- Gout is an auto-inflammatory disease caused by a disorder in purine metabolism and the resulted chronic elevation of blood (serum) uric acid (i.e., hyperuricemia)
- Men have a higher risk of gout at a lower given blood level of uric acid, and at a lower age than women – generally 10 years earlier.
- Women who go through early menopause, or have estrogen deficiency are at higher risk than women who progress through menopause at a normal age, due to oestrogen’s role in increasing uric acid excretion.
- Insulin resistance increases risk of gout, as insulin reduces uric acid secretion. The relationship between insulin resistance and gout is more pronounced in women than in men.
- There is a bi-directional relationship between high blood pressure and gout: ie if you have high blood pressure, your risk of gout goes up (independent of diuretic medication that is taken), and if you have gout, your risk of developing high blood pressure also increases. High blood pressure can result in damage to kidney and a reduction in uric acid excretion, and the inflammation associated with gout can stiffen and damage arterial walls, and reduces production of nitric oxide – which helps widen arteries.
- Genetics play a role in determining risk associated with gout – and people with a particular genetic profile (such as those of European descent with the SNP sequence SLC2A9 as an example) have an increased risk, as do those with ABCG2 rs2231142. However, as with any genetic risk factor, lifestyle determines if these genes are switched on or off, so while this information could be useful (and more people are starting to find out their genetic profile and determine what it means for their health), it is your lifestyle habits predominately regulate overall risk
- Triglycerides increase in the bloodstream when people overeat refined carbohydrate foods, and recent research suggests a reduction in serum uric acid occurs when triglycerides decrease.
- Alcohol intake is associated with an increased risk of gout – beer more so than wine.
- Overall fructose load in the diet is the only type of carbohydrate that is known to increase uric acid levels, potentially because when metabolised, it depletes phosphate and therefore doesn’t help produce ATP (energy) in the body and instead increases uric acid production. Fructose from processed food (and particularly sugary sweetened beverages) can elevate insulin levels and increase risk of insulin resistance. There may be a genetic element to this also, with people who have polymorphisms in SLCA9 and ABCG2 genes responding unfavourably to a load of fructose.
- A large cross sectional survey found that people following a vegan diet had the highest serum uric acid concentrations compared to fish eaters, meat eaters and vegetarians, independent of smoking status or alcohol intake.
- While seafood is often cautioned against for people who experience gout due to its purine content, a number of studies have failed to find a relationship between seafood intake and serum uric acid levels. Those that have found a relationship may not have adjusted for body mass index (BMI), which can confound the relationship as it did in this study. Indeed, those populations who are at greater risk today (such as Maori and Pacific among New Zealand population) enjoyed a traditional diet of predominantly seafood, vegetation, tubers and gout was non-existent.
What to do?
- Look after your gut. Bacteroides caccae and Bacteroides xylanisolvens are increased, and Faecalibacterium prausnitzii and Bifidobacterium pseudocatenulatum depleted in the gut of people who experience gout, suggesting a strong correlation with the presence of gout. F prausnitzii is one of the most abundant bacterium in the gut of a healthy individual, helping produce short chain fatty acids butyrate, which is fuel for our gut bacteria, and the provision of B pseudocatenulatum improves markers of gut wall integrity. So these are pretty important! While this doesn’t necessarily mean that the provision of certain bacteria through probiotics will reduce gout attacks, it does suggest that inflammatory processes of the gut play a role in the presentation of gout and provides further evidence of the importance of a diverse population of bacteria in the gut for overall health.
- Supplementing with 1500mg vitamin C reduces serum uric acid and its antioxidant functions may also help kidney function by reducing inflammation.
- Like your coffee? You don’t have to go without if you have gout and in fact, 4-5 cups per day have found to decrease serum uric acid that isn’t seen with green or black tea, or total caffeine intake. Decaffeinated coffee has afforded similar benefits, leading investigators to suggest the phenol content (phytochemicals) might increase insulin sensitivity and decrease serum insulin, as discussed above insulin levels have a positive correlation with uric acid due to decreased renal excretion. Furthermore, xanthines, either in caffeine or in coffee itself, could inhibit xanthine oxidase – an enzyme that increases reactive oxygen species (and inflammation).
- Magnesium intake is associated with a decreased serum uric acid level in males, and marginal intakes is associated with higher levels of markers in the body indicative of inflammation. Magnesium is low in soil which makes dietary sources of the micronutrient not as high as they once were, therefore supplementing with magnesium of 300-600mg/day (depending on bowel tolerance) is likely a good idea. (To be honest, I’m a big fan of magnesium supplementation for pretty much anyone male or female, given it’s a co-factor in over 300 processes in the body).
- Tart cherry extract – not just useful for sleep – is found to reduce the prevalence of gout flare ups in cross sectional studies, potentially due to the presence of polyphenols including anthocyanins, and vitamin C found in the fruit, which have anti-inflammatory and antioxidant affects.
- The consumption of low fat dairy products is linked to a lower risk of gout in larger population studies.*
- Anecdotally (as in, I didn’t find any study on pubmed to support this), baking soda is used to increase pH level of the blood (¼ teaspoon in water), thus making uric acid in the blood able to be excreted. If you know of any studies around this that I’ve missed, let me know!)
While a low purine diet is often recommended as a dietary prescription for people with gout, many purine-containing foods (such as seafood and vegetables) do not contribute to hyperuricemia or gout and may in fact be protective. The effects of red meat consumption on serum acid levels are arguably hard to disentangle from other elements of the modern dietary pattern, and are often in conjunction with higher alcohol intake, lower fruit and vegetable consumption and higher fast-food intake – all contributors to inflammation in the body. In addition, the agricultural practices of the cattle industry in countries such as the US where many of the epidemiological studies that associate red meat with poor health (including higher serum uric acid levels) include the use of antibiotics, poor farming practices and animals that are grain and not grass fed, altering the fatty acid profile of the meat to be higher in omega 6, pro-inflammatory fats. Furthermore, processed and fresh meat is often grouped together – thus a steak is viewed the same as a hamburger from a fast-food outlet – the latter often being in the company of a bun, fries, mayonnaise made with industrial seed oils and a sugar sweetened beverage – the adverse effects which many, myself included, argue cannot be adjusted away by a statistician when determining risk.
*I don’t think you need to start consuming low fat dairy if right now you’re enjoying the benefits of full-fat dairy in the context of an awesome diet. I think this could well be indicative of overall lifestyle patterns. I’d be surprised if there were studies showing that risk of gout is increased in a diet that is whole food, minimally processed, an abundance of vegetables that also incorporated full-fat dairy products.