Exercise protects you from stress

womenactiveThere are few of us who can honestly say they are not stressed out at least some of the time. Too much to do, not enough time, looming deadlines, financial concerns, health problems, etc. can all cause us to feel on edge.

Your heart rate and blood pressure soar, you start perspiring, sleeping becomes a challenge, you’re irritable, and so on.

As you might have imagined, chronic psychological stress negatively impacts on your physical health, increasing the chances of countless chronic diseases. Additionally, stress can also reduce your lifespan.

Findings on a more cellular level suggest that psychological stress expedites the aging process of your body’s cells. Specifically, stress has been correlated with telomere shortening of a cell’s chromosomes. Every time a cell divides, and it replicates and shares the genetic information wound up in its chromosomes with its new copy, the new cell retains a slightly smaller end section of the chromosome, termed the telomere. When the telomere gets to a critical length, the cell reaches a point it can no longer divide properly.

When this begins to occur on a systemic level, you are in trouble.

And this is essentially what happens with aging, leading to cellular senescence.

So what effect, if any, does exercise have on this negative impact of psychological stress on cellular aging?

A recent study investigated this very question in a sample of 63 healthy post-menopausal women who were assessed for stress via questionnaire, physical activity levels over a 3 day period, and telomere length via a process I barely understand, so I won’t try to explain (it is Friday, after all).

For purposes of comparison, the women were divided into sedentary (< 33 minutes during the 3 days) or active (>33 minutes during the 3 days) – not a very high bar for activity.

Not surprisingly, participants with higher levels of stress were less likely to exercise, have higher BMI, less years of education, and shorter telomere length.

In terms of exercise protecting you from the negative cellular effects of stress, the authors found the following:

Among sedentary individuals, a 1 unit increase in perceived stress was associated with a 15-fold increased risk of having short telomeres (in the lower tertile of telomere length in the entire sample).

Among active individuals, a 1 unit increase in perceived stress had NO RELATIONSHIP with telomere length.

In other words, those who are active (and just barely so, based on the categorization in this study: 11 mins per day) seem to be protected against the cellular damage caused by cognitive stress

Keep in mind these analyses accounted for differences in BMI, education, age, and anti-oxidant use.

Bottom line:

Just in case you needed another reason to be physically active, regular activity may protect your cells from the damage caused by daily stresses of modern life. Unfortunately, those people who could benefit the most from physical activity – stressed individuals – are least likely to be active.

Peter

Puterman, E., Lin, J., Blackburn, E., O’Donovan, A., Adler, N., & Epel, E. (2010). The Power of Exercise: Buffering the Effect of Chronic Stress on Telomere Length PLoS ONE, 5 (5) DOI: 10.1371/journal.pone.0010837

Category: News | 2 Comments

On the road again

First day of school, 2014

First day of school/work, 2014

The past 12 months have been quite busy for my wife and I.  In September I defended my PhD at the University of Ottawa/Children’s Hospital of Eastern Ontario.  In December we moved across the country to Halifax so that I could begin a post doctoral fellowship at Dalhousie University.

Coincidentally, the day that we drove out of Ottawa in a 14 foot Uhaul, we also found out that my wife is pregnant.  That day was also a massive snowstorm (if anything makes driving a massive truck in a snowstorm even more stressful, it’s knowing that you’re about to be a first-time parent!).  After a short time in Halifax, we have now moved again – this time to Prince Edward Island, where I have begun work as an Assistant Prof in Applied Human Science*.  That makes for 2 separate moves within 7 months (and a single pregnancy!).

I’m really excited to be starting what is essentially my dream job.  I’ll be in a relatively small school doing both teaching and research, which was always my goal.  And it’s in the part of the world/Canada that my wife and I have wanted to be in all along.  I think that both the department and the community will be an excellent fit, and it’s been a very positive experience for us so far.

As I transition from post doc to prof, I wanted to take a moment to publicly thank my post doctoral supervisor Chris Blanchard, as well as his team at Dalhousie.  Although I was only in his lab for 7 months, he was extremely generous to me both in time and in resources.  We’ve begun some very interesting projects that will start to trickle out soon (one is currently under review, two others will be submitted shortly), and have begun prepping for some very cool future projects.  Chris and his team were excellent to my wife and I, and we both thoroughly enjoyed our time in Halifax.  I would also like to thank the Heart and Stroke Foundation for their funding of my work at Dal.  And it goes without saying that I am forever thankful of all the good folks at the HALO research group in Ottawa.

I should also mention that when I was putting together my application for this position I leaned very heavily on the tremendous resources that have been collected by Dr Becca in her Tenure Track Aggregator (in addition to the help of many colleagues).  In particular, I found the Prodigal Academic‘s  posts to be very helpful, despite being in a very different field and dealing with very different types of academic institutions.  Similarly, this handy list of questions to ask/prepare for from SERC was unbelievably helpful. If you are applying to an academic job, I cannot recommend that you click on those above links highly enough.  I also had a lot of help from the Centre for University Teaching at the University of Ottawa, and the Centre for Learning and Teaching at Dal.

However, while I found a ton of advice online about how to prep my application for my current job, I’m cognizant of the fact that grad school is not a perfect preparation for life as an academic.  And so I’d like to ask for input from anyone who has once been in my shoes as a new faculty member: 

  • What did you do that worked well?
  • What would you do differently?
  • How did you balance the responsibilities of teaching and research?
  • How did you transition from being a student/trainee to being a prof/mentor?

And from anyone who was ever a student:

  • What did your profs/supervisors do that you liked best?
  • What did they do that you liked least?
  • What would have improved your experience as a student?

I’ll be doing both teaching and research, so I’m interested in your thoughts on either or both.  If you’re uncomfortable commenting under your real name, feel free to comment anonymously (the email line needs to be completed, but as far as I know, it need not be a valid email address).  And if you’re completely uncomfortable posting online but would like to share, feel free to email me at saunders dot travis at gmail. I’d rather have comments available so that others can benefit/reply, but I’ll take advice in any form that I can get it.  

As for what this will mean for the Obesity Panacea, probably not much.  I will continue to post when I have time (aiming for 1-2 posts/week between Peter and me), focusing mostly on topics that I am currently working on (I will try to work in some posts related to my course content as well, so that it’s not 24/7 sedentary behaviour).  Peter and I began this blog almost 6 years ago, a month before I defended my MSc.  So for the handful of people who have been reading since then (I’m looking at you, Angie & Yoni!), you’ve actually seen a frightening amount of my professional development!

As always, thanks for reading, and I look forward to any advice you’d like to share!

Travis

*As always, a reminder that the opinions and info expressed on the blog belong to Peter or I (or the guest post author, as appropriate), and do not reflect those of any other institution or funding agency.  I hope that’s pretty obvious, but this is a good opportunity for a reminder.  It is also why I don’t specifically list my active academic affiliation(s) here on the blog, although they are by no means a secret.

Category: Miscellaneous, News | Tagged | 7 Comments

Walking meetings: a step in the right direction?

Image by Sangy23.

Image by Sangy23

Today’s post comes from Allana Leblanc.  You can find more on Allana at the bottom of this post.

Right next to coconut water, and standing desks, “walking meetings” are the newest buzzwords for the ever trendy workplace.  A quick Google search will show pages of magazine articles and news stories touting the benefits of taking your work to the streets.  Travis has mentioned them a couple times here, and a summer student with the Healthy Active Living and Obesity Research Group gave a compelling overview of why they are beneficial to health.

Not to beat a dead horse, but I want to share with you the results of a recent article on the benefits of walking meetings. But rather than the health benefits of walking meetings, I want to talk about the benefits for creativity.  Because in a series of 4 experiments, Oppezzo and Schwartz show that walk is your first step to a creative day (full text available here).

To test creativity, they used a couple different tests, but basically, during the sitting, or walking conditions, participants were audio recorded while they completed different word association tasks.  After the test was over, they were scored according to novelty and appropriateness of their responses

Experiment 1

Two conditions:

  1. sitting + test
  2. walking on a treadmill + test

Results: Walking on a treadmill produced an average creative output of 60% higher than sitting.

Experiment 2

Three conditions:

  1. sitting + test, followed by treadmill walking + test
  2. treadmill walking + test,  followed by sitting + test
  3. sitting + test,  followed by more sitting + test

Results: The walking condition, was associated with the highest test scores.  Order of the conditions also mattered so it wasn’t just that people were getting better at the tests.  Walking had a carryover effect such that the walking + sitting condition produced higher scores than the sitting + walking condition. The sitting + sitting condition produced the lowest scores for creativity.


Continue reading »

Category: Guest Post, Peer Reviewed Research, Sedentary Behaviour | Tagged | 4 Comments

Why you should serve unhealthy snacks in a small bowl

snack bowlIt is often stated that the accumulation of excess body weight is a simple matter of energy intake exceeding energy expenditure. While this notion is certainly correct, it does not account for the myriad of factors that drive one to consume more calories than necessary.

Take for example the size of a bowl from which you eat your snacks.

Could this simple factor play a role in the number of calories you may consume?

Back in 2005, Wansink and Cheney performed a wonderfully simple study and found that when snacks are offered in a large bowl, people take 53% more food (146 extra calories) and eat 56% (142 calories) more than when offered the same amount of food but in a smaller bowl (roughly half the size of large bowl).

In the study, 40 graduate students were invited to attend a Super Bowl party (not sure why I was never involved in such “research” in my department). Right after they entered the party, the participants were led to 1 of 2 snack bars where they were offered snacks to consume during the game.

Both snack bars had the same amount of identical snacks (roasted nuts and pretzel/chip variety mix).

While the one buffet offered the snacks in 2 large bowls (4 L capacity) the other offered the same quantity of snacks in 2 medium bowls (2 L capacity).

Each participant served themselves on 10-inch plates, and had their plates weighed prior to joining the other participants in another room and watching the game.

One hour later, each participant filled out a survey and the amount of food they ingested was measured (difference between how much initially taken and how much was remaining).

A total of 5 of 40 participants did not take any snacks when offered. It is not reported whether these individuals were smuggling carrot sticks in their pockets. Regardless, they were swiftly and forcibly removed from the party. (Okay, that didn’t actually happen. The non-snacking weirdos were allowed to stay at the party and probably make the rest of the participants feel guilty.)

The effect of bowl size on caloric consumption was not influenced by body weight, hours since last meal, age, or education. However, gender did play a role; males were more susceptible to the influence of bowl size.

Take home message?

If you have friends coming over for a party, or you’re making snacks for yourself or your family, try the following: place the healthy snacks in large bowls and the unhealthy ones in small bowls. Theoretically, this would result in a greater consumption of healthy snacks and a limited consumption of unhealthy ones.

To help limit my intake of all things salty, especially chips and prezels, I now only ever buy the “single serve” packs. If I am really craving something awful, it guarantees I have to leave the house and head to the grocery store to score some snacks. No more family size bags of chips – it may be economical, but it certainly ain’t helping my waistline.

Even better, you can do away with the unhealthy snacks altogether.

Peter

Wansink, B. (2005). Super Bowls: Serving Bowl Size and Food Consumption JAMA: The Journal of the American Medical Association, 293 (14), 1727-1728 DOI: 10.1001/jama.293.14.1727

Category: News | 2 Comments

Do antihistamines make you gain weight?

Man Sneezing“Achoo!!”

Some folks have allergies that flare up on a seasonal basis. This spring has certainly not been kind to this group.

But if you’re like me, battling your allergies is a year-round affair. The common antihistaimnes available at every drug store, including Cleratin, Reactine, and Aerius, have all at one point or another helped me breathe. More recently, I’ve also been using saline nasal rinses as well as intranasal corticosteroid sprays.

However, the off-the-shelf antihistamines many of us take to get us through allergy season have an additional effect: they may increase appetite. Despite the fact that increased appetite is a fairly well-known side-effect of antihistamines, the packaging of my allergy meds had no mention of this.

Histamine is a neurotransmitter which, in addition to mediating the inflammatory response, and thus symptoms of allergies, suppresses appetite. Thus, antihistamines, which work by blocking the H1 histamine receptor, may remove this appetite suppressing signal.

Not surprisingly, a paper published in the journal Obesity suggests a possible link between the use of anti-histamines and body weight.

In the paper, Ratliff and colleagues used data from the National Health and Nutrition Examination Survey during the 2005-2006 years.

“268 adults (174 females and 94 males) reported use of an H1 antihistamine and completed all outcome measure components. 599 age- and gender-matched controls (401 females and 198 males) were used as a comparison for body measurements, plasma glucose, insulin concentrations, and lipid levels.”

What did they find?

“After adjusting for gender, prescription H1 antihistamine users had significantly higher weight (P < 0.001), BMI (P < 0.001), waist circumference (P < 0.001), and insulin levels (P < 0.005) compared to healthy controls.”

Specifically, controlling for age and gender, those who take anti-histamines were 55% more likely to be overweight than their non-allergy-suffering peers.

However, the increased risk of overweight with antihistamine use was more pronounced for men than women (70% vs 21% increased likelihood).

No differences between the groups were observed for any of the other metabolic risk factors studied.

Of course, as I mention often with this type of study, the results merely suggest a correlation between antihistamine use and body weight; countless other confounding factors may be playing a role. Nevertheless, the preliminary observation is intriguing.

In addition to the direct effect on appetite stimulation, the increased weight observed with antihistamines may also be due to increased sedation, suggest the authors. Theoretically, at least, the increased sedation may lead to a decreased energy expenditure and weight gain. However, most current antihistamines are only mildly sedative at best.

I have tried to think back to times when I take antihistamines and recount whether I had an increased appetite or sedation, and I’m not sure my personal experiences corroborate this observation. Then again, since I’m a fairly chronic antihistamine user, I’m probably unlikely to notice this change.

For the sake of proper breathing, I’ll stick to my anti-histamines.

I wonder if any of our readers have noted a change in appetite or wakefulness when taking antihistamines.

Peter

Reference:

Ratliff, J., Barber, J., Palmese, L., Reutenauer, E., & Tek, C. (2010). Association of Prescription H1 Antihistamine Use With Obesity: Results From the National Health and Nutrition Examination Survey Obesity, 18 (12), 2398-2400 DOI:10.1038/oby.2010.176

Category: News | 4 Comments

Too much sitting may increase cancer risk

Lazy boyYou’ve heard it here more than once: sitting too much is bad for you. Unfortunately, much of our everyday life is comprised of prolonged sitting – from your car, to your desk, to your dining table, to your couch. There’s just no escaping the temptation to sit. Sometimes, despite your best efforts, sitting is the only socially acceptable option. (Ever tried standing in a movie theatre or at dinner in a restaurant? This guy has)

Sitting too much increases your risk of a variety of diseases and early mortality even if you are at a healthy weight and you regularly exercise. For instance, as Travis previously summarized, a “longitudinal study from Australia reports that each hour of daily television viewing is associated with an 11% increase in the risk of all-cause mortality regardless of age, sex, waist circumference, and physical activity level.”

Some have gone as far to suggest that sitting is the new smoking. How is that for an ominous metaphor?

In case you needed more proof that excess sitting is, in fact, killing you – here it is, courtesy of a new study published in the Journal of the National Cancer Institute: too much sitting is also associated with an increased risk of certain cancers.

In the study, the authors analyzed data from 43 individual studies including a total of 68 936 cancer cases (a study or studies, or a meta-analysis in science-geek parlance). Across all these studies they compared the risk of a specific cancer in the most versus the least sedentary group.

Comparing the highest levels of sedentary behavior to the lowest, the study observed a significantly higher risk for three types of cancers of the colon, endometrium, and lung.

Specifically, for each 2-hr increase in daily sitting time, the risk for colon cancer, endometrial cancer, and lung cancer, increased by 8%, 10%, and 6%, respectively.

Similar observations were reported for the specific behaviours of TV viewing time and occupational sitting time as well as total sitting time.

As has been described in other similar studies, these associations were true regardless of how much individuals exercised. In other words, not only do we all need to try to be physically active, we have to ensure we’re not falling into the category of an active couch-potato. That is, one who exercises for an hour a day, but spends the rest of his/her time with their butt firmly planted in a chair or couch.

As always, we have to keep in mind the limitations of this type of study. One of the first lessons we all learn in an entry statistics class is that correlation does not equal causation. An increased risk of certain cancers with increased idle time has been observed consistently across many studies, but this does not definitively prove that sitting causes cancer.

Nevertheless, limited lab studies in humans and animals have provided some insights into the mechanisms by which this might happen. The authors of this paper suggest a number of ways in which sitting may lead to cancer – with the mechanism potentially differing based on the type of cancer in discussion. At this point, however, the picture remains blurry.

What is less unclear is the fact that we’d all likely do ourselves a favour by spending less time on our ischial tuberosities (sitting bones).

Peter

Reference:
Daniela Schmid, Michael F. Leitzmann. Television Viewing and Time Spent Sedentary in Relation to Cancer Risk: A Meta-analysis. Journal of National Cancer Institute. 2014. DOI:10.1093/jnci/dju098

Category: News, Obesity Research, Peer Reviewed Research, Physical Activity, Sedentary Behaviour | 1 Comment