Treating Chronic Pain With Diet

Approximately 20% of adults (~50 million) in the United States are affected by chronic pain, defined as pain on most days or every day in the past six months. In addition, an estimated 8% of US adults (~20 million) experience high-impact chronic pain, defined as chronic pain that has limited life or work activities on most days or every day in the past six months.1 Many turn to opioids for relief. In the US, widespread use of opioids to treat acute and chronic pain is believed to have contributed to the estimated 10.8 million people who misused opioids in 2018.2

According to the National Institute on Drug Abuse, nearly 130 people die every day following an opioid overdose; those opioids include prescription pain relievers.3 In addition:

  • 21-29% of patients prescribed opioids to treat chronic pain misuse them.
  • 8-12% of patients prescribed opioids develop an opioid use disorder.
  • 4-6% of patients who misuse prescription opioids transition to heroin.3

“For millions of people across the globe, excruciating pain is an inescapable reality of life,” writes Allyn L. Taylor in a 2007 article published in The Journal of Law, Medicine & Ethics.4 Does it have to be this way?

Opioid Use & Risks

For centuries, opioids have been an accepted therapy for pain patients; a 2005 Medicaid study showed that more than 50% of opioid prescriptions were for doses higher than 90 MME (morphine milligram equivalents) and for periods of more than six months.5 However, research shows that the extended prescription of opioids for the treatment of chronic pain has questionable benefits and significant risks that include the following:6

  • Constipation and abdominal pain
  • Tolerance – physiologic adaptation
  • Physiologic dependence and withdrawal
  • Opioid misuse
  • Depression
  • Hormonal dysregulation
  • Opioid-induced hyperalgesia
  • Cardiovascular events
  • Suppressed breathing and accidental overdose

And yet, in 2014, for example, US retail pharmacies dispensed 245 million prescriptions for opioid pain relievers; of these prescriptions, 65% were for short-term therapy (less than three weeks),7 but 3­-4% of the adult population (9.6-11.5 million persons) were prescribed longer-term opioid therapy.5 While the overall US opioid prescribing rate dropped to 58.7 prescriptions per 100 people (191 million prescriptions) in 2017, some counties reported rates that were seven times higher.8

Opioid Alternative – Nutrition

Millions of Americans are dependent on, or abuse, prescription opioids, and legislators have begun restricting ease of access to prevent misuse. On the heels of this opioid epidemic, both practitioners and chronic pain patients have begun seeking alternatives to pharmaceuticals. The Functional Medicine (FM) model provides guidance to clinicians looking to treat pain patients without the use of opioids, through modifiable lifestyle factors like diet.

A 2019 systematic review of studies that tested the effect of nutrition on chronic pain found that nutrition interventions had a significant impact on pain reduction, with altered overall diets and changes in specific nutrients having the greatest effects.9 In the following video, IFM educator Kristi Hughes, ND, IFMCP, discusses how a nutritional therapeutic strategy may improve outcomes for patients experiencing chronic pain.

Inflammation, the Elimination Diet, & Specific Conditions

There is increasing evidence that diet can contribute to systemic inflammation,10 and pain perception is commonly related to inflammatory stimulus and mediators.11 The most explored dietary triggers for chronic pain include cow’s milk antigens (alpha-lactalbumin, beta-lactoglobulin, casein), wheat and wheat gluten, eggs, and soy proteins.10 Because food intolerances and allergies can be challenging to diagnose, and testing for these disorders is variable in terms of sensitivity and specificity, many researchers believe that elimination diets are the gold standard for diagnosis of food reactions.12-14 Encouraging wholesome eating is an essential part of treatment management, while also investigating possible immune reactivity to food in patients with inflammation and pain.15-17

Chronic Musculoskeletal Pain

Dietary markers, including low fruit and vegetable consumption, have been identified for inflammatory arthritis.16 The journal Rheumatology published a study that found that a gluten-free, vegan diet improved the signs and symptoms of rheumatoid arthritis (RA).10 A raw, vegan diet, rich in antioxidants and fiber, was shown in another study to decrease joint stiffness and pain in patients with RA.18 A 2018 study suggested consumption of a plant-based diet decreased pain and improved quality of life for subjects with reported chronic musculoskeletal pain; however, the study was small, with only 14 participants, the results were based solely on self-reporting, and no control group was used.19

Interstitial Cystitis

In patients with interstitial cystitis/bladder pain syndrome, nearly 90% report sensitivities to a variety of foods.20 Questionnaire-based literature suggests that citrus fruits, tomatoes, vitamin C, artificial sweeteners, coffee, tea, carbonated and alcoholic beverages, and spicy foods may exacerbate symptoms, while calcium glycerophosphate and sodium bicarbonate may improve symptoms. This suggests that a controlled method to determine dietary sensitivities, such as an elimination diet, may play an important role in patient management.20

Fibromyalgia and Central Sensitization

A 2015 review in Clinical and Experimental Rheumatology found that among non-pharmacological treatments for chronic pain, nutrition is a promising tool for fibromyalgia syndrome patients.21 In fibromyalgia patients with celiac disease, more than one-third of patients who removed gluten from their diet were able to discontinue opioid therapy for chronic pain.22 In chronic pain patients with central sensitization, including those with whiplash, temporomandibular disorders, lower back pain, osteoarthritis, and fibromyalgia, among others, a study found that the ketogenic diet may diminish the hyperexcitability of the central nervous system.23

Research into the role of nutrition in modulating chronic pain continues to accrete.24 How can nutritional assessment and counseling be integrated into the Functional Medicine protocol for treating pain patients? Learn more at IFM’s Applying Functional Medicine in Clinical Practice (AFMCP), where a team of experienced Functional Medicine clinicians teaches participants how to use IFM’s tools to improve outcomes for patients with chronic pain and other disorders.

Learn More About Functional Medicine


  1. Dahlhamer J, Lucas J, Zelaya C, et al. Prevalence of chronic pain and high-impact chronic pain among adults – United States 2016. MMWR Morb Mortal Wkly Rep. 2018;67(36):1001-1006. doi:15585/mmwr.mm6736a2
  2. National Institutes of Health. NIH HEAL initiative research plan. Last Updated October 25, 2019. Accessed January 14, 2020.
  3. National Institute on Drug Abuse. Opioid overdose crisis. Revised January 2019. Accessed January 14, 2020.
  4. Taylor AL. Addressing the global tragedy of needless pain: rethinking the United Nations single convention on narcotic drugs. J Law Med Ethics. 2007;35(4):556-570,511. doi:1111/j.1748-720X.2007.00180.x
  5. Volkow ND, McLellan AT. Opioid abuse in chronic pain—misconceptions and mitigation strategies. N Engl J Med. 2016;374(13):1253-1263. doi:1056/NEJMra1507771
  6. Lembke A, Humphreys K, Newmark J. Weighing the risks and benefits of chronic opioid therapy. Am Fam Physician. 2016;93(12):982-990.
  7. Krebs EE, Gravely A, Nugent S, et al. Effect of opioid vs nonopioid medications on pain-related function in patients with chronic back pain or hip or knee osteoarthritis pain: the SPACE randomized clinical trial. JAMA. 2018;319(9):872-882. doi:1001/jama.2018.0899
  8. Centers for Disease Control and Prevention. U.S. opioid prescribing rate maps. Published October 3, 2018. Accessed January 14, 2020.
  9. Brain K, Burrows TL, Rollo ME, et al. A systematic review and meta-analysis of nutrition interventions for chronic noncancer pain. J Hum Nutr Diet. 2019;32(2):198-225. doi:1111/jhn.12601
  10. Hafström I, Ringertz B, Spångberg A, et al. A vegan diet free of gluten improves the signs and symptoms of rheumatoid arthritis: the effects on arthritis correlate with a reduction in antibodies to food antigens. Rheumatology. 2001;40(10):1175-1179. doi:1093/rheumatology/40.10.1175
  11. Ronchetti S, Migliorati G, Delfino DV. Association of inflammatory mediators and pain perception. Biomed Pharmacother. 2017;96:1445-1452. doi:1016/j.biopha.2017.12.001
  12. Wood RA. Diagnostic elimination diets and oral food provocation. Chem Immunol Allergy. 2015;101:87-95. doi:1159/000371680
  13. Dupont C. Diagnosis of cow’s milk allergy in children: determining the gold standard? Expert Rev Clin Immunol. 2014;10(2):257-267. doi:1586/1744666X.2014.874946
  14. Ballmer-Weber BK. Value of allergy tests for the diagnosis of food allergy. Dig Dis. 2014;32(1-2):84-88. doi:1159/000357077
  15. Seaman DR. The diet-induced proinflammatory state: a cause of chronic pain and other degenerative diseases? J Manipulative Physiol Ther. 2002;25(3):168-179. doi:1067/mmt.2002.122324
  16. Vandenkerkhof EG, Macdonald HM, Jones GT, Power C, Macfarlane GJ. Diet, lifestyle and chronic widespread pain: results from the 1958 British Birth Cohort Study. Pain Res Manag. 2011;16(2):87-92. doi:1155/2011/727094
  17. Totsch SK, Waite ME, Sorge RE. Dietary influence on pain via the immune system. Prog Mol Biol Transl Sci. 2015;131:435-469. doi:1016/bs.pmbts.2014.11.013
  18. Hänninen O, Kaartinen K, Rauma AL, et al. Antioxidants in vegan diet and rheumatic disorders. Toxicology. 2000;155(1-3):45-53. doi:1016/S0300-483X(00)00276-6
  19. Towery P, Guffey S, Doerflein C, Stroup K, Saucedo S, Taylor J. Chronic musculoskeletal pain and function improve with a plant-based diet. Complement Ther Med. 2018;40:64-69. doi:1016/j.ctim.2018.08.001
  20. Friedlander JI, Shorter B, Moldwin RM. Diet and its role in interstitial cystitis/bladder pain syndrome (IC/BPS) and comorbid conditions. BJU Int. 2012;109(11):1584-1591. doi:1111/j.1464-410X.2011.10860.x
  21. Rossi A, Di Lollo AC, Guzzo MP, et al. Fibromyalgia and nutrition: what news? Clin Exp Rheumatol. 2015;33(1 Suppl 88):S117-S125.
  22. Isasi C, Colmenero I, Casco F, et al. Fibromyalgia and non-celiac gluten sensitivity: a description with remission of fibromyalgia. Rheumatol Int. 2014;34(11):1607-1612. doi:1007/s00296-014-2990-6
  23. Nijs J, Malfliet A, Ickmans K, Baert I, Meeus M. Treatment of central sensitization in patients with ‘unexplained’ chronic pain: an update. Expert Opin Pharmacother. 2014;15(12):1671-1683. doi:1517/14656566.2014.925446
  24. De Gregori M, Muscoli C, Schatman ME, et al. Combining pain therapy with lifestyle: the role of personalized nutrition and nutritional supplements according to the SIMPAR Feed Your Destiny approach. J Pain Res. 2016;9:1179-1189. doi:2147/JPR.S115068

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