Tuesday, September 23, 2014

Sedentary Behaviour and Depression: Not just about less physical activity

In the world of sedentary behaviour research one question usually permeates any discussion among experts and non-experts alike.

It goes something like this: "So I see you've shown an association (causal or otherwise) between sedentary behaviour and health risk X. But isn't this really just about less physical activity?"

We all know that not getting enough physical activity means that there's a higher risk of being unhealthy, generally speaking. We now know, or at least have enough evidence to date to suggest, that excess sedentary behaviour is also associated with poorer health. Sedentary behaviour just refers to low-movement behaviours while in a sitting or reclined posture - in real world terms, this is just called sitting too much.

So I wasn't surprised to find yet another study on the ill-effects of sitting on our health. The authors pooled data from 13 cross-sectional studies and 11 longitudinal studies, or 193 166 people, which examined the association between sitting and the risk of being diagnosed with depression. The "main" finding was that individuals were 25% more likely to be diagnosed with depression if they were in the highest sitting group, as compared to the lowest sitting group. Of course, we don't know (and may never know) whether more sitting causes depression or depression causes more sitting. In my opinion, there seems to be evidence for both directions and the association may truly be bi-directional.

What's most interesting to me about this study - above and beyond the main finding - is a sub-analysis that they ran. The authors compared the effect of sitting on depression between studies that accounted for physical activity level, and those that did not. In the studies that did not account for physical activity, the likelihood was 34% [1.34 (1.22 to 1.48)], and for those that did account for physical activity, the likelihood was 12% [1.12 (1.06 to 1.18)]. This is to be expected, as physical activity is typically thought to be protective against depression, so adjusting for it should partition out some of the effect. However, even after adjusting for physical activity, there is still an association between sedentary behaviour and depression!

This underscores the importance of considering physical activity levels when examining the links between sedentary behaviour and health outcomes. Of course it's just good science, but even if only to silence the critics. I do believe that, conceptually speaking, physical activity and sedentary behaviour represent distinct and separate constructs. However, practically speaking these may be difficult to disentangle, especially with respect to the links with health and disease - it's just intuitive that a change in one necessitates an inverse change in the other. As researchers, we need to provide convincing evidence that this intuitive association between sedentary behaviour and physical activity does not necessarily exist.

Remember the conversation above? Some of the best evidence we have today would seem to suggest that the link between sedentary behaviour and depression is not just about less physical activity, but also about sitting too much. Practically speaking, the distinction is like splitting hairs, but conceptually speaking these two are "sitting" in quite different camps.

Monday, July 14, 2014

Do we need better health literacy, or better health journalism?

"Scientists have discovered a new miracle drug for breast cancer!"
"A new study suggests that chocolate is good for your heart!"
"Active video games offer promise in the fight against obesity!"

These are just a few of examples of news headlines that could be brought to you by your science/health journalism professionals. While I've just made these up on the spot, you've probably read or heard headlines similar to this (or exactly like this) before.

Today's post is brought to you in response to a terrific article by Adriana Barton in the Globe and Mail. In Health literacy 101: The science of how to read the science, Ms. Barton provides some useful information for those of us (which is most of us!) who are consumers of health-related media. In our information-age, tech-savvy world it is easier than ever to access information on the latest scientific studies. Journalists have taken advantage of this new-age of reporting and publish secondary articles on scientific reports daily, even hourly. The valid, and honest, interpretation of this scientific information varies tremendously. Enter the article mentioned above on health literacy, which in my view is really science literacy, something that we are struggling to uphold as the number of students eligible for, or obtaining, STEM degrees is low in Canada compared to our peer countries (a topic for another day...).

While I applaud Ms. Barton's efforts to provide some support for citizens consuming news about scientific studies, I think the article was brief to a fault. Coming from someone in the sciences, rather than a journalist, here are several other ways that you can improve your "health literacy".

1) Be skeptical: Ms. Barton noted that many media articles on scientific articles did not disclose any conflicts of interest. While a perceived conflict of interest does not imply any conflict of interest at all, it is a crucial piece of information that provides the reader with an additional lens to critique the article. Likewise, just because a study is funded by industry, that doesn't necessarily mean the article is garbage. There are plenty of scientific articles with no industry funding that are garbage too!

2) Read carefully.  Try to tease apart the numbers when journalists don't provide any. Often this can be a red flag that something is up, or that the writer is bending some findings to suit their purpose. In the article above, Ms. Barton quotes a JAMA Internal Medicine study, and writes: "Of 1,889 media reports on health research published from 2006 to 2013, Schwitzer and a team of 38 physicians and science writers found that half relied on a single source for the article, or failed to disclose the conflict of interest of sources." Now, read that again. Half of the media reports relied on a single source OR failed to disclose conflicts of interest. These are two different faux-pas with different meanings, and the author doesn't say how many of the reports fall into which category. This could mean than 49% used a single source while 1% failed to disclose, or it could be evenly split, or most articles committed both writing-offenses, while only a handful did either. It turns out that the original article doesn't differentiate between these two in their criteria, so this isn't Ms. Burton's fault at all, but this is a good example of how the numbers can be buried to make a point one way or another.

3) Greed is universal. Ms. Burton sheds light on an important aspect of publishing in the medical and scientific world. Publishing is academic currency - simply put, it's an efficient way for researchers to advance their careers. As with any field, greed can lead to people doing some strange things. In many ways, a lot of research is upheld to their researchers' own ethics...interpret this how you will, but this means is that there will always be variability in the integrity of published work. Most of the time the published work is probably good, but sometimes it's crap. What Ms. Burton didn't mention is that greed is universal. Journalists also live in a world governed by the publish or perish mantra and must publish their work to advance in their career. For those who have earned their way to full-time reporting positions, they are often required to publish every week, or even every day! There are countless examples of journalists twisting the words of researchers or mis-representing the findings of scientific articles- see this PLoSOne article on ADHD in the media (and the corresponding news article that goes with it). There's even a prize for being the best at it: the Orwellian Prize for Journalistic Misrepresentation. Now to be fair, it is a two-way street - the quality of a press release is related to the quality of a news report - it's just that on one side we have articles that are peer reviewed for their scientific rigor, and on other side we have articles that are peer reviewed for their "wow" factor, or their ability to enhance/maintain readership. I'll leave it up to you to decide which side to trust more.

4) Beware the percent! Simply put, try to read beyond articles which state findings in relative terms only. Ms. Burton did a great job above by telling us how many media reports there were in the study - kudos! As she alludes to in her article (credit where credit is due, I always say), a 50% reduction in risk means something very different for a risk of 1 out of 100 000 than it does for 1 out of 10. Be weary of articles that report only the relative terms, and in my view, especially those that convert absolute terms to relative terms.

Truth be told, I don't believe that all of the media spin put on scientific articles is accidental. I've seen absolute terms in a scientific article be translated into relative terms in a media article just to increase the "wow" factor. Errors in reporting may be due to external factors, such as incorrect findings in the first place (I've noticed a lot of John Ionannidis citations in researching this post) or selection bias in the types of articles that are passed along (such as those this elicit an emotional response). But in a field where 'spin' is not only acknowledged but actively used as a tactic, I just don't buy the picture of the accidentally misinformed reporter. This article in the CBC does a lot of externalizing in discussing inaccuracies in the media. Of course, there is blame all around - for everyone - although we can argue about who holds more of it.

For the consumers of health media I wish you good luck in sifting through the good and the bad. Science isn't easy to understand, and science writing is hard enough to do, let alone read. The media offers an efficient medium to translate this information for you, but it is increasingly important to be critical of what you read in the age of post-print media.

My advice to those writing in health media is to describe the study in one easy to read sentence up front, containing all of the details needed to make sense of the finding. Use spin carefully - it is a powerful tool, and with great power comes great responsibility. Use absolute terms and provide numbers where possible. Do your homework and understand what these numbers mean - this is often troubling in media articles that present findings as likelihoods when the article uses odds ratios. And please, PLEASE, provide the link to the original article!

Monday, March 10, 2014

Google glass, household media plans, and competing with the screens

I empathize with parents today. Technology is omnipresent, appealing, and addictive. When challenged to get their children outside more, parents have asked me "sure, but how can I compete with the screens?".

There isn't an easy answer to this. To try to provide some answers, or at least generate discussion, my colleague and I Allana LeBlanc wrote an article for the Ottawa Parenting Times about healthy active living in a modern world. What follows here is an elaboration on the idea of competing with the screens.

I don't think that technology is going anywhere, anytime soon - and nor do I think it should. While screen-based technology has the potential to be harmful, especially to children, I also think that our technology is allowing us to communicate and interact as never before. That being said, the researcher in me is terrified of Google Glass. Considering how harmful we know screens are to children's health, if the idea of walking around with a screen 24/7 doesn't scare you, it sh
ould. (Can I say that on Blogger!?)

As with anything, it's the role of parents to teach their children moderation with screen-based media. Children today do spend too much time in front of screens, and credible organizations, such as the American Academy of Pediatrics, are recognizing this. When I was a child, I loved playing video games - still do, in fact. But screen time was something that was allowed on a rainy day or when there otherwise weren't opportunities for active play (such as long car rides). Of course, one size does not fit all, and parents should be encouraged to develop their own strategies using the evidence and guidelines, such as those from the AAP, to help them.

Regardless of the strategies that parents want to employ to reduce their kids' screen time, I think an integral part of any approach is to develop a household media plan. Parents will have different household rules regarding media and I think that's a good thing - it needs to be tailored to what you and your children want if it's to be sustainable while still being enjoyable. There is no one best strategy, or at least we haven't found it yet, but there are some general ideas that may help parents and families guide the development of their household media plan:

1) As far as screens go, less is better.

2) Rules around the timing of media use may be helpful, such as: no texting at the table, no phones in the bedroom overnight, and no television after 9:00. Again, these types of guides should be personalized to suit the needs of the family and the age of the child.

3) Using screen-based media after school is known to affect health. For instance, every 60 minutes that a 11-14 year old boy spends sedentary after 3:00pm is associated with 1.4 kg/m higher BMI and a 3.4 cm higher waist circumference (read the article here). I think that we could have a major impact on the health of children if every child was encouraged to play outdoors after school instead of using screen-based media. This is a critical area where parents can have a profound impact on the health of their children.

 CBC news' Pauline Dakin recently did a story on the effect of social media on teens. Social media is re-defining how children communicate with each other and with the world, and is largely becoming a new way of life. Now I wouldn't suggest that if you can't beat 'em, join 'em, but I do think that maintaining open lines of communication with children about screen-based media and social media is a good thing. Adults may be wise to educate themselves as to the purpose and uses of different social media apps, both to have intelligent conversations with their children when making household media plans, as well as to protect their children too. I'll spare you the Sun Tzu quotes, but I think a little "know thine enemy" may be in order.


Monday, March 3, 2014

Are today's playgrounds too safe?

I completed a survey today by Dr. Mariana Brussoni and Susan Herrington from the University of British Columbia, entitled: Are Today's Playgrounds too Safe? I would encourage you to respond to the survey here. It takes under 5 minutes to complete and it's actually quite fun to reminisce. Please note that I'm not involved with this project in any way and my opinions here may not be reflective of the opinions of the researchers above.

I want to comment on the notion of playground safety just briefly. I'll disclose my bias here - the playgrounds that I typically see in Ottawa do not appear to be any more, or less, safe than the ones I played on. Structurally or physically speaking they quite resemble the play structures that I played on a child. Slides, ladders, ropes, sand, etc. Maybe this isn't true for some (or most) playgrounds, but I'll be sure to keep a lookout around my neighborhood for anything that doesn't look 'normal' to me.

While I don't believe the playgrounds have changed too much (ok maybe a little - the rubber mats that have replaced sand are kind of silly), a lot of things around the playground have. For starters, parents' attitudes about playground safety have changed. On the survey above there is a term called "rough and tumble play" - I responded that, yes, I did do this as a child. I don't know many adults my age who would respond no to this. But I imagine that this is something that's a big no-no at the playground nowadays.

My favorite place to play as a child was the woods at the cottage (that's camp to my hometown residents of Northern Ontario!). Here, children of all ages from the neighboring cottages worked together to build multilevel forts. Big forts...forts you could live in - seriously, we had shingles on the roof. On most days we would kiss our moms goodbye and head into the woods with our tools just after breakfast and we usually needed to be reminded to eat sometime in the early afternoon, only to scarf down food as fast as we could to re-join our friends. We got cuts, scrapes, bruises (not just our egos when we weren't allowed to use the 'big' ax) and a occasionally someone cut their finger with a jack-knife (Ah-Hem...Sass). We actually nicknamed one of the trails 'the bloody foot trail'. But you know what? We had the best damn fort in the bay and we were proud of it.

As the oldest child in our small fort-building industry, it was often my job to delegate tasks to other children - after all, what's a construction site without a foreman around, right? Some of the jobs weren't so fun, and it was tough to delegate them to the other kids knowing this. I like to joke that everything I learned about leading a team I learned building forts in the woods of Horseshoe Bay, ON.

Back to the survey. Are playgrounds too safe? I don't really think so - perhaps marginally more safe than they already were, but it's not like there are any axes, jack-knives or bears hanging around playgrounds (usually, anyways). I think the problem is that kids might be spending too much time being supervised at the playground than building forts in the woods.

Tuesday, February 25, 2014

Dietary components, natural ingredients, and missing the forest for the trees.

First off, my apologies to the loyal Mikepedia followers for my absence - it was a busy few months, but my thesis is submitted at last!

I'd like to talk a little bit about food.

The food that we eat today is different than that of our primordial ancestors. It doesn't have to be, but in a Western diet it usually is. Food is different because we genetically modify it, mass produce it, endow it with supernatural-like shelf lives, and add chemicals to it. Chemicals likazodicarbonamide, for instance, which Subway has recently taken out of their bread largely due to an online protest by concerned consumers.

In the information age it's difficult to ignore how our food has changed. People are concerned, and rightfully so I say, about what's in their food - about what they're putting into their bodies and on their table for their families. It's easier than ever to critique what industry and food producers incorporate into their foods, and I think this is a good thing.

Where it gets murky for me is the concept of a 'natural' ingredient. Branding slogans like "all natural" or "no artificial ingredients" are misleading to people, and I believe they are self-serving. Often, ingredients are considered natural, or 'healthy' (please note the quotations!), if their name can be pronounced - we've no doubt heard this from some bread and cold cuts companies who claim that they "make their products with ingredients that you can actually pronounce". It's as if the difficulty in pronunciating an ingredient has anything to do with it's nutritional value, potential toxicity or association with disease risk.

You know what else is 'natural', and easy to pronounce? Arsenic. Or how about lead? There are some other compounds that are natural and not very easy to pronounce, like epibatidine which is secreted by an Ecuadorian poison dart frog, which is also highly toxic.

If you have concerns about the food that you eat, then good for you. I'd fight for your right to know what's in the food you're eating any day. But if you're truly interested for the sake of your own health, not just to participate in an anti-industry, anti-synthetic compound crusade, the article above suggests starting with reducing 3 of the compounds in your diet that are associated with the highest chronic disease risk of all: sodium, fat and sugar. These are the leading 3 dietary components independently associated with chronic disease risk. So let's refocus our lens from a micro- to macro- level, and let's not miss the forest for the trees for disease risk.