Gout and diet: sorting fact from fiction

Diet and alcohol intake are no longer thought to play as big a role in gout as previously thought, yet patients with gout often show great interest in how they can improve their diet. Below are answers to common myths.

Myth 1: poor diet and excess alcohol cause gout 

Because a painful gout flare sometimes coincides with excessive intake of alcohol or specific foods, it is not surprising that some patient’s attribute their gout to their diet.

WHAT WE KNOW: The primary contributors to gout are a genetic predisposition, impaired kidney function and obesity. Each of these factors can lead to an elevated serum urate concentration (SUC) increasing the risk of developing gout. 

In susceptible people, excess consumption of certain high-purine foods (see next myth) or alcohol can lead to an acute change in SUC that can trigger a gout flare. The diuretic effect of alcohol can also lead to dehydration, further elevating SUC.

The essential and most effective and efficient way to lower urate levels is with medication, typically allopurinol. That said, while dietary management alone will not control gout, adopting a healthy balanced diet with limited alcohol consumption will contribute to successful gout management, as well as management of common comorbidities such as diabetes or obesity.

Myth 2: all purines are bad 

Historically we have been told to provide blanket advice to patients that all high-purine foods contribute to gout flares and should be avoided.  

WHAT WE KNOW: two-thirds of purines are produced by the body with the remaining one-third produced by our diet. Purines are metabolised into uric acid which is normally reabsorbed or excreted. 

Purines from animal sources, particularly red meat and some seafoods (e.g. shellfish), can increase the risk of gout because they tend to raise serum urate concentrations. Alcohol, especially beer, also contains purines that contribute to higher serum urate. Sugary drinks are high in fructose, which is broken down by the body into purines. In contrast, plant-based purines do not appear to have the same effect, even from those foods described as purine rich like mushrooms, beans and lentils.

It’s not clear why purine types are not equal when it comes to the amount of uric acid they can produce. Among the four purine bases, adenine and hypoxanthine (which are  the main purines in animal and fish meats) have been reported to be more uricogenic than guanine and xanthine. 

While they may not all be equal, no purine is in fact ‘bad’, so telling patients to completely avoid certain high-purine foods isn’t necessary or helpful. Instead, encourage moderation and a balanced diet that reflects their personal, cultural and religious preferences and includes, where possible, plenty of vegetables, grains, low-fat dairy products and adequate hydration with water.

Myth 3: take vitamin C to treat gout

Vitamin C has been a supplement of interest for gout for many years. 

WHAT WE KNOW: there is some research suggesting vitamin C supplements may cause  a slight decrease in serum urate concentration and a modest reduction in risk of developing gout among adults who have not been previously diagnosed with the condition. However, any effect is minimal and not sufficient to recommend a role in prevention. 

Among patients diagnosed with gout, vitamin C supplementation has no clinically significant effect on serum urate concentrations when compared to allopurinol. In addition, there is no evidence that vitamin C supplementation can lessen the severity or frequency of gout flares in patients with established gout.

Myth 4: drinking cherry juice concentrate reduces the risk of flares

Tart cherry juice is a popular alternative therapy for gout management, but the scientific evidence supporting its effectiveness is limited and inconsistent.

WHAT WE KNOW: in studies involving healthy volunteers, concentrated tart cherry juice mildly lowered urate levels, but had no effect when given to people with gout. 

Other research has suggested that consuming cherries or cherry concentrate might be able to reduce risk of acute flares due to their high levels of anthocyanins - naturally occurring anti-inflammatory molecules. However, the National Institute for Health and Care Excellence (NICE) assessed these studies, noted they were low quality, with small sample sizes and short follow-up, and concluded the evidence was not robust enough to make any recommendations.

Take-aways for your patients

	Maintain a healthy weight and balanced diet: while no specific diet is endorsed, maintaining a healthy weight and balanced diet can significantly benefit gout management.
	Maintain adequate hydration: encourage water intake and advise a reduced consumption of  beverages high in fructose (added or natural), such as non-diet soft drinks and fruit juices.
	Lowering alcohol intake is recommended: in addition to containing purines, alcohol can also cause dehydration – two factors that can increase serum urate concentrations. Encourage patients who drink alcohol to do so in moderation, in line with national guidelines.
	Reduce consumption of animal-based purine-rich foods: this includes foods like anchovies, sardines, scallops, mussels, bacon, beef, liver, turkey, veal,  and venison.

Other points to consider when counselling patients regarding diet and lifestyle:

• be mindful of comorbidities: consider existing dietary advice for other conditions to avoid conflicting guidance.

• address culturally-specific beliefs: for better adherence to dietary recommendations, consider culturally-specific beliefs about health and lifestyle. Information prepared specifically for Aboriginal and Torres Strait Islander patients is available via the Staying Moving Staying Strong program by Arthritis Australia. In-language information for Māori, Samoan, and Tongan patients is available at Arthritis NZ.

• keep a flare diary: track when flares occur and note what was being consumed at the time. This can help identify potential triggers and plan for pre-emptive management to reduce future attacks.

The Quality Use of Medicines Alliance has worked in collaboration with Arthritis Australia to develop an updated patient fact sheet available now to share with your patients.

For more free Quality Use of Medicines education, check out QHUB on Medcast