Saturday, December 15, 2012

Wait for it

My commute, on a good day
On most days I bike to work. It’s my way of “walking the walk” – I write enough about the benefits of exercise, it would be a little embarrassing if I were a couch potato. Riding in involves climbing a big hill early(ish) in the morning, but I usually just get into a low gear and think about stuff and I barely notice it.

Not this morning.

This morning, there was a headwind. A cold headwind. It felt like I was pedaling against a wall. I was trying to convince myself that I was enjoying it – looking at the view, trying to feel the oxygen in my brain. But at some point I let out a big sigh and thought “who am I kidding, this is miserable!”.

Even so, I knew full well that tomorrow, I would be back on the bike first thing in the morning. So I wondered – why do I continue to bike in, even in the winter, in the rain, in the cold, up the hill – even though I sometimes don’t derive any immediate pleasure or benefit? The answer, of course, is that rationally, I know that no matter how miserable it is at the moment, in the long run it’s good for me – it’s good for my health, my weight, my ability to prevent and fight illness, and, as anyone who reads this blog knows, my ability to ward off cognitive decline as I get older.

This process of holding off on immediate rewards (driving in to work in a warm car with some Christmas music playing) to benefit from later rewards (health) is called delayed gratification. It was most famously studied using marshmallows: in a well-known study, young children were given the choice between eating one marshmallow immediately, or waiting a few minutes and receive two marshmallows (giving rise to some pretty hilarious antics). The researchers followed-up on the children many years later, and found those who were successful in displaying delayed gratification (and so resisted eating the one marshmallow) were doing better on several outcomes such as academic success and ability to handle stress.

In a more recent study, a team of researchers investigated whether there is a link between the ability to delay gratification as a child and weight in adulthood. They found that one’s performance on a delayed gratification task (similar to the marshmallow experiment) was associated with his or her body mass index (BMI) thirty years later. In short, the kids who were able to wait the longest for a bigger reward had lower BMIs as adults. Interestingly, another study found that children who already have a high BMI score poorly on a delayed gratification task – a nice convergence of evidence from different sources.

Avid Scientific Chick readers can no doubt point to an important limitation of this study. Repeat after me: correlation does not imply causation. The fact that kids who did well at delayed gratification later had lower BMI’s does not mean that being good at delayed gratification causes one to have a lower BMI. There are several potential confounders here, some of which were not controlled for, such as the BMI of the participants as children. That said, the findings remain interesting – it’s not completely out of the park to think that improving self-regulation and self-control could have an impact on weight.

There is a little coda to my earlier story about biking against a wall of wind.

About halfway up the hill, at the peak of my frustration, almost as if on cue, a huge coyote emerged from the forest, and started trotting along the bike path as I was biking. It was a big fluffy beast, and for a second I was scared, but it was minding its own business, and eventually started making its way across the street. Still excited from my encounter, I turned my head, and there was another equally huge coyote sitting just next to the bike path, in the forest, staring me down. I couldn't believe it. I've seen coyotes before, but never this big, never this close, and never on my way to or from work. They were beautiful creatures and my heart was warmed. Delighted with this turn of events, and with the fact that this morning’s gratification was instant and not delayed, I grinned like an idiot all the way to work. 

Reference: Preschoolers’ delay of gratification predicts their body mass 30 years later. Schlam TR et al. (2012) The Journal of Pediatrics Aug 18 [Epub ahead of print].

Thursday, December 6, 2012

You're not that tired

A few years ago, good friends of mine dragged me to a viewing of Touching the Void, a movie about the extraordinary survival of a mountain climber against all odds. I remember coming out of that movie thinking, “Wow, when I complain that I’m tired, I’m really not that tired – I have so much more in me”. It might sound corny, but over the years, I’ve thought about this movie several times, and it has inspired me in many ways.

Which part of your body decides when you can and can’t go on? In exercise science, the debate has been going on for years. Some researchers think it’s the heart – you can only exert your big muscle so much. Others link stamina and endurance to lung capacity – measures like VO2 max (how much oxygen your body transports and uses during exercise) have been linked to performance in sports. More recently, measures like the lactate threshold (the exercise intensity at which lactic acid starts to accumulate in your blood) have become popular. Professional athletes are poked and prodded to try to figure out what makes a winner, but somehow with each theory comes at least one or two outliers. 

In an effort to investigate what drives people to push themselves and what sets the limits, British researchers came up with an interesting experiment using cyclists.

Each cyclist in their study had to complete four trials of 4 kilometers on a stationary bicycle. The first trial was just to get used to the equipment and the setting. The second trial was the real deal – they had to go as fast as possible, and their time was stored and used as the “baseline” time, or their “personal best”. During the last two trials, the participants “raced” against themselves – an avatar representing them was projected onto a big screen in front of them, and they could track their progress in relation to that of their avatar. The idea is that the avatar on the screen was going at the same speed as the cyclist’s 2nd trial (the one used to set their personal best). The researchers were hoping to learn whether a cyclist could beat their trial time by chasing themselves to the finish line, thus establishing a new best time.

You can probably guess the outcome of the study: all the participants beat their best time when they raced against it. But there’s a twist: in one of the last two trials, the researchers tricked the cyclists: the avatar was actually going 2% faster than their previously established personal best. And every participant beat that time, too! So guess what? It’s not in your heart, or your lungs, or you legs. It’s all in... your brain.

What the study tells us is that you have a little energy reserve, even when you think you’re going all out. Your brain doesn’t want you to tap that reserve, because if you get into that habit, you might use it up and die. So it keeps it hidden. It makes you feel like you’re going to die even though you’re not. But the reserve is available – throw in a little deception and a little competitiveness (or, in the case of the mountain climber, a little actual fear for your life), and you can gain access to it.

So there you have it! Next time you didn’t sleep well and you’ve been going all day at work and running errands and working out and you just feel like collapsing on the couch and having a nap… Dr. Julie says… Collapse on the couch and have a nap. But do it knowing you could also clean the house if you really wanted to.

Reference: Effects of deception on exercise performance: implications for determinants of fatigue in humans. Stone MR et al. (2012) Med Sci Sports Exerc. 44(3):534-41.

Friday, November 30, 2012

It's time to have "the talk"

Please enjoy this cuteness as a reward for reading this post
No, I'm not talking about the "birds and bees" talk. This "talk" is one you should have with your parents, or your partner, not your children. It's not an easy talk. You're not going to want to talk about it. They are not going to want to talk about it. But the discussion is important, and it should take place sooner than later. This "talk" is about advance health care directives.

Essentially, establishing "advance health care directives" (sometimes called a "living will") means deciding ahead of time how you want to be treated if you are no longer able to make decisions for yourself because you are ill (for example, with dementia) or incapacitated (for example, after a car crash). These decisions include things like whether you'd want to have a feeding tube, be treated with antibiotics, or be resuscitated with CPR if your heart fails (and many other decisions!). In general, people go about this in one of two ways: either by appointing someone to make decisions for them should it be necessary, or by writing down instructions for treatment, such as the kinds of treatments they would be ok with and the kinds they wouldn't want. Ideally, the advance directives should be a combination of both.

Now you're probably sitting there thinking "I'm way too young for this" (aren't we all), or "my parents are well, there's no need". And that's exactly the problem: by the time you need advance directives, chances are it will be too late. Our ability to make decisions for ourselves over our lifetime is like a bell curve: it's pretty low when we're young, still low-ish in our pre-teen/teenage years (hence the need for the "birds and bees" talk), then it peaks in adulthood, and starts declining again as we get older. So ideally we should start this discussion at our peak. I know I'm being a complete bummer suggesting we all sit down and talk about death and illness at our peak. But there's a good chance you'll thank me later.

I'm currently attending the Leadership Program for Physicians and Leaders in Long-Term Care in Vancouver (my talk is tomorrow and I should definitely be preparing for it instead of writing this!). There's a lot of discussion at the conference around advance directives. The main problem is that a lot of people don't have them!

There's some uncertainty over how much physicians actually follow advance directives. In some areas they have to and in others they don't. Really what it comes down to is everyone is better off if they have at least had the discussion - at the conference, one presenter mentioned how older adults who have advance directives tend to enjoy a better quality of life, and a better death. I know, I know. You're don't want to be reading about death on a Friday night. If you need a break, here are some kittens: click here.

As I said before, it's not an easy discussion. "Ah, ok, so, yeah, one day I might have dementia, or be in a car accident and suffer brain damage, and well I think I'd rather...". But hey, a lot of discussions are unpleasant ("Ah, ok, so, yeah, I dropped your brand new iPhone in the toilet"). So just do it. And don't just sit down and write this by yourself, either - speak to a loved one, or a relative, about what your thoughts are, and also involve your doctor - they can absolutely help with this, and may be able to provide you with useful tools. Advance directives should be an ongoing discussion, not a one-time thing - revisit your choices once in a while, and always keep someone in the loop.

I realize this isn't my most uplifting post, but as science moves forward, we face new choices that are important to talk about. So chatter away!

Thursday, November 15, 2012

Go lift some weights and call me in the morning

In my last post I told you that I would reveal the one thing you can do to have a significant, positive and lasting effect on your brain health as you get older. See if you can spot it in the following list:

a) Learn to dance Gangnam style
b) Join a choir
c) Catch a wave
d) Pump some iron

Ok, that was a trick question. All of these answers are somewhat correct, but I was looking for the "most" correct answer (flashbacks to undergrad, anyone?): Pump some iron.

I realize I sound like a broken record - I've already written about how aerobic exercise can promote healthy aging here and here, and I've even already written about resistance training, or lifting weights, here.

So why am I at it again? Because it's important!
I'm fresh out of the 2012 Aging and Society Conference, where researchers came together to discuss what works and what doesn't when it comes to healthy aging. It turns out everyone pretty much agrees that exercise is hands down the most effective intervention to keep your brain cells happy into old(er) age. All sorts of different types of exercise, ranging from simply walking to attending resistance training classes, are associated with different types of improvements in cognition, memory, and even brain size. 

Of course, there are different levels of effort involved with different types of exercise, or even when talking about a single form of exercise. When my friend Jess asks me to go for a walk, she means a power walk: it usually involves going up hills, sweating like a pig (even though pigs, ironically, don't sweat much), and barely having enough breath for girl talk (though somehow we always seem to find it). When my friend Al and I go for a walk, what he means is a "mosey": we stop to look at the view, pet the dog, chit chat with strangers, and have more than enough breath for lengthy discussions about life, work, and the possibility of alien lifeforms. When it comes to brain health, whether you're walking or pumping iron, a little sweating and effort can go a long way. For example, resistance training has been proven to be most effective when the load, or how much weight you are working with, increases over time. So kick the intensity up a notch: there will still be plenty of time for chit chat around a post-exercise, antioxidant-rich mug of matcha (my new obsession - stay tuned).

Now that the obvious has been (re)stated, I want to take this opportunity to discuss the idea that perhaps lifestyle interventions such as exercise could be prescribed by your doctor. We know that exercise can improve cognition in aging but also conditions like depression. Should physicians prescribe lifestyle changes? Or are diet, exercise, and other lifestyle activities choices we should make ourselves? How would you feel if your doctor prescribed you exercise instead of pills? Would you be more motivated to exercise if the prescription came from your doctor instead of from your friendly Internet science blogger? Your thoughts in the comments!

Thursday, November 8, 2012

If only I had a (better) brain: Part II

Can we "train" our brains to be brighter, sharper, faster? 

A while back I wrote a post about a big study looking at "brain training". The researchers wanted to know whether training programs that look like video games (like Brain Age and Lumosity) could significantly improve brain performance on various tests. The results, in a nutshell, showed that while participants improved on the tasks they trained on (e.g., if the game involved ranking balls from smallest to biggest, the participants got *really* good at ranking balls from smallest to biggest), the improvement didn't carry over to general brain function.Turns out ranking ball sizes doesn't help you remember where you left your keys this morning.

Two years later, what's the word?

I'm going to shift a little from how I normally do things (review a single article) and tell you about findings I learned about at the recent Aging and Society conference. At the conference, several researchers talked about brain training in the context of aging. We know that as we get older our cognitive abilities decline - we forget names and words, misplace our shopping lists, and process information a little bit more slowly. Wouldn't it be fantastic if we could just spend ten minutes a day playing games on our iPad and successfully counter this decline? Of course it would be fantastic. Not just for us, but also for the companies who are trying very hard to convince us to buy their products to improve our cognition.

The problem is that skills are specific. If you want to become a fabulous jazz pianist, you have to play the piano (preferably jazz songs, too). If you want to become a star ballet dancer, you have to practice ballet. If you want to become a better mountain biker, you have to mountain bike - road biking will improve your leg strength and fitness, but ultimately it won't make you a better mountain biker. So why should things be any different for brain skills?

As it turns out, they aren't. Two years later, nearly all the research conducted in the field of brain training is turning up the same results: people only get better at the tasks they trained on - the improvement doesn't cross over to more general skills, different skills, or everyday life. In one study, a researcher compared a commercially available brain training program with what she called an "active control" - a group that simply played regular video games like Tetris. She found that the group who spent time on the commercially available brain training program actually saw some aspects of their cognition decline compared with the control group. Bummer.

Now don't throw out your Brain Age game yet - everyone at the conference agreed that engaging your brain in training programs is better than not doing anything. And most of the researchers felt that while the programs don't work now, it's not to say they'll never work. We are increasingly more knowledgeable about how the brain works, what happens when we get old, and what different training tasks do. So it's quite possible that sometime in the near-ish future (don't ask me when) we could see the advent of brain training programs that do have a significant and lasting impact on cognition.

Until then, there is one thing you can do to have a significant and lasting impact on your brain health... And I'll tell you in the next post.

Saturday, July 21, 2012

Cheezy poofs only taste good when all is right

In our early years, we are taught about the five senses: hearing, sight, taste, touch and smell. These senses (supposedly) make up our own personal toolbox for perceiving the world around us, and we are initially taught that our senses give us an accurate representation of what we perceive: cookies always smell like cookies, cheezy poofs always taste oh-so-good.

This idea that our brain perceives the world exactly as it is starts to break down when we are exposed to optical illusions: images that differ from what we think is real. One of my favorite ones is on the right: the A square and the B square are actually the same shade of grey, even though we perceive them to be different. As it turns out, neuroscientists are increasingly finding out that most of our senses, not just vision, are far from perfect when it comes to representing the world accurately. How we feel, what we are doing, what we just did, pretty much anything can influence our perception.

In a recent study about perception, researchers investigated the relationship between morality and taste. They started by having participants read a short story. Not everybody got the same story to read: a third of the participants read a story in which something morally bad happens (shoplifting, or a politician accepting a bribe), a third read a story in which something morally good happens (a gift to a homeless family, or a good Samaritan stopping a mugging), and a third read a story in which something boring happens (a student choosing a major, or waiters chit chatting). The participants were then asked to rate the morality of the story, and not surprisingly, they rated the stories exactly as you would expect – the shoplifting and bribe-accepting as being morally bad, and so on.

The researchers then pretended that the study was over, and that they were now starting a new study that had to do with product-testing. The participants were asked to drink a teaspoon of a mysterious drink (in reality, diluted blue Gatorade), and then rate the taste of the drink on a scale from very disgusting to very delicious. Can you see where this is going?

As you might have guessed, the participants that had read a “morally bad” story rated the drink as more disgusting, and the participants that had read a “morally good” story rated it as more delicious (the ones who got the boring story rated it somewhere in the middle). That is to say, the participant’s experience of a moral judgment significantly influenced their perception of taste. Seems like we can’t trust any of our senses!

The researchers discussed the results of this study in the context of how we process morality and so on, but I think it’s even more interesting to think of this as a prime example of just how much our brain puts a personal slant on everything we experience. I also see implications for issues like overeating and emotional eating.

Can you think of a time when food tasted different because of emotional reasons? Share in the comments!

Reference: The bitter truth about morality - virtue, not vice, makes a bland beverage taste nice. (2012) Eskine KJ et al. PLoS One 7(7): e41159.

Monday, July 16, 2012

Sitting ducks die... Maybe.

I think it’s pretty safe for me to assume that you’re sitting down right now. Some of you might be so lucky to have a treadmill desk (on my long list of wants) or you might be reading this on your mobile device while waiting in line at the grocery store, but chances are most of you are sitting. Many people around the world do what I call “sitting for a living”, meaning working at a desk for the larger portion of the day. A recent study reported that Taiwan, Norway, Saudi Arabia and Japan are the “most seated” countries with people sitting over 6 hours per day. It’s a no-brainer that sitting all day is bad for your health – it’s been associated with health issues like Type 2 diabetes and cardiovascular disease. Conversely, it’s also known that exercise is good for you and helps prevent health issues like – you guessed it – Type 2 diabetes and cardiovascular disease. Based on these findings, the government has established guidelines suggesting adults get at least 150 minutes of moderate to vigorous exercise per week to benefit from physical activity.

Long work hours combined with all this evidence about the health benefits of exercise has led to a new label: what I call the “active couch potato”, one who is both sedentary and physically active. These people, like me, work 8- to 10-hour days at a desk, but also exercise – for example, they cycle to work, or jog regularly. So the question becomes: is regular exercise sufficient to offset sitting all day on most days?

A recent study tries to shed light on the relationship between sitting and life expectancy, regardless of exercise. After seeing a number of dubious headlines about this study such as “Sitting less can boost your life expectancy” and “Sitting ourselves to death” (gasp!), I thought I’d take a look at the original research and report back.

The researchers carried out a “meta-analysis”, which essentially means an “analysis of analyses”. They looked through previously published scientific articles on the topics of sitting and life expectancy, pooled the results together, and crunched the numbers to get a “big picture”. To make their results easier to understand, they divided sitting habits in three levels: level 1 means sitting less than a quarter of the time in a normal day, level 2 means sitting about half the time, and level three means sitting three quarters of the time or more. What their results show is that going from level 2 or 3 to level 1 (meaning sitting less) can mean a gain of 2 years in life expectancy.

So what? Do we really conclude that sitting is a silent killer?

Not so fast. We have many reasons to believe that sitting is bad for our health, but this article isn’t necessarily one of them. For one thing, the researchers themselves point out that their results don’t mean that someone who sits less can expect to live longer. Life expectancy is a measure that can only apply to populations, not to individuals, so while the study is relevant in a “big picture” kind of way, it means little for your own personal habits and life expectancy.

The authors also make one big assumption in their model: that sitting more causes a shortened life expectancy. However, the study results don’t tell us whether there is a direct cause-and-effect relationship. I talked about confounders in previous posts, and this is a perfect place to continue this discussion. For my new readers, confounders are variables that the researcher didn’t take into consideration, which could explain his results in a different way. For example, in this instance, the researchers find that sitting more shortens life expectancy. However, the real explanation could be that people who sit more end up eating more spicy Cheetos, and it’s the chemicals in the spicy Cheetos that actually shortens their life expectancy. See what I mean? Of course this is a silly example, but you get the idea (and of course I will never give up spicy Cheetos).

Can you think of possible (silly or not!) confounders in this study? Share in the comments!

You can count on more articles about sitting in the future. Since this one didn’t really answer whether sitting and exercising cancel out, I’ll keep looking.  

Reference: Sedentary behaviour and life expectancy in the USA: a cause-deleted life table analysis. (2012) Katzmaryk PT, Lee I-M. BMJ Open 2:e000828.

Sunday, July 8, 2012

Hurray for Higgs

There has been a lot of discussion in the news recently about the discovery of the Higgs boson particle at the Large Hadron Collider in Geneva.

I'm sure some of you would like to know more about this, and I would have loved to write a good post about the discovery and its implications. Sadly, my knowledge of subatomic particle physics is somewhat limited (and by limited I mean nonexistent).

So instead, I recommend the following video for an introduction to the Higgs boson:

What is the Higgs Boson?

And since this wouldn't be a proper Scientific Chick article without a good measure of hype debunking, here's a more critical take on the news:

Cross-Check Blog


Friday, July 6, 2012

Healthy aging: As easy as do-re-mi ♪ ?

We’re all growing old – for all the recent advances in science and all the predictions of science fiction, this is still an inescapable fact. By 2050, there will be roughly 89 million older adults in the US, twice as many as there are now. While old age chases most of us down if we’re lucky, that doesn’t mean we’re entirely powerless in the process.

Previous entries in my blog looked at various ways to promote healthy aging: walking and lifting weights, eating less, learning languages. Some of these lifestyle changes, like exercise, are easy to incorporate later in life, while others, like bilingualism, may depend on the environment you grew up in. Today’s new finding about healthy aging fits in the latter category. It's a bit like a lottery: were you one of the lucky ones who benefited from an anti-aging activity in your youth?

Researchers were interested in how the brain responds to sound. We already know that brain structures that lie at the base of your brain, called subcortical structures (sub > beneath, cortical > the outer layer of your brain) are important for detecting fast-changing sounds like the ones we make when we talk. The precise timing of your brain reacting to sounds degrades as you get older, and scientists believe this is why grandma sometimes doesn’t really follow what you’re saying.

In this study, the researchers measured the precision of this timing by putting electrodes on participants’ heads (the outside only!) and recording the signals their brains generated when they heard the syllable “da”. As expected, the older participants didn’t have as precise a timing as younger ones. More interestingly, however, was that this age-related decline wasn’t nearly as bad in participants who were musicians.

So the take-home message is that lifelong musical experience can help make your brain better equipped to deal with aging. No doubt it also comes with other benefits - my grandma, in her eighties, had forgotten much of her adult years but still delighted fellow residents of her care home with her flawless rendition of the "Sweet bye and bye". Now of course while this is an interesting article, the results don't come as a huge surprise – by now you probably have figured out that the whole “use if or lose it” saying has a lot of truth to it.

Conveniently, I just bought a piano. Now if only I could reap all the benefits just by looking at it…

Reference: Musical experience offsets age-related delays in neural timing (2012) Parbery-Clark A, Anderson S, Hittner E, Kraus N. Neurobiology of Aging 33:1483.e1-1483.e4.

Thursday, June 28, 2012

Science does not rest!

Science lovers, I shall neglect you no more!

Scientific Chick is back at it. There have been so many developments while I have been away from this blog - new findings about obesity, Alzheimer's disease, gene therapy, stem cells, cancer, sex, you name it!

I'm pondering new features for this site - for one thing, I promise to get a better picture up there soon! I would like to have a more interactive format, perhaps a forum for debates, seeing as new developments in science, health and technology do not come without controversy...

In the meantime, though, I'll be bringing some new science stories that I think you'll find interesting, and the occasional ridiculous headline, since I love them so much.

Stay tuned! And thanks for sticking around so patiently!

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