Sunday, August 07, 2011

Moving towards a whole foods, plant-based diet


I love to cook, and when I say cook, I mean I love Mario Batali and Anthony Bourdain meals, heavy on the meat, fat, and cheese. I never had much of a sweet tooth, but I certainly cannot deny that I crave animal fat. You could put a fresh, homemade chocolate cake in front of me, and not even a taste bud stirs, but make a juicy dish of braised shorts ribs and I become one of those kids in a Mischel experiment.

Recently, my brother and I got into a little argument. We never argue. During a banal phone conversation, he claimed that if everyone turned vegan, the world would be a better place. Being the one with a Master’s degree in health science, I disputed his claim. I threw out some facts, which mostly demonstrated my own bias against veganism.

A few weeks passed, during which time I stumbled across T. Colin Campbell’s book The China Study. The author tells the story of growing up on a dairy farm, drinking milk and eating meat every day, and then coming to the realization that animal-based foods cause cancer, heart disease, and a smorgasbord of chronic diseases.

Campbell was a respected researcher at MIT, and his early research on casein (milk protein) showed that it facilitated cancer tumor production or tumorogenesis in the livers of rats, while vegetable protein suppressed tumor production. He conducted an impressive range of studies on animal models demonstrating that dietary fat from animals, either in milk or meat, facilitated cancer more than leading carcinogens such as aflatoxin. This evidence led him to conduct one of the largest human nutrition epidemiological studies, in China.

This observational study compared lifestyle, dietary factors, and standard biological measures to investigate the amount of influence on all major chronic diseases across most of China, a country with a vast array of regional differences.

One of his major points is that only a small percentage of cancer development can be explained by genetics, while what we eat plays a much larger role, even more than known chemical carcinogenic exposures.

Important findings from the China Study:
1.     High dietary fat is positively associated with heart disease (by increasing bad cholesterol in the blood) 
2.     High animal protein consumption is positively associated with high cholesterol
3.     High animal protein consumption is positively associated with breast cancer
4.     Low animal protein consumption is associated with later menarche in women (through estrogen)
5.     Later menarche is strongly protective against breast cancer
6.     Late menopause is associated with higher breast cancer
7.     Animal protein consumption extends exposure to estrogen because it initiates early menarche and later menopause
8.     Animal protein is associated with many other chronic diseases as well.

If you Google “critiques of the China Study,” you will find some solid, honest criticisms. There is no question that there are some flaws in the study. However, what large-scale, cross-cultural study doesn’t have issues? I myself worked on one in India, and I can say this is a difficult type of study to pull off without flaws. Some of the critiques I read say that Campbell is biased towards a plant-based diet and only looks at studies that confirm his perspective. I think this criticism is off-target. Campbell may very well be biased, but he is totally transparent on every level. There are no hidden deals with the fruit and veggie oligopoly, unlike the meat and dairy industries’ backing of research favorable to them.

Others say he extrapolates too much from his research, and I agree with this to a point. My biggest issues with Campbell's argument are these:
1.     China in the 1980’s had many differences with westernized nations, going well beyond diet alone.
2.     He does an excellent job explaining the pathogeneses of some cancers and casein but I am not clear on other cancers.
3.     World cancer stats from 2002 show India with less incidence, prevalence, and mortality than China. This could be explained by China’s increase in animal protein consumption due to increases in incomes, but incomes in India have risen as well. (Although most Indians are vegetarian, they consume high amounts of milk, cheese, yogurt, and other animal-source foods.) More on this below.
4.     Comparing rural population health to urban population health is problematic.
5.     Western-based questionnaires, although translated, are challenging in a different cultural context. For example, people in China could define some food items differently than people in the US.

Even though I feel there are some over generalizations, the author is very clear about the weaknesses of study designs and provides a breadth of evidence, including randomized trials involving diet. The fact that the author provides so many peer-reviewed studies is a strong aspect of the book.

His advice uses a precautionary principled approach. He notes that one should do some research on plant-based proteins and a few essential nutrients that plants do not provide.  He also points out that diet has a huge effect on one’s metabolism and that in turn affects one’s physical activity. So he is not saying, as some criticize, that all you need to do is change your diet. He says that it is the biggest factor to change and also points out that moderate exercise is necessary.

Another strength of the book is that Campbell provides detailed explanations of why other competing dietary theories miss the mark. More often than not, popular diets do not provide any evidence to check the claims they make. This book’s credibility lies in how Campbell frames his argument using a Hill’s criteria-type of evidence evaluation, which lays out all the mechanisms of actions and pathways, discussing and citing research other than his own, thus adding consistency, coherence, and plausibility to his argument. He doesn’t just present one argument or one pathway like so many dietary theories. Another fact that adds credibility to Campbell’s argument is that the American Cancer Society added their own dietary recommendations, while less stringent about animal-based protein, they recommend increasing vegetable consumption. This is intriguing because the author discusses that they were previously opposed to Campbell’s position regarding any association between diet and cancer. Clearly, Campbell is a pioneer in this area.

His dietary recommendations might be even more extreme than evidence dictates, but as he repeatedly advocates a more safe-than-sorry approach. This is where I feel he is especially refreshing in an area like health and nutrition, where industry has infiltrated every nook and cranny to propagate its agenda, from government agencies to universities. There is so much conflicting information that no one actually knows how much animal protein is too much. So it seems prudent to err on the side of consuming a lot less than the more generous recommendations allow.

Perhaps the biggest question lingering for me is that I would like to see Campbell address India in his analysis. During my own research in India, I conducted a 200-person survey of western fast food eating habits. India is a fascinating case because it is a country of vegetarians, but the disease that claims the most lives is cardiovascular disease (CVD).

For India’s Hindu majority cows are sacred, which changes diets in two ways:  a taboo against killing cows means little beef is consumed, and milk is considered a divine gift so it is consumed whole and is incorporated into many dishes. My longstanding criticism of vegetarianism applies here. Just because someone is vegetarian doesn’t necessarily mean that they eat “healthier.” Lots of junk food is technically vegetarian, and many vegetarians substitute high consumption of dairy products for meat.

Using Campbell’s argument, high dairy consumption could explain high CVD mortality in India. But I am not sure how cancer fits in. I will have to research cancer rates, but I do know that diary consumption in India is at least equal, if not significantly more, than in China. So I am curious if Campbell’s theory of casein as a cause for cancer addresses this inconsistency.

While there may be leaps in some of Campbell’s claims, I have no doubt that diet plays a huge role in health and disease. The associations he has compiled are truly impressive. Equally impressive is the fact that he is not trying to sell his own cookbook or proprietary food system. He lays out very simple, clear guidelines for people to follow to change their diet. It is not some 3-week crash diet but is nothing short of a paradigm shift of typical eating habits.

After reading The China Study, I am definitely decreasing my consumption of animal-based protein (and my family’s, since I do most of the cooking). It will be a slow and demanding process, but the evidence seems clear. Tonight: roasted zucchini, pan-roasted turnips with poppy seeds, and radicchio pancakes. Bon appetite!

Stay tuned for more updates on my dietary paradigm shift, as well as commentaries on the counter position that we owe our great gains in human evolution to a meat-based diet. That claim is important in the Paleo-Diet, the Atkins Diet, and Gary Taubes’s interesting book Good Calories, Bad Calories, which I’m reading now.

Sunday, June 26, 2011

How our environment makes us fat


You could walk down the aisle of any place where people gather, like a mall or a Wal-Mart, and hear some remark pertaining to obesity. In fact, weight bias is a popular topic among health researchers. As someone who was obsessed with social psychology as an undergrad, I was not surprised to find the fundamental attribution error (FAE) at the core of this bias. The theory is simply that people often attribute personality faults to other individuals, but they rely on situational or environmental factors to explain their own behavior. In the case of obesity, many people often think of obese people as lazy and not very smart. Many people, especially in the US, think it comes down to personal responsibility.  However, if they themselves were obese they might blame too many hours at the office or too many family obligations for not having time to eat right and exercise, stacking the odds against weight loss.

Just to be clear, humans do make choices, but as the saying goes “genetics loads the gun and the environment pulls the trigger.” People usually make the easy choice. It is easy to blame obese people for their girth, especially in lieu of delving into the complexity of the obesity problem. So we shall dig a little deeper.  

The origin of homo sapiens could be 30,000 years ago or longer. For most of that time we lived in smaller groups, getting our food from hunting and gathering. The agricultural revolution didn’t happen for another 20,000 years. Thus most of our adaptations would have come about for the hunter-gatherer environment. Conservation of energy would have been key to surviving under those conditions. That means we would only use our precious energy if a lion were stalking us or if we were starving. If not, we would sit around and save resources until that lion attacked or food sources dwindled. Humans rarely had to worry about too much food; usually we had too little. Therefore, humans haven’t evolved to become sated. We have no upper limit to our food intake. Have you ever watched an episode of Man vs. Food? Nature was our fitness coach and our dietary regulator.

Add to this a market-driven food system with a laissez-faire governmental approach and you have a recipe for disaster. This is the most supported explanation for the rampant obesity problem facing the world today. How could 60% of human beings on this planet become lazy and fat in just a few generations? And most importantly, when our food system was based on natural cycles the prevalence of obesity was far less. With regards to evolution, our bodies have not had time to adapt to this new and seemingly endless supply of food.

Health researchers use the term “obesigenic environments” to describe environments that foster obesity. These are places that have a high density of fast food outlets, with little access to fresh fruits and vegetables, and with a scarcity of parks and green spaces. So the opportunities for eating healthier and for getting physical activity are decreased. Over the past few centuries, humans have created more and more comfortable environments for themselves, further disconnecting from nature’s regulatory features. Therefore, “fat and lazy” is not truly an accurate description of people who are obese. It gives short shrift to the massive changes humans have brought about during recent history.

If you are obese or know someone who is it might be more productive to take these factors into consideration before making a flippant remark or even blaming oneself for being overweight. By taking this perspective, more opportunities open up to intervene. Our work environments, our food shopping environments, and our neighborhoods all have contributed to our obesity problem, and they are the areas that quite possibly present some solutions. Interventions to built environments have been shown to help people increase their physical activity. By increasing access to fruits and vegetables people will make healthier choices. So instead of making the fundamental attribution error, maybe we should work towards identifying places to change the immediate environment so the easy choice can be the healthy choice.

Monday, April 04, 2011

The Prevention Paradox: an Argument for the Use of Individual-Centered Approaches for the Promotion of Healthy Body Weights

When a country is bombarded by multiple disease epidemics, the question of resource allocation is essential. Many people in public health first seek a population-level approach such as banning soda machines in schools. These large-scale interventions have been shown to shift the population towards a healthier mean (Puska, 2002). In spite of this, obesity manifests itself in a population in a complex and stochastic manner that often pits the food industry against public health and the health of individuals. For this case in particular, we need to take a two-pronged strategy, combining population approaches at individual-level interventions. One group doing this is the Centre for Healthy Weights - BC, a prototype clinic and provincial resource centre based at BC Children’s Hospital in Vancouver (2011).

The population approach to behaviour change was the brainchild of Geoffrey Rose, based on his research in Kenya, where he noticed that the population-mean blood pressure of Kenyan men was lower than men in England (Rose, 1985). This observation led him to use epidemiology for diagnosing a population instead of an individual. This produced a plethora of population-level interventions such as seat belt use and tobacco control measures.

Ever since Rose, public health has touted interventions at the population level as the most effective both in terms of cost and impact (Gaziano et al., 2007). We often forget that he also wrote about the weaknesses of population-level prevention. He explained that the “prevention paradox” leads to poor motivation for an individual to change his or her behaviour, and this in turn affects physician motivation (Rose, 1985). The prevention paradox explains how behaviours that are statistically risky at a population level might not actually result in an individual developing the disease. We all know the proverbial 90-year-old who smoked a pack of cigarettes a day, ate junk food, and is a better bowler than their younger teammates. The fact is that statistics cannot make predictions at the individual level. So in conjunction with a population approach we need to work with individuals to create positive lifestyle changes, particularly those people with a propensity towards visceral adiposity. Geoffrey Rose called this approach of using “interventions that are appropriate to the particular individuals advised to take them” a “high-risk” strategy (p. 35,1985).

This is why targeting at-risk children for lifestyle change, like the method used by the Centre for Healthy Weights - BC, is one way to expand beyond a population approach. The centre doesn’t use a one-size-fits-all strategy because obesity is a complex epidemic, manifesting itself differently in each individual. Thus it also calls for a contextualized approach, which customizes behaviour change according to an individual’s needs. This helps families navigate through the complex minefield of risk factors created by technologized societies. By delivering health education based on the strengths and weakness of the particular family, the customized health education approach helps each family learn how to make sustainable healthy choices. For example, if a family that has good eating but poor exercise habits gets referred to the centre, the interdisciplinary team will work with the family to overcome obstacles to integrating physical activity into their lives while supporting and acknowledging the family’s strengths.

Although a contextualized approach would not be cost-effective for the whole population, we must remember that Rose himself, in his classic paper “Sick Individuals and Sick Populations”, called for using a high-risk strategy and a population strategy side by side (1985). In fighting a complex problem like obesity, the question of cost-effectiveness might not be the right question. On the one-hand, the CHW might not appear to be cost-effective, but considering how healthy options are thwarted by so many factors in this consumer-driven society, we need to embrace behavior change at the individual level while working at the population level to make the healthy choices easier.



References

Centre for Healthy Weights – BC (2011). Services. Retrieved on March 12, 2011 from http://www.bcchildrens.ca/Services/SpecializedPediatrics/CentreHealthyWeights/Services/default.htm

Puska, P. (2002). Successful prevention of non-communicable disease: 25 year experiences with North Karelia Project in Finland. Public Health Medicine, 4(1):5-7.

Gaziano, T.A., Galea, G., Reddy, K.S. (2007). Scaling up interventions for chronic disease prevention: the evidence. Lancet, 370:1939-146.

Rose G. (1985). Sick individuals and sick populations. International
Journal of Epidemiology, 14: 32–38.

Thursday, March 24, 2011

Concept Mapping: Quelling the Anxiety of Complex Problems

Some public health problems are pretty straightforward. Implementing a vaccination program in an area of high incidence of polio, for example, might be fraught with political or infrastructure obstacles, but we know if we administer the vaccine to the population, polio will decrease and lives will be saved. This is a “tame problem.” On the other hand, there are large, abstract issues whose boundaries are unclear, which are aptly called “wicked problems” (Rittel and Webber, 1973).

One such wicked problem is insidious, spanning all levels of society, from the cell to the population, and it has kept me up for more nights than I care to admit. This is the social determinants of health, the complex web of socioeconomic conditions that affect the health of individuals as well as communities (Raphael, 2004).

A video on the social determinants of health by Lemongrass Media commissioned by Vancouver Coastal Health clearly demonstrates the predicament. It features a married couple representing people of high socioeconomic status (SES) and two unmarried individuals representing people of low SES. This cinematic juxtaposition of high and low SES brings home the message that social factors and money affect the quality of one’s life and health. That stark contrast also brought up many emotions for me when witnessing how people of lower SES struggle with being able to access the services needed to raise a child or even pay for necessary medications (2010).

One of the obstacles endemic to addressing wicked problems is how overwhelming they can be, setting in a kind of stress-induced paralysis (Finegood, 2011). A common stress management tool is to break down a large problem into smaller problems and tackle them one by one. This is where the process of concept mapping can be extremely useful.

Another way of looking at concept mapping is creating a “thinking tool,” which can help access one’s tacit beliefs regarding an intractable problem. The authors of Sketching at Work describe their book as a guide to visual problem solving, stating that concept mapping “invites the drawer to explore a change in perspective” (Eppler and Pfister, 2010, p. 7).

In my own process of concept mapping of the social determinants of health, I realized that I previously thought researching causation and helping people were the same thing. But making a concept map helped me realize that this wicked problem is so complex that if we took the time to fully determine causation before acting, more and more people would be lost.

When I sketched out the pathways that led to poor health I saw how one’s level of education is clearly connected to the kinds of jobs one can attain and how that leads directly to the amount of income one can make. Those pathways are interconnected with healthcare access, food choices, autonomy, security, and awareness of risk and disease. All of these factors are interrelated and extremely complex. Real people are dying every day, and there comes a time when scientists have to put the search for causation on hold and apply their powers to ameliorating the problem. I finally understood why Kreiger and Zierler call for epidemiologic theory to go beyond the narrow focus of “modeling causation and explaining error” (1996) and instead espouse that whatever the means of causation, be it direct or indirect, intervening in social determinants such as education and early childhood development is a high priority.

Because drawing a concept map helped me get to a deeper understanding of this wicked problem, others on the causation bandwagon might be served by making their own map. Fixating on causation in part perpetuates the problem by creating a delay in action. Changing perspective is important in helping science become more aware of the complexity of the problem and move towards figuring out solutions without understanding exact casual mechanisms.

References:

Eppler, M.J., Pfister, R. (2010). Sketching at Work. Switzerland:University of St. Gallen.

Finegood, D.T. (2011).The complex systems science of obesity In J. Cawley, (Ed.), Handbook of the social science of obesity. (p 1-48). USA: Oxford University Press.

Krieger, N., Zierler, S. (1996). What explains the public’s health?: A call for epidemiologic theory. Epidemiology, 7(1):107-109.

Lemongrass Media (2010). Videos: Social Determinants of Health. Retrieved on January 26, 2011 from http://mainsite.lemongrassmedia.net/pop-health-the-new-agenda/

Raphael, D.(2004) editor. Social Determinants of Health:Canadian Perspective: Canadian Scholars’ Press Inc. Toronto

Rittle H.W.J., Webber, M.M., (1973). Dilemmas in a general theory of planning. Policy Sciences, 4: 155-169.

Tuesday, March 15, 2011

Justifying Simplicity in the Face of Complexity

Anyone contemplating the problem of chronic disease plaguing countries in the second or third stages of the epidemiologic transition has to be awed by its overwhelming complexity. Of course, many of these diseases are heavily influenced by modern dietary patterns interwoven with many biological and social factors (Popkin 2001; Glass and McAtee, 2006). Here in Canada the problem is no less significant, and Health Canada is working hard on this problem. One area that I will focus on is the food guide, which was developed as one small tool in this battle.

When looking at the latest iteration of Health Canada’s food guide the first graphical element I see is a dizzying array of information simultaneously competing for attention. Further compounding the problem is a cacophony of nutritional messages that come in every shape and form of media, from TV to magazines to Twitter. The overall picture can totally bewilder anyone trying to make healthy lifestyle changes. It is no surprise that public health’s efforts to change behavior are equally as complex as the problems they are trying to change, but does the messaging have to be complex, too?

One important theory from social psychology says no. The limited resource view, developed by Roy Baumeister, states that the brain has only so much glucose to devote to given tasks, and when glucose levels become depleted people will give up more challenging problems (Baumeister et al, 2003;Baumeister and Vohs, 2007). One such challenging problem is changing one’s behavior. People of low socioeconomic status (SES) tend to be taxed by social exclusion, prejudice, and higher levels of work stress (Marmot, 2005). Thus, when faced with challenges like losing weight, exercising, or changing dietary habits, many people simply throw in the towel and quit (Baumeister et al, 2003). I think Health Canada’s food guide can take some advice from this theory and simplify its message.

Here are my three recommendations to Health Canada’s Food Guide Advisory Committee. One is to make a commitment to simpler, more meaningful messages that an average person can understand and follow. Forget about the recommended daily allowances of dairy, grains, proteins, and oils and fats plus leave off the last page with 8 other recommendations. It’s too much information. Focus on the part with the biggest bang for the buck: fruits and vegetables.

If there is one thing you can suggest about increasing health through dietary change it is increasing consumption of fruit and vegetables. Increased fruit and vegetable consumption is associated with eating less processed foods and reducing mortality from coronary heart disease (CHD) and many types of cancer (Crowe et al, 2011:Dauchet et al., 2006). Those two diseases claim the most lives of Canadians (WHO, 2005).

My second recommendation to Health Canada would be that instead of spending so much money and effort on a printed food guide that is widely distributed, I would use the budget differently. I would scale down the food guide and make it web-only, targeted to health educators, institutions who specifically need it, and motivated individuals. Then I would hire a marketing/PR firm to develop a really simple, punchy logo/image and ad campaign to focus on the essential message, one that becomes engrained in the public psyche.

Finally, my third approach would be to work like gangbusters to convince partners in the battle against chronic disease, such as the Heart and Stroke Foundation, BC Cancer Agency and others, to support Health Canada’s message for increasing fruit and vegetable consumption.

Creating a movement of social change needs a consistent, simple message. The average person is being bombarded by all kinds of information; they are stressed and they don’t have the cognitive resources to make the kinds of changes that the current food guide recommends. They just need a simple message to follow.



References

Baumeister, R., Vohs, K.D. (2007). Self-regulation, ego depletion, and motivation. Social and Personality Psychology Compass , 1(1):115-128 DOI:10.111/j.1751-90042007.0001.x

Crowe FL, Roddam AW, Key TJ, et al European Prospective Investigation into Cancer and Nutrition (EPIC)-Heart Study Collaborators. (2011). Fruit and vegetable intake and mortality from ischaemic heart disease: results from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heart study. Eur Heart J 2011; DOI:10.1093/eurheartj/ehq465.

Dauchet, L., Amouyel, P., Hercberg, S., Dallongerville, J. (2006). Fruit and vegetable consumption and risk of coronary heart disease: a metanalysis of cohort studies. Journal of Nutrition, 136(10):2588-2593.

Glass, T.A., McAtee, M.J. (2006). Behavioural science at the cross roads in public health: extending horizons, envisioning the future. Social Science and Medicine 62:1657-1671.

Marmot, M.(2005). Social determinants of health inequalities. Lancet, 365:1099-104.

Monday, February 21, 2011

Psychosocial Stress and CVD


It seems like eons that I have been trying to write a blog post that discusses how social factors influence health without losing the depth and complexity of the issue. Recently, I made a simple short status update on Facebook about psychosocial stress and cardiovascular disease(CVD). Quickly, some of my friends from all corners of the US chimed in and enriched my understanding of the topic. I then sat down trying to write another post after being influenced by all of my friend's input. Soon, I realized that this discussion took a more organic approach; similar to that of a grad seminar session, and it was already captured in print. After getting the permission of all but one of my friends/contributors, I posted it. I am so thankful to have such curious friends who love to engage in these types of deep discussions.


Chris Aloia:

Doing a lot of reading on psychosocial stress and CVD. Wow, mind blowing!

Katherine Moss: What's CVD?

Barbara Martinez:
Cardiovascular disease

Katherine Moss: Ahhh thanks.

Name withheld and writing rephrased: Can you elaborate on what you are studying? It seems obvious that stress causes disease is there anything else?

Chris Aloia:
a direct causative pathway has not been established etiologically, at least in humans. Most of the research points to stress as a modifier. Meaning that high stress causes poor lifestyle choices, which lead to poor health outcomes. Only a few researchers consider stress a direct cause. So there is a big debate that has been going on for at least 10 years and it has my full attention.

Dana Janezic:
The evidence is there for a direct cause in baboons though so it really won't surprise me when they find it for humans.

Chris Aloia:
yeah, Sapolsky again! But you can't randomize humans to stress. I think one group in Germany did it once, it is called torture. But there have been some awesome studies by extremely clever researchers. I buy it as a direct causal agent. The implications are intense!

Katherine Moss:
Kind of gives new meaning to the phrase "broken hearted"

Dana Janezic:
I'm of the school that thinks that when it comes to testing humans, we will be creative enough to come up with tests that don't involve torture. I really don't understand people who just give up and relegate human sciences to soft sciences... when we live in a world where people were creative enough to figure out how to test for the existence of neutrinos.

You're absolutely right, the implications are paramount. Think about the 30 year fixed rate mortgage in these terms. 30 years is a long long time for bad things to happen to a person all the while they have the stress of the obligation on that monthly note. It's particularly interesting when you consider the fact that the 30yfrm is a political creation...

Aaron Irons:
Stress can indeed be a direct cause of cvd, whether left brained methods of perception, research or experimentation come to a widely held consensus or not. I mean that respectfully, while recognizing inherent biases in perception and thus accepted routes of validation which can become so familiar and accepted that the mental structures used to do analytical analysis can become their own barriers to equally valid insights and experience as well. With this respected such methods certainly have their use and place. As long as we remember to also release over attachment to them and allow for equal validity of so called right brain feeling, experiential, creative and perceptual capacities.
Even the short term effects of perceived stress with its effects of blood pressure, heart rate, adrenaline, fight or flight response can noticeably effect cardiovascular system unhealthfully to point of triggering angina, heart attacks and possibly strokes. Body sometimes overcompensates in its responses to perceived stressors by releasing, inhibiting or creating insulating fats, hormones or other chemicals which can have their own damaging effects.

Chris Aloia:
Aaron, you bring up a great point. There is consensus that acute stress can induce a heart attack. However, short term stress does affect the cardiovascular system but to extrapolate that to CVD mortality is where things get VERY hazy.

And you are also right that individual perceptions of stress play major role, which again confounds the stress as direct causal agent theory because what triggers one person's stress response may not another.

Everyone is searching for hormones that are more stable markers for early stage CVD. Even Sapolsky has baboon blood in storage for the sole purpose of a discovery of a new hormones. Incredible! Thanks to all for posting. it helps me put this whole field into perspective.

Katherine Moss:
Here's an idea for a study that doesn't involve torture. Put out a call for volunteers to participate in a study who describe themselves as "under severe stress". They would fill out a form describing their stressors: such as death in the family, job loss, divorce, child with medical issues, etc. Maybe they could be interviewed as well. Interview questions could include what level of social support people have, how often they see family and friends, if they feel comfortable discussing problems, if they belong to a church or other clubs, etc...Then they donate blood and it is examined. They have full cardiovascular workup. It could be a longitudinal study where they follow same subjects over time and ask about their stress levels and then compare results of heart tests? I realise that self selection isn't the best way to gather participants, BUT you would be getting people who subjectively see themselves as "stressed" which, as you say, varies from person to person even though they may be going through the same situations one person's stress might be greater than another. Just some thoughts. I'm sure someone is already doing this type of thing?

Chris Aloia:
Yeah this has been done many times. The key is there is NO stable measure of stress. Self-reported stress can be confounded by lifestyle choices because people who report higher levels of stress are usually of low-income. low-education, they smoke more, etc etc. So no one knows which causes what. Does stress cause poor lifestyle choices? Do poor lifestyle choices create higher levels of stress? Is it education? Is it childhood SES? Crazy interwoven complexity and I love it.

Katherine Moss:
What if the researchers eliminated those of low income or education or those who smoke from the pool?

Katherine Moss:
I'm sure there are plenty of rich, well educated smokers who are stressed. In fact, they could use college professors as a start! LOL

Chris Aloia:
Besides all these very interesting ideas above, there is also a political side. There is a mountain of evidence that shows a good chunk of the explanation for poor health outcomes are from social structures. The implication here is that what many call "human agency" is not as strong as some Republicans might argue. The pulling one up from the boot straps happens a lot a lot a lot less in low-income areas and even middle-income as well. This means the elites not only get the cash, the babes, the vacations, but they also live longer. Got to love that! Human civilization is more animal than human in my mind. I have no trouble with Darwin.

Katerine Moss:
sad but true.

Friday, February 18, 2011

Sustainable Health Promotion

On February 2nd, Denise Stevens, the head of Matrix Public Health Solutions, the company that leads the Community Interventions for Health (CIH) project, was beamed into our classroom via Skype to present the CIH project strategy for chronic disease prevention. She laid out an extremely ambitious health promotion strategy that spanned 3 risk factors: tobacco, unhealthy diet, and physical activity; 3 countries: Mexico, India, and China; and 4 approaches: health education, social marketing, community mobilization, and structural change (Stevens, 2011).

The CIH intervention I think is the most emblematic of what it takes for sustainable health promotion is their tobacco reduction campaign in China, which has “smoking center inspectors” enforcing a city wide no-smoking ordinance. This one got my attention because not just anybody can waltz into China, a country that the WHO reports is “the world's largest producer and consumer of tobacco,” and establish an anti-smoking police force to enforce a CIH strategy. I had been studying sustainable health promotion for almost a decade, from WHO’s EPI to BRAC and including my own struggles with small-scale community health promotion. It seems I have never been able to grasp that elusive ingredient for sustainable health promotion. So here was someone drinking from the Holy Grail; I shot my hand up to ask, “how did you make that happen and who pays for it?”

It turned out that she knows the retired head of the Chinese version of the CDC and that the Pepsico foundation is a major funder behind CIH’s projects. She pointed out the prestige that comes from working with American partners is a bigger incentive for many of her international partners than money.

This funding and prestige revelation led me to research the Pepsico Foundation. Its goals and mission are in step with Pepsico’s own corporate mission and are found on the corporate website. CEO Indra Nooyi supports taking the lead in corporate responsibility and cultivating sustainability in the environment and health arenas (2010b). With Pepsico specifically in mind, I drew a concept map to illustrate the interaction between a corporation attempting to create a sustainable health promotion program in a globalized world and the communities it serves. With Pepsico’s war chest and corporate efficiency, they can fund community projects all over the world and gain access to academic and political elites “to help devise solutions to key global challenges” (Pepsico, 2010b). My map also shows the cycle of profits that fuel Pepsico, as their mission cannot be totally altruistic.

The hard truth is that health systems all over the world struggle to deliver primary care or health promotion, especially to the least fortunate (Frownfelter and Dean, 2006; Holman and Lorig, 2004). One of the main reasons for this is that the demand for secondary and tertiary care is less affected by price (Roberts et al, 2004). This means that when people are sick they are willing to pay whatever it costs to save their own life. This high demand creates a stable need for professionals and thus status becomes attached.

“Basic food” is another high demand commodity (Roberts et al., 2004 p. 164). There will always be a demand for food, and companies that control the food market are some of the richest and most powerful. Ironically, many of their products are partly responsible for exacerbating the prevalence of some chronic diseases.

In contrast, health promotion, and even primary care are extremely price sensitive and do not generate the high revenues like acute care services (Roberts et al., 2004). Simply put, people in general don’t value something that may prevent possible future costs and are less willing to create a demand for those services. This is why I believe that corporations are better poised to deliver health promotion. The new trend in corporate responsibility and sustainability provides the funding, visibility, and sustainability for health promotion in ways that other entities cannot support. Thus, it is important that we in public health can see this as an opportunity to develop public-private partnerships to ensure that such corporate campaigns deliver the right information.


References

Frownfelter, D., Dean, E. (2006). Cardiovascular and pulmonary physical therapy evidence and practice. St. Louis, Missouri: Mosby Inc.

Holman, H., Lorig, K. (2004). Patient self-management: a key to effectiveness and efficiency in care of chronic disease. Public Health Reports, 119:239-243.

Pepisco. (2010a). Corporate fact sheet. Retreived on . Retrieved on February 6, 2011 from www.pepsico.com/Download/PepsiCoCorporateFactSheet.pdf

Pepisco. (2010b). Letter from Indra Nooyi. Retrieved on February 6, 2011 from http://www.pepsico.com/Purpose/Performance-with-Purpose/Letter-from-Indra-Nooyi.html

Roberts, M. J., Hsiao, W., Berman, P., Reich, M.R. (2004). Getting Health Reform Right: A Guide to Improving Perfomance and Equity. New York, Oxford University Press.

Stevens, D. (2011). A systems oriented solution to a complex public health problem. [PowerPoint slides] Retrieved on February 19, 2011 from Simon Fraser University webct http://webct.sfu.ca/webct/cobaltMainFrame.dowebct?appforward=/webct/viewMyWebCT.dowebct

WHO. Towards a tobacco-free China. Retrieved on February 16, 2011 from http://www.wpro.who.int/china/sites/tfi/

Thursday, February 10, 2011

The History of Tai Chi and Health-Part V: Tai Chi in Western Culture

This is the last article in the history of Tai Chi and Health series

The current view of Tai Chi in Western popular culture is that it is primarily a Chinese exercise for elderly people, and not one particularly ideal for cardiorespiratory fitness. Some people who are interested in martial arts see Tai Chi as a viable form of martial arts training. The definition used commonly by both Western and Eastern researchers is that “Tai Chi is a low impact, low to moderate intensity exercise incorporating elements of balance, strength, flexibility, relaxation, and body alignment” (Taylor-Piliae and Froelicher, 2004, p.49).

A broader view, however, is presented in a 2002 demographic survey done in the United States, which found that more than 2.5 million people practiced Tai Chi and 500,000 practiced Qigong (Birdee et al., 2009). The age range was evenly split throughout all age groups, countering the stereotype that Tai Chi is primarily for older adults. Birdee et al. posit that because Tai Chi has roots in martial arts, it increasingly may be viewed as masculine and attractive to younger people (2009). The majority of the Tai Chi and Qigong users was Caucasian, but proportionately there was no difference in race or ethnicity; most had a healthy BMI and self-reported good health. The authors also found that 11.4% of the users practiced Tai Chi for a cardiovascular workout. From this study, it would appear that a large number of people perceive Tai Chi as a cardiovascular workout and good for health maintenance.



It is really important to stay open and re-invent yourself and re-invent Tai Chi. Many people, especially physical activity researchers want to place activities into categories. As a researcher myself, I understand the rationale for this. There has to be some kind of standardization so other researchers can test hypotheses. The problem is then the practice becomes limited. As a Tai Chi practitioner and someone who wants their life to be a work of art, I seek to be unlimited. Tai Chi is fresh and new NOT only an ancient exercise for elderly people.

Sunday, February 06, 2011

The History of Tai Chi and Health-Part IV: Tai Chi and Chronic Disease


In 1973 in Hunan Province, an archaeologist unearthed a silk scroll dating back to c. 168 B.C., which depicted exercise postures. Below each embroidered pictograph was a written “exercise prescription” for different types of diseases, many of which were chronic conditions (Cohen, 1997). This evidence suggests that long before this recent surge in research, early Taoists had devised a method of self-care in the form of exercise to manage chronic conditions. Today, a growing body of evidence suggests that Tai Chi may be an efficacious intervention for the primary, secondary and tertiary prevention of CVD, diabetes, and the determinants of those diseases (Kaptchuk, 2000; Taylor-Piliae and Froelicher, 2004; Thornton, 2008; Yeh et al., 2008). However, of all the studies conducted on a broad variety of diseases, the literature on Tai Chi for the primary prevention of CVD is one of the least explored.

Sunday, January 23, 2011

The History of Tai Chi and Health-Part III: Tai Chi’s Use for Health Promotion

When Mao Zedong took power of China in 1949, he outlawed all traditional practices, including TCM, Tai Chi, and Qigong, and viewed them as superstitious (Chen, 2004). However, during health reforms Mao and his advisors began to see Traditional Chinese Medicine, including Tai Chi and Qigong, as an opportunity to aid in primary healthcare (Xu, 2010). Mao saw individual physical fitness as a sign of a strong nation. Qigong and Tai Chi fit into his vision of active masses, and his efforts in primary care inspired much of the Alma Ata conference in 1978 (Janes, 1999; Xu, 2010). Because Mao was a modernist who believed in science, a tremendous research effort began to explore Tai Chi and Qigong. Thus, Tai Chi and Qigong had to prove not to be merely a mystical superstition through using tools of scientific observation, which at that time were mainly large case studies (Kaptchuk, 2000; Xu, 2010).

Today in North America, Tai Chi has a variable and intense research history. It has been used and studied as an intervention on AIDS patients, haemophiliacs and just about every type of disease imaginable. One search on Google Scholar using the search term “Tai Chi” yielded 24,700 hits, and a search of the Cochrane Library website brought up reviews on Tai Chi and hypertension, headaches, depression, rheumatoid arthritis, fall reduction, and dementia.

One of the first influential studies on Tai Chi in the US was in 1996, when a team of researchers received funding from the National Institutes of Health to study Tai Chi and fall reduction (Wolf et al., 1996). There have been many studies replicating its efficacy in fall reduction, and it is included in many recommended guidelines for that purpose, including those issued by the Canadian Society of Exercise Physiology (CSEP, 2008), the US Department of Health and Human Services (US DHHS, 2008) and the American Physical Therapy Association (APTA, 1999).

Not many studies have been conducted on exploring its potential use in primary prevention, meaning preventing disease before people get a disease. I think this lack of research has to do with many preconceived notions people have linking Tai Chi with elderly people or because it is slow. Also, there is some controversy in exercise science fields as to how much of a role VO2max plays in prevention of cardiovascular disease. Recently, there has been some research that suggests musculo-skeletal strength plays a larger role than previously thought. If that is the case Tai Chi can maybe a good exercise for the primary prevention of cardiovascular disease.

Next The History of Tai Chi and Health-Part IV: Tai Chi and Chronic Disease

Thursday, January 20, 2011

The History of Tai Chi and Health-Part II: The origin of Tai Chi

The origins of Tai Chi are rooted in mythical Chinese culture. The Chinese credit the celebrated hero Zhang San Feng with the creation of Tai Chi. Legend has it that he observed a hawk attacking a snake. As the battle between the two animals ensued, the snake repeatedly used relaxed evasive movements to elude the aggressive attacks of the hawk. Finally, the exhausted and frustrated hawk flew away. There are several versions, using different birds, but this is the basic myth (Frank, 2003). However, the true origins of Tai Chi are in dispute. The first historical record shows Tai Chi was developed in the 17th century in Chen Village (Yang, 2010). Later, Tai Chi was passed on to Yang Lu Chan, who developed the Yang style, which is now the most popular and most researched.

Yang Lu Chan’s grandson Yang Cheng Fu became the inheritor of the Yang tradition. He defined Tai Chi as “the art of concealing hardness within softness, like a needle in cotton” and asserted that “its technique, physiology, and mechanics all involve considerable philosophic principles” (Wile, 1983, p.3). He popularized Tai Chi for the masses and distinguished two levels, the civil and the martial (Wile, 1983). The civil is the “essence” and can be used for development of health, which is referred to as a type of gong, or practice or skill. In this way it falls under the umbrella of Qigong, a type of Qi-based exercise that literally means the practice (gong) of moving life’s vital energy (Qi) (Cohen, 1997). The martial is the “function,” which has the civil in mind but can be used for self-defense (Wile, 1983). Traditionally, Tai Chi is often taught in this martial manner, in which learning the form is not an end unto itself but a first step in which the basics are internalized. Then, after a year or so, the student learns push hands and sword practice. Thus, Tai Chi is a martial art that contains within it self-healing principles intertwined in martial movements.

As Tai Chi has developed through the centuries and through various schools of practice, it has become not one specific set of movements but can be practiced in different forms. Empty hand forms are usually the main focus of most Tai Chi classes. “Long forms” contain many more movements than “short forms,” which are not traditional but are modified to ease the learning curve. Different traditional styles are descended from the Chen but have evolved as various families transformed them, including the Yang, Wu, Sun, and Li styles. The variability of forms and intensities of physical activity among them is one of the challenges in understanding Tai Chi.

This infusion of healing movements with martial movements signifies Tai Chi as a unique exercise. Many people compare it to Yoga but it is quite different because of this martial aspect. I know of many people who study Tai Chi solely for martial practices but predominantly Tai Chi is a healing exercise. This is especially the case in the US, where so many combative styles are promoted. Tai Chi has a comparative advantage in that it offers a mindfulness Qi-based exercise.

The next post will explore Tai Chi’s involvement in Health Promotion

Monday, January 17, 2011

The History of Tai Chi and Health-Part I: Tai Chi and Traditional Chinese Medicine

This series of blog posts will be in 5 parts. Hopefully providing a broad and in-depth picture of Tai Chi. For the first installment of The History of Tai Chi, we must explore its connection to traditional Chinese medicine or TCM.

Tai Chi is part of traditional Chinese medicine (TCM), both of which are indigenous practices from China. Because these holistic approaches are rooted in a time when doctors did not have today’s powerful medical and technological tools at their disposal, physicians tended to treat the whole person and the environment around them (Cohen, 1997; Kaptchuk, 2000). TCM, born thousands of years ago, epitomizes this approach (Hong, 2004; Kaptchuk, 2000). Health systems of that era were radically different from today, with no medical technology to speak of; secondary and tertiary prevention was not as efficient or effective. Consequently, people who lived prior to the advent of modern medicine had to be resourceful and devise systems of primary prevention, which were essential for survival.

At the basis of the TCM system stands Qi, which is often translated as a fundamental form of vital energy that animates all living things (Yang, 2009). Some scholars explain Qi’s place in Chinese thought as “a formless ‘reality,’ which, though not graspable by the senses, is immanent in all things” (Xu, 2010, p. 967). This belief in Qi is also essential to Tai Chi, which shares many principles with TCM and has been integrated into the TCM system.

Both Tai Chi and TCM are rooted in the Chinese philosophy called Taoism, which is based on intense observations of patterns in nature, such as the movement of water, wind, and rocks. Early Taoists developed treatises on longevity, hygiene, and immortality, and these ideas fuel much of Chinese culture. Feng Shui, dietetics, martial arts, painting, and TCM all use the same paradigm or explanatory model of how the universe works (Kaptchuk, 2000; Kohn, 1993; March, 1968). The individual is but a microcosm of the universe, and to achieve harmony or happiness, one should align himself or herself with Qi to stay in harmony with the melding of energy and matter (Kaptchuk, 2000). If an individual becomes un-aligned or a blockage occurs, then disharmony can fester and “dis-ease” or disease will result (Yang, 2009).

Taoism is represented graphically by the icon known in the west as the “yin-yang” symbol, which illustrates a balanced interrelationship of opposites—for example, night and day, and hot and cold, etc. (Frank, 2003; Kaptchuk, 2000). Embedded in its Taoist roots, Tai Chi literally means “grand ultimate point,” (Yang, 2008) the point of balance in the yin-yang. The oldest known writing that discusses yin-yang theory is the “I Ching,” or “The Book of Changes,” which describes the natural ebb and flow of energy in the universe and how that effects change, written during the Bronze Age, 1100 B.C. (Hong, 2004) (Yang, 2010). Tai Chi’s main aim, to harmonize or align oneself with Qi, was summed up by the Taoist sage Chuang Tzu in the 4th century B.C.: “Set your body straight, see everything as one, and natural harmony will be with you“ (Lan, 2002, p.217).

Next post will explore the beginnings of Tai Chi.

Thursday, January 13, 2011

Alton Brown and the Science Behind Salt



For a few years in late 1990’s, I worked in a kitchen gadget store in Seattle. We made many product recommendations to our customers, and of all the celebrity chefs we touted, Alton Brown received the highest ratings. Unfortunately, he chose to use his celebrity status and reputation against the public health campaign for salt reduction.

Alton Brown is a successful author, television show chef, and TV show presenter who writes and produces many cooking shows on the Food Network. Brown’s main show, “Good Eats,” presents him as a culinary expert, and his television work has made him a very influential person in the food industry. That is why I was shocked and disappointed to see Brown adding his unique touch of comedy and science to the promotion of salt, sponsored by Cargill, a multinational corporation that produces salt and other food products. Cargill and many others in the processed food industry have been battling public health and its salt reduction campaigns since the 1970’s

Cargill’s latest crusade to promote salt includes an interactive website dedicated to Brown’s pitch: http://www.salt101.com/#/intro. The website features Brown as a tour guide/lecturer at Salt 101 Labs. In an extremely formal environment that screams power, he spouts about 10 facts about salt, such as “salt is goood!” “salt is a necessary component to the natural functioning of cells,” “sodium chloride, NaCl, is a compound all humans need to survive,” and “whoever controls salt is in power, and in my home it is me; I control the salt.” The message is clear, salt is not only tasty, but it is also good for you, life sustaining, and powerful. There are also interactive games where, for example, you can move Brown’s arm to season a meal with salt.

After viewing the intro, the user can click to enter the “lab” or the “kitchen.” Both links present authoritative information about salt with a bias towards using more. Brown is in his element explaining technical details to viewers. He excels at explaining the science of food, such as human taste, the chemical make-up of salt, and why it is so effective at enhancing flavor. The scientific facts sound reasonable and non-controversial, and it is unlikely there are factual errors in the science Brown presents. The real problem with the videos is not inaccuracies in scientific reporting but what information is omitted. In fact, there is only one potentially negative comment about salt: putting salt on snails will kill them because they are mostly made of water.

The one potentially redeemable aspect of the video is that they do recommend sea salt—Diamond Crystal sea salt to be precise—because sea salt has less sodium than regular salt. But this is still without much value because of the excessive promotion of adding salt to food.

While it is true that salt is necessary for sustaining life, the missing pieces of information are that humans only need a tiny amount (1,200 to 1,500 milligrams per day) and that excess salt consumption (above 2,300 mg per day) is strongly associated with serious health risks like hypertension, cardiovascular disease (CVD), and stomach cancer Cardiovascular disease is the number-one killer globally, and hypertension is one of the strongest predictors of CVD mortality. Brown’s salt industry presentation does damage to the health initiatives trying to reduce mortality.

There is no doubt that we as humans have cultivated a salt craving. Much of the world’s population consumes salt in quantities of greater than 6,000 milligrams per day, with Eastern European and Asian countries averaging higher than 12,000 milligrams per day. In 2004, the average Canadian daily salt consumption was 7,800 milligrams. Observational studies going back to the 60’s, conducted on indigenous peoples where salt consumption is low have shown that hypertension, the leading cause of CVD mortality, is extremely low there as well, making them a low-risk population. These groups of people had salt intake levels hovering around 1,000 milligrams per day.

Companies like Cargill make their money by “adding value” to food, which means they process it for the consumer. Processed foods account for 70% of the salt in the Canadian diet. For example, the label on a pack of Oreo cookies states that one serving (three cookies) has 160mg of sodium, which is 1/14th of the maximum recommended amount. To further encourage people to put additional salt on chocolate covered cookies and ice cream—a recipe proposed by Brown in the video--is nothing short of dangerous to public health.

Such companies have an incentive to promote salt content in foods, and consumers have built a taste for it. The taste for salt can be reduced, but it can be difficult to change, so any doubt cast on the evidence or authoritative messages proclaiming that salt sustains life make it that much harder for public health practitioners to protect consumers.

The exact pathogenesis of salt is not known, and that leads to the doubt exploited by industry. That is why an etiological understanding of salt’s effect in humans is an important step in regulating the processed food industry. Thus far, the most accepted explanation is that excess sodium in the human system can lead to decreased sodium excretion and water retention. This increases plasma volume and increases vascular tone and contractility, which increases blood pressure, resulting in hypertension.

The Salt 101 video portrays salt as healthful, nourishing, and empowering. By combining Brown’s comedic genius with the persuasive potential of social media, Cargill seduces viewers to ignore those charged with protecting the public health.

(References available upon request)