Читать книгу Breakfast is a Dangerous Meal: Why You Should Ditch Your Morning Meal For Health and Wellbeing - Terence Kealey, Terence Kealey - Страница 30
ОглавлениеBlood glucose and breakfast: the unhealthy majority
In Chapter 1 I reported how both Professor Christiansen and I had found that blood glucose levels rose disproportionately after breakfast in type 2 diabetics, and that – because raised levels of blood glucose are dangerous – breakfast was in consequence an unusually dangerous meal for those patients. Simultaneous discovery is a feature in sciencefn1 (famously, Charles Darwin had to rush his Origin of Species into print in 1859 after Alfred Russel Wallace had had the same insight into evolution by natural selection) so, equally, this type 2 diabetic breakfast discovery has been made independently by at least four other research groups.
Rather than force the reader to plough through all the papers, I’ve collated them in the box on the next page.
Blood glucose levels after breakfast in type 2 diabetes
in 2009 Dr Raj Peter and his colleagues from the Diabetes Research Unit, Penarth, UK, studied forty-nine patients with type 2 diabetes. Though he fed them the same meals at breakfast, lunch and dinner, breakfast increased their circulating blood glucose levels by 35 per cent more than did lunch or dinner. Dr Peter thus confirmed that, for type 2 diabetics, lunch and dinner were the most important meals of the day; breakfast was dangerous1
in a study on 248 patients with type 2 diabetes, a Montpelier/Swansea research collaboration gave their subjects only half as many calories at breakfast than at lunch or dinner, yet ‘the highest peak glucose value … was observed in the post-breakfast period’.2 And we are not talking small differences: breakfast, though containing only half as much food as either lunch or dinner, drove blood glucose levels 40 per cent higher from baseline
and in 2013 Dr Hans Guldbrand and his colleagues from the department of medicine in Linkoping, Sweden, found that if type 2 diabetics skipped breakfast and, instead, bundled it into a large lunch, their post-lunch blood glucose levels were no higher than if they had eaten only a normal lunch, thus confirming that lunch was, for type 2 diabetics, a safer meal than breakfast3
finally, in 1996, Dr Guenther Boden and his colleagues from the Temple University School of Medicine, Philadelphia, on studying six type 2 diabetics, found that in the morning their livers pour glucose into the bloodstream. Dr Boden’s ‘results are compatible with a large body of evidence showing [that] in patients with non-insulin dependent diabetes … plasma glucose levels rise in the early morning hours’.4
Clearly, therefore, to eat breakfast and thus further raise blood glucose levels when they are naturally at their highest must be dangerous for these patients.
Further, there are two conditions that are closely associated with type 2 diabetes, namely prediabetes and obesity, and these patients’ blood glucose levels after breakfast confirm that, for them too, breakfast is a dangerous meal (see below).
Blood glucose levels after breakfast in prediabetes and obesity
in 2006 Dr Maria dos Santos and her colleagues from the University of São Paulo, Brazil, on studying fifteen subjects with prediabetes, found their blood glucose levels after breakfast were higher than after lunch or dinner, even though they ate only half as much at breakfast than at the other two meals5
and in 1988 Dr Polonsky of the University of Chicago, on studying fifteen obese people, found that if he gave them only half as many calories at breakfast than at lunch, their glucose levels nonetheless rose nearly twice as much, thus showing that breakfast was clearly a dangerous meal for them.6
But just as it seemed that breakfast had been confirmed to be dangerous in type 2 diabetes and its associated conditions, two studies were published in 2015 apparently showing the opposite. They were published jointly by Professors Daniela Jakubowicz (Tel Aviv University) and Oren Froy (Hebrew University of Jerusalem). The message of their first paper7 was reported, accurately, on 25 February 2015 by The Times in its headline: ‘Diabetics better off with high-energy breakfast’.
That was a startling message yet, oddly, the study does not show breakfast to be a safe meal. In fact, its breakfast findings are indistinguishable from Professor Christiansen’s. So, on studying eighteen middle-aged type 2 diabetics, Professors Jakubowicz and Froy found that, like Professor Christiansen’s patients, they woke in the mornings with high blood glucose levels, at around 7 mmol/l, and that when they ate a breakfast of 700 calories, their blood glucose levels rose even higher than Professor Christiansen’s. So Professors Jakubowicz and Froy had actually confirmed that, for type 2 diabetics, breakfast is a dangerous meal. So how did their paper turn into a story of breakfast safety?
Well, let’s look at their other 2015 paper,8 whose message was accurately summarised by Tel Aviv University on its website: ‘Diabetics who skip breakfast provoke hazardous blood sugar spikes.’9 The website continued:
The clinical study was conducted on 22 type-2 diabetics who averaged 56.0 years old, with a mean Body Mass Index of 28.2 kg/m2 [i.e. they were overweight]. Over the course of two days, the participants consumed precisely the same numbers of calories and the same balanced meal – milk, tuna, bread, and a chocolate breakfast bar – for lunch and dinner. The only difference was that one day they ate breakfast and the second day they fasted until lunch. ‘We theorized that the omission of breakfast would not be healthy, but it was surprising to see the high degree of deterioration of glucose metabolism only because the participants did not eat breakfast,’ said Prof. Jakubowicz. The researchers found that participants experienced extraordinary glucose peaks of 268mg/dl (14.8 mmol/l) after lunch and 298mg/dl (16.5 mmol/l) after dinner on days they skipped breakfast, versus only 192 mg/dl (10.6 mmol/l), and 215 mg/dl (11.9 mmol/l) after eating an identical lunch and dinner on days they ate breakfast.
That looks pretty damning of skipping breakfast, but there are three points about the professors’ own university website report that are wrong. First, the figures are incorrect. Actually, the participants’ glucose peaks at dinner on the days they ate breakfast were 236, not 215 mg/dl, so the differences between the breakfast-skipping and breakfast-eating days were not so extraordinary (298 against 236). Less grievously, but still odd, the website also reported the figure for the breakfast-skipping dinners incorrectly (298 v 294 mg/dl).
Second, the website said that the experiments were performed ‘over the course of two days’ but, actually, they were performed over the course of six days. This is important because of the third error, which was contained within the quote from Professor Jakubowicz: ‘it was surprising to see the high degree of deterioration of glucose metabolism only because the participants did not eat breakfast [my italics].’ But that wasn’t the only change. In fact, when the patients were skipping breakfast they were on the third day of a weight-loss regime, whereas when they were eating breakfast they were not: unlike Professor Christiansen, Professors Jakubowicz and Froy had not compensated for the breakfasts their patients missed (i.e. they did not increase their food at lunch and dinner) so when they got their patients to skip breakfast they were also putting them on weight-loss diets – reducing their intake from 2,100 to 1,400 calories a day – and measuring the differences only on the third day.
