Last month I threw together an infographic on the 12 Ways Fructose Destroys Your Body.  It’s a good summary, but the lawyer in me loves footnotes.  So here is the detail behind the claims that picture makes.  Well, it’s the detail behind seven of them.  The rest will come in the next post on this topic.

1.    Fructose rots your teeth

The first part of your body that fructose touches is your teeth and they are usually the first to go in its path of destruction.

The statistics are clear. Populations exposed to sugar for the first time go from ‘background’ levels of decay (of around 4 cavities per 100 teeth) to ‘modern’ levels of around 24 cavities per 100 teeth. The mechanism is known and the science is uncontroversial. Not even Coca-Cola dares deny that sugar and tooth decay go together like peas and carrots.

Tooth decay is caused by bacteria called S. Mutans (Streptococcus Mutans). S. Mutans loves a good feed of sugar. And after it gets some, it produces lactic acid as a waste product. It’s that lactic acid that can do the damage to our teeth. But if the only sugar in our diet is glucose or carbohydrates that are converted to glucose, our saliva quickly neutralizes the acid and we regenerate any damaged enamel.  This means t0oth decay is kept to the minimum.

But, if there is some fructose available as well as glucose then through a quirk of evolutionary biology, S. Mutans can build itself a saliva proof home.  

We call this little anti-saliva shield, plaque. Plaque binds S. Mutans to each other and to the tooth enamel. It traps the lactic acid against the tooth surface, protects it against the waves of saliva and gives it time to eat through the enamel.

2.    Fructose inflames your gut

Our small intestine can become inflamed when toxic molecules normally attached to bacteria (endotoxins) escape through our intestinal walls and into our bloodstream.  Our immune system has an inflammation reaction to endotoxins.

Binge drinking alcohol will produce exactly that effect.  Unfortunately so will overconsumption of fructose.  If you drink alcohol all day every day then fructose will not be noticeably adding to the problem, but if you are like most people and your daily poison choice is sugar, then it is probably responsible for your inflamed gut.

Unfortunately both alcohol and fructose also appear to increase the populations of bacteria which produce endotoxins in our intestines (something charmingly termed bacterial overgrowth). So we get the double whammy of more endotoxins in our gut and doors left ajar (gut permeability) to let them into our bloodstream.

3.    Fructose destroys your liver

After absorbed fructose hits your bloodstream, next stop is the liver.  We are adapted to a diet where most carbohydrates are glucose or glucose based.  So we have exquisitely finely tuned feedback loops which tell us we are full when we’ve taken on enough glucose.

Those loops don’t fire for fructose, so our liver will merrily convert any that it finds straight into fat.  That fat is stored in the liver and exported into our bloodstream.   Because we all have such a high fructose diet more than a third of Adults now have (NAFLD) Non Alcoholic Fatty Liver Disease as a result. NAFLD can then progress through various disease stages and ultimately end in cirrhosis requiring a liver transplant.

By the way there is interesting speculation that the trigger for converting mere fatty liver into cirrhosis is an immune response to endotoxins leaking from the gut.

4.    Fructose takes out your pancreas (and your eyes and limbs)

Our bodies convert most carbohydrates to glucose. In healthy people that glucose is pumped out to the cells that need energy via our bloodstream. Cells that need energy, signal their desires by moving glucose receptors to the cell surface (kinda like hanging out the “this room needs servicing” sign in a hotel).

But when fructose-fat accumulates in the liver and bloodstream, it affects something called insulin sensitivity.  The receptors never get to the cell surface (or if they do, it’s in smaller numbers). The result is that the glucose goes sailing by. The maid doesn’t know the room needs her and our bodies starve in a sea of food.

Because the glucose doesn’t get used by the cells (or not as many of them), it stays in the bloodstream longer and the result is a longer than normal high blood sugar concentration.  This is called insulin resistance or pre-diabetes.

Our body usually responds to insulin resistance by pumping up the insulin levels until the glucose is cleared.  If we ask our body to run on overdrive like that for years, for most of us, our pancreas (the insulin maker) will pack it in and we will need to get daily insulin injections to live.  Along the way, the persistent high blood glucose will result in blindness and limb amputations for many sufferers.

5.    Fructose makes us fat

Our appetite control hormones are exquisitely balanced to ensure we have just the right amount of energy on hand.

But when that balance is disrupted, our fuel management system can veer wildly out of control. A disrupted appetite control system can store too little or too much fuel. Too little looks like anorexia, too much looks like, well, most of us. Obesity is a symptom of a failure of the balance of hormones controlling how much food we take in.

When the pancreas attempts to cope with elevated blood glucose (caused by fructose derived fat) by ramping up insulin, it is only fixing the immediate problem. All that extra insulin doesn’t make the damaged cells any less insulin resistant, it just means that undamaged cells use the insulin to make fat.  In other words the blood glucose is cleared from the bloodstream by making us fatter.

Just for good measure, fructose also interferes directly with leptin signalling.  Leptin is our long term energy storage hormone, the one that tells us not to eat between meals.  Fructose makes us less sensitive to that hormone and as a result we eat more of everything.

This double dose of hormone dysfunction causes us to store too much fat in our cells, but the body is not aware the fat is there and keeps demanding food. Our appetite control system thinks we are starving even while we have more than enough fat being packed away (usually in very unsightly places).

When an obese person restricts the amount of food they eat, they are not changing the underlying error in the appetite control system. The body thought it was starving before the diet, now it’s really starving. It will not use the fat store to satisfy its need for food because the hormonal disruption means it doesn’t even know it’s there.

The hormones will force the body to sacrifice muscle and even organs to make up for the missing calories. And the whole time, the dieter will feel like they are starving to death.

6 & 7. Fructose messes up your kidneys (and gives you gout)

When fructose is converted to fat by our liver, a significant amount of a waste product called uric acid is produced.  Our kidneys are our built in pool filter for removing waste products like uric acid.  But they can be overwhelmed by the quantities that will be produced by the amount of fructose in the modern diet.  When that happens our kidneys start to fail.  And this is likely to be why excess uric acid has been associated with significant increases in kidney disease in a long line of rat studies and more recently in human trials.

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.

A side effect of that failure to remove uric acid is that it accumulates in the joints of the feet and ankles, causing a form of acute arthritis called gout.  If you suffer from gout, then it might be time to get your kidney function tested.

And that’s the first 7 ways fructose wrecks your body and health.  I’ll detail more in the next post, but if you want a preview check out my infographic – 12 Ways Fructose Destroys Your body.