Introduction

This brief summary section lists current evidence relating to the influence of nutritional features on pelvic pain in general, and a number of specific conditions in particular. Some of the evidence is clear, while much of it remains equivocal, with a mixture of conflicting research evidence, and anecdotal evidence, clouding the conclusions. Despite some uncertainty, there is evidence that inflammatory processes can safely be modulated by a variety of nutrients and dietary strategies that involve anti-inflammatory and antioxidant substances in the diet. Several preventative measures also appear to be fairly solidly established (involving the balance of lipid substances omega-3, omega-6, etc. in the diet). In general, two areas stand out: the influence of diet on inflammatory processes, and the influence of vitamin D deficiency on a number of pelvic floor disorders affecting women.

Inflammation

Butrick (2009) notes that when muscle fibre trauma occurs, inflammatory mediators (e.g. bradykinin, serotonin, prostaglandins, adenosine triphosphate, histamine) are released locally, resulting in sensitization of muscle nociceptors, reducing their mechanical threshold. This results in muscle hyperalgesia and mechanical allodynia in which innocuous pressure may be perceived as painful. If prolonged, this peripheral sensitization leads to central sensitization, via a series of neuroplastic changes that occur in the central nervous system. These processes are described in greater detail in Chapter 3.

While pharmacological control of inflammation is clearly an option, there are also well-founded strategies for modulating this process, via dietary manipulation.

Dietary anti-inflammatory strategies

• Herbs such as turmeric can suppress expression of cyclo-oxygenase-2 (COX-2); and nutmeg inhibits release of tumour necrosis factor (TNF-α) (Sanders & Sanders-Gendreau 2007).

• Lopez-Miranda et al. (2010) report that phenolic compounds in olive oil have antioxidant and anti-inflammatory properties, prevent lipoperoxidation, induce favourable changes of lipid profile, improve endothelial function and have antithrombotic properties. Oleocanthal, a compound in olive oil retards the production of pro-inflammatory enzymes cyclo-oxygenase-1 (COX-1) and COX-2.

• A study by Beauchamp et al. (2005) suggests that 50 ml or 3.5 tablespoons of olive oil has the same effect as a 200-mg tablet of ibuprofen. Note however that consumption of 50 ml olive oil as an anti-inflammatory intervention requires caution, as this volume of olive oil contains in excess of 400 calories. This is of importance in chronic pelvic pain (CPP), since studies (Greer et al. 2008) have noted that weight loss leads to significant improvements in pelvic floor disorder symptoms.

• Moschen et al. (2010) confirmed that weight loss is an effective anti-inflammatory strategy, achieving its effects by decreasing expression of TNF-α and interleukin (IL)-6 as well as by increasing anti-inflammatory adipokines such as adiponectin.

Antioxidants and anti-inflammatory nutrients

Mier-Cabrera et al. (2009) and Kamencic & Thiel (2008) have demonstrated that, in endometriosis, oxidative stress may be improved by use of antioxidant compounds. Antioxidant nutrients have been shown to protect against cell-damaging free radicals, and to reduce activity of COX-2, a major cause of inflammation (Nijveldt 2001, Kim et al. 2004). Closely tied to anti-inflammatory strategies are nutritional approaches that emphasize enhanced intake of antioxidant foods containing phytochemicals such as carotenoids, flavonoids, limonene, indole, ellagic acid, allicin (from garlic) and sulphoraphane.

Examples include:

• Resveratrol, a polyphenolic found in the skins of red fruits, including grapes, is an antioxidant and is also found in wine. It has antichemotactic activities, as well as being a regulator of aspecific leukocyte activation (Jang et al. 1997, Bertelli et al. 1999, Szewczuk et al. 2004, Indraccoloa & Barbieri 2010).

• Resveratrol has been found to be a more potent anti-inflammatory agent than aspirin or ibuprofen (Takada et al. 2004)

• Carvacrol (derived from the essential oils of oregano and thyme) efficiently suppresses COX-2 expression (Baser 2008, Hotta et al. 2010)

• Antioxidant anthocyanins from pomegranate (POMx), and blueberry extract (Vaccinium corymalosum) which is also rich in anthocyanins, have been shown to have active antioxidant and antinociceptive properties (Torri et al. 2007).

• POMx inhibited inflammation associated with activated human mast cells, involved in disease processes associated with connective tissues (Zafar et al. 2009).

• Mixtures of antioxidants – resveratol, green tea extract, α-tocopherol, vitamin C, omega-3 polyunsaturated fatty acids (PUFAs), tomato extract – were found, in a placebo-controlled study, to modulate inflammation in overweight males.

• Bromelain, an aqueous extract obtained from both the stem and fruit of the pineapple plant, contains a number of proteolytic enzymes with anti-inflammatory and analgesic properties (Maurer 2001, Brien et al. 2004).

• Catechins and epicatechins, found in red wine and tea (particularly green tea), are polyphenolic antioxidant plant metabolites that quench free radicals and provide protection against oxidative damage to cells (Hara 1997, Yang et al. 2001, Sutherland et al. 2006, Kim et al. 2008).

• In a 14-day, prospective randomized study, involving a total of 284 patients affected by chronic bacterial prostatitis (CPB; NIH class II prostatitis), Cai et al. (2009) evaluated the therapeutic antioxidant effects of extracts from the plants Serenoa repens and Urtica dioica (ProstaMEV®) and curcumin, as well as the antioxidant plant-derived nutrient quercitin (FlogMEV®) extracts, compared with prulifloxacin. One month after treatment, 89.6% of patients who had received prulifloxacin as well as ProstaMEV® and FlogMEV® (Group A) reported no symptoms related to CBP, whilst only 27% of patients who received antibiotic therapy alone (Group B) were recurrence-free (P < 0.0001). Six months after treatment, no patients in Group A had recurrence of disease whilst two patients in Group B did.