Do older mothers really live longer? And what does it mean if they do?

Photo by Chris Zielecki via Flickr. CC-BY-NC-SA.

Photo by Chris Zielecki via Flickr. CC-BY-NC-SA.

You may have seen the headlines: “Older mothers tend to live longer,” was how TIME put it. NPR chose a more careful but similar phrasing: “Older moms take heart: You may be more likely to live longer.” But the study didn’t show what you might expect.

(Disclaimer: I wrote one of the many news briefs on this, though not the ones linked above. That’s why I had occasion to read the paper so closely.)

First of all, the older moms weren’t that old when they had their last child (which is the date the researchers counted: age at the last child’s birth, regardless of when or whether earlier siblings may have been born). Women who are older when they have their last child are likely to be older at menopause, but those dates are often separated by a decade, and clearly there are a lot of different factors at play in their social lives, not just their biology, in determining whether they have a child at a later age.

The women in this study were born on the order of 70 to 100 years ago, so we’re looking at women making decisions about family planning from roughly the 1940s through the 1970s. That’s nearly a generation of difference between subjects in the same study, although the researchers say they were only looking at women over 70 because going any younger would be too drastic of a difference in social factors.

But the biggest thing that didn’t always get reported about this study was that the controls—the women who were judged as NOT living to extremly old ages—were also very old. The median age of the extremely old women was 100; in the group of deceased women used as controls, the median was 92. So if a woman finished having kids (for any reason) before the age of 33, she was more likely to end up in the group that “only” lived, on average, to 92.

As a study to tell us about the health of the average woman who has babies late in life, this stinks. But that’s not what the study was meant to do. It’s one of the analyses that comes out of the Long Life Family Study, which enrolls not just individuals, but families in which several siblings live to exceptional old ages. The idea is that if there are genes for super-longevity, these families would have them.

So it was within this population that the researchers looked for links to fertility. Some historical studies had shown that women who finished having children later in life were likely to live longer. Women from those times didn’t have the same contraception options that we (well, some of us) do today, so the factors involved may be more biological.

The researchers were considering some evolutionary hypotheses that would link fertility and longevity: perhaps women that are fertile longer are somehow better able to conserve energy in a way that would help them live longer. And they admit (for example, in quotes in the NPR article) that studying the women’s actual age of menopause would be more useful in the quest for genes that can confirm their hypothesis. That data, they say, isn’t available yet.

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Bullet Points: This article has no waiting period

In December of 2012, I was asked my thoughts on the Sandy Hook shooting on Twitter, and if I was going to write about it through a public health lens. I said no – I didn’t want to weigh in so soon, and I didn’t really know where to start. Sandy Hook capped off a year where 130,437 people were shot by firearms. Of these, 31,672 people died, with almost 60% listed as suicides. Since that exchange, there have been several more mass shootings (defined as 4 or more fatalities in one instance - not including the shooter), and I kept surfing the internet to explore the arguments on both sides of the gun control debate. As pointed out by Kathleen Bachynski over on The 2×2 Project’s series on gun violence, aptly titled “Fully Loaded“, if “measles or mumps killed 31,672 people a year, we would undoubtedly consider the situation to be a public health emergency.”


The Smith & Wesson Model 29 became a classic after the Dirty Harry movies starring Clint Eastwood were released

The issue is, I’m not inherently against owning firearms. Sure, I don’t understand it, and it makes little to no sense to me how owning a gun makes you feel safer given how every other country in the Western world doesn’t and they seem to be getting along just fine, but that’s not the point. Many gun owners own firearms for self-defence, but use them mainly for fun and recreation – shooting targets and hunting are two of the major uses. More importantly though, Americans don’t want to give up their firearms, and that attitude isn’t going away any time soon: Anyone who thinks advocating for a universal ban on firearms in the US is wasting their time.

The support for firearms is highlighted by the NRA and their attitude following any mass shooting. When the NRA can stand up and brazenly declare that this would never have happened if everyone else was armed, and, more importantly, have people believe them, the mere idea that firearms are the problem is a non-starter. The whole idea that “the only thing that can stop a bad guy with a gun is a good guy with a gun” is unbelievably foreign and alien to me. It sounds like a cheesy line in a 1980s action movie, where the city has been overrun by crime and the only thing between civilization and chaos is one lone officer who doesn’t care for regulations – not the speech you give following a mass shooting where 20 children and 6 teachers died. It all feeds into a belief that we’re all fighting against each other rather than being on the same side, which is exactly what the NRA and gun manufacturers want.


Wayne LaPierre took to the stage following the Newtown Massacre to promote a plan where armed guards would patrol schools around the country. That’s his “solution.”

Divisive Politics

While exploring this issue further, the biggest obstacle I found in reducing gun violence is how much of a hot button issue this is. The issue is often painted as an “us vs them” battle, with strong militaristic language, and hyperbole in spades, exacerbated by the fact that one side is literally pointing guns at the other. When a discussion around gun control is met with “I’ll give you my gun when you take it from my cold, dead hands,” there’s no sense in engaging. And politicians aren’t going to either – the NRA donated $650,000 to congressional candidates in the 2012 election, effectively ensuring that no real change happens, and any objections to current policies are met with swift and immediate condemnation. In fact, the only major federal piece of gun legislation that has been enacted in the past 10 years was the Protection of Lawful Commerce in Arms Act, which, I kid you not, prevents gun manufacturers and dealers from being held liable if their products were used in crimes. Now while this makes sense (you’d never sue Chevrolet if you were hit by an Impala), the fact that this is the only piece of federal legislation that has been passed is a telling indication of the priorities that exist at the highest levels of government. Even something as simple as forcing mandatory background checks is met with resistance at the Senate, being voted down 54-46, despite 91% of Americans being in support of criminal background checks.

But is polarization this the only way forward? Are we truly okay with the status quo as it stands right now? We don’t need or want extreme solutions – arming everyone or removing all guns are not feasible options. However, there has to be a middle ground, where rational minds sit down and determine how can we best approach this problem, and what would be a viable solution.

Quality of the data

A major issue in the discussion of gun violence is that we simply don’t know what works as the data on gun violence is sorely lacking. This is largely driven by the fact that the CDC hasn’t been allowed to conduct research on firearms since 1993. The fascinatingly titled Omnibus Consolidated Appropriations Bill states on page 245 “none of the funds made available for injury prevention and control at the Centers for Disease Control and Prevention may be used to advocate or promote gun control.” So we have very little data available about firearms, and the largest organization in the US that could research it was effectively muzzled from being able to explore this issue and provide us with (any) options. Now, some stats do remain, such as those collected by the FBI, or by private citizens. However, the elimination of a whole area of public health from the CDC’s mandate is a decision that is almost Machiavellian in nature. My colleague Margaret Winker at Speaking of Medicine weighed in on this last January, and summed the practicalities of the situation up well:

“Research that had been conducted to date found that a major argument for gun ownership, protecting oneself at home, was not effective, and gun ownership was in fact associated with an increased risk of homicide. This threat to pro-gun lobbyists was blocked through NRA lobbying Congress, preventing research on a public health threat that claims 30,000 lives a year in the United States. Lifting the ban will reinvigorate this critical area of research; unfortunately, few researchers would pursue a career path with essentially no steady source of funding, so much-needed gun research will not happen overnight.” (Emphasis mine, from Speaking of Medicine)

Without good data, how can we possible make good decisions?

Bringing people together

Finally, if there was an easy solution to the gun violence epidemic, it would have come about by now. But the solution requires us to sit down at a table together and discuss what is going on, and if there’s a way to stop these senseless deaths from occurring. This doesn’t just refer to the mass shootings – most gun-related fatalities are suicides. How can we prevent these deaths from happening, and how can we get these people the help they might need? This isn’t a “new” problem by any stretch – the number of deaths due to firearms has stayed relatively constant at 10.3 per 100,000 every year since 1999. Solving the gun violence epidemic will require leadership, commitment from those from both the pro-gun and pro-regulation sides, and above all, putting petty politics aside to prevent these senseless deaths from occurring. Part of the issue here will require investing money into research as to why people are using guns in this manner, and if there are ways we can get them help before they decide to use them to kill themselves and others. The role of public health in the gun violence sphere is really in figuring out why, creating interventions that will ensure that it never gets to the point of a gun being used.


Thanks to @Crommunist and @ryanclassic for the title suggestion!

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Exercise is safe during pregnancy, but not enough docs know that.

Pregnant women are getting the wrong messages on exercise—often because their doctors cling to old-fashioned ideas.

I was inspired to write about this after reading a post from another PLOS blog, Obesity Panacea, discussing whether exercise is safe for pregnant women. (Short answer: yes.) It’s a topic I’m quite familiar with, having taken a lot of grief about it myself: I ran a marathon while I was pregnant with my second child.

Yes, the kid turned out fine.


I was lucky to be working with midwives who recognize the evidence base supporting exercise in pregnancy, but a 2010 survey of providers suggests that’s a rare situation. Although 99% of the doctors and midwives said that they believed exercise in pregnancy is beneficial, a whopping 64% of them still gave patients the outdated advice to keep their heart rate below 140 beats per minute.

The rule, proposed in 1985, was meant to restrict pregnant women to light to moderate exercise For some of us, a brisk walk gets us up to 140, though it would allow some women to do light jogging. There is, in fact, no reason why women should keep their heart rate below any particular number; the scientist who came up with it explained to ESPN that it was a “guesstimate” based on zero empirical evidence. And so the group that first issued the rule, the American Congress of Obstetrics and Gynecology, removed it from their next set of guidelines.

That means that in the 2010 survey, those providers were giving out a 25-year-old rule that had been retracted since 1994. Worse, 60% of the MD’s in the study had no idea that the rule had been changed.

This is a small taste of what exercising pregnant women are up against.

While exercise is helpful during pregnancy to manage weight gain and blood sugar, and to keep the mom-to-be from going stir crazy, publicizing it as a public health message is sort of unfair when it’s given alongside draconian restrictions. Pregnant women who take to the gym for anything more than a gentle yoga class (full disclosure: I sprained my pelvis in a gentle yoga class) are met with stares and that classic, infuriating question:

“Does your doctor let you do that?”

A doctor, or midwife, doesn’t have the authority to “let” a pregnant woman do something—which also implies that everything is prohibited until the doctor says it’s OK. Rather, evidence should be used to weigh risks and benefits, and ultimately the choice is up to the woman herself.

My midwives asked about my training and race-day plans for hydration and fueling (pregnant women are prone to low blood sugar while exercising, and overheating, while rare, can be dangerous to the fetus) and advised me on some warning signs that could indicate trouble with my pelvic ligaments: if you feel this, stop. Otherwise, they encouraged me to keep exercising as long as I was “listening to my body,” which may sound like woowoo advice but is solidly backed by evidence—absent other problems, pregnant women voluntarily slow down or stop when their temperature rises, for example (thus making obsolete the oft-repeated and probably never-followed advice to stick a thermometer in your vagina mid-workout).

Even though it seems intuitively right, somehow, to advise a pregnant woman that her choices for exercise are walking, yoga, and swimming (or, as I like to put it, “walking gently in a field of pillows”), studies repeatedly fail to find any detriment to mom or baby from even vigorous exercise.

If you can’t imagine wanting to exercise while pregnant, it could be you just don’t have a vivid imagination. I went running 3-4 times per week during the height of my morning sickness, because I knew from experience that I would feel even worse if I stayed in bed. Although I met women who cheered me on, including one who had been out for a run at 40 weeks the day before she delivered her daughter, I had to stop running around 6 or 7 months (shortly after the above picture was taken) but completed a grueling 18-mile hike just so I would have something else to do. Some women can stay motivated to exercise by a goal of “staying healthy for baby” or “training for the birth,” but not all of us. I’m in the camp that needs goals and challenges.

When hiking got too hard, I went to my air-conditioned local gym and lifted weights, including endless kettlebell swings with 35 pounds because that was the biggest bell my gym had, and barbell squats with ever-lightening weight, maybe 85 pounds on a good day. That came to a sudden but temporary stop after I mentioned my routine to a midwife who told me that pregnant women “shouldn’t lift more than 25 pounds.”

Lift 25 pounds how? I said. There’s a big difference between a 25 pound deadlift and a 25 pound bicep curl.

“Just, you shouldn’t lift more than 25 pounds. That’s the rule.”

None of the midwives could tell me where the rule came from, or whether it applied to people who were experienced at weightlifting and were using proper form and breathing appropriately. Finally, one midwife sighed over the phone and said, Look, there are pregnant women who run marathons but it’s not like we recommend that to everybody.

“I ran a marathon back in May,” I told her.

“Oh!” she said. “Oh! I remember you now.” In the end, she agreed that I could go ahead with the same type and intensity of exercise I’d been doing before pregnancy, easing up on the weight depending on how I feel.

I did some further research and found that the 25-pound limit comes from studies of women who had to lift heavy objects at work. The studies found that this correlated with a small increase in risk of miscarriage and preterm birth, which may or may not have been due to the lifting; another school of thought simply holds that the weight you lift while pregnant should be a little bit less than you would lift otherwise. My midwife admitted that while the evidence on cardio exercise (like running) in pregnancy comes from a small pool of research, the evidence on the risks and benefits of lifting is nearly nonexistent.

And so, as in the case of drugs for pregnant women, we need better research. Pregnant women are exercising anyway; researcher James Clapp admits in Exercising Through Your Pregnancy that many of his studies followed women who chose to disregard guidelines, since he couldn’t ethically randomize them to follow the guidelines or not.

Spoiler alert: the babies pretty much all turned out fine.


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Sunscreen doesn’t protect against skin cancer?

You need more sunscreen than this!

You need more sunscreen than this!

New research published last week in the journal Nature gives us some insight into the molecular reasons why UV light causes skin cancer, and also key evidence that sunscreen doesn’t completely protect against UV damage to the skin (1). As we head into the summer months, this information is vital to protecting yourself against skin damage, so read on.

Malignant melanoma is the type of skin cancer that kills. This year, there are expected to be 76,100 new cases in the United States, with 9,710 deaths (2). Almost all of these cancer cases and deaths are preventable through sun protection.  The worrying thing is that malignant melanoma is becoming increasingly common.  Either we are becoming less careful with sunscreen in pursuit of golden brown sun-kissed skin, or else UV light from the sun is getting stronger over time.  Perhaps it’s both. Either way, if you are a human with skin who doesn’t shut themselves up indoors all day, you need to look out for yourself.

Our bodies are smart, and we have built-in genes that protect us from sun damage.  For example, freckles, which are genetically-based, form because the skin is producing extra melanin (pigment) to cover up and protect our fragile DNA from UV light.  However, before this new research in Nature, we didn’t really know how UV light causes skin cancer at a molecular level.  The researchers found that the UV light caused mutations in a gene called Trp53, a so-called ‘tumour suppressor’ gene as it is one of our bodies natural protections against cancer.  Professor Richard Marais, the lead investigator on the research, said,

“UV light targets the very genes protecting us from its own damaging effects, showing how dangerous this cancer-causing agent is” (3)

Most importantly for your day-to-day life is the finding that sunscreen doesn’t provide full protection against these DNA-damaging effects of UV sunlight.  Their research, using mice at risk of skin cancer, found that SPF 50 sunscreen did not protect against the development of melanoma with UV sunlight exposure.  This means that, although sunscreen protects us against sunburn, it might not protect against skin cancer.  Of course, this research was conducted in mouse models and not among humans (it would be unethical among humans), but the research seems compelling and is already causing a big media splash.

Of course, the media attention is warranted.  Skin cancer causes a huge amount of unnecessary pain and mortality each year, and we can do a lot to prevent it.  The results of this study led Professor Richard Marais to conclude,

“This work highlights the importance of combining sunscreen with other strategies to protect our skin, including wearing hats and loose fitting clothing, and seeking shade when the sun is at its strongest” (3)

Never forget that as long as you are in the sun, you are at risk for skin cancer.  Also, don’t forget about the awful ageing effect that the sun can have on your skin.  No one wants unnecessary wrinkles, sun spots, and that overall leathery shoe look.  Because melanoma often starts from a dark freckle or mole, keep an eye on your moles with the ABC’s:

  • Asymmetry: The shape of one half does not match the other half.
  • Border that is irregular: The edges are often ragged, notched, or blurred in outline. The pigment may spread into the surrounding skin.
  • Colour that is uneven: Shades of black, brown, and tan may be present. Areas of white, grey, red, pink, or blue may also be seen.
  • Diameter: There is a change in size, usually an increase. Melanomas can be tiny, but most are larger than the size of a pea (larger than 6 millimetres or about 1/4 inch).
  • Evolving: The mole has changed over the past few weeks or months.

The US National Cancer Institute also has a lovely collection of pictures of what melanoma looks like.

Take care of yourself, and have a good summer!


1) Viros A, Sanchez-Laorden B, Pedersen M, Furney SJ, Rae J, Hogan K, et al. Ultraviolet radiation accelerates BRAF-driven melanomagenesis by targeting TP53.

2) National Cancer Institute. Melanoma. (accessed 12 June 2014).

3) Briggs H. Skin cancer: Sunscreen ‘not complete protection’. BBC. 11 June 2014. (accessed 12 June 2014).

Image source:

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Why do we get less healthy as we age?

Image cred: SG-Works

The clock is ticking…
Image cred: SG-Works

As we get older, we almost inevitably experience health problems. Whether it’s a specific disease, such as cancer, or a general decline in physical and mental functioning, the accumulation of years we spend on this earth results in wear and tear to our bodies. Several cancers often develop due to multiple “hits” to our genomes by environmental factors such as smoking, chemical exposures, and stress, which add up over our lifetimes to literally leave a biological footprint on our bodies through causing genetic aberrations. This is an example of how the trendy scientific concept of ‘gene-environment interactions’ works in causing disease. Another example is that of telomeres – like the plastic bit on the end of a shoelace, telomeres are the bits of DNA at the end of our chromosomes. They protect against loss of genetic code when our cells divide, and are thought to hold the secrets to human ageing. But, I digress – if you want to read more about telomeres, click here (1), here (2), or here (3).

It’s easy then to feel defeated and accept that things will get worse as we get older.  We begin life pristine, with soft fresh skin and strong bodies and minds. I’m in my mid-twenties, and can already feel the loss of my teenage metabolism, energy levels, and sun damage-free skin. Will it only get worse from here? Maybe it will, but maybe not. The wear and tear of ageing seems inevitable, but many other negative health effects of ageing may not be.

How many of the ill health effects of ageing are due to the specific social and material environments of the world we live in today?

Because our world is constantly changing with each generation that inhabits it, the exposures that we encounter often in turn vary by generation. Subsequently, comparing disease rates and exposures across birth cohorts may provide us with some clues to the causes of poor health and their historical explanations.

Image Cred: Cancer Research UK

Trends in smoking and lung cancer in men and women
Image Cred: Cancer Research UK

The most classic example of an environmental exposure (when I say “environment”, I mean literally anything outside of the body – such as a chemical agent, a lifestyle practice, or even the broader social, economic, or political environment) and its related health outcome changing over time is cigarette smoking and lung cancer. See the above graph for the changing rates of cigarette smoking over the latter half of the 20th century for men and women in the United Kingdom – and the striking mirroring of lung cancer rates 20-30 years later. Since women began smoking later than men – for reasons including social acceptability and appearance that also related broadly to feminist movements in the mid-20th century – you can see how the curves are different for women. As you can see, lung cancer rates are decreasing among men, while we are still under the peak of high lung cancer among women due to the above social reasons. Clearly, this historical explanation of smoking rates explains lung cancer rates today, which are of course socially contingent and not inevitable.

Although we don’t need these graphs to know that smoking causes lung cancer, this type of research is useful for understanding what we don’t know about health in contemporary times. In the early 1990s, there was an epidemic of suicides among young adults in Australia. Recent research attempted to understand whether this rise in suicide rates was because Australians born in certain years were more likely to commit suicide, or whether there was something particular about Australia in the 1990s that made people commit suicide regardless of when they were born (the authors hypothesised that high unemployment rates were the culprit), or whether people are more likely to commit suicide as young adults, regardless of when they were born or when they died (4). Using statistical methods to separate out the effects of birth year, age, and time period, the study found that men born after 1970-74 were more likely to commit suicide than those born before then (4). Men in this age group were subject to high unemployment and unstable employment, which may in part explain the suicide rates. A definite causal link cannot be made with this research, but it adds to our knowledge about what happened and can help with future predictions about the consequences of economic uncertainty.

So, it appears that some of the health problems we encounter today are not inevitable and always have historical and social reasons. Maybe I can’t avoid losing my metabolism and gaining wrinkles over time – but I can avoid eating the plethora of sugary, processed foods which are ubiquitous in the food system today.  I can also avoid tanning my skin, the consequences of which are becoming clear, as rates of melanoma skin cancer are currently rising. Obesity will become known as a major global health problem of our time. Last week, it was announced that 2.1 billion people in the world are overweight or obese (5). Why is this happening? Are humans more sedentary than we were twenty, fifty, or one hundred years ago? What has changed in our overall social structure to cause this tipping of our individual energy systems to be, on the whole, in a surplus? Sugar and processed foods probably have something to do with it. What else can you think of? A bit of scientific evidence, combined with critical and creative thought can help you to understand the crazy world we live in today, and how it affects your own body and health.


  1. Seigel LJ. Are telomeres the key to aging and cancer? (accessed 30 May 2014).
  2. Heidinger BJ, Blount JD, Boner W, Griffiths K, Metcalfe NB, Monaghan P. Telomere length in early life predicts lifespan. PNAS 2012;109:1743-8.
  3. Shammas MA. Telomeres, lifestyle, cancer, and aging. Curr Opin Clin Nutr Metab Care 2012;14:28-34.
  4. Page A, Milner A, Morrell S, Taylor R. The role of under-employment and unemployment in recent birth cohort effects in Australian suicide. Soc Sci Med 2013:93:155-62.
  5. Ng M, Fleming T, Robinson M, Thomson B, Graetz N, Margono C, et al. Global, regional, and national prevalence of overweight and obesity in children and adults during 1980-2013: a systematic analysis for the Global Burden of Disease 2013. Lancet 2014. doi: 10.1016/S0140-6736(14)60460-8
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Think you know why obesity rates are rising? You’re probably wrong.

Obama Versus Cutting The Fat

It’s bacon! …Right?
Photo by Raymond Bryson, CC-BY

I know what’s been causing obesity rates to rise. So do you. So does just about everyone. Unfortunately, most of us are probably wrong.

As I tell my students, correlation doesn’t prove causation, but that’s not why we use it. We look for a correlation because if it goes the opposite way from what we expect, that tells us our hypothesis is wrong or incomplete.

So if you have a pet theory about obesity—and, really, everybody has a pet theory about obesity—a correlation can tell you if you’re totally on the wrong track. Say you believe it’s because people don’t exercise as much anymore. But if you checked and found that people are in fact exercising more, that would disprove your theory, right? Or at least clue you in that the story is more complicated than you thought it was at first.

What the correlations show

In a new report, researchers at the University of Illinois have analyzed obesity trends in a way only an economist could love: poring over a multitude of correlations. Obesity rates by age group, by race, gender, education level, and income. Fruit and vegetable prices, leisure time, food expenditures as a percentage of income, daily calories per capita. Consumption of carbs, protein, and fat. Measures of car culture and food deserts.

And they found that the data contradicts a lot of popular pet theories. We exercise more than we used to; we eat more vegetables, too. We have more free time and cheaper food. Some groups of people are thinner than others—but they are gaining at about the same rate as everyone else.


Image credit: Julie McMahon (graphics)

Studying a cross-section of the population would show you that black women have higher BMIs than the other groups shown here, but to focus on that cross-section is to ignore the larger trend: all of the groups are steadily gaining weight.

Similarly, the authors call out a book on the “Colorado diet,” based on the idea that Colorado has the lowest obesity rate in the US at 20%. But put its trend on a graph alongside Mississippi’s (34.6%, second-highest as of 2012) and the lines are parallel.

It’s not a paradox; epidemiologists have long discussed the idea that if everybody in a population is exposed to the cause of a disease, studying cross-sections will only show you who is most susceptible. The true cause may be so common it’s invisible.

Or, as the Illinois authors put it:

To understand the obesity epidemic, rather than asking a question such as “Why are people in Colorado thinner than people in Mississippi?” we need to ask why are people in Colorado gaining weight at the same rates as people in Mississippi?

This isn’t a biochemistry paper, so it doesn’t provide any insights on what is happening in people’s bodies. But here’s the rundown on what the data seems to support. (Disclaimer: almost all data presented in this paper is from the USA.)

Work isn’t taking time away from cooking: We’re actually working fewer hours; what’s increased is leisure time and transportation time.

We may be exercising more. Four minutes more per day in 2012 than in 2003, although that’s self reported. The authors also believe a decline in physically demanding work doesn’t account for obesity rates, since obesity has risen equally among all groups, including children.

Food isn’t too expensive. Or at least, we’re only spending less than 10% of our income on it, compared to 20% in the 1950s and 25% in the 1930s (which is comparable to medium-income countries today). The implication: we could afford to spend more on food, we just don’t want to.

We’re eating lots of fruit and veggies. Now, it’s not enough to meet guidelines (in fact, even if we ate all the veggies produced in the US, we still wouldn’t meet the guidelines). But fruit and vegetable availability has increased over time, and consumption has been relatively steady.

It’s not food deserts. Low-income neighborhoods have fewer supermarkets, but distance to a supermarket doesn’t correlate with obesity or the quality of a person’s diet. When a new supermarket opens, residents’ fruit and vegetable consumption doesn’t change.

It could be TV and video games. That fits the time trend; they specifically track the introduction of VCRs.

It could be sodapop. Consumption of sugar-sweetened beverages is going up and up, and the timing is right.

Or carbs in general. The authors don’t dig into this one, but see this JAMA article (or the accompanying NYT op-ed) for an explanation. Carbs promote insulin which promotes hunger and weight gain. And back to the economists, they point out that carb intake increased most sharply during the 1980s focus on lowering dietary fat.

Can you find holes in these arguments? You’re smart. I’m sure you can. Some of the data is self-reported, some relies on unreliable metrics (hello BMI), and there are tons of un-accounted-for confounders. But it’s time to take a scientific, skeptical look at your own pet theory in view of this data. Could you be wrong?

Let the armchair epidemiology begin, er, continue.

Tattered Cover Bookstore, Denver. IMG_6329

Photo by bookchen, CC-BY


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Going to #CPHA2014


The 2014 CPHA conference will be held in Toronto, ON | Picture courtesy Wikimedia

Next week, I (Atif) will be heading to the Canadian Public Health Association Conference, where I’ll be presenting at two different points.

I’ll be chairing a session titled “Youth Injury Prevention in Canada – Where should we direct our intervention resources.” It promises to be an interesting presentation, where we’ll be discussing injury in Canada, and where to start tackling the problem of injury. This session is scheduled for Wednesday, May 28th from 1:30pm – 3:00pm.

Injury represents one of the most important negative health outcomes experienced by young people in Canada today. Injuries inflict a large burden on children and adolescents and their
families and communities. Injury events are costly in so many ways, whether measured in premature mortality, or the pain, disability, lost productivity and emotional consequence of non-fatal events.

This panel will be made up of child injury researchers and advocates who will make their case for different forms of injury prevention intervention. At the end of this panel, delegates will: understand more about the burden of youth injury in Canada; be aware of at least four different avenues for injury prevention intervention (primordial intervention, context-level interventions, safe sport and peer-influence interventions); have identified the rationale, strengths and limitations of each intervention approach; and have learned more about ways to undertake and gain support for youth injury prevention (from the CPHA conference program).


Click to go to the conference website

My second presentation is one of the studies from my PhD, titled “The influence of location of birth and ethnicity on BMI among Canadian youth.” This is a study that’s in press (woo!), and represents my own research focus. This one will be in the Kenora Room, on Thursday May 29th 2014, from 11:00am to 12:30pm.

Body mass indices (BMI) of youth change when they immigrate to a new country. This occurs by the adoption of new behaviors and skills, a process called acculturation.

We investigated whether differences existed in BMI by location of birth (Canadian vs foreign born) across 7 ethnic groups, both individually and together. We also examined whether time since immigration and health behaviors explained any observed BMI differences.

Data sources were the Canadian Health Behaviour in School-Aged Children Study and the Canada Census of Population. Participants were youth in grades 6-10 (weighted n = 19,272). Sociodemographic characteristics, height, weight, and health behaviors were assessed by questionnaire. WHO growth references were used to determine BMI percentiles.

Foreign-born youth had lower BMI than peers born in Canada, a relationship that did not decrease with increased time since immigration. Similarly, East and South East Asian youth had lower BMI than Canadian host culture peers. Finally, Arab/West Asian and East Indian/South Asian youth born abroad had lower BMI than peers of the same ethnicity born in Canada. These differences remained after controlling for eating and physical activity behaviors.

Location of birth and ethnicity were associated with BMI among Canadian youth both independently and together.

Our findings stress the importance of considering both ethnicity and location of birth when designing and implementing interventions. While currently either one or the other is addressed, our study shows there is heterogeneity in BMI by specific ethnic groups depending on whether they were born in Canada or not.

As always I’ll be trying to livetweet the conference. I’ll be using the #CPHA2014 hashtag, so feel free to follow along online! As always, there are a wide range of presentations and workshops, so I’m excited to attend.

If you’re attending the conference, leave a comment with details of your own presentation so that other readers can attend your talks. And if you see me at the conference, be sure to say hi!

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The Revolution is Nike? Staying fit in the era of ‘Big Running’

Photo: Lindsay Kobayashi

Photo: Lindsay Kobayashi

Two nights ago, I ran the Nike ‘We Own the Night’ 10 kilometre run in London, United Kingdom.  ‘We Own the Night’ is targeted at women, encouraging health and fitness in a safe and non-competitive environment.






'We Own the Night' race gear | Photo: Lorena Fuentes

‘We Own the Night’ race gear | Photo: Lorena Fuentes

What’s the movement? Well, it’s about being a healthy and fit runner, where you are also empowered as a woman by running at night time.  And of course, it’s about wearing Nike while you do it.  Is this a bad thing?  At a time when lack of physical activity and the epidemic of overweight and obesity is one of the biggest global health concerns, the increased popularity of running events like ‘We Own the Night’ could be a positive sign for social trends in activity.

Pre-race group shot | Photo: Lindsay Kobayashi

Pre-race group shot | Photo: Yegee Lee

I rolled up to Victoria Park in London with my two female friends who cajoled me into entering, and we marvelled at the watertight organisation of the event.  There might as well have been giant neon Nike signs directing us to the park.  In some places, there really were.  Bright green and purple (the race colours) lights illuminated the trees leading up to the park.  Feeling like lemmings, we joined the steady stream of girls dressed in neon spandex and the identical turquoise race t-shirt that we were all instructed to wear.  We checked our gear bags, danced around to the DJ already spinning beats from the massive festival stage, and went to warm up.

At this point, we began to realise that this event was not about running at all.  It was about Nike making money, capitalizing on a discourse of empowerment and health for women by partaking in ‘We Own the Night’.  On our way to warm up, we passed two girls decked out in their race gear, downing ice cream from the food carts – with 15 minutes to go before the race start.  Everyone was snapping pics with the Nike branding washed over the park and checking out the shopping and photo ops in the Elle tent (a co-sponsor of the event).

Aside from us and one lonely male runner – no one out of the 10,000 entrants warmed up on the park’s track specifically designed for running.

An empty running track at warm-up time

An empty running track at warm-up time | Photo: Lindsay Kobayashi

Instead, there was an official warm-up, where instructors decked out in Nike gear on the main stage led the group through a series of aerobics.  Ok, a warm-up is good… But since when have aerobics been a preparation strategy for long distance running?  When was the last time you saw Mo Farah do aerobics before crossing the start line of a 10k race?  I understand the nature of the group event that includes all fitness levels, but if Nike really wanted to empower women to begin and continue to include running in their lifestyles, maybe they should take away the pre-race ice cream cart and teach us how to properly warm up for a running distance that requires a delicate blend of speed and endurance.

The start line | Photo: Yegee Lee

The start line | Photo: Yegee Lee

And how was the race itself? It was mostly great.  The course was clearly marked, helpful volunteers were everywhere, and there were water stations and live music at various points.  The level of organisation, demonstrative of the power Nike has to throw around, was a nice benefit to being at corporate event.  At the finish line, we all received a custom-made necklace by a London designer, Alex Monroe.  Monroe designs jewellery for Liberty London, who also has a partnership with Nike.  The necklace was gorgeous.  I overheard many women laughing while citing the necklace as their main reason for entering.  Is that the right type of motivation for exercise?  Let’s not forget that Nike wants us (Londoners in particular) to purchase from their Nike X Liberty Collection and this run was a prime opportunity for advertising.  They have the money to spend on these necklaces if it generates future purchasing and brand loyalty, as I’m sure it will.

And what about feeling empowered, in the first place as being a woman who runs, but also as a woman running at night time?  Does ‘Owning the Night’ mean that I’m a strong, determined, goal-achieving, and perhaps even a feminist woman? If it means that I’ve just participated in a big-branded event that featured running in addition to major product placement under a tenuous discourse of empowerment and fitness, then not at all.  But sure, it can be about empowerment (and I would not say female empowerment, but rather athletic empowerment), if ‘Owning the Night’ is about completing, or hitting a personal best for a 10k run.  And that’s all it needs to be.  As a regular runner who’s done several long-distance races in the past, I didn’t feel like this was a huge milestone for me.  But, I do remember how gratifying and empowering it was when I first began running.  Discovering how far your body can go is a high that’s completely indescribable.  I’m sure that many women felt that way on Saturday, and that is a great thing.

The necklace | Photo: Lindsay Kobayashi

The necklace | Photo: Lindsay Kobayashi

Running doesn’t need to be so branded.  To be active and healthy, we don’t need to be ingrained to desire the latest Nike Free shoes or Nike+ SportWatch, or especially any of the women’s apparel from the ‘Own the Night’ Boutique (yes, it exists, and we were all encouraged to go shopping there before the race).  Running is one of the most accessible forms of exercise out there – all you need are shoes and pavement and you’re set.  If more people ran, the population would enjoy incredibly higher levels of health and well-being.  It’s important to not get tied up in the discourse of feeling fit and empowered because the branding makes you feel that way, rather than because you are actually getting fit and achieving goals.  Of course, the two things aren’t mutually exclusive – corporate sponsorship and athletics have gone hand in hand for years.

But, the bottom line remains that Nike, among all other brands, just wants us to buy their stuff.  It’s arguable that there are many greater evils than selling fitness, but that’s a whole other conversation.  Of course, Nike does do positive, action-based things – they hold races this like one, organise running clubs, donate to charities, and provide training plans, but that’s also part of their marketing strategy.  If you exercise, you are also a consumer and the bottom line of big companies like Nike is always to profit from you.  Don’t get me wrong, ‘We Own the Night’ was great fun and memorable event.  I will probably purchase from Nike in the future, and I am definitely going to wear my Alex Monroe/Nike branded necklace.  I just refuse to accept the subtle marketing idea that I need Nike (or any other big brand) to be an empowered, healthy, and fit individual.  We need to be aware of the effect branding can have on us, especially when it comes to health.  Focus on feeling empowered, healthy, and fit because it comes from within you and what you do, rather than from buying into a brand that sells you that image.

Category: Epidemiology, Fitness, Industry, Running, Social Media | 4 Comments

Male Circumcision Part 5: Measuring Health Provider Burnout

Since 2007, The WHO and UN AIDS have been recommending voluntary medical male circumcision (VMMC) as an important strategy for HIV prevention, particularly in settings with high HIV prevalence and low levels of male circumcision (1).

This is of course a lofty and ambitious goal. In order to obtain the 80% coverage they would need for this campaign to be successful, these public health professionals would have to perform 20.33 million circumcisions between 2011-2015, and a further 8.42 million from 2016-2025.

VMMC Collection Image CollageAs you can imagine, this campaign requires an incredible amount of time and resources, and the impact this can have on practitioners is an important aspect of delivery. Not only must these people be trained medically to perform these procedures quickly and efficiently, they must also be taken care of to ensure that they can sustain delivery of the program and quit. This is a particular problem in the countries participating in the study, as they have critical shortages of healthcare professionals who are qualified to perform these procedures, with none having more than 1 physician per 1000 people. However, very little research has focused on these individuals and the consequence of being involved in these interventions.

How does the VMMC campaign impact practitioners?

To further our understanding of what happens to these healthcare providers, Perry and colleagues conducted a research study, recently published in the journal PLOS ONE (7) as part of the new VMMC collection. Practitioners in Kenya, South Africa, Tanzania and Zimbabwe were surveyed in 2011 (n=357) and 2012 (n=591). The study intended to describe the medical professionals associated with VMMC in these countries, differences between the countries, as well as then look at factors associated with job-related burnout.

Their findings were striking. In 2011, Tanzanian providers had very specific surgical roles, with some only performing the surgery (47%), and some exclusively assisting (12%). However, by 2012, this had shifted, with 99% both performing and assisting depending on need.

Filling the Training Gap

Very few providers had received formal training in VMMC in medical and nursing school, with the notable exception being Kenya, where 21% of providers received training. In the remaining countries, less than 5% of providers received this training in medical school. To counter this in the VMMC scale-up, almost all providers received additional VMMC specific training (above 97% in all countries but South Africa).

Program Duration and Burnout

In terms of duration of work, the median number of months each provider was performing VMMC ranged from a low of 10 months in South Africa, to a high of 31 months in Kenya. Research findings showed that providers had performed between 400 and 2400 procedures during their time in the VMMC program, with some as high as 4700.Burnout was incredibly common, with a shocking 89% of Kenyan providers reporting that they had witnessed feeling burnout frequently or occasionally, a number that was considerably higher than their South African (49%) and Zimbabwean (36%) peers.

The chaps_soweto campaign. Image source:

So how do we prevent burnout?

Here’s where things get interesting. Once the researchers had all the information above, they could start looking at what predicts burnout, and thus provide guidelines on tangible issues that can be targeted for change. Factors such as age and number of months worked were significantly associated with burnout – the older you are, and the longer you work there, the more likely you were to burn out. Not all the findings were this predictable.

Conversely to what you might expect, according to the study, burnout was not due to number of surgeries performed. Those who performed a high volume of surgeries, i.e. 1000 or more, were less likely to report being burnt out than those who did a low number, i.e. less than 100.

In fact, those who performed a high number of surgeries were half as likely to burn out as those who did a low number. Speculatively, this may be due to a high dropout rate at the start of the process, or a “mental resiliency” that is built up from doing a high number of procedures. One of the most positive findings was that providers reported their work as being very fulfilling. However, this didn’t prevent burnout. Despite almost all Tanzanian providers reporting work fulfillment, burnout still persisted.

When asked about why they continued, many VMMC providers expressed pride in their work, and the reward that came from knowing they were helping their own community.

Tapping into this feeling of doing important and valuable work, as well as providing support for those who are new to the VMMC clinics, might help turn the tide on the spread of HIV.


1) World Health Organization. Voluntary medical male circumcision for HIV prevention. (accessed 22 April 2014).

2) Baily RC, Moses S, Parker CB, Agot K, Maclean I, Krieger JN, et al. Male circumcision for HIV prevention in young men in Kisumu, Kenya: a randomised controlled trial. Lancet 2007;369(9562):643-56.

3) Njeuhmeli E, Forsythe S, Reed J, Opuni M, Bollinger L, et al. Voluntary medical male circumcision: modelling the impact and cost of expanding male circumcision for HIV prevention in eastern and southern Africa. PLOS Med 2011;8:e1001132. doi:10.1371/journal.pmed.1001132

4) Hankins C, Forsythe S, Njeuhmeli E. (2011) Voluntary Medical Male Circumcision: An Introduction to the Cost, Impact, and Challenges of Accelerated Scaling Up. PLOS Med 2011;8(11):e1001127 doi:10.1371/journal.pmed.1001127

5) Centres for Disease Control and Prevention. Male Circumcision. (accessed 22 April 2014).

6) Patterson BK, Landay A, Siegel JN, Flener Z, Pessis D, Chaviano A, et al. Susceptibility to human immunodeficiency virus-1 infection of human foreskin and cervical tissue grown in explant culture. Am J Pathol 2002;161(3):867-73.

7) Perry L, Rech D, Mavhu W, Frade S, Machaku M, Onyango M, Adudde DSO, Fimbo B, Cherutich P, Castor D, Njeuhmeli E, Betrand J. Work experience, job-fulfillment and burnout among VMMC providers in Kenya, South Africa, Tanzania and Zimbabwe.

Go here to find all the papers in Voluntary Medical Male Circumcision (VMMC) for HIV Prevention: Improving Quality, Efficiency, Cost Effectiveness, and Demand for Services during an Accelerated Scale-up

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Male Circumcision Part 4: “Public Health is a Noble Profession”

As part of our special coverage of the Voluntary Medical Male Circumcision collection, I recently sat down with Emmanuel Njeuhmeli, a public health physician who was heavily involved with the VMMC initiative. For those interested in a career in public health, and in infectious disease epidemiology, his perspective is enlightening.

3_E Njeuhmeli_Iringa Tanzania External Quality Assurance Site Visit_Oct 2013

Emmanuel Njeuhmeli at Iringa,Tanzania for an External Quality Assurance SiteVisit_Oct-2013

1: Hi Emmanuel, and thank you for taking the time to speak with us. To start, could you tell me a little about yourself?

I am a public health physician holding a medical degree and two master’s degrees, one in public health and the other in business administration. I have been involved with HIV/AIDS prevention, care and treatment program design, coordination, implementation, monitoring, and evaluation since 1998 in various countries, mostly in Central, West, Eastern and Southern Africa. I have been involved with the scale-up of Voluntary Medical Male Circumcision (VMMC) since November 2008.


2: How did you get involved with USAID? How long have you been there?

 After graduating from medical school, I was involved with both public health and clinical medicine for several years, mostly implementing HIV/AIDS prevention, care and treatment in the field in several countries. I decided to go back to school and get a Master of Public Health degree (MPH) and an MBA to be able to work at a more strategic planning level, building on my skills and experience gained in the field. I have been with USAID since November 2008 as Senior Biomedical Prevention Advisor. In this position, I am the Agency technical lead for providing support to priorities countries in Southern and Eastern Africa to introduce and accelerate the scale-up of VMMC. During these years, I have also been Co Chair of the PEPFAR Male Circumcision Technical Working Group (ed note: PEPFAR = United States President’s Emergency Plan for AIDS Relief).

3: Why male circumcision? That’s not usually an approach you hear about when you consider HIV reduction strategies.

There is a biological explanation for why circumcised men have lower rates of infection with HIV and several other sexually transmitted infections. Studies have shown that the foreskin contains many immune system target cells, for example Langerhans cells. Like other immune cells, they have an affinity for foreign bodies including HIV. In addition, the warm, moist area under the foreskin promotes the growth of bacteria, particularly anaerobic bacteria, which are associated with inflammation and may recruit additional immune cells to the area, further increasing vulnerability to HIV infection. The foreskin is also a delicate mucosal tissue that is more vulnerable to micro-tears and other breaks in the skin than is the tougher, more keratinized skin of the circumcised penis. Finally, uncircumcised men have higher rates of other STIs, which we know are a risk factor for HIV acquisition.
4: How long has this project been in the pipeline?

The scientific papers summarizing the results of the three clinical trials were published in 2005 (South Africa) and 2007 (Kenya and Uganda). In March 2007, the World Health Organization and the Joint United Nations Program on HIV/AIDS (UNAIDS) issued a recommendation that countries with high HIV prevalence and low male circumcision rates should add VMMC to their prevention programming. Following this recommendation, many countries in the East and Southern Africa region began the process of adding VMMC to their HIV prevention programs, and shortly after that, PEPFAR and the Bill and Melinda Gates Foundation (BMGF) made resources available to support the scale-up of VMMC, engaging implementing partners to support Ministries of Health in the priority countries. In December 2011, global partners including UNAIDS, PEPFAR, WHO, BMGF, the World Bank, in consultation with the priority countries, launched a five- year action framework to further accelerate the scale-up of VMMC. The papers included in this PLOS collection summarize many of the lessons learned during the accelerated scale up, during which time nearly 6 million men and adolescent boys have been reached with comprehensive VMMC services. This includes risk reduction counseling, HIV testing and linkage to care if necessary, STI screening and treatment and condom provision and promotion.
5: What was the hardest part of doing this project?

 Introducing a new health product or service is never easy, but scaling up VMMC seemed particularly daunting at the outset because the task involved providing millions of surgeries – in countries with an acute shortage of healthcare workers and very limited surgical capacity – to a population (young men) that typically has very little interaction with the health system.

To be honest, many people doubted that it could be done at all, let alone safely. What these papers demonstrate is that it is indeed possible to rapidly scale up safe and high quality services, even in resource constrained settings. The VMMC community has worked hard to document our lessons learned so that others working in the HIV response and in other critical health areas can learn from our experiences.


6. What has the reaction been “on the ground”? Have people bought into the project or has it been a very slow process?

Overall the VMMC scale-up has been very successful, although progress has been greater in some countries than in others, largely due to differences in demand for the service. At present, all 14 countries have embraced the HIV prevention potential of VMMC and are moving forward with the scale-up. We find that in many settings, HIV prevention program managers and frontline healthcare workers embrace the opportunity afforded by VMMC, which is different from many other prevention strategies in that a relatively brief interaction with the health system will provide a man a lifetime of partial protection. This is not to say that it has been easy; male circumcision is closely associated with culture and religion in many African countries, and it has been very important to involve community and religious leaders, including traditional and political leaders, so that people understand that VMMC is about promoting health rather than changing one’s culture, ethnicity or religion. Adolescents have been early adopters of VMMC and in some cases have encouraged adults in their communities to examine their stance on medical male circumcision.
7: What could the future public health implications be of your work?

 My work over the past six years has focused on the introduction of VMMC as a new HIV prevention intervention, and subsequently, acceleration of the scale-up of VMMC in priority countries in Eastern and Southern Africa. VMMC was recommended in March 2007 by WHO and UNAIDS for countries with high HIV prevalence and low male circumcision prevalence as part of their HIV prevention portfolio.

Scaling up VMMC would avert millions of HIV infections, saving lives and significantly decreasing the future investments needed to provide HIV treatment. Modeling studies have shown that a combination approach of scaling up both VMMC and HIV treatment would have the largest impact on the epidemic and would be more cost-effective than scaling up treatment alone. VMMC is one of the most effective and cost-effective HIV prevention approaches currently available.

In 2011, we published results from mathematical modeling we did in collaboration with UNAIDS demonstrating that countries in Southern and Eastern Africa have the opportunity to avert potentially close to 3.4 million new HIV infections in the next 15 years and generate a potential cost savings of $16.5 billion in treatment costs if VMMC is  scaled up.  We also demonstrated that while the intervention focuses on males, the benefits are for both males and females. In a country like Zimbabwe, for example, scaling up VMMC alone could potentially avert up to 42% of new HIV infections that would have occurred otherwise. The faster the program can be brought to scale, the higher the impact will be, so any day or month that passes without this intervention being scaled up is a missed opportunity.
8: What advice do you have for future public health professionals who are interested in field work?

 Public health is a noble profession that allows us to save people’s lives millions at a time with our work. With adequate resources, one is able to identify health issues faced by specific populations, look for evidence in terms of what interventions can be implemented to overcome those issues, design the interventions and implement them efficiently. It is rewarding when you evaluate the work done and you can translate that work into numbers of lives saved.

My advice for any young public health professional is to gain experience in the field. They need to understand the population they intend to support and there is only one way to do that besides looking at the data, and that is to involve the community from the beginning in the solutions that are meant to address their health issues. Community buy-in is key in implementing any public health program.  The knowledge and experience you acquire while consulting with community stakeholders is invaluable.


We’d like to thank Emmanuel Njeuhmeli for offering his time and insight for this interview. For those interested in learning more, the PLOS open access VMMC collection can be found here:  Voluntary Medical Male Circumcision (VMMC) for HIV Prevention: Improving Quality, Efficiency, Cost Effectiveness, and Demand for Services during an Accelerated Scale-up


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