Gout, kidney stones and high blood pressure: are the current dietary guidelines more harmful than helpful?

Why they could be making matters even worse, and what you need to do instead.

Photo by Alicia Christin Gerald on Unsplash

Anyone with one or all of the unholy trilogy of gout, kidney stones and high blood pressure has probably reduced dietary purines, as advised. After all, purines increase uric acid levels and high uric acid is responsible for those crystal deposits that cause so much pain.

But it is becoming increasingly clear from the evidence that this advice is worse than ineffective.

Let’s dissect this seemingly contrarian view one question at a time.

What is uric acid?

Uric acid is a product of the breakdown of purines. It is dissolved in blood and filtered by the kidneys. Although it is a normal part of urine, approximately 90% of filtered uric acid is reabsorbed back into the blood.

Is uric acid a bad thing?

No – it is a powerful antioxidant, indeed the most abundant antioxidant in the blood.

Furthermore, low uric acid production is a risk factor for neurodenerative diseases, including Parkinson’s, multiple sclerosis and Alzheimer’s.

What are purines?

Purines are compounds found in almost every natural food. Generally speaking, fish and meat, especially organ meats, have the highest amounts and plant foods have the lowest, with some exceptions.

source

But more significantly, two-thirds of the purines in your body do not come from diet. They are made in various organs and tissues and found in every cell of the body.

Purines are what fuel the cell. The basic unit of energy produced by the mitochondria of each cell is called adenosine triphosphate (ATP) and ATP is a purine.

Purines, along with pyrimidines, form the building blocks of DNA and RNA.

They are also involved in the metabolic pathways of carbohydrates, fats and amino acids, platelet regulation, and cell signalling.

Purines, clearly, are not the enemy.

So what’s the problem?

Too much uric acid is the problem. Excessive levels of uric acid is called hyperuricemia. Hyperuricemia is usually defined as serum levels greater than 6 mg/dL in women and 7 mg/dL in men. Anyone can be affected, but women less so than men, until they are post-menopausal and no longer benefit from the protective effect of oestrogen.

Hyperuricemia is surprisingly common. In fact, 21% of the general population is estimated to be affected, and of those people, 90% - 95% display no symptoms. For that reason, hyperuricemia is not considered a pathological state.

‘Hyperuricemia does not indicate a pathological state because it is extremely prevalent in the general population and is asymptomatic in 90% to 95% of people.’

However, too much uric acid can in some people be detrimental to health, and like everything else that causes disease, rates of hyperuricemia are increasing and it is much more common in economically-advanced countries.

What are the effects of hyperuricemia?

Hyperuricemia is a well-known risk factor gout, a form of arthritis that causes hot, swollen joints, most frequently in the big toe, as uric acid forms crystal deposits that settle in joints. They can also settle in the kidneys and form kidney stones.

It is also associated with hypertension. It decreases the availability of nitric oxide, a substance needed to relax blood vessels and keep blood pressure within the normal range.

Other complications include metabolic syndrome.

Metabolic syndrome is a cluster of symptoms that include obesity, high blood pressure, high blood fats and insulin resistance.

Men are more affected than women as they have naturally higher levels of blood uric acid.

‘Hyperuricemia is a key risk factor for the development of gout, renal dysfunction, hypertension, hyperlipidemia, diabetes and obesity.’

What causes hyperuricemia?

Now we’re getting to the crux of the matter.