Dating advice from your friendly neighborhood finch

In the animal kingdom, it's well established that by interacting with some individuals and avoiding others, you can influence your experience with natural selection (read: your chance of mating with a hot stud/chick). I think this paradigm is especially obvious in the high school setting: hanging out with the footballers and the cheerleaders increases your odds of mating (or at least, attempting to mate), while hanging out with the geek squad (ah, the good old days) definitely decreases your chance of mating (Glee, anyone?).

A while back, I wrote about dating lessons we can learn from monkeys. Today, I'll share with you the results of a recent study that highlights a dating lesson we can learn... from birds. American researchers set out to analyze the social networks of a species of wild finches to study the relationship between how pretty they are (ornament elaboration), how social they are (social lability), and how successful they are at mating. So they captured and banded a whole bunch of finches, and tracked them year-round.

The researchers found that less elaborate males (the "ugly" ones) shifted social groups more often than the prettier males. When it came to finding a mate, this party-hopping behavior somewhat compensated for their ugliness: the highly social birds were more successful at finding a mate when compared with equally ugly but less social birds.

There's an important lesson here: to increase your chance of mating, it might be a good idea to vary who you hang out with. I'm sure Dear Abby would approve.

Reference: Structure of social networks in a passerine bird: consequences for sexual selection and the evolution of mating strategies. (2010) Oh and Badyaev, Am Nat 176(3):E80-9.

To supplement or not to supplement

Health information can sometimes be a real puzzle*. For example, your doctor may recommend that you take a calcium supplement, since calcium is important for strong bones. Then, the next day, you may read in the news that calcium supplements will give you a heart attack, which is exactly what happened to my mom last week. What should you do? Like most medical interventions, it’s all about risks and benefits. While a new study (you may have already heard of) highlights a risk of calcium supplements, don’t throw away the bottle just yet.

The researchers carried out a meta-analysis: a study of studies. Essentially, they searched for previous studies of calcium supplementation (compared with a placebo) and compiled them together to try to tease out effects that each single study may not have detected. Overall, the researchers ended up analyzing 11 studies between 1990 and 2007, for a total of 12,000 participants. In all the studies, 143 people who were taking calcium supplements had a myocardial infarction (a heart attack), compared with 111 people who were taking the placebo. This represents an increase in the risk of myocardial infarction of 31% for those taking calcium supplements. Interestingly, calcium supplements were only associated with an increased risk of myocardial infarction in people who already had a big calcium intake through their diet (more than 805 mg/day).

This study will no doubt shake things up in the fields of cardiovascular health and osteoporosis prevention. However, there is one important caveat with this analysis: the researchers did not look at studies where the supplement was a combination of calcium and vitamin D. Therefore, one cannot assume that calcium/vitamin D supplements would lead to the same risks. In fact, another recent study in women reported that calcium and vitamin D administered together had no effect on the risk of heart disease. It’s also important to remember that when weighing risks and benefits, calcium (and vitamin D) does a lot more than just strengthen your bones: it has also been shown to play a role in the prevention of certain cancers.

One thing is for sure: dietary calcium intake is safe. So go ahead and enjoy the moo juice.
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*You’ll be pleased to hear that I am dedicating my postdoctoral training to solving the puzzle.

Reference: Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. (2010) Bolland et al. British Medical Journal [Epub ahead of print].

Relevant science for a summer party

I've been busy. I would like to say that I've been enjoying the wonderful Vancouver summer, but in academia, summer rhymes with grant writing. This means that I spend most of my days writing up long-winded research proposals that describe the exciting science I'd carry out if only (insert name of funding agency) would give me the (insert large amounts of money) I need. Of course, each funding agency (usually charitable organizations or government organizations) has slightly different requirements. One wants an 11-page proposal in New Times Roman font in size 12 with the references as part of the proposal. The other wants an 14-page proposal in Arial font size 11 with the references in an appendix. So on and so forth. So yeah, buckets of fun.

Interestingly, trying to convince others that my brilliant ideas should be funded also makes me wonder how other types of research get funded. Since this is the summer and I'm sure you'd prefer some light reading, I thought I'd share a little gem of an article on a topic of utmost importance that really illustrates my point about funding: the best possible way to... Pour champagne.

French researchers (who else?) looked closely at two different ways of pouring champagne into a champagne glass (a flute): (1) the traditional way, which consists of letting champagne fall vertically and hit the bottom of the flute, thus generating a thick head of foam, and (2) the "beer-like" way, which consists of pouring the champagne on an inclined flute wall, which generates less foam. The researchers analyzed a number of parameters such as the concentration of dissolved carbon dioxide and the temperature of the champagne. As it turns out, serving champagne chilled (4-12 degrees Celsius) in the beer-like way minimizes the loss of dissolved carbon dioxide, a parameter of utmost importance since it impacts various aspects of the champagne-tasting experience. The researchers stress the value of their research and call for revisiting the traditional way of serving champagne, especially when champagnes are to be compared in competitions.

Wow. Seriously, who funds this? And most importantly, why is it that some researchers have all the fun? The fine print tells us that the researchers "thank Champagne Pommery for regularly supplying (them) with various champagne samples". I think I missed my calling.
Reference: On the losses of dissolved CO2 during champagne serving. (2010) Liger-Belair et al. Journal of Agricultural and Food Chemistry. [Epub ahead of print].

I'm not making it easier for you with this picture

In my last post I wrote about how children think junk food is tastier when there’s a cartoon on the package. As adults, we may be wiser to such blatant marketing schemes, but we still love our junk food, Shrek or no Shrek. Take pop for example: as of 2006, the production value for carbonated soft drinks in Canada was $2 billion. We also like our donuts: one of the biggest sources of added sugars in our diet is bakery goods. While it’s sometimes nearly impossible to resist the enticing aroma of fresh cinnamon buns baking at the coffee shop, think twice before you splurge: a new study suggests that added sugars in the form of fructose is positively linked to high blood pressure.

High blood pressure, or hypertension, affects over 5 million Canadians, and is increasingly affecting teenagers. It’s a direct risk factor for many nasty conditions, like heart failure and stroke. Interestingly, the increase in the prevalence of hypertension mirrors the increase in our consumption of fructose. And while technically, fructose is a type of sugar found in fruits, it is not thought that the increase in fructose consumption is due to eating more apples. The culprits are sweetened drinks, processed foods and those deadly cinnamon buns.

To address this question directly, American researchers analyzed the data from the very, very large (>4500 participants) National Health and Nutrition Examination Survey. Not surprisingly, the more fructose you consume, the higher your risk of hypertension. This fructose intake/high blood pressure relationship holds even when you control for a number of other factors, including demographics, physical activity, other diseases, calorie intake, alcohol intake, salt intake, and others.

This study highlights what we call an “independent association”, which is not to be confused with a cause-and-effect relationship. There is not enough data to say that eating a lot of fructose leads to hypertension, only that those two things seem to occur together. However, the study has some strong features, namely that it is looking at a very large sample of people, and that it controls for many possibly confounding factors (an important one being salt intake, as it can lead to hypertension).

On the plus side, it’s very easy to limit your fructose consumption by decreasing the amount of pop you drink and the amount of processed foods you eat. On the downside, cinnamon buns are oh-so-very-tasty...

Reference: Increased fructose associates with elevated blood pressure. (2010) Jalal DI et al. J Am Soc Nephrol [Epub ahead of print].

Is Scooby-Doo to blame?

In this age of pre-prepared processed meals and endless hours on Facebook, it’s no wonder kids are getting fatter. In the US, obesity rates have doubled for preschoolers (2-5 years old) and more than tripled for children 6-11 years old. To explain this alarming obesity trend, many blame the accessibility and affordability of fast food. As a graduate student I often relied on cheap take-out to sustain myself. Luckily I quickly discovered that in Vancouver, sushi costs less than a McDonald’s meal, offering an interesting alternative. If my rent didn’t force me to live below the poverty line (hey, this PhD’s got to be worth something, right?), I would have thought this was heaven. In any case, I’m digressing. Cheap fast food is one part of the equation, kids drooling, lifeless, in front of the computer and the television is probably another part. Interestingly, a recent study suggests that another contributor to the obesity crisis is no other than… Scooby-Doo. And Dora. And Shrek.

The researchers were interested in finding out if putting the image of a popular character on the packaging of a product (this marketing ploy is called “character licensing”) is an effective way to sell food to kids. To test this, the researchers studied three foods: graham crackers, gummy bears and baby carrots. The participants in the study, children aged 4 to 6 years old, were presented with two packages of the same food item (for example, graham crackers). The only difference was that one of the packages had a sticker of a cartoon character (Scooby-Doo, Dora or Shrek) on it. The kids were then asked to say if one of the two foods tasted better, and if so, which one. They were also asked which food they would prefer to have for a snack.

So, does it work? Are children that oblivious to this obvious and dubious marketing trick (Scientific Chick challenge: Write a sentence with more than 3 words ending in -ious)? Absolutely. Overall, children perceived the food items with the cartoon on them to taste better than the ones in the plain packaging. This finding was statistically significant for the “junk” food (the crackers and the gummy bears). Not surprisingly, the children also indicated they would prefer the snacks with the characters on the packaging. As it turns out, character licensing is especially effective in children because they lack the ability to understand that the advertisement is meant to be persuasive.

You would think that all you would have to do to solve the obesity crisis is to slap Elmo’s face on broccoli and apples, but the fact that the character licensing experiment didn’t work as well with the carrots suggests this wouldn’t necessarily do the trick. The researchers only studied 40 children, a relatively small sample size to draw out any solid conclusions, but it’s still an interesting finding. I find it a little worrying that cartoon characters can lead to a more positive perception of the taste of junk food. I find it very worrying that food and beverage companies spend more than $1.6 billion per year on advertising for kids. I guess Ramen advertises for grad students and nobody gets worked up about that.

Reference: Influence of licensed characters on children’s taste and snack preferences. (2010) Roberto et al. Pediatrics, 126(1):88-93.

The little-known benefits of pumping iron

At the risk of sounding like a broken record, exercise is good for you and your brain. That being said, most studies looking at exercise and cognitive function evaluate aerobic exercise (the kind that gets your heartbeat going). The other kind of exercise, resistance training (strength training with weights), has not been of much interest, perhaps due to the old stereotype that has been plaguing bodybuilders forever: big biceps, small IQ (although big biceps never stopped anyone from becoming governor of California). Switch the young lads for older women, though, and a recent study from a team of researchers at the University of British Columbia (represent!) suggests that gaining muscle can translate into a better brain.

The study looked at 135 women between the ages of 65 and 75 over the course of a year. The women were assigned one of three groups: group one took a one-hour resistance training class once a week, group two took a one-hour resistance training class twice a week, and group three, the control group, took a one-hour balance and stretching class twice a week. The women were all evaluated for a range of cognitive functions at the start of the study, at the six-month point, and at the end of the study (at the 12-month point).

The bad news is that strength training for six months, whether once or twice a week, didn’t lead to any changes. The good news is that if you stick to it for a year, you only need to train once a week to see an effect. After 12 months, the researchers found that all the women who underwent strength training showed a significant improvement in attention. The researchers evaluated attention using the well-established Stroop test (see image below), where the names of colors are written in an ink of a different color (for example, the word blue is written in red ink). To assess attention, the participants were asked to name the color of the ink (and not the word) as fast as they could (try it!). The once-a-week and the twice-a-week resistance training groups significantly improved on this task, while the performance of the balance and stretching group slightly deteriorated.

This improvement in cognitive function didn’t come without a price. The women in the once-a-week resistance training group complained of joint and muscle pains more than the women in the two other groups. It seems that the sweet spot for both an improvement in cognition and a lower risk of pain is to train twice a week (at least). This makes sense to me: the more frequently I exercise, the more my body gets used to the motions. It is also worth noting that the researchers tested other cognitive tasks such as memory and these didn’t show any change with resistance training.

Overall, though, I think this study is great news. I know that many older adults shy away from rigorous aerobic exercise (even young adults… *cough cough*), so this could be an easier alternative to help with brain health. And even if the “brain benefits” of resistance training could be a little more impressive (like by curing Alzheimer’s disease, while we’re at it), on the plus side, strength training also improves gait speed (your natural walking speed), and an improved gait speed is associated with a significant reduction in mortality. So if you don’t exercise for your brain, do it for your lifespan.
Reference: Resistance training and executive function: A 12-month randomized control trial. (2010) Liu-Ambrose T. et al. Arch Intern Med 170(2):170-8.

If I only had a (better) brain

Scarecrow, from the Wizard of Oz, desperately wanted a brain. Given the financial success of the brain training industry, it seems he’s not the only one hoping for cognitive enhancement. “Brain training” refers to the improvement of cognitive function by the regular use of computer exercises. Recently, it’s popped up everywhere, targeting kids through video games like “Big Brain Academy” to older adults through iPhone apps like “Lumosity”. While brain training companies are stuffing their pockets, the question remains: does it work?

A team of researchers from the UK set out to test how well brain training works. They teamed up with a popular science show on television and recruited over 11,000 healthy participants. The participants completed a general initial assessment of cognitive function (the “benchmarking” assessment), then started a regimen of 10-minute training session three times a week for six weeks. The online training sessions tested a broad range of cognitive functions: short-term memory, attention, math skills, and so on. These tests were designed to be similar to those found in commercial brain training programs. The researchers followed the progress of the participants over the six weeks of training and concluded the study with a final general benchmarking test similar to the initial one.

The good news is that the researchers saw a significant improvement on the specific tasks the participants trained on. The bad news is that this improvement did not extend to general cognitive function. These results mean that while you can improve at, say, a specific memory game that involves remembering the items in a scene, this won’t necessarily translate to better memory in your everyday life (where did I put my keys again?).

As can be expected, the study was criticized, especially by individuals with a commercial interest in brain training. Some suggested that the participants didn’t train long enough or often enough to see an improvement in general cognition. Others said that it’s not because these researchers didn’t observe an improvement that it’s impossible to achieve cognitive enhancement through computer games. However, it’s important to keep in mind that the study also scores some good points: the researchers looked at a very, very large number of participants, and the games used for brain training mimicked those that are commercially available.

Personally, the last thing I need is a reason to spend more time in front of the computer, and I like to think that fresh air is a terrific cognitive enhancer. What do you use to maximize your brain power? Coffee? Naps? Share in the comments!

Reference: Putting brain training to the test. (2010) Owen, AM et al. Nature 465:775-8.