Wednesday, April 23, 2014

How Lifestyle Affects Your Gut Bugs

Dr. Jens Walter, Associate Professor and Campus Alberta Innovation Program (CAIP) Chair for Nutrition, Microbes and Gastrointestinal Health, University of Alberta

Dr. Jens Walter, Associate Professor and Campus Alberta Innovation Program (CAIP) Chair for Nutrition, Microbes and Gastrointestinal Health, University of Alberta

In my show, “Stop Being a Yo-Yo“, I joke about the notion that the bugs that live in your gut can be significant contributors to your weight problems.

All joking aside, the emerging recognition that your intestinal flora (a fancy term for gut bugs) can indeed affect your metabolism and other aspects of your health in rapidly evolving into one of the most promising avenues of nutrition and obesity research.

Reason enough for me to welcome Jens Walter, a new recruit to the University of Alberta as the Campus Alberta Innovation Program (CAIP) Chair for Nutrition, Microbes and Gastrointestinal Health.

Jens describes his research interest as follows:

“Dr. Walter’s research is primarily concerned with the microbial ecology of the human and animal gastrointestinal tract and the metabolic and immunological interactions between the microbiome and its host in relation to health. He views the interrelationship of gut microbes with their host as a symbiosis and is especially interested in the evolutionary processes that have shaped this partnership and the biological outcomes for both the host and the microbes. He is also interested in how environmental factors (such as diet and lifestyle) and historic processes impact the microbial communities in the gut and what consequences their effects have for the host. His research, which is inter-disciplinary and highly collaborative, has resulted in several publications on the evolution of the model gut symbiont Lactobacillus reuteri, the importance of environmental (diet) and host factors (host genotype) on the composition and functionality of the gut microbiota, and the impact of diet on gut microbial ecology in relation to health.”

As a regular reader you will appreciate my excitement in having Jens join our institution as we venture into studying the role that gut bugs may play in obesity.

On a personal note, the fact that Jens hails from Germany and we share an interest in music makes this recruitment even more attractive.

I certainly wish Jens all the best in his new position and look forward to future collaborations.

@DrSharma
Edmonton, AB

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Tuesday, April 22, 2014

Ten Years of Eating Organic Foods Does Little To Reduce Your Risk of Cancer

organic-logoThere is a widespread belief that conventional use of pesticides, antibiotics and other factors in “industrial” farming may promote the incidence of cancers – a risk that could be avoided by eating “organic”.

According to a paper by Kathryn Bradbury and colleagues, published in the British Journal of Cancer, this may not quite be the case.

The researchers examined prospective data of 620,000 middle-aged UK women on the relationship between the incidence of a variety of cancers and self-reported consumption of organic foods.

Over the 9.3 years of follow-up, there was no relationship between the consumption of organic foods and the incidence of all cancers.

In a subset analyses there was a statistically ‘borderline’ reduction in non-Hodgkin lymphoma, a finding that is perhaps more attributable to statistical chance than to any plausible biological hypothesis.

So, while eating “organic” may have a certain “healthfulness” appeal, a lower risk of cancer may not be a notable benefit.

@DrSharma
Edmonton, AB

ResearchBlogging.orgBradbury KE, Balkwill A, Spencer EA, Roddam AW, Reeves GK, Green J, Key TJ, Beral V, & Pirie K (2014). Organic food consumption and the incidence of cancer in a large prospective study of women in the United Kingdom. British journal of cancer PMID: 24675385

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Monday, March 10, 2014

Will Replacing Vending Machines With Slot Machines Reduce Childhood Obesity?

slot machineIn Western countries, both childhood and adult obesity have long been linked to socioeconomic status – in short – not having enough money (and/or education) can make you fat.

This may be the most obvious explanation for an intriguing finding by Jessica Jones-Smith and colleagues published in JAMA, showing that opening or expansion of American Indian-owned casinos were associated with a significantly decreased risk of childhood obesity in those communities.

The basis for this hypothesis was the simple fact that for some American Indian tribes in the US, casinos provide a significant source of income for the people living in those communities.

The researchers looked at repeated cross-sectional anthropometric measurements from fitness testing of American Indian children (aged 7-18 years) from 117 school districts that encompassed tribal lands in California between 2001 and 2012, of which 57 gained or expanded a casino, 24 had a preexisting casino but did not expand, and 36 never had a casino.

Using changes in the number of slot machines per capita as a measure of economic expansion (each slot machine was associated with an increase of around $550 in per capita annual income), the researchers found that every additional slot machine per capita reduced the probability of childhood overweight and obesity by about 0.2 percentage points.

Given that on average the opening or expansion of a casino resulted in about 13 additional slot machines per capita – the average reduction in obesity probability would be about 2.6% points.

Obviously, as the authors acknowledge, factors other than simple economics may have played a role in this relationship.

Thus, as always with these type of studies,  assuming a direct causal relationship between adding slot machines and reducing childhood obesity obesity may be too simplistic.

Less critical observers may nevertheless jump to the conclusion that battling childhood obesity in tribal communities may be as easy as replacing vending machines with slot machines.

@DrSharma
Copenhagen, DK

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Friday, February 21, 2014

Will Eating More Fruit Reduce Childhood Obesity?

sharma-obesity-fruitDon’t get me wrong – I am all about fruit. I have no problem eating 5-10 servings of fruit and veggies each day and could probably eat more.

So, if we could only get all kids to eat more fruit, I say, “Go for it” – even if it does absolutely nothing for their weight.

In fact, I believe that fruit and veggies are so good for us, that even if our kids ended up gaining a few extra pounds from all the good stuff, they’d still be better off than before.

Unfortunately, apart from there not being a shred of evidence from any intervention study that I know of, showing that getting kids to eat more fruit and veggies will do much in terms of reducing their likelihood of packing on the pounds, I am not even sure we have a proven strategy that will actually get them eating more fruit in the first place (anecdotal stories aside).

Thus, I was not all that surprised by the findings of Michael Bourke and colleagues from the University of Manchester’s Institute of Public Health, published in the Journal of Epidemiology and Public Health, showing that getting kids to eat more fruit is far more difficult than one might think.

Their systematic review of literature of interventions to increase fruit and/or vegetable consumption in overweight or obese children and adolescents revealed a total of five studies describing seven interventions all of which used family-focused approaches to increase daily fruit and vegetable consumption.

Only one intervention reported a lasting statistically significant increased consumption of fruit and vegetables – the key word here being “statistically” – whether or not this change was “clinically” relevant remains debatable.

Given these rather sobering findings, the authors wisely conclude that,

“Successful public health interventions tackling childhood obesity will need to take a holistic approach and target behaviour change in multiple aspects of children’s lifestyles and their surroundings, including nutritional education, parental support and physical activity.”

That said, I would question the wisdom of why anyone would consider targeting fruits and veggies as a way to reduce childhood obesity in the first place.

If fruits and veggies are good for you, then all kids should be eating more of them – I am certainly not aware of any data suggesting that overweight and obese kids are specifically “undereating” fruits and veggies. If I am informed correctly, skinny kids are also largely failing to meet the recommended number of servings.

I am also not aware of any studies that conclusively show that lack of fruit and veggies is a major cause of childhood obesity.

Finally, I have yet to see any evidence that getting overweight kids to eat more fruit and veggies will actually do anything for their weight. In fact, given that we now know how difficult it is to get kids to eat more fruit and veggies, I doubt if we’ll ever see a study proving this point one way or another.

But if we agree that more fruit and veggies are good for kids, I see no reason to focus this question on overweight and obese kids in the first place.

In fact, by doing so, we are implying that there is something specifically wrong with the amount of fruit and veggies eaten by overweight kids – compared to normal weight kids.

This kind of framing is what puts the “blame” squarely on the overweight kids (or more likely on their parents) – thus propagating the “lifestyle choice” notion of obesity causation.

Thus, while I understand that it is far easier to get research funding and perhaps papers accepted in journals when the issue can be framed in the context of “obesity” than in more general terms, we should not forget that the more general terms are the actual problem.

Eating too few fruit and veggies is not an obesity problem or an issue in any way specific to obese kids. Framing research on fruit and veggies as a potential solution to this problem is both misleading and stigmatizing.

Are our kids eating enough fruit and veggies? Probably not.

Is there an easy way to change this? If yes, we have yet to find it.

Has any of this anything to do with reducing childhood obesity? I sincerely doubt it.

@DrSharma
Edmonton, AB

ResearchBlogging.orgBourke M, Whittaker PJ, & Verma A (2014). Are dietary interventions effective at increasing fruit and vegetable consumption among overweight children? A systematic review. Journal of epidemiology and community health PMID: 24436339

 

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Thursday, February 13, 2014

Guest Post: Everything You Must Know About Pregnancy and Weight Gain

Zach Ferraro, PhD, University of Ottawa

Zach Ferraro, PhD, University of Ottawa

Today’s post is from Zach Ferraro, PhD, a former CON-SNP National Executive member (2008-12), CON Boot Camper (2008) and Inaugural recipient of CON Rising Star Award (2012). Currently, Zach is a clinical research associate in the Division of Maternal-Fetal Medicine at the Ottawa General Hospital and PT Professor in Human Kinetics at the University of Ottawa. He is also a member of the CON 5 As for pregnancy working group.

Regular readers of these pages will recall that the intrauterine environment plays a vital role in healthy neonatal development and is directly influenced by maternal nutrition, physical activity, xenobiotics and pregnancy weight gain. This interaction is commonly referred to as ‘fetal programming’ or more appropriately termed fetal plasticity. That is, the ability of the developing fetus to grow and respond to external stimuli whether intrauterine or environmental. Thus, all prenatal exposures, positive and negative, have the potential to affect the short- and long-term health of the child.

It is now well-established that excess gestational weight gain (GWG) is an independent predictor of large for gestational age (LGA) neonates and postpartum weight retention (PPWR) in the mother. Simply, moms who gain greater than the recommended amount of weight, according to their pre-pregnancy BMI, subsequently carry this excess weight forward into the next pregnancy causing a rightward shift in their BMI after delivery. In addition, babies born large (LGA) tend to track their excess weight throughout life and are at greater risk of becoming obese as adults. Although the mechanisms explaining these associations are far from unraveled, both LGA and PPWR exacerbate what is referred to as the intergenerational cycle of obesity.

So what can care providers do to help minimize the ill-effects of excessive GWG? Several lifestyle interventions during pregnancy are reported in the literature and have yielded mixed results. This is largely due to heterogeneity in intervention type (diet or physical activity or psychological support or all the above) and intensity (intensive clinical intervention vs. hands off approach). We, in addition to others, have also reported that knowledge transfer between patients and providers may be partially responsible for the limited treatment effects seen in some interventions. Nonetheless, in the absence of any between group differences in GWG guideline adherence and maternal-fetal outcomes between lifestyle intervention and standard care, it is important to remember that healthy living behaviours were not harmful and may have resulted in increased fitness and/or alterations in body composition (which is rarely if at all ever measured). Thus, healthy living trumps numbers on the scale, something readers of these pages are all too familiar with.

Given the many known benefits of appropriate GWG how can we help providers implement, and patients adhere to, recommendations and in turn improve maternal-fetal outcomes? In the fall of 2013 the Institute of Medicine (IOM) chaired a workshop entitled “Leveraging Action to Support Dissemination of Pregnancy Weight Gain Guidelines” to help address this important clinical issue. A link to the 97 page report can be found at the end of the post. During the workshop the IOM heard from clinical experts, scientists, researchers and public health advocates on topics ranging from communicating the pregnancy weight gain guidelines, how to support behaviour change, implementing the guidelines, an overview of the importance of the first 1000 days and collaborating to increase messaging and uptake of the guidelines. Following the workshop it was concluded that strong and consistent messaging was required to assist with patient-provider uptake. Additionally, several resources including physical activity and GWG prescription pads were shared as examples of tools care providers could use with patients. A conceptual model, GWG poster, an easy-to-read information pamphlet, GWG tracker, 5 common myths heard from expectant mothers, and an interactive online tool were also highlighted.

To conclude the IOM committee recommended adopting a ‘before, between and beyond’ approach to connect pregnancy care with general health care to take advantage of the adage ‘prevention before conception’. Changing the structure of prenatal care was suggested to encourage visits earlier in pregnancy as a way that reflects each woman’s unique situation and risk profile; noting that the reversal of early excessive GWG is challenging at best. Lastly, recommendations to motivate women to adopt healthy behaviours by initiating a dialogue between patient and provider were suggested to leverage action across the continuum of prenatal care. It is important to note that many of these recommendations are included within the soon to be released CON 5 As for Healthy Pregnancy Weight Gain.

As the GWG research continues to mount and novel prenatal interventions using sophisticated technology attempt to facilitate behaviour change, care providers and patients require immediate tools/strategies to help improve maternal-fetal outcomes. In addition to the CON 5 As for Pregnancy, providers can be confident recommending routine physical activity (in those without contraindications), nutritional guidance and caloric literacy given that the caloric requirements of pregnancy are modest (~300 kcal/day in term 2 and 3), encouraging a food diary and physical activity log and tracking GWG on their own using the tools provided within the report. Collectively, patients and providers can work together with open dialogue to ensure optimal health and wellness for mom and baby.

You can follow Dr. Zach Ferraro on twitter @DrFerraro for frequent discussion on the topic. More details can be found at www.DrFerraro.ca

References:

Institute of Medicine (2013). Leveraging Action to Support Dissemination of Pregnancy Weight Gain Guidelines

Ferraro ZM, Boehm K, L Gaudet, KB Adamo. Counseling about gestational weight gain and healthy lifestyle during pregnancy: Canadian maternity care providers’ self-evaluation. International Journal of Women’s Health. 2013:5 629-636. 

Ferraro ZM, N. Barrowman D. Prud’homme, MW. Walker, M. Rodger, SW. Wen, KB. Adamo. Excessive gestational weight gain predicts large for gestational age neonates independent of maternal body mass index. Journal of Maternal-Fetal & Neonatal Medicine. 2012;25(5):538-542.

Institute of Medicine (2009). Weight Gain During Pregnancy: Reexamining the Guidelines

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In The News

Diabetics in most need of bariatric surgery, university study finds

Oct. 18, 2013 – Ottawa Citizen: "Encouraging more men to consider bariatric surgery is also important, since it's the best treatment and can stop diabetic patients from needing insulin, said Dr. Arya Sharma, chair in obesity research and management at the University of Alberta." Read article

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