- Sugar consumption is linked to a rise in non-communicable disease
- Sugar's effects on the body can be similar to those of alcohol
- Regulation could include tax, limiting sales during school hours and placing age limits on purchase
The evidence is clear: even at Starbuck's it's hard to find some actual coffee (not to mention the impossibility of a 'small' coffee) in amongst the choco-banana-raspberry flattes. And then there are the Scots' deep-fried Mars bars. Who could doubt that our commercially whetted sweet tooth is the tooth that bites with poisoned fangs? But is the evidence actually so clear?
The conclusion looks suspiciously in need of the "correlation is not causation" reminder. Indeed, a reader who posted a comment on the paper in Nature, Geoff Russell, pointed this out with cogent examples. We'll reproduce his entire comment here, as it makes the point well.
- Geoff Russell said:
Australia provides a natural test of the sugar-is-the-evil-bullet theory. We don't produce much corn here, so continue to use cane sugar for most of our sweetening. In the 1960s we didn't have an obesity epidemic. How much sugar did we consume? According to the FAO, 52.3 kg per person per year in 1965 (of 55kg total sweeteners).
What about now, in the midst of our own obesity and type 2 diabetes epidemics?
We are down to 39.6 kg of cane sugar per person per year, with an additional 8kg of non-sugar sweeteners. Overall there has been a modest decline in all sugars despite a rise in obesity and diabetes. How has our food supply has changed over the past 4 decades? We have more Calories. If may be tempting to attribute the US obesity crisis to sugars, but obesity increases elsewhere demonstrate that more Calories and less exercise are a sufficient explanation.
Similarly, compare Cuba and Italy. Cuba consumes 500 kCal per day of sugar and Italy just 300 kCal, Italy has an obesity/type 2 diabetes problem while Cuba's rates are very low. Historically, Cuba has eaten even more sugar than she does now ... without the evil consequences that this article portends.There is no denying, of course, that obesity and what are usually thought of as its sequelae are public health problems in much of the world. Whether or not said sequelae are indeed sequelae of obesity, or whether obesity and the rest are, individually, consequences of fat consumption, or sugar consumption, or processed food in general, or simply of excess calories relative to energy usage (too much munching in front of the telly) has still not been determined, though many have their favorite candidates. Cholesterol, saturated fat, red meat, the non-Mediterranean diet, not enough exercise, and others.
There's a fundamental problem with this simple sugar analysis when it doesn't reliably predict on either the individual or population basis (as Geoff Russell's comment points out). Sugar, and/or what it's usually allied with, may well have detrimental effects on health, but clearly it's not as simple as is being said. There's a well-known issue in epidemiology called the ecological fallacy, whereby we paint individuals with a brush dipped in a population-based paint. That is, when we attribute generalizations about a group to causation at the individual level -- stereotyping is an example, but so is the (erroneous) assumption that because, say, risk of heart disease is higher among people who smoke, everyone who smokes will have a heart attack.
It simply can't be possible that sugar is the single or even primary cause of the obesity etc. epidemic. Too many healthy people consume a lot of sugar for this to be true. And surely too many unhealthy people don't. Trying to attribute this vast epidemic to a single dietary substance is denying the complexity of these diseases and of causation. Unfortunately (in our view), people are beginning to feel so fiercely about sugar as the root of all evil that they are (in our view) no longer able to assess the science. Instead, it's become such a strongly held belief that it's in danger of becoming a dogma that no longer needs to be tested, or the supporting studies examined with a skeptical eye. That's never a good thing.
This is relevant for an MT post not because we don't want it to be true because we both OD on sugar all the time (we don't), or that we only eat celery and carrots (we don't), but because it relates to the general problem of inferring causation, especially when we can't do definitive experiments. That is the common situation in human and evolutionary genetics. So, it's worth sitting contemplatively over a cup (small) of coffee discussing whether there are better ways to know about weak, gradual, or complex causation.
One lump, or two?