Monday, October 5, 2015

Approach to nutrition

Warning: this article is a bit... boring. But I feel it is required both to introduce my future posts about myth busting, and also to justify my position against those diets that are based on dogmata.

The Big Idea

Nutrition is a science which studies the interactions of living organisms and their food, the metabolic processes involved in the phases of digestion and assimilation, and finally: the ability of the body to utilise the nutrients. If everybody involved in nutrition and dietetics stitched with this, we would be doing great and reliable research in this field.

Unfortunately this is not what is happening nowadays.

There are many reasons why research in the field of nutrition keeps bringing contradictory results. Some are political, some are economical. Often money is not even involved and that's probably the most sad of the reasons: people choose a dogma and try to justify it by tweaking the researches (if they are researchers) or pretending it works if they are just adopters of a particular diet.

Why do I say that dogmatism is the saddest of the reasons? First of all exactly because there is no money involved: were they at least getting an economical advantage!!! Ok, seriously now: the problem with dogmatism is that people are lying to themselves, that's why I find it sad.

Inconsistencies of the results

Nutrition is the most controversial of sciences. There are so many ways to alter the conclusions of a study that you can prove... basically anything:
  • cherry picking of data: just decide in advance what you want to prove and choose the data that support your thesis. Notable examples are the Seven Countries Study or the more recent China Study, the manifesto of vegetarians and vegans.
  • ignoring alternatives: this is when the proponents take in consideration the current way and their way, no alternatives. The risk is that some of the alternatives are better than what is being dogmatized, so must be ignored a priori. An interesting example is the comparison between CAFO and a plant-based diet which depends on agriculture: the quality of food and the environmental impact of the second is obviously better. The proponents forget to mention that holistically managed livestock have an even better impact on the environment. Another example is how we came to the conclusion that salt causes high blood pressure (hint: the quality of salt matters).
  • bad comparisons: any diet is better than the Standard American Diet, this is matter of fact. When you read that people on a plant-based diet are healthier, the comparison is always with fast food... ever wondered why the claim isn't: people on a plant-based diet are the healthiest (hint: it is not true). The same critique can obviously be done for any other diet.
  • biases, the most common is the healthy person bias. When people decide to follow a particular regimen for health, independently which one, that's definitely not the only radical change they will do in their lifes, for example: ditching junk food, stop smoking, reducing coffee/alcohol, doing sport. Most researches are highly biased because of this, with the result that any diet do in fact provide benefits. Some researches claim that "proper adjustent have been done to take into account blah blah...". I personally find that with a pool of 30 subjects, adjustment is just another word for messing around with statistics...
  • messing around with statistics and mathematics in general: this is the most difficult to debunk and requires some analytical skills. In general, playing with numbers permits to achieve incredible results. In case you were wondering how is it possible that in order to produce 100 grams of hamburger you need to waste 2300 liters of water.
  • generalizations, this is another interesting one: saturated fats and trans-fatty acids cause cardiovascular disease. True, I myself agree. What about saturated fats alone? This is also the way milk has recently become the number one villain. I promised I was going to dedicate a post on this, and I renew my promise.
  • concentrating on the benefits while ignoring the side effects, one example is the study of the Seventh Day Adventists, they may in fact have less heart problems, but alas... have higher rates of cancer.
  • studies too short, sometimes the side effects arise after years, I am thinking for example of the hormonal imbalances caused by prolonged low-carb diets, or the deficiencies in vitamins and essential fatty acids of a 100% vegan diet. Paleo diet itself hasn't been around long enough to test its validity in the long run.
  • the case study, taken as an example that the dogma works and everybody should do the same. I already mentioned that everybody is different, and I am pretty sure that in this world there are people with genetic adaptations who can do extremely well on a high-fat diet (Inuit), or a 100% animal protein diet (Masai), or a grain-based diet (European Alps), or the grandma who lived to 116yo eating bacon every day. Even a plant-based diet may work sometimes: rare but existing, some Freaks of Nature don't become insulin resistant despite a high-carb diet, can efficiently convert carotenoids into Vit-A and ALA into DHA, and have soil bacteria in their guts that produce Vit-B12. Isolated cases are not the proof that it works for everobody.
  • relying on outdated and wrong results just because they support what we want to prove now, like considering dietary cholesterol the direct cause of high blood cholesterol and a risk factor for CVD, and come to the conclusion that butter and yolks are bad (hint: butter and yolks are healthy).
  • bad raw data... this is usually the case of studies that base their sources on phone calls or questionnaires: questions difficult to understand, question with double senses (do you eat dairy, yes I eat cheeseburgers and cheesecake), weird aggregation (do you eat red meat, bologna, pepperoni, sausages), etc.
I could probably write an endless papirus of examples (observational studies, lack of double-blind, placebo effect...), but I stop here. I wanted to present some common fallacies just to make you, the reader, aware that: yes, indeed it is possible to manipulate a research and trust me, it is done regularly.

Some words on dogmata, and conclusions

Political and economic interests drive the research in nutrition. Diets also fall victim of dogmatism.

Ethics and love for animals is a very noble thinking, but unfortunately the lack of reliable science behind a vegan choice make it a very questionable option from a nutritional point of view. I often read studies on the alleged benefits of a plant-based diet because I still want to believe that it is possible. My great disappointment is that all the researches are flawed, so the question is: if a plant-based diet is so good... why cheating?

Ditching grains and dairy a priori for dogmatic reasons is an insult to the hundreds of generations that subsisted on them, and opens the door to grotesque substitutes like breads from nut flours or nut milks, both definitely less healthy than the food they are meant to replace. But apparently that's ok, as long as the dogma is honoured.

Personally, as I already mentioned, my choice falls on Traditional Diets. I believe that, with an eye to their biochemical individuality and before trying the latest fads, everybody should first attempt to honour the diets of their own ancestors which is, just to be clear, 150 years ago.

I hope my position is clear and understood, although I don't expect everybody to share it. I wanted to publish this post anyway so that I can link back to it in future ones when I'll speak about myth busting or I will present my analysis of researches.

If you are a regular reader you probably guessed already that the post ends with a friendly: stay tuned!

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