The Effect of Diet on Chronic Inflammation and Related Disorders Following Spinal Cord Injury

Spinal cord injury (SCI) is a condition commonly associated with a state of chronic inflammation due to a number of factors. A loss of motor and sensory function typically results in a greater susceptibility to the development of acute secondary health complications such as urinary tract infections and pressure sores resulting in frequent bouts of inflammation. The loss of mobility also places these individuals at an elevated risk for the development of a variety of metabolic disorders such as obesity and type 2 diabetes; each of which are independently associated with chronic inflammation. Additionally, elevated levels of circulating proinflammatory cytokines and autoantibodies have been shown to be present in the serum of individuals with SCI even when asymptomatic for other secondary health complications. As such, following SCI, individuals are commonly in a state of perpetual low grade inflammation. It has yet to be established whether or not such elevations in proinflammatory mediators are beneficial to patients or if they are in fact surrogate markers of further neurological impairment. Such mediators play critical roles tissue repair however, it is also well established that the immune system has the ability to communicate with other systems of the body. As such, the immune system has the ability to influence and be influenced by other systems suggesting that immune dysfunction has the capability (and likelihood) of influencing the nervous system to some degree. A variety of neurological and behavioural disorders including depression, cognitive impairment, and neuropathic pain have each been linked to a state of chronic inflammation and are each at a dramatically elevated prevalence following SCI.

Pro-inflammatory mediators have been suggested to influence the nervous system via both direct and indirect mechanisms. There is evidence to suggest cytokines may directly influence somatic nerves by altering ion channel kinetics through channelopathy. Pro-inflammatory cytokines have also been shown to possess the ability to up-regulate key enzymes resulting in protein imbalances and/or increased production of neuromodulatory proteins, which may influence the severity of a variety of neural disorders.

Presently, the majority of treatment strategies for conditions such as major depression and pain utilize drug treatments which target "downstream" enzymes and receptors. As such, these treatments provide fairly rapid and affective relief from symptoms. However, as this strategy does not target the inflammatory basis of such disorders it provides only a temporary solution whereby symptoms are likely to return upon the cessation of the treatment. In addition, long term use of certain drug treatments such as selective serotonin re-uptake inhibitors (SSRI's) may only enhance biochemical vulnerability and exacerbate symptoms long-term. An understanding of how the immune and nervous systems interact may provide a unique opportunity to treat neural and behavioral disorders by targeting aspects of the immune system via anti-inflammatory interventions.

Natural anti-inflammatory interventions including a diet consisting of foods and supplements with anti-inflammatory properties may be an effective option for treating inflammation in this population. As this treatment strategy will target the inflammatory basis of many disorders it would be expected to lead to a reduction in pro-inflammatory mediators thereby leading to more sustainable long-term immune improvements. Despite this, surprisingly little research has focused on the use of anti-inflammatory foods for the treatment of chronic inflammatory conditions, and effects specific to SCI have been almost completely neglected.

The research objective of the present study is to evaluate the effects of a reduced inflammatory state by means of an anti-inflammatory diet on depression, cognitive impairment, neuropathic pain, and somatic and autonomic nerve function. Participants will be placed on a 3 month anti-inflammatory diet consisting of daily supplementation including omega-3 polyunsaturated fatty acids, InflanNox (curcumin), anti-oxidants, chlorella, and a vegetarian protein powder. A focus on foods and supplements with natural anti-inflammatory properties is expected to lead to beneficial reductions in the incidence of infections as well as positive metabolic adaptations. Together, this should help to reduce elevated levels of proinflammatory mediators. It is hypothesized that a reduction in pro-inflammatory mediators will result in positive alterations in enzyme regulation leading to beneficial changes in protein balances and ultimately improvements in each of the measures of outcome.