US research says sugar causes high blood pressure and heart disease irrespective of weight gain but critics doubt results
Sugar is a bigger threat to health than many suppose, according to a study which claims it causes metabolic illness such as high blood pressure and heart disease whether or not we put on weight.
The study was carried out by Robert Lustig, a paediatric endocrinologist in San Francisco and writer of the book Fat chance: the hidden truth about sugar. Writing in the Guardian , he says the lives of 43 obese children in the care of his clinic dramatically improved when the sugar in their diet was replaced with starchy foods like crisps. They eat the same number of calories, he says, and yet their metabolic illnes, which can cause diabetes, was reversed within 10 days.
The study, published in the periodical Obesity, is evidence, says Lustig, that a calorie is not a calorie the claim he makes in his volume and which has been contested by many scientists who say the damage sugar does is through its calorific content alone.
In the study, carried out at the UCSF Benioff childrens hospital San Francisco and Touro University, California, the 43 children, aged nine to 18, had all been referred to hospital because of their weight and significant related health issues, such as high blood pressure.
They were given nine days of food prepared for them by the clinic and told to weigh themselves daily. The added sugar in their diet was reduced from 28% to 10% and the fructose a kind of sugar believed to be particularly problematic from 12% to 4% of total calories. Sugary food is hereby replaced by starchy food such as turkey, hot dog, crisps and pizza.
After nine days, the researchers say, most aspects of the childrens metabolic health improved their diastolic blood pressure, bad LDL cholesterol and triglycerides fell, fasting blood glucose went down and insulin levels were cut by a third. Their liver function exam results improved.
But in spite of Lustigs affirmations that he has proved his thesis, the reaction to the study was muted. The results are not convincing to me this is a very small examine, and it has not been statistically well-controlled, said Naveed Sattar, prof of metabolic medication at Glasgow University.
Also, when people are losing weight, even if modest, their metabolic changes can seem larger than they actually are one needs to see results once folk return to their habitual country after theyve finished losing weight. Overall, such studies is of modest interest but is far from convincing.
Tom Sanders, prof emeritus of nutrition and dietetics at Kings College London, said the study needed to be viewed with some scepticism because it was uncontrolled. It did not compare the children with a similar group who continued to eat a high-sugar diet. The comparison instead was attained with their weight and health before such studies while on their usual diet. But it is well known that obese children underestimate and under-report food intake, particularly of soft drink and snack foods, said Sanders.
This is a fundamental flaw in such studies. It is likely that the changes in metabolic outcomes observed can be explained by the experimental diet providing fewer calories than the childrens usual intake.
Given that sugar and starch contain roughly the same quantity of calories per gram, he said: It is just inconceivable that isocaloric substitute of sugar from starch would have such a large effect on metabolism. In fact it denies the basic the statutes of thermodynamics.
Read more: www.theguardian.com