaway P, Hyman M, Jin Y, Beidelschies M, Husni ME. The impact of functional medicine on patient-reported outcomes in inflammatory arthritis: A retrospective study. PLoS One. 2020 Oct 8;15(10):e0240416.