It’s not just drink. Toast and potatoes could cause liver damage
Researchers call for rethink over disease that hits 20 per cent of us
HOW much have you been drinking? was Dr David Unwin’s standard question when a patient’s tests showed their liver wasn’t functioning properly. Your liver health can be measured by a blood test for a protein called gamma-glutamyl transpeptidase (GGT) — if your levels are high, it suggests that your liver is under pressure and is usually taken as a sign that you are drinking too much alcohol.
Indeed, Dr Unwin, a Gp from southport, Merseyside, explains: ‘Like many other doctors, I used to assume patients often underestimated the amount they drink and that alcohol was the main reason for a raised reading.’
But Dr Unwin doesn’t think like that any more. That’s because some of his patients have raised GGT levels, but drink very little or nothing at all.
Instead their raised levels are due to non-alcoholic fatty liver disease, which is linked to diet. An estimated 20 per cent of Britons have this condition — twice as many who have type 2 diabetes.
In some cases, it can progress to serious liver damage and ultimately liver failure. However, it is not just a precursor to liver problems.
some experts believe it could also be a key warning that the patient is at higher risk of other conditions such as heart disease and diabetes.
The conventional wisdom on nonalcoholic fatty liver disease is that eating too much is what’s caused the problem, as excess calories are simply stored as fat in the liver.
But some experts, including Dr Unwin, believe sugar and starchy food pose a particular threat.
‘They cause a problem because they are rapidly turned into glucose and the body’s first port of call for storing glucose is in the liver,’ he says.
What the liver can’t store is then stored as body fat.
The solution, he says, is simple: a low- carbohydrate diet. That means less glucose in the liver and so less fat.
And Dr Unwin has proven this theory in a study just published in the specialist journal Diabesity in practice. He selected 69 patients in his practice who had very high levels of GGT and put them on a low-carb diet for 13 months.
ESSENTIALLY, they ate mainly green veg, lower-sugar fruit such as blueberries, nuts, fish, eggs and meat. The idea was to cut out all added sugar and reduce starchy carbs, such as bread and potatoes, while increasing the amount of healthy fats from olive oil or butter.
‘The results were striking,’ says Dr Unwin. ‘The first thing that happened was their GGT readings dropped by an average 47 per cent. That makes sense because the liver is the first destination of new glucose supplies.’
After that came an improvement in other key health markers — on average, blood sugar levels dropped by a remarkable ten points, about the same amount achieved by some diabetes drugs — the patients’ weight fell by 11 lb, while the ratio of ‘good’ to ‘bad’ cholesterol went from 4.3 to 3.8, even though the patients were all eating more fat.
The British Liver Trust, which supported the trial, described it as ‘ a very useful insight on how liver function can improve’ and said it held out the hope that low-carb diets could help cut premature deaths from liver disease.
But Dr Unwin’s way of looking at fatty liver disease is at odds with the mainstream, especially when it comes to eating fat.
The advice from the NHs, for instance, is that a low-fat diet is the best way to prevent and treat fatty liver disease.
And last week, researchers reported on the first possible drug treatment for the condition.
Researchers at Birmingham University had given a daily injection of the diabetes drug liraglutide to 14 patients for three months — four out of ten lost their liver fat.
Their weight also dropped, they had less sign of liver damage and improved diabetic markers.
‘ That’s interesting, but it’s hardly an ideal treatment,’ says Dr Unwin. ‘The drug needs to be injected daily and comes with the risk of nausea and diarrhoea. It also costs the NHs £1,400 a year.’
But not only does he argue that diet and cutting carbs hold the key to treating non-alcoholic fatty liver disease, Dr Unwin and others say the condition is more important than it is often regarded, with raised GGT acting like a canary in a coal mine — an early warning — that the glucose levels are up and the fat stores in the liver are bulging, with diabetes and heart disease down the line. ‘Non-alcoholic fatty liver is the third great epidemic of modern times, joining diabetes and obesity as major threats to health,’ says Dr Unwin.
‘And sugar and carbs look like the culprits. It’s tempting to hope that having eaten our way into all three epidemics, we can eat our way out again by cutting back on sugar and starch.’
Roy Taylor, a professor of medicine and metabolism at the University of Newcastle, has shown how blood tests for GGT can pick up signs of fatty liver years before a patient then goes on to develop diabetes.
As he has said: ‘Before diagnosis of type 2 diabetes there is a long, silent scream from the liver.’ Nonalcoholic fatty liver disease also pushes up the heart disease risk.
‘The long-running Framingham heart disease trial found a high GGT increased cardiovascular disease risk by 65 per cent,’ says Dr Unwin. ‘Now it looks as if we have a way to bring it down.’
Alan Threlfall is one of the patients who took part in Dr Unwin’s fatty liver trial. Aged 43 and weighing 19 st — he is 5 ft 8 in — he’s had type 2 diabetes for more than 12 years and described his life as ‘horrendous’.
ALAN and his wife Katy have three young children, but he says he’s had no real life with them. ‘I was sleeping 18 hours a day. I was so tired every step was like walking though wet concrete,’ he says.
‘I’d run a marketing business with Katy, but I had to stop that two years ago. I was ready to throw myself off a building.’
At the start of the trial, Alan’s GGT level was extremely high at 223 — when the healthy range is from zero to 50 — and his blood sugar level was often three times the normal level.
Four months later, his GGT has dropped to 78 and his blood sugar levels had gone from 90 (a sign of out of control diabetes) to 43.
He’s gradually coming off medication, has lost 2 st and his weight is still dropping.
Alan describes it as a miracle. ‘Within a week, I felt the fog of fatigue start to ebb away. Just being able to play with the children is wonderful,’ he says.
Critics have claimed that the dramatic improvements reported by patients such as Alan aren’t to do with cutting back on carbs, but are due to weight loss; the extra fat in a low-carb diet makes you feel fuller, so you eat less.
But ‘ this doesn’t fit with what the trial found’, says Richard David Feinman, a professor of cell biology at the state University of New York Downstate Medical Center in Brooklyn.
He co-authored the paper Dr Unwin wrote on his study and is an international expert on carbohydrate metabolism.
‘If the drop in GGT was a direct result of weight loss, you would expect to see the two dropping together,’ he says. ‘But that isn’t what happens.
‘Instead the improvements in GGT come really quickly, within a few weeks at the beginning, before significant weight loss has even started.’
The challenge, of course, with all diets is whether you can keep it up. But Dr Unwin is optimistic.
‘On the trial, they followed it for an average 13 months, but my wife and I, along with many of the patients, have been on it now for nearly three years.
‘I’m 57 and have just run a 10km (six-mile) race in 52 minutes as my body has adapted to using fat, rather than carbs, for fuel.
‘It’s certainly not the Atkins diet, which has too much protein and not enough greens.
‘Feeling healthier and having enough energy to play with your grandchildren is motivating. It feels like good medicine when people improve their lives through lifestyle changes and without taking medication.
‘so, surely this is worth some further investigation?’