Sheffield Medical School, Division of Genomic Medicine, Sheffield, UK. E-mail: michael{at}mikesnaith.demon.co.uk
Gout has been a relatively well-defined condition for centuries, throughout which diet has featured in its treatment. In this context, it is rather difficult to distinguish diet from medication. Medical opinion, admixed with clinical observation and anecdotes, has reflected contemporary health beliefs up to and including modern times (Fig. 1). For example, the Hippocratic school recommended barley water, for which I can think of no particular virtue. However, white hellebore was also suggested. This may be because it bears some of the characteristics of colchicum, to which it is related. However, it may also have been because, by producing diarrhoea, it equated with therapeutic gastrointestinal purging. Dehydration and ketosis would have worsened hyperuricaemia, but dysentery was said to be beneficial for gout. To Hippocratic purging, Galen added venesection and spring sea voyages, perhaps for some therapeutic vomiting. Colchicine, discovered by the ancient Greek and Islamic physicians, fell out of favour in the 18th century, with the Sydenham-inspired abandonment of purging. When colchicine was reintroduced, it was as much a treatment for dropsy as for gout. Anecdotal observation, deductive reasoning and the power of placebo all conspired in the development of medical treatments for gout as much as other conditions.
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The mid-20th century saw a rapid expansion in the understanding of nucleic acid chemistry, including purine metabolism. A strict low-purine diet can lower plasma urate by around 20%. However, the development of uricosuric drugs, then of xanthine oxidase inhibition, encouraged enthusiasm for a pharmacological magic bullet, and dietary advice was dropped from most standard medical texts and practice. Now that the relatively health-conscious western middle classes may be belatedly endeavouring to reverse the trends towards ever more atherosclerosis, the less well-educated, wealthy or motivated are certainly not. Contributors to internet chat rooms on dietary treatments for their gout favour Montmorency cherries and celery seeds over colchicine and allopurinol.
The sociological, dietary, metabolic and genetic aspects of gout are now coming together with the recognition of the critical role of insulin resistance in linking vascular disease, diabetes and urate retention. A drug such as fenofibrate is found to have unexpected benefits for urate levels; a diet high in protein, restricted in calories but not specifically in purine, is shown to reduce urate. Rheumatologists should have regard for their gouty patients cardiovascular status, not just because they are good physicians but also because it may be good for the management of gout. Diet is back.
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