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Saturday, January 7, 2017

In Defense of Artificial Sweeteners for 2017


The new year has arrived! Naturally, everybody everywhere has pledged to start a new diet and join their local gym.

Following this temporary nationwide shift in diet and exercise habits, every major news outlet is running silly advice articles promising readers the weight loss results they want if they tweak their habits in just the right way.

Most of this advice is typical pop-science boilerplate, unworthy of anyone's valuable time. But there's one bromide I've seen repeated more than usual this January: the claim that artificial sweeteners will make you fat.

I've seen everyone from HuffPo health writers to bona fide nutrition experts smugly asserting that your diet soda will stunt your weight loss effort and even push your weight in the wrong direction.

Bullshit.

With that eloquent thesis laid out, we're going to go through every fallacious reason people give for swearing off artificial sweeteners, and we're going to rely on the best science that's available.

Artificial sweeteners stimulate your appetite

If you're a fly. None of us are flies, so we could move on to more interesting facets of this debate. But disingenuous health writers also like to point out that overweight, diabetic people are more likely to drink diet soda than slimmer, metabolically healthy people. That's got to tell us something about the negative effects of sugar substitutes.

Of course, we could discount every diet ever conceived as ineffective since only fat people and diabetics go on diets to slim down. Or as the authors of a recent PLoS One article put it, " ... findings from observational studies might be biased by residual confounding ... as overweight/obese people are more likely to consume [artificial sweeteners] in an attempt to control weight." This didn't stop the authors from cautioning against consuming sugar substitutes, of course.

Some dieters do gain weight when they switch to sugar substitutes, but that's because they eat more than they otherwise would, assuming they can get away with an extra slice of pizza because they're abstaining from Code Red Mountain Dew. Though that's no reason to blame artificial sweeteners for stimulating your appetite.  

Impaired self-control

According to this study, low blood sugar predicted a lack of self-control in a series of tasks that involved regulating emotion and suppressing negative thinking. Consuming a sugary drink helped participants in this study perform better on subsequent self-control tasks.

The paper is interesting and underscores the importance of properly regulating blood sugar, a point stressed by advocates of low-carb and paelo diets, mind you. However, the geniuses at The Conversation took this as evidence that sugar substitutes impair self-control since they didn't spike blood glucose the same way the sugary milkshake used in the study did.

It's widely accepted that high blood sugar is the primary cause behind weight gain. Therefore, you should obviously avoid sugar substitutes because they don't spike your blood glucose like sugar does. Think through that a few times, then read on.

Artificial sweeteners are full of chemicals

I won't patronize anyone by smugly harping on the obvious retort that everything is full of, or rather composed of, chemicals. But this objection to artificial sweeteners is usually grounded in the ambiguous claim that the especially nasty chemicals in your diet Coke somehow damage your metabolism by harming your gut health.

The best support that can be mustered for this link between poor gut health and artificial sweetener consumption is this paper in Nature, in which the researchers altered the microbiota of mice by feeding them saccharine and increasing their glucose intolerance. The problem, though, as the researchers state is that "... human individuals feature a personalized response to [artificial sweeteners], possibly stemming from differences in their microbiota composition and function..."

The authors go on to argue that the changes they saw in these mice likely occur in humans as well, however, because they found "significant positive correlations between [artificial sweetener] consumption and several metabolic-syndrome-related clinical parameters ..." To find that correlation, they relied on self-reported data around artificial sweetener consumption. Of course we all know how awfully unreliable food frequency surveys are.

These limited results leads us on a search for better studies, preferably those in which the researchers didn't study rodents and then infer that people have the same reaction to artificial sweeteners.

Clinical Studies

A few papers of this sort have been published, but the results are mixed. Some studies show no effect whatsoever, others indicate that sugar substitutes  can help people lose a modest amount of weight. None implicate artificial sweeteners as culprits in causing weight gain.

The naysayers handle this as expected. They claim that dieters who switch to diet soda lose less weight than dieters who drink only water, though the difference is clinically insignificant--only 2.6 lbs in the cited study. If you're severely overweight or obese, losing two pounds won't do much for your health, and it's certainly less than you had in mind when you thought up your weight loss resolution.





I hope you see the theme here. The research returns an inconclusive result or suggests--as does common sense-- that sugarless, calorie-free sweeteners aid weight loss. Yet again and again we're told to avoid sweeteners.

N=1?

One point worth acknowledging is that everyone is indeed slightly different. Some people stuff their faces with junk food, for instance, and maintain the slender figure everyone else wants. So it's at least possible that some people gain weight when they eat sugar substitutes while others don't. But exceptions prove rules more often than they refute them.

Let me borrow a cliche from psychology and point out that humans aren't individually all that special. Being the narcissists we are, we like to think that we're the special case that bucks the trend. But that's usually hubris. There'd be no point in studying nutrition if everyone was so different from one another.

Conclusion

What seems most reasonable given the evidence we've discussed is this: there is some small sliver of the population that doesn't react well to sugar substitutes. This is true of vaccines, anti-depressants and a variety of other medical interventions. That fact, however, is not a good foundation for a blanket condemnation of sugar substitutes.

So as we head into another year, let's quit wasting everyone's time with speculative suggestions and make the changes we know will help us lose weight. There are certain foods that should be avoided generally, but Splenda probably isn't one of them. Unless someone wants to provide some better evidence.

Sunday, November 20, 2016

Will Trump Be a Disaster For Science Policy? Part II

Read part I here.

On certain science policy issues, Trump's critics have overstepped. We covered the most popular examples in part I. Now let's look at a few subjects where Trump may have some explaining to do. A bit later we'll get into the good things Trump is likely to do for science.

Vaccines

On vaccines Trump appears to be truly awful, if his 2012 comments are any indication. Moreover, during the campaign this year, the President-Elect met with prominent anti-vaccine advocates. According to Science, he spoke favorably of the vaccine-autism link and promised to watch some woo-filled documentary about the subject.

There are a few intervening factors that may sway Trump away from pursing policies that are in line with his previous statements about vaccines, however. The first, of course, is that Trump is a good salesman if he's anything at all. And every salesman knows you don't disrespect people whose money and support you're after. Telling the folks from Age of Autism that they're utterly insane would've been an unlikely way to earn their votes.

 Politicians, after all, are known for their duplicity, and I wouldn't put it past Trump to smile, shake someone's hand and promise them what they want, only to ignore them later on down the line. This is usually a downside to the political process. In this case, though, it could mean President Trump stays away from vaccine quackery.

On a related note, politicians sometimes bow to pressure from advisers, bureaucrats, and other powerful interests inside and outside of Washington, even when they truly do support a cause. Trump could do the same, secretly harboring oddball views on vaccines while publicly shelving any policy that could do harm to public health. Just compare Obama's campaign promises to what he did once he took office to see the most recent example of this phenomenon at work.

We'll have a chance to test this possibility, too. As Science points out, Trump will soon have the opportunity to appoint some important public health officials. This is assumed to be a bad thing, since Trump could very well appoint a vaccine denier. But because there are so few qualified physicians and researchers who espouse any degree of skepticism around vaccine efficacy, Trump will be choosing from a pool of mostly pro-science candidates. He would have to go out of his way to appoint a crank of Andrew Wakefield's caliber. None of this is to excuse Trump should he embrace anti-vaccine hysteria in office. That would be shameful on his part, and we should all say so if he does.

GMOs

Crop biotechnology is another subject on which Trump has been ambiguous, but his comments here have been a little clearer and give me some hope that he'll come down on the side of science. The Genetic Literacy Project reported last month that Trump said agricultural policy should be determined largely by the market, and mandatory labels for genetically-modified food have nothing to do with free-market economics. GLP also pointed out that Trump took down a tweet which suggested that GMO corn may cause "issues in the brain." He also told the Iowa Farm Bureau that biotechnology should be used in food production and food labeling rejected.

The potential upsides of Trump's science policy

We've covered the worst examples where Trump has strayed from accepted scientific wisdom. So let's look at a couple of issues where Trump is likely to advance science.

Energy

Trump has made some very encouraging comments about nuclear power, arguing after the 2011 Fukushima disaster in Japan that "[i]f a plane goes down people keep flying. If you get into an auto crash people keep driving.” He has also said that we need to continue developing our ability to produce natural gas. This is the flip side of Trump's climate policy; climate change skepticism typically goes hand-in-hand with a desire to produce more energy, so Trump will very likely pursue policies that make energy production far easier.

Science Funding

There's been much hand wringing over the possibility that Trump will slash science funding because of his comments about climate change. The critics, ironically enough, don't see that they're shooting themselves in the foot. On one hand, they say the science of climate change is settled, and don't you dare question your betters who have studied the subject in great depth, Mr. business mogul man! But they then turn around around and lambaste The Donald for his supposed unwillingness to pursue climate research. These people clearly can't think forward.

But being both a real estate developer and a populist candidate interested in rebuilding the country, it's likely that Trump won't shy away from funding science research, which Republicans are pretty good at historically. And much like Reagan, Trump's skepticism of big government will probably wane when it comes to building infrastructure and investing in basic science projects. Specifically on the question of climate science, there are questions left unresolved and worth researching. The problem, as climatologist Roy Spencer has explained, is that they center around natural climate variability. Those kinds of questions can't be used to justify an expanding EPA and the kinds of wealth-transfer climate change mitigation programs the IPCC is so eager to push.

Summary

What we have in Trump when it comes to science policy seems typical of recent presidents: some good, some bad and a lot of unknowns. Science, sadly, really hasn't been a key issue in any presidential election in recent decades, so we have little more to go on than a handful of public statements and the resulting speculation. We'll just have to see what happens.




Saturday, November 19, 2016

Will Trump Be A Disaster For Science Policy? Part I

It's happened. Americans elected Donald Trump President of the United States. The tears of anguish cried by social justice warriors everywhere is enough to make Trump's victory a positive development, but the scientific community, too, is distraught over the election results. They see Trump's victory as a huge loss for the progress of science in America. Michael Lubell, director of public affairs for the American Physical Society in Washington, for example, warned that Trump will be “the first anti-science president we have ever had.”

That's an absurd claim considering the track records of just our last two Presidents, but Lubell's comments seem to summarize the perspective of mainstream science at the moment, so let's use that as our starting point and propose a slightly more realistic scenario: Trump is hardly a champion of science. His comments on science policy thus far have been mixed and we don't know yet how he will address certain important issues. That being said, the sky certainly isn't falling and there is hope that Trump could do some good for science in the coming years.

Before we can deal with the potentially positive science developments under the Trump Administration, we have to dispel the hysteria that surrounds this discussion. So let's look at the typical exaggerated claims the anti-Trump crowd has rallied around thus far.

Climate Change

Every year world leaders gather for a climate change meeting known as the United Nations Climate Change Conference. The participants discuss the threat posed by climate change, pledge to combat it with whatever means they can--and ultimately do nothing. The most recent conference in Paris, COP 21, was a terrific waste of time and resources which produced the largely non-binding Paris Agreement. If enforced the Paris Agreement would have a minimal, almost undetectable impact on global temperatures while squandering trillions of dollars the world simply does not have.

Trump has promised to withdraw the United States from the Paris Agreement, to the consternation of every bureaucrat and lobbyist who stands to benefit from its enforcement. Despite his simplistic comments that man-made climate change isn't real, Trump has some scientific justification in pulling US support for the agreement. Dozens of studies published in the last five years have found that the IPCC's climate models are far too sensitive to moderate increases in greenhouse gas emissions, and thus the disaster scenarios projected by these same models are probably unrealistic.

The science world stares at Trump quizzically when he says that we still don't know a lot about the earth's climate; but it's a sentiment echoed by many climatologists and backed up by good data.

Fracking

Affordable energy is an essential part of economic growth. It makes recovery from depressions possible and fuels the third world's progress out of grinding poverty. Fracking has been a key player in this story, and Trump has rightly thrown his support behind the technology. His critics, though, have latched onto his comment that Fracking poses "zero health risks."

Technically, the critics are correct. Fracking does produce some externalities and isn't 100 percent safe. But that didn't stop the EPA from releasing a study last year concluding that fracking, as currently practiced and regulated, doesn't pose a risk to drinking water. Other studies, likewise, have reached the same conclusion. And I'd hardly count the Obama EPA and Yale university as shills for Donald Trump.

So let's add fracking to the long list of imperfect technologies that nonetheless make all of our lives better, things like nuclear power, vaccines and electronic cigarettes--all issues on which the Obama administration has a depressing track record, mind you.

Evolution

Of course, no discussion about a supposedly scientifically illiterate administration would be complete without a few words dedicated to evolution denial. And Mike Pence has indeed burped out a few bromides about the lack of supporting evidence for evolution throughout his career.

So I suppose this could serve as our first example of the Trump Administration's science denial in action. But we've known for years that evolution denial is a bipartisan phenomenon, with as many as 50 percent of Democrat voters claiming that they reject Darwin's theory, as well. This doesn't excuse Pence's ignorance, of course, though it does illustrate that our rejection of established science has deeper sociological roots than "Republicans are dumb and hate science."

The silver lining here is that evolution denial doesn't carry the same policy implication that, say, nuclear energy denial does. Nobody is denied affordable electricity because Darwin offends the religious sentiments of some Americans, for instance.

I'm all too familiar with the argument that rejecting evolution catalyzes science denial of all sorts. But it's not a compelling thesis because science denial tends to follow people's preconceived political views. People deny science inconsistently and only when their pet issues are affected. Greenpeace just love, love, loves! climate science, though they're not so fond of biotechnology. Still, even if Trump and Pence end up backing creationists attempts to get Genesis into the biology classroom, a scenario that seems unlikely, it's not clear how successful they'll be. Creationists lose badly in court and our science educators are really good at disabusing their students of doubts about Darwin.

In part II we'll discuss a few other issues where Trump's views are questionable, then look at some beneficial changes that could arise in the next four years.