How about we stop Kidney Disease?

By October 8, 2010Sugar

What will put the most Australians in hospital this year? Car accidents? No way. Heart attacks? Nup. Cancer? Not even close. No, it’s Kidney Disease. But a series of recent studies suggest there is a very simple way to turn that statistic around.

Chronic kidney disease is now responsible for more than 1 in every 7 hospitalisations. And that rate has gotten very bad, very quickly. Between 2001 and 2008, hospital admissions for kidney dialysis alone increased by 71 per cent.

The news is even worse for indigenous Australians. At the end of 2007, they were being treated for kidney disease at six times the rate of the rest of the Australian population. This is why the number hospitalisations in the Northern Territory increased by an incredible 120 per cent (almost 20 per cent per year) in the same period.

The NT has another interesting claim to fame (aside from Croc Dundee). According to Coca-Cola it has the highest per capita consumption of Coke in the world. Increasingly the science is starting to suggest that is more than a mere co-incidence.

We don’t know what causes most forms of kidney disease and we certainly can’t cure it (other than by replacing the kidneys). But there is a line of studies going back over half a century that suggest the answer (to the mystery of the cause and the cure) might lie in something called uric acid.

Uric acid is a waste product created when we digest red meats. Like most waste products circulating in our blood stream, it is removed from our systems by our own little pool filter system, the kidneys.

Simply put, the theory goes that if you have too much uric acid, you end up clogging the filters in the kidneys and (over time) this degrades their capacity to work at all. There’s a line of rat studies you couldn’t jump over to prove exactly that cause and effect relationship. But rats process uric acid differently to humans (and other higher primates) so there’s always been a question mark about those studies.

In 2008, a major study conducted by the Vienna University went a long way to answering the question in humans. In that study 21,475 (initially) healthy subjects were tracked for 7 years. Their uric acid levels were compared to the occurrence of kidney disease. The outcome was an unequivocal correlation. The higher a person’s uric acid levels, the higher their likelihood of developing kidney disease. Full stop.

If eating meat was the major cause of increased uric acid production, you’d expect to see a steep increase in the amount of meat we eat over the last few decades (to go along with the sharp rise in kidney disease). But according to the CSIRO, our red meat consumption has been steadily falling since the 1970s.

It turns out though, that there’s another truly excellent way to increase the amount of uric acid in a human’s bloodstream. Feed them sugar.

In 1989, the US Department of Agriculture’s carbohydrate research team proved that they could cause a significant spike in uric acid levels just by feeding people the fructose half of sugar (it is half glucose and half fructose) at the levels (then) normally consumed by the average US citizen (20 per cent of calories – exactly the same as the current Australian suggested intake).

A much larger 2008 study of 4,867 US school children (unsurprisingly) found the same strong association between increased sugary drink consumption and uric acid levels. And an analysis published in the same year took that further by linking sugary drink consumption with the onset of kidney disease in adults using a similarly large database of results.

Uric acid is a by-product of the way our livers metabolise fructose. And unlike meat, sugar (and therefore fructose) consumption figures have all been one way traffic (up, big time) in the last five decades.

While all of that evidence is strongly persuasive, it isn’t proof. No-one has purposely fed a large group of people fructose (and kept it away from a similar group) to see which ones died of kidney disease first. But I rather suspect, sadly, we are inadvertently conducting our own little experiment on the indigenous population.

Aboriginal and Torres Strait Islanders consume around twice as much sugar-sweetened soft drink as the rest of us (which is very high because Australians are in the top ten per capita consumers in the world anyway). So (given their high indigenous population) it’s no wonder the Northern Territory featured so prominently in Coke’s statistics. And it’s even less wonder (given what the science is saying about fructose) that it features so prominently in our kidney disease statistics.

Kidney disease is massively debilitating. The only effective ‘treatment’ is getting hooked up to a dialysis machine three times a week. Meanwhile the number of people needing that treatment is growing at the rate of 6 per cent every year.The only ‘cure’ is replacing the kidneys (if you’re lucky enough to get to the head of the transplant queue (currently the wait is about four years) before you die.

Kidney disease is now killing more Australians than either breast or prostate cancer and more than twice as many as die on the roads every year. But the evidence is mounting that there is a very simple preventative measure. Don’t eat (or drink) sugar.

So how about we give that a go before the next generation destroys their kidneys too?

Image courtesy of bejim /