Spinach and gout: Spinach packs a real nutrient punch. But is it safe to eat with gout? Read on to discover why a natural compound in spinach may be the deciding factor, even more so than its purine content.
Is spinach safe to eat with gout?
In order to determine if spinach can increase (or decrease) the risk of gout, we first need to take a look at the root cause of gout…
The starting point for gout is too-high levels of uric acid in the bloodstream, a condition called hyperuricemia (spelled hyperuricaemia in some countries). If this persists over an extended period then the saturation point at which crystals of monosodium urate can form out of uric acid may be reached. When this occurs microscopic needle-like crystals can settle in the joints and connective tissue, causing acute inflammation, in other words, a gout flare or attack.
Uric acid is a natural byproduct of the metabolic breakdown of chemical compounds called purines which exist in our body’s cells and in the cells of the food we eat. Around 70% of purines comes from our own cells with approx. 30% coming from the food we eat. So the impact of purines in food should not be underestimated.
As a result, gout sufferers are usually advised to change to a low-purine diet in which:
- low-purine foods can be eaten freely.
- moderately-high purine foods have to be limited in both portion size and frequency of consumption.
- high-purine foods have to be avoided altogether.
So next, we need to find spinach’s purine content…
Purine Content of Spinach
Spinach is considered a moderately-high purine food so, according to the strategy above, it has to be consumed in moderation. That is to say, no more than 1 x 3.5 oz (100 g) serving per day. And not everyday either. By following this rule spinach shouldn’t cause any gout problems.
But why not avoid it altogether if we have to limit it in our diet? Wouldn’t that be a whole lot easier?
Well, we could remove it from our diet, but spinach has so much to offer in terms of its health benefits outside of gout…
Nutrients in Spinach
Spinach is widely regarded as a superfood because it’s packed full of nutrients and low in calories.
One cup of raw spinach contains:
- 0.86 g of protein
- 7 calories
- 0.81 g of iron
- 30 mg of calcium
- 167 mg of potassium
- 24 mg of magnesium
- 2,813 international units (IU) of Vitamin A
- 58 micrograms of folate (vitamin B9)
It also contains good amounts of vitamins B2, B6, C, E, and K, fiber, manganese, copper, phosphorus, and thiamine.
Health Benefits of Spinach
Because spinach packs such a nutrient punch, several studies have suggested it may help to:
- manage diabetes
- strengthen your immune system
- promote healthy skin and hair
- prevent some cancers
- promote a healthy digestion
- prevent asthma
- control blood pressure
- promote heart health
- strengthen bones
- promote healthy eyes
- prevent macular degeneration
- reduce inflammation
So you can see that, even though a gout sufferer needs to limit its consumption because of its purine content, spinach is such a nutritious vegetable that it would seem a bit silly to stop eating it altogether.
Or would it?
There is a serious problem, which cannot be ignored, and it’s got nothing to do with purines…
Risk of Kidney Stones
One of the biggest problems with eating lots of spinach is a heightened risk of kidney stones due to its high oxalate content.
Oxalate is an organic compound found in many plants but in particularly high amounts in spinach. As it passes through the digestive system oxalate molecules can bind with calcium molecules in the kidneys to form very tiny crystal-like structures.
These tiny crystals can then bind together again to form a larger, more solid mass in the kidneys, which we refer to as a kidney stone. Around 80% of all kidney stones are calcium oxalate stones formed in this way.
However, there are ways to help minimize the risk…
Jessianna Saville, writing in the National Kidney Foundation website, explains in some depth the following strategies for reducing the risk of kidney stones:
- Stay well-hydrated with water.
- Incorporate high calcium foods into your diet. [*See my note below.]
- Keep your salt and sodium intake low!
- Limit intake of any food or beverage with added sugar and other sweeteners, such as high fructose corn syrup.
- Moderating protein intake may lower the chance of stone formation.
- Eliminate excessive intake of high oxalate foods.
*Note: I know, this particular strategy seems counterintuitive, since it’s calcium oxalate that forms the kidney stone! Why on earth would we eat even more calcium?
Well, here’s my non-scientific understanding of how this may work…
Kidney stones are usually formed in the kidneys / urinary tract when there’s a lot of oxalate and calcium compared to the volume of urine being produced. Overtime the urine can become saturated with oxalate and calcium which can then more easily bind together as crystals. These calcium oxalate crystals can then ‘clump’ together to form kidney stones.
But when oxalate binds with calcium in the gut less oxalate and calcium is absorbed through the intestinal wall into the bloodstream. Instead more of the calcium oxalate is eliminated as a waste product in stools.
So, if we can get more oxalate to bind with calcium in the gut, then less oxalate will pass through the intestinal wall into the bloodstream, so less will pass into the kidneys, thus reducing the risk of stones.
And one way to get as much oxalate as possible to bind with calcium in the gut is to consume even more calcium, not less. Consuming more calcium gives even more calcium-binding opportunities for oxalate in the gut, which then gets excreted through stools rather than through urine.
Note: It’s best to get the extra calcium from dairy sources such as low-fat milk, cheese, and yogurt, as it’s much more easily absorbed than plant-sourced calcium, including supplements.
And there are other ways to reduce the risk; for example, by ensuring that all high oxalate foods are soaked, steamed, or cooked so that much of the oxalate leeches out of the food and never gets ingested in the first place.
So, can you eat spinach if you have gout?
We can’t ignore the fact that spinach is moderately high in purines. So us gout sufferers have to avoid it or, at the very least, limit its consumption as set out earlier.
Then again, it’s one of the so-called ‘superfoods,’ with a load of health benefits, so it might be in our own best interest to not avoid it altogether.
But, it’s also a high oxalate food and, as such, brings a higher risk of kidney stones, although there are several ways to help mitigate against that risk.
So, if it can be consumed in moderation without affecting your gout, and you could reduce the risk of stones using those earlier strategies, is there any reason why you shouldn’t eat it, albeit in moderation?
Well, there may be…
It’s known that certain individuals are predisposed to kidney stones, aside from the added risk of consuming high oxalate foods…
The Mayo Clinic lists the following high risk factors:
Factors that increase your risk of developing kidney stones include:
- Family or personal history. If someone in your family, you’re more likely to develop stones, too. And if you’ve already had one or more kidney stones, you’re at increased risk of developing another.
- Being obese. High body mass index (BMI), large waist size and weight gain have been linked to an increased risk of kidney stones.
- Digestive diseases and surgery. Gastric bypass surgery, inflammatory bowel disease or chronic diarrhea can cause changes in the digestive process that affect your absorption of calcium and water, increasing the levels of stone-forming substances in your urine.
- Other medical conditions. Diseases and conditions that may increase your risk of kidney stones include renal tubular acidosis, cystinuria, hyperparathyroidism, certain medications and some urinary tract infections.
If you recognize any of those high risk factors in your life, then you are predisposed to kidney stones. So you may have to seriously consider avoiding spinach altogether.
If you aren’t predisposed to stones, you might wish to think about eating limited amounts of spinach, but only as long as you incorporate those strategies for reducing the risk of stones. Even then the risk doesn’t totally disappear.
Personally, I’ve taken spinach out of my diet because I’ve had kidney stones in the past. But, truth be told, I probably would have done so even had I not been predisposed to stones. That’s just me. I’m risk averse.
At the end of the day, it’s entirely your own decision whether or not to include spinach in your gout diet. But do your due diligence first. Certainly talk to your doctor about it, especially if you are predisposed to kidney stones.
