Gout

Chapter summary

• Gout is increasing.
• The author says the most likely driver now is added sugar, because fructose directly raises uric acid.
• The interaction with kidney function matters: uric acid must be cleared.

What gout is

• An inflammatory arthritis caused by high uric acid in the blood, which forms crystals in joints. It often strikes the big toe and causes severe pain and swelling.
• Uric acid is a by-product of purine metabolism. Purines are higher in red meat, organ meats, turkey, some fish and seafood.
• Some uric acid is normal and acts as an antioxidant. Excess acts as a pro-oxidant and may be linked to insulin resistance.
• Gout was once called the “rich man’s disease”. Lead in food and drink vessels may have contributed.

How common is it?

• New Zealand rates rose from 3 per 1,000 in Europeans and 27 in Maori (1958) to 30 and 70 by 1992.
• In a US managed-care database, prevalence rose from 2.9 per 1,000 in 1990 to 5.2 per 1,000 in 1999, and may have doubled again since.

Where views differ

• Conventional view: Purine-rich foods, especially red meat, and alcohol are key risk factors. Patients are told to cut them.
• The sugar view: Purines alone do not trigger attacks. Uric acid is often normal or low during an attack. Fructose raises uric acid, and high intakes drive many features of metabolic syndrome, including high triglycerides and insulin resistance.
• Confounding: Red meat is part of a Western diet pattern high in sugar, vegetable oils, sweet drinks and refined grains. Heavy meat eaters also tend to smoke, drink and weigh more. Studies try to adjust for this but cannot fully remove it.
• Evidence for fructose: A cohort study of men (Choi and Curhan, 2008) linked soft drinks and fructose to higher gout risk. A rodent study found fructose can induce metabolic syndrome through uric acid.
• Mechanism under study: The transporter GLUT9 helps clear uric acid, including via the gut. Kidney clearance remains important.
• Caveat: Naturally occurring fructose in whole fruit is relatively benign in small amounts. The concern is high intake.

Take-away points

• Avoid sugary drinks and alcohol, both of which raise gout risk.
• Rather than only cutting purines, cut fructose.
• See your doctor if you have repeated attacks. Medication may be needed.

References

• Kresser, C. (2013) Will eating a paleo diet cause gout?
• Angelopoulos, T. et al. (2009) The effect of high-fructose corn syrup consumption on triglycerides and uric acid. J Nutr 139(6):1242S-1245S.
• Nakagawa, T. et al. (2006) A causal role for uric acid in fructose-induced metabolic syndrome. Am J Physiol Renal Physiol 290:F625-F631.
• Roddy, E. and Doherty, M. (2010) Epidemiology of gout. Arthritis Res Ther 12(6):223.
• Choi, H. and Curhan, G. (2008) Soft drinks, fructose consumption, and the risk of gout in men: prospective cohort study. BMJ 336:309-312.
• Cordain, L. et al. (2005) Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr.
• Wallace, K. et al. (2004) Increasing prevalence of gout and hyperuricemia over 10 years among older adults in a managed care population. J Rheumatol 31:1582-1587.
• Doherty, M. (2009) New insights into the epidemiology of gout. Rheumatology 48(suppl 2):ii2-ii8.