Nearly two years ago towards to Birth of the Blob, I wrote a comment on a poorly nuanced RTE report about the association between diabetes and 7up (and other sweetened soft drinks). If true it needed to be stated in a less hysterical fashion to convince me. One of the factors that tuned my skepticism antenna was the fact that diet coke appeared to make you even fatter than regular sugar-loaded soft-drinks. Although, when the increase in diabetes was properly contexted by BMI, the apparent association disappeared. Turns out I was quite possibly >!gasp!< wrong . . . to think that aspartame and saccharine were irrelevant to the obesity epidemic.
It's all in the microbiome, stupid: the 10,000 species of bacteria that we all tote around with us, mostly in the large intestine. On 18th September last year, there was a nutrition report which laid out some pretty convincing evidence that drinks loaded with artificial sweeteners, far from being a solution to our increasing girth might actually be making things worse. Check out the work of Eran Elinav from the Weizmann Institute in Israel. Elinav at the movies! One of the early (that's as long ago as 2006!) studies searched for twins, identical and fraternal, who differed primarily in trouser size. They took twin-paired samples from the twins' intestinal flora and introduced them into germ-free (caesarian-sectioned, brought up in a bubble eating gamma-irradiated mouse-chow) genetically identical mice. The mice receiving the 'obese' bacteria reliably ballooned out, while their cousins who received slim bacteria gained weight at half the rate. Why is this important? Because we have in the last 100 years developed an epidemic of "metabolic disease" - a syndrome involving the woes of Western society: obesity, diabetes, fatty liver, high blood pressure and heart disease.
They have now done similar controlled experiments with mice getting artificial sweeteners in the water and mice getting glucose. The mice taking saccharine.etc. rapidly developed glucose intolerance. If you experience the following symptoms and are not recovering from a night on the batter, you might consider seeing your diabetologist: Feeling very thirsty; Dry mouth; Extreme tiredness Blurred vision; Drowsiness; Frequent need to urinate; Loss of muscle mass. Glucose intolerance essentially means that glucose doesn't get cleared from the blood circulation quickly after food intake but hangs around rather than getting converted into glycogen for future use. Apart from anything else, glucose is a universal currency and you are much more likely to develop septicaemia if you are hyperglycaemic - peripheral gangrene, anyone? Convincingly, this glucose intolerance evaporated when the mice had their intestinal flora eliminated with a short course of broad-spectrum antibiotics.
Perhaps the most important factor that has developed from Elinav's huge sampling of people, their lifestyle, their circulating glucose levels and their microbiome and cross-referencing of these different threads (or tsunamis - we're talking terabytes of information, here) of data is that Folks are Different. The Atkins diet may work a charm for that lady you met at the water-cooler . . . and her sister; but will do nothing at all for you because your bacteria are not her bacteria. When I was working in St. Vincent's Hospital a dozen years ago, we were just beginning to talk seriously about personalised medicine: only 50% of people with chronic Hepatitis C Virus infection will respond to interferon-α therapy, and it costs €12,000+ a year, so we'd dearly like to know who will respond: not least because the side-effects of interferon are almost as bad as the disease. Now we are clearly talking about personalised intestinal bacteria. There are people out there, whom I've never met who have something in common: they have essentially the same bugs as me and therefore the same pitch of glucose intolerance, possibly similar food preferences, the same sort of winter sniffles.
As this intestinal flora changes radically and within a couple of days when we have a change in diet, it is not beyond belief that the bugs inside are telling us what to eat. That, frankly, seems a little invasive.