Pain is a normal response to an injury to the body and an important protective mechanism. It is also a common feature of many disease processes. Acute pain, for example following surgery, will normally settle in time but chronic pain, usually lasting more than 3 months, has a major impact on the quality of life for many people. The most common conditions causing chronic pain include arthritis and back pain, affecting all age groups but mostly the elderly. Other common pain conditions are associated with cancer, gastro-intestinal disorders (visceral pain), abnormal nerve function (neuropathic pain) and musculo-skeletal disorders.
The perception of pain is an individual response based on previous experience, cultural and psycho-social issues and is closely linked to depression and anxiety states. It is estimated over 3 million people live with chronic pain in Australia with a similar prevalence in New Zealand. This creates a huge burden on the individual and state caused by lost earnings, health care costs and reduced quality of life.
The cause of chronic pain development is multifactorial; management involves treating the underlying disease process, judicious use of pharmaceuticals and interventions, physical therapy, psychological support including stress management, relaxation techniques and an anti-inflammatory diet such as a whole food plant-based diet low in added sugar and oil. For difficult-to-treat persistent pain a multidisciplinary pain management program has been shown to have higher success rates for long term positive outcomes although access to these programs is limited.
The nutrition prescription
A whole food plant-based diet contains many anti-inflammatory phytonutrients including antioxidants and has been shown to reduce pain symptoms in arthritis and low back pain.
Painful exacerbations of arthritis can occur after eating certain “trigger” foods which include high sugar foods and drink, meat and dairy, gluten and alcohol. Autoimmune diseases causing painful arthritis include rheumatoid arthritis, lupus and psoriatic arthritis. Dietary changes which exclude animal products and increase the amount of fibre from plant foods can reduce inflammation and joint pain.
In another study, nearly half of subjects noted the effect of food on their symptoms. The best foods to reduce pain were blueberries and spinach, and pain exacerbations were caused by sugary drinks and desserts. Chronic musculo-skeletal pain conditions such as fibromyalgia have also been shown to benefit from similar dietary changes in a recent systematic review.
Diabetes may be associated with painful peripheral neuropathy and studies have shown remission from painful burning sensations in 81% of patients after eating a plant based diet low in oil for 20 weeks.
Cardiac disease is often complicated by angina pain due to coronary atherosclerosis. By treating the underlying condition with a whole food plant-based diet low in added oil the angina symptoms frequently reduce rapidly.
Other instances of atherosclerosis occur in the vertebral arteries affecting the spine leading to disc degeneration and low back pain  and in the arteries to the lower leg causing pain on walking described as intermittent claudication. These painful conditions may also be prevented and mitigated by a whole food plant-based diet which lowers blood cholesterol levels and reduces atheroma build up.
Migraine pain can be prolonged and debilitating and can be triggered by certain dietary factors. It is important to identify what foods act as triggers and eliminate these from the diet. Based on RCT data, the PCRM suggests eating a simple diet of cooked plant foods from the “safe” list for 2 weeks and then slowly reintroducing other foods.[9, 10]
Painful periods and cyclical mastalgia related to menstruation can also be helped by plant-based diets, with specific benefit from ginger, flax seeds and saffron.
Cancer pain is often multifactorial and difficult to manage. At least one in three cancers can be directly attributable to known modifiable risk factors. Certain plant foods have specific anti-cancer effects, including mushrooms, celery, garlic, turmeric, legumes and pulses, green tea and fibre rich foods. In a study on prostate cancer, intensive lifestyle interventions including a whole food, plant-based diet were shown to reverse markers of disease progression compared to control.
Pain is associated with many disorders in the gastro-intestinal tract. These include gastro-esophageal reflux (GERD), cholecystitis (gallstones), pancreatitis, ulcerative colitis, irritable bowel syndrome, Crohn’s disease, diverticular disease and haemorrhoids. Diets rich in saturated fat (found primarily in animal products and discretionary foods) have been associated with exacerbations in most of these conditions, while foods high in fibre are protective. These include whole grains, legumes and pulses, green leafy vegetables and fruit. A variety of whole plant foods provides the mix of soluble and insoluble fibre to feed our gut microbiome optimally, resulting in healthy gut functioning.
Medical supervision of diet change
Shifting to a low fat plant-based diet can lead to rapid reductions in medication needs. Patients with any existing conditions or disease history are advised to consult with a qualified healthcare professional such as a GP or dietitian before undertaking diet change.
Q: How does a plant-based diet help with inflammation?
A: There are several ways in which a whole food plant-based diet can reduce inflammation in the body.  Diets high in plant foods with a variety of dietary fibre types protect the integrity of the gut and the diversity of the gut microbiome, reducing the risk of inflammation in the central nervous system and the entire body.  A plant-based diet also contains fewer inflammatory compounds than meat and dairy products, and also typically contains a higher concentration of antioxidants, which are helpful in counteracting the harmful effects of inflammatory compounds and alleviating pain. 
Q. I’ve heard that a low fat diet is effective in reducing pain. Is it also necessary to be plant-based?
A. Many studies have shown that a plant-based diet has various benefits for pain reduction, as well as being naturally low in fat. Dairy in particular has been shown to increase gut permeability and have pro-inflammatory effects.  Following a whole food plant-based diet may reduce chronic pain and make it easier to maintain a healthy body weight.
Miller A, Sanderson K, Bruno R, Breslin M, Neil AL. The prevalence of pain and analgesia use in the Australian population: Findings from the 2011 to 2012 Australian National Health Survey. Pharmacoepidemiol Drug Saf. 2017;26(11):1403-1410. doi:10.1002/pds.4301
Oslund S, Robinson RC, Clark TC, et al. Long-term effectiveness of a comprehensive pain management program: strengthening the case for interdisciplinary care. Proc Bayl Univ Med Cent. 2009;22(3):211-214. doi:10.1080/08998280.2009.11928516
Tedeschi SK, Frits M, Cui J, et al. Diet and Rheumatoid Arthritis Symptoms: Survey Results From a Rheumatoid Arthritis Registry. Arthritis Care Res. 2017;69(12):1920-1925. doi:10.1002/acr.23225
Alwarith J, Kahleova H, Rembert E, et al. Nutrition Interventions in Rheumatoid Arthritis: The Potential Use of Plant-Based Diets. A Review. Front Nutr. 2019;6:141. doi:10.3389/fnut.2019.00141
Elma Ö, Yilmaz ST, Deliens T, et al. Do Nutritional Factors Interact with Chronic Musculoskeletal Pain? A Systematic Review. J Clin Med. 2020;9(3). doi:10.3390/jcm9030702
Bunner AE, Wells CL, Gonzales J, Agarwal U, Bayat E, Barnard ND. A dietary intervention for chronic diabetic neuropathy pain: a randomized controlled pilot study. Nutr Diabetes. 2015;5(5):e158. doi:10.1038/nutd.2015.8
Massera D, Graf L, Barba S, Ostfeld R. Angina rapidly improved with a plant-based diet and returned after resuming a Western diet. J Geriatr Cardiol JGC. 2016;13(4):364-366. doi:10.11909/j.issn.1671-5411.2016.04.005
Kauppila LI. Atherosclerosis and disc degeneration/low-back pain--a systematic review. Eur J Vasc Endovasc Surg Off J Eur Soc Vasc Surg. 2009;37(6):661-670. doi:10.1016/j.ejvs.2009.02.006
Bunner AE, Agarwal U, Gonzales JF, Valente F, Barnard ND. Nutrition intervention for migraine: a randomized crossover trial. J Headache Pain. 2014;15:69. doi:10.1186/1129-2377-15-69
Barnard ND, Scialli AR, Hurlock D, Bertron P. Diet and sex-hormone binding globulin, dysmenorrhea, and premenstrual symptoms. Obstet Gynecol. 2000;95(2):245-250. doi:10.1016/s0029-7844(99)00525-6
Whiteman DC, Webb PM, Green AC, et al. Cancers in Australia in 2010 attributable to modifiable factors: summary and conclusions. Aust N Z J Public Health. 2015;39(5):477-484. doi:10.1111/1753-6405.12471
Watzl B. Anti-inflammatory effects of plant-based foods and of their constituents. Int J Vitam Nutr Res, 2008;78(6):293-298. doi:10.1024/0300-9818.104.22.1683
Ornish D, Weidner G, Fair WR, et al. Intensive lifestyle changes may affect the progression of prostate cancer. J Urol. 2005;174(3):1065-1069; discussion 1069-1070. doi:10.1097/01.ju.0000169487.49018.73
Eswaran S, Muir J, Chey WD. Fiber and functional gastrointestinal disorders. Am J Gastroenterol. 2013;108(5):718-727. doi:10.1038/ajg.2013.63
McDougall J, Bruce B, Spiller G, Westerdahl J, McDougall M. Effects of a very low-fat, vegan diet in subjects with rheumatoid arthritis. J Altern Complement Med N Y N. 2002;8(1):71-75. doi:10.1089/107555302753507195