Thursday, 4 August 2011

#18: In Spite of All the Danger

A number of interesting articles in the Globe and Mail recently that I feel a need to comment on. I sum them up and put in my own two cents.

First up: "Want to live to 100? A healthy lifestyle won't help, study finds"

Summary: Eating poorly, not exercising, being overweight, drinking and smoking may not decrease one's lifespan to the extent that most people believe. Rather, living long may be more about getting a lucky set of genes.

So what: Research and articles like this one are highly problematic in that they provide evidence and excuses for people to ignore good health advice, justify unhealthy lifestyles/behaviour and divert responsibility away from themselves to something obscure and beyond their control (genetics). There is an overwhelming amount of high-quality, thorough scientific evidence that supports the notion that eating healthy, getting regular physical activity/exercise, not smoking, drinking only moderately and maintaining a healthy body weight are associated with improved quality and quantity of life and well-being. Individual studies such as this one, which represent a small but boisterous minority using a very specific population (~500 Ashkenazi Jews), should not be used to divert attention away from that vast majority of research on the importance of a healthy lifestyle. Do genetics play a role in longevity? No doubt about it! But while you can’t change the genes you were given, the environment in which you live (your lifestyle/behaviours) can be an equally, if not more, important player in optimizing longevity (called epigenetics).

Want to live longer? Eat a healthy, balanced diet; don't smoke; exercise/be physically active every day; drink moderately (and socially) and maintain a "healthy" body weight. Moreover, surround yourself with friends, family and loved ones; be thankful, optimistic and open-minded, and finally, remember to look both ways and always wash your hands.

Another interesting article: "The ‘McRunner’ diet: How much does nutrition matter?

The jist: You must have seen this one. Similar to the potato and Twinkie "diets" of 2010, some guy decided to eat only* McDonald's for the month prior to running a marathon and then went out and ran a PB of 2:36 something (ie he did it really well!). The question becomes: how important is diet for physically active individuals?

The simple answer: Diet and nutrition are extremely important for EVERYONE! This article is but another example of poor journalism that propagates confusing messages which confound and mislead the general population. The McRunner ran an average of 160km a week and trained extremely hard for many months prior to eating this “diet”! Very few runners ever train at this intensity and even those who do aren't guaranteed similar results. This guy also obviously has a good genetic endowment that makes him able to train hard and get good results which again is very unique and rare (Playing the genetics card can go both ways). It's also important to note that he kept his energy intake consistent around 3200 calories per day which is actually at the lower end for a 6 foot ~140lb guy like this (I eat about the same amount and run 50km less!). It is also essential to note that his non-McD's foods included water, energy gels and multivitamins. This might be the most important info that is largely ignored in the article. The multivitamins specifically were likely essential to his maintained health and vigour as I doubt that any combination of McDonald’s food can provide all the vitamins and minerals needed or would they provide optimal training fuel. And because the "diet" only lasted 30 days, it is also important to consider how he would have faired if he continued for 2 months, 4, 6, a year?! I would wager that we would be presented with a much different story...perhaps an obituary!

The point here is that individual examples almost always make for very poor generalizations. This is exactly what the McRunner article and the previous longevity study have done: taken highly specific samples and put forth their unique circumstances as general fact. This is also unfortunately among my own personal biases and perhaps may be a fundamental human trait. We see that something works for one person and then assume it should work for all (making the false assumption that the world is somehow fair). This sadly, isn't true and can apply to most situations. In fact a lot of the criticism I receive pertaining to my criticisms of overweight/obese individuals is largely misplaced due to this fact. I am criticised for assuming that by eating less and moving more, weight can be lost and obesity eliminated! Obviously, this isn't the case and I admit will not work for everyone (although it should work for most). There are many good individual examples of overweight people who eat well and exercise regularly and whose weight will not change a bit. It is thus highly unfair to lump them in with the (many?) "others" who we assume eat too much, exercise too little, have no willpower or control, are slovenly, lazy and personally irresponsible (stereotypes are generally true!). So just like the BMI does a poor job of ascribing health in individual persons, it is generally accepted and accurate for determining trends at the level of large populations. Likewise, obesity is largely a social problem (and yes, it is a problem) at the level of large populations (2/3 of Canadians!) that is all too often suggested as an individual personal problem. Its resolution is thus more likely to come by changing the society/environment in which populations live rather than all the individual persons. How we begin to do this is a topic for another day…

Getting back on track: There is no right way to eat or a perfect diet to follow. The McRunner is a good example of someone who can do something that most others could (and should) not attempt. Athletes are a good example of this. We can eat far more food in general and considerably more "junk" or "unhealthy" foods and seemingly get away with it. Others might have a "fast" metabolism and never put on weight. A further problem here is determining one's perceived level of "healthiness" by their appearance or weight. There are plenty of skinny and thin people out there that represent a ticking time-bomb of ill health; while many slightly overweight people are in pristine condition.

Increased physical activity does not provide a free pass to consume as much and more of whatever foods we desire. Rather, it requires more careful and thoughtful consideration to the types and amounts of fuel needed to maintain a healthy and functional body. The long term implications of consuming large quantities of poor quality, highly processed, artificial foods is still largely unknown and so while there may be no apparent acute or short-term negative effects, the lasting and long-term effects may be severe and life-threatening.

Finally, we need to stop thinking about population sized problems (poor nutrition/diet, increased rates of overweight/obesity and decreased physical activity levels) by focusing on individual examples, persons and samples. It just doesn’t work. That said, there is also a time and a place for gross generalizations (especially if they are true) rather than select, context-specific examples that don't really hold true across multiple contexts. The long and the short of it I guess is that putting forth individual examples as fact/truth is highly problematic and should generally be avoided. Oversimplified, sweeping and generalized statements like these are much preferred:

Most people who smoke, drink heavily, eat poorly, are overweight and don't exercise will NOT live longer than those who adopt healthy lifestyles and behaviours.

Genetics DO play a major role in every aspect of our lives and who we are but they are NOT the be all and end all and should not be used as an excuse for helplessness.

Most people (including athletes) should NOT eat McDonald's everyday (or even for 30 days) but some could and would even survive and be in good health.

Most people who are overweight DO eat too much and move too little and for most of these people eating LESS and exercising MORE will lead to decreased weight and overall better health.

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