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.

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.

Social Determinants of Health: is Psychosocial Stress the Primary Determinant and what are the Implications for the Field of Epidemiology?

The evidence linking social factors to health outcomes has been researched since the 1940s (Krieger, 2001). The so-called social determinants of health has generated its own field of research called social epidemiology. The whole field hinges on social constructs or structural hierarchies embedded in human societies that heavily affect health. Psychosocial stress is one such risk factor that has been identified as an explanation for how social factors influence health outcomes. One of the big debates in public health is centered on competing theories of causation for the social determinants of health. This paper is an analysis of what the argument between psychosocial theorists and the neo-materialists says about the future of epidemiology.

One of the largest studies to garner support for the psychosocial risk factor is a case-control study by Rosengren et al. (2004). This large, multicentre study found an association between psychosocial stress and acute myocardial infarction (AMI). The researchers operationalized psychosocial stress by asking questions about eight variables: stress at work, stress at home, general stress, financial stress, stressful life events, locus of control, feeling depressed, and clinical depression. They concluded that the effects of psychosocial stress were independent of lifestyle factors such as socioeconomic status, smoking, and education and that “the size of the effect was less than that for smoking but comparable with hypertension and abdominal obesity”(p. 961).

The three dominant models of causation for the social determinants of health are neo-materialism, psychosocial theories, and the effect modification hypothesis (Jayasinghe, 2011; Marmot and Wilkinson 2001) as pictured in figure 1.Epi Final Dag

The neo-materialists posit that the root cause is the structure of society and the political system, and that the key to solving this problem is through development—providing material needs to people. The psychosocial theory is closer to the biomedical model in that it argues that there is a direct effect on the body’s immune system through the impact of stress from the environment, and that leads to higher rates of mortality. The effect modification hypothesis positions stress as a “risk regulator” (Marmot and Wilkinson 2001). This means that people in low-income groups have higher levels of stress, which in turn causes those people to make poor lifestyle choices, such as smoking tobacco or consuming excessive amounts of alcohol, and thus have poor health outcomes (Lynch et al., 1997).

The heated debate between these differing camps of causal models is both political and methodological in nature. The neo-materialists posit that the major factor is one’s materials or assets and that having a home, car, and computer are proxies for a higher quality of life. Research has confirmed that once one’s basic needs are met, there are significant health improvements(Macleod, et al., 2001; Lynch et al., 1997). Neo-materialists derive a large part of their evidence from studies on the ecological level, which makes it difficult to generalize to individuals. They also argue that the material level is more amenable to change than psychosocial stress, saying that reducing stress throughout the population is difficult if not impossible (Marmot and Wilkinson 2001).

The psychosocial theorists contend that people’s health is more than their material circumstances and, moreover, that understanding the exact physiological mechanisms of action provides a clearer picture of the disease process(Marmot and Wilkinson 2001). The psychosocial variable has proven to be a highly stable measure, albeit sometimes a subjective one. One of the major points of contention is that humans cannot be randomized to treatment groups; therefore we cannot truly ascertain causation because we have to resort to animal models to experiment on. This type of research brings us closer to understanding causal mechanisms, but because humans and primates are vastly different—despite being 98% genetically similar—we cannot fully accept evidence from those studies. However, there has been compelling evidence in primate models that shows conclusively that social hierarchies lead directly to higher levels of stress in those species. Many psychosocial theorists have measured stress objectively with biomarkers such as cortisol and glucocorticoids, which lead directly to atherosclerotic plaque build up, a major risk factor for cardiovascular disease (Sapolsky, 2005). Another argument made by the psychosocial theorists is that social hierarchies embedded within a country mask the neo-materialist’s hypothesis and demonstrate that key components of the psychosocial variable, autonomy and social capital, are the important building blocks to good psychosocial health(Marmot and Wilkinson 2001).

The effect modification hypothesis has strong evidence linking low socioeconomic status (SES) with poor behavioural choices, and some studies have shown that people of low SES are less likely to change their behaviour (Lynch et al,1997). This means that people in low SES groups have higher levels of stress and, due to their low income, cannot afford higher quality foods and health care, which in turn negatively affects their health. Many argue that this blames the individual and is the least productive of all theories(Lynch et al,1997). The criticism here is not so much about methodology as it is about the politically unsavory way it analyzes people.

From a reductionist point of view, the psychosocial theorists have a stronger argument than the neo-materialists because newer technological advances create the possibility that as time advances our abilities to measure will get better and better. According to the hierarchy of evidence, ecological studies are lower ranking, and psychosocial studies command a higher level of evidence. But because it is so difficult to reduce the social determinants of health into neat categories such as education or SES, there is a call from some contemporary epidemiologists for a paradigm shift away from such reductionist searches for causation.(Jayasinghe, 2011; Krieger 1994; Glass and McAtee 2006) Although reductionism works well in identifying strong infectious agents, it is ill-equipped to handle many complex systems like the social determinants of health(Jayasinghe, 2011; Glass and McAtee 2006)

This debate about causation is a digression from the real issue, which is to find workable solutions to issues raised by the social determinants of health. Epidemiology is in a state of transition or stagnation, depending on whether you view the glass as half empty or full. Many epidemiologists seem content to push an outdated model that can’t address many of today’s problems(Jayasinghe, 2011; Krieger 1994; Glass and McAtee 2006) To refocus on problem solving means moving epidemiology from a field distracted by concern with causation and controlling for bias and shifting it instead towards following Kreiger’s assertion that whatever the means of causation, be it direct or indirect, intervening on social determinants such as education and early childhood development should be a high priority in addressing health outcomes (1996).

References:

1.Krieger, N. Theories for social epidemiology in the 21 century: an ecosocial perspective. International Journal of Epidemiology. (2001);30:668-677.
2.Rosengren, A., Hawken, S., Yusuf, S. et al. Association of Psychosocial Risk Factors with Risk of Acute Myocardial Infarction in 11,119 Cases and 13,648 Controls from 52 Countries (the INTERHEART study): Case-control study. Lancet. (2004);364:953-962.
3.Jayasinghe, S. Conceptualising population health: from mechanistic thinking to complexity science [electronic article]. Emerging themes in Epidemiology. (2011). 8:2 http://www.ete-online.com/content/8/1/2.
4.Marmot, M., Wilkinson, R.G. Psychosocial and material pathways in the relation between income and health: a response to Lynch et al. British Medical Journal. (2001);322:1233-1236.
5.Lynch, J.W., Kaplan, G.A., Salonen, J.T. Why poor people behave poorly? Variation in adult health behaviours and psychosocial characteristics by stages of the socioeconomic life course. Social Science and Medicine. (1997); 44(6):809-819.
6.Macleod, J., Smith, S.D., Heslop, P., Metcalfe, C., Carroll, D., Hart, C.Are the effects of psychosocial exposures attributable to confounding? Evidence from a prospective observational study on psychological stress and mortality. J Epidemiol Community Health. (2001);55:878-884.
7.Sapolsky, R.M.The influence of social hierarchy on primate health. Science. (2005); 308(648); (doi: 10.1126/science.1106477).
8.Krieger, N. Epidemiology and the web of causation: has anyone seen the spider? Social Science Medicine. (1994);39(7):887-903.
9.Glass, T.A., McAtee, M.J. Behavioural science at the cross roads in public health: extending horizons, envisioning the future. Social Science and Medicine. (2006); 62:1657-1671.
10.Krieger, N., Zierler, S. What explains the public’s health?: A call for epidemiologic theory. Epidemiology.(1996);7(1):107-109.

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.

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.

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.

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.