Chronic fatigue syndrome: oxidative stress and dietary modifications
Chronic fatigue syndrome (CFS) is an illness characterized by persistent and relapsing fatigue, often accompanied by numerous symptoms involving various body systems. The etiology of CFS remains unclear; however, a number of recent studies have shown oxidative stress may be involved in its pathogenesis. The role of oxidative stress in CFS is an important area for current and future research as it suggests the use of antioxidants in the management of CFS. Specifically, the dietary supplements glutathione, N-acetylcysteine, alpha-lipoic acid, oligomeric proanthocyanidins, Ginkgo biloba, and Vaccinium myrtillus (bilberry) may be beneficial. In addition, research on food intolerance is discussed, since food intolerance may be involved in CFS symptom presentation and in oxidation via cytokine induction. Finally, recent evidence suggests celiac disease can present with neurological symptoms in the absence of gastrointestinal symptoms; therefore, celiac disease should be included in the differential diagnosis of CFS.
(Altern Med Rev 2001;6(5):450-459)
Chronic fatigue syndrome (CFS) is a relatively common disorder, particularly in women, affecting 522 women and 291 men per 100,000. (1) In addition to the characteristic persistent fatigue, CFS patients often complain of a number of symptoms including headache, joint pain, gastrointestinal (GI) disturbance, cognitive dysfunction, visual disturbance, and paresthesia. (2, 3)
Pathological changes have been observed in CFS patients, including white matter lesions in the CNS (4-6) and cerebral hypoperfusion. (7-9) Other findings that suggest CNS involvement include vestibular dysfunction (10,11) and gait abnormalities. (12,13) Immune response also appears to be impaired; specifically, elevated levels of interferon alpha, transforming growth factor beta, interleukin-4, interleukin-6, interleukin-1 alpha, and tumor necrosis factor alpha (TNF-[alpha] have been observed. (14-19)
The purpose of this paper is to integrate various branches of current research in an effort to highlight the importance of antioxidant capacity and food intolerance in CFS. First, recent studies will be reviewed that indicate oxidative stress is involved in the pathogenesis of CFS. This suggests antioxidants may be beneficial in the management of CFS. Glutathione (GSH), N-acetylcysteine (NAC), [alpha]-lipoic acid, oligomeric proanthocyanidins (OPCs), Ginkgo biloba, and Vaccinium myrtillus (bilberry) would therefore be dietary supplements with potential therapeutic benefit. Second, the literature will be reviewed that suggests food intolerance may be involved in CFS symptom presentation and in oxidation via cytokine induction.
Although food intolerance can be an important consideration in the presentation of this heterogeneous disorder, evidence also suggests celiac disease should be included in the differential diagnosis of CFS. Celiac disease may present primarily with neurological symptoms in the absence of gastrointestinal symptoms.
Current Research on Oxidative Stress in CFS
The role of oxidative stress in CFS is an emerging focus of research. Although it is uncertain whether oxidative stress is a cause or a result of this illness, recent studies have demonstrated that oxidative stress contributes to the pathology and clinical symptoms of CFS. Theoretically, oxidative stress can be caused by an increase in the generation of reactive oxygen species, of which mitochondrial dysfunction is believed to be a main source, or it can be caused by a decline...