miércoles, 13 de noviembre de 2019

Has the Game Really Changed?

You know a nutrition documentary is making a big splash when your friends start texting you to ask for your opinion. As most nutritionist/dietitians will agree, generally, your friend's interest in nutritional science will end at what is going to help them look good on the beach that summer or make them stronger/faster in their chosen sport.
 We had originally planned to give the documentary The Game Changers a miss, not because we have anything against vegetarianism or veganism, or to use the new trendy term "being plant based", in fact, quite the opposite. We often promote on our social media "meat free" days and are constantly badgering our patients to reduce their animal products in favour of vegetables and legumes. No, we didn't want to watch the movie because we suspected it would be a series of anecdotes passed off as "proof" that a plant based lifestyle is the ONLY way, and that if you don't convert right now you are evil and you will die when you're 50, if you're lucky.
 However, when a friend is asking your professional opinion you can't reply "sorry mate, I couldn't be bothered to watch it", and then be expected to be taken seriously at a later date.
 Before we get stuck in, I would like to point out that this review will not be an in-depth look at the studies and evidence that were put forward during the documentary. That has already been done quite extensively and so there's not much point in repeating ourselves. Further more, most people, who only have a passing interest in nutrition, are not going to want to hear all about research and statistical analysis. It is our job as nutritionists/dietitians to take that information and put it into "normal" language.
 With that in mind, if you do in fact want to look at the science in a more in-depth way, I would recommend going to Asker Jeukendrup's site https://www.mysportscience.com/ where you will find a great critique of the evidence featured in the documentary.
 This review will be more of an overview of the documentary as a piece of film and the reason why, as someone who works in sport nutrition, I found it so infuriating.

The documentary taken purely at face value is brilliant. It is entertaining, emotive, thought provoking and motivational. It is really well shot and the narrator's journey from injury to recovery is fascinating. The athletes featured are all really interesting and to choose sports such as Strongman or American football, as opposed to Yoga, the stereotypical domain of the "whimpy vegan", was a very clever move from the directors of the film. And to top it all off, Arnie is in the movie! Who doesn't love Arnie???

 Where the wheels started to come off was when the coaches and Drs said things like "sport nutritionists say we have to eat meat" or "sport nutritionists say we need protein for energy". I was immediately confused because both of those statements were totally false. Anyone with even the most basic knowledge of nutrition would know that protein is not our primary energy source. And nor I, nor any nutritionist I know, have ever told anyone that they must eat meat.
 As the movie progressed it started to appear that it was advocates of the plant based lifestyle Vs sports nutrition of 30+ years ago. It didn't surprise me in the slightest when Arnie, a 72 year old man, described how he thought that he had to eat meat to hit his protein targets. Let's not forget that his pro bodybuliding career was from 1968 to 1980. You would hope science had moved on a fair bit in 40 years.
 The film makers then reveal that carbohydrate from plants and not protein from animals is the main fuel source for athletic performance as if they have just revealed the biggest kept secret in human history. Again, this puzzled me because this was nothing new, a quick browse through any sport nutrition literature would tell you exactly the same. But the film makers don't mention up to date sport nutrition. Instead they quote some German bloke from the 19th century who said vegetarians could never be athletes. A shocking statement yes, but also one that has nothing to do with modern sport nutrition. Pick any topic in science and compare it to what people thought 200 years ago and yes it's interesting and quite probably shocking but it has little to do with science in the 21st century.
 And then if going back 200 years wasn't enough, we do the inevitable trip back 100,000 years to our Paleo ancestors. And guess what? Turns out we didn't eat that much meat after all.
 It is fairly logical that when we had to spend time and energy to catch, kill and butcher our meat instead of just going down the shops, we wouldn't have eaten that much of it. Instead we relied more on fruits, vegetables and nuts for our energy source. That doesn't mean we didn't eat any meat at all. If we never ate meat we wouldn't have evolved the ability to eat meat. Next time you're down the park have a chew on some grass and see what happens. That is what happens when you eat something you're not supposed to.
 Apart from having little if anything to do with modern humans, no one in the sport nutrition world, at least nobody credible, is saying that human beings are carnivores.
 This leads nicely to the next point which, as infuriating as I find it, I must admit, this film is not the only one guilty of this. The constant comparison between a human and either the lion or gorilla to make a point about what we should or shouldn't eat is plainly ridiculous! You may as well compare us to trees and suggest we just stand in the sun all day. We are humans, not lions, not dogs, not gorillas, not sharks. We have all evolved on very different paths and so making comparisons is just a waste of time.

Moving away from the attack on outdated nutritional science onto the athletes themselves and things are not much better. This is probably the part of the movie that shocked me the most. No, not the fact we see plant based athletes exist, because again, we all knew that. What really shocked me was how appalling most of the diets of the featured (non-plant based) pro athletes were. I couldn't believe it when one of those pro American footballers was describing how his diet basically consisted of KFC. Or when the Titans guys were saying their pre-game meal was mountains of steak. As mentioned before, a big dollop of protein pre game is neither what is needed nor what is recommended, so I was totally flabbergasted that a sport as rich as American football had such poor sport nutrition support. Its not surprising at all that once you take somebody off a junk food diet they feel better. Hardly groundbreaking stuff that one.
 We see the same story with the firefighters, who were mostly overweight and pretty unhealthy looking, they were taken off their dreadful diets and shock horror, they felt better. 
Returning to steak, we got a little snap shot of everybody's favourite pantomime villain, Connor Mcgregor, and how his pre fight diet of 3 steaks a day backfired (who saw that coming?) and his plant based opponent, Nate Diaz, had more energy in the tank and eventually beat him. While it is not directly mentioned, it is heavily implied that because Diaz is plant based he won that fight. Again, what the standout message for me here was not Diaz being plant based but how Mcgregor was allowed or advised to eat nothing but steak before a fight. Yes, it sounds good in the press conference but in reality it is not going to help you much when your muscles are screaming for energy and you've hindered their ability to utilise glycogen through going low-carb. If McGregor had a sport nutritionist for that fight, something I doubt, I hope he fired him/her afterwards.
 Then we move on to Dotsie Bausch, the Olympic track cyclist, and we are told how she went through a transformation after leaving meat out of her diet. We see images of her smashing it in the gym and speeding round the track, whilst she describes how proud she felt "stood on the podium with a medal round her neck" at the 2012 Olympics. Now, to the majority of the viewers of this documentary they will probably think that she came away as Olympic champion. The choice of words and the editing of the clips from the race certainly gave that impression. I remember as I was watching the movie I was thinking "hang on a minute USA didn't win the women's team pursuit in 2012". I know next to nothing about American football, and little more about MMA but cycling is my sport, so I knew something fishy was going off here. I paused the movie and double checked online for the result, and sure enough, USA were beaten in the final by Britain (1). By quite a margin as well, nearly 5 seconds. I'm not for one second saying Bausch didn't win because she was plant based, I'm saying the omission of the fact her medal was silver, still an unbelievable achievement, was a very strange decision by the film makers, especially after the song and dance they made about Diaz beating McGregor.. A silver medal at the Olympic games is something to be very proud of and a clear demonstration that yes you can be plant based and get to the very top. There was no need to edit it in such fashion to lead you to falsely believe she won. Of course they will argue they never said she won, but they didn't say she came second either.
 They also heavily imply that the sudden turn around of the Titans' fortunes is down to a load of their players moving to a plant based diet. At the risk of sounding like a stuck record, I would argue it is probably more to do with them moving away from a junk food diet.
An important point to remember whenever elite athletes are concerned, there is always an elephant in the room when it comes to their diet and/or training plans which renders their comparison to mere mortals like us utterly pointless. I'm sure you know what I mean, but if you don't have a quick read about about else Arine was taking bucket loads of, spoiler alert, it wasn't soy.

Putting to one side the smoke and mirrors of the movie makers, these stories of athletes are nothing more than anecdotes. They are the movie equivalent of "this worked for me so it must work for you", which, as powerful as these anecdotes are, and watching a vegan athlete lift 550kg is certainly powerful, they are nothing more than a demonstration that in those cases those particular athletes can achieve amazing feats whilst being plant based. That's it. Nothing more. They are not proof that every athlete on Earth should become a plant based one.
This is where I was really disappointed with the film. I felt like the film makers were more interested in attacking the Low-Carb (LCHF) movement and the American meat industry rather than putting together a really great, scientifically sound documentary. If instead of attacking the sport nutrition sector with 30 year old data they invited some of the top sport nutrition minds on the movie, such as Asker Jeukendrup or Louise Burke or even my old lecturer Nigel Mitchel, a sports nutritionist for EF cycling team and (wait for it) a vegan, they would have got a more up to date view that wouldn't have altered greatly an important message from the film, eat more plants! But instead, they decided to go full conspiracy theory and started comparing meat to tobacco with the end result of not only ruffling the feathers of most sport nutritionists worldwide, but also damaging the value of the documentary. What I can never understand about these nutrition zealots is, if their chosen diet or lifestyle is unquestionably "the right way", why don't they just let the science speak for itself instead of resorting to dodgy tactics? for example, it's funny how the film mentions "industry sponsored science" but fails to mention the director is a major share holder in a vegetable protein supplement company. I'm sure they just forgot.
 If as a consequence of this movie people reduce their meat intake and increase their vegetable intake then fantastic! There's very little argument to be had when it comes to the fact that we eat too much meat and not enough veg. But that doesn't mean we all have to go full vegan! Even the guest Drs on the film say "predominantly plant based", which is a fancy way of saying balanced diet. This evangelical approach that food documentaries are currently taking is exhausting. It was the same with the low-carb movies, it's the same with the vegan ones and I'm sure it will be same with the fasting ones. Be it with our food or our politics, we appear to be living in a time where we must be A or B, black or white, yes or no, fat or thin. We slap a label on ourselves and we won't even entertain the idea of taking a bit from column A and a bit from column B. All that these documentaries achieve with their cherry picked, one sided science is to create further mistrust and confusion between the general public and the nutritional science industry, which, in turn, leaves the door open for the real con artists and quaks, of which there are plenty.

So finally, has the "game" really changed thanks to this film? The answer is a resounding NO I'm afraid. The film did not show us anything that wasn't already known in the current world of sport nutrition. We know plant based athletes can make it to the very top, we know a diet of red meat is not good for athletic performance (or health) and we know most of the developed world eats too much meat. Their decisions to portray sport nutrition as an outdated meat obsessed cartel, to cherry pick data and stretch the truth with clever editing has utterly diminished the credibility of the film, which I think is a great shame.
The one ray of hope from this film is that many athletes still eat like teenage boys and so we sport nutritionists are still very much in need.

1. https://en.wikipedia.org/wiki/Cycling_at_the_2012_Summer_Olympics_%E2%80%93_Women%27s_team_pursuit

Interpretación del perfil lipídico

Una de las tareas del dietista es la de interpretar los análisis de sangre relevantes. Uno de los más frecuentes que nos vamos a encontrar es el del perfil lipídico. 
Éste normalmente consistirá en colesterol total, triglicéridos, colesterol HDL, LDL, no HDL, y riesgo lipídico.

El colesterol total, como su nombre indica, consiste en el colesterol que se encuentra en la sangre. Este número debe valorarse según el riesgo cardiovascular del paciente. Por ejemplo, un paciente que ha tenido un infarto no tiene los mismos objetivos de colesterol total que una persona que no lo ha tenido. Dependiendo del laboratorio, suele andar por los 200mg/dl, pero una vez más, depende del riesgo cardiovascular individual. Los valores de colesterol total no se encuentran afectados por la ingesta inmediata, por lo que serán válidos aunque el paciente no se hiciera los análisis en ayunas. Sin embargo, cambios en la dieta más a largo plazo sí que tendrán efecto sobre los valores de colesterol total, así como medirlo cuando el paciente tiene una enfermedad agudizada , ya que una estado inflamatorio y una ingesta reducida harán que los valores sean anormalmente bajos. Cuando más grave sea la enfermedad, más reducidos podrían estar los valores de colesterol total. Un valor de colesterol total más bajo de lo normal en un paciente que se encuentra bien y no está enfermo ni toma medicación para reducir el colesterol podría padecer hipocolesterolemia hereditaria.

Es una lipoproteína muy importante para evaluar el riesgo cardiovascular. Un valor bajo es característico del síndrome metabólico y las causas pueden ser variadas: obesidad, diabetes, hipertrigliceridemia, etc. Este resultado tampoco está afectado por la ingesta inmediata, por lo que nos vale si el paciente no está en ayunas. Es importante señalar que un valor alto de HLD no está relacionado con enfermedad cardiovascular. 

Colesterol no HDL
Este valor se obtiene restando al colesterol total la fracción de HDL y nos muestra la cantidad de colesterol que contienen otras partículas distintas al HDL. La mayoría está contenido en LDL, pero otra parte puede estar contenida en otras lipoproteínas que pueden ser aterogénicas. En 2014, las guías NICE recomendaban mediar el colesterol no HLD para monitorizar pacientes en tratamiento con estatinas, con un objetivo de reducción del 40%.

La hipertrigliceridemia es una factor importante para la evaluación del riesgo cardiovascular. Si el nivel de triglicéridos es muy elevado, existe el riesgo de desarrollar pancreatitis aguda. Cuanto mayor el nivel, mayor el riesgo (1). Para medir los triglicéridos sí que es importante encontrarse en ayunas. Hay que tener en cuenta que las estatinas (la medicación típicamente usada para disminuir el LDL, generalmente no tiene efectos sobre los triglicéridos). 

En general, el LDL es útil cuando estamos monitorizando la evolución de pacientes como hipercolesterolemia familiar. La mayor parte del colesterol total está formado por LDL, así que cuando el colesterol total disminuye, el LDL le acompaña, y generalmente por las mismas razones, como un cambio de peso por una mejora en la dieta. El LDL es calculado en laboratorio usando la fórmula de Friedewald, que tiene en cuenta el colesterol total, el HLD y los triglicéridos. Como decíamos antes, al ser importante que el paciente esté en ayunas para medir los triglicéridos, el resultado de LDL no nos valdría si éste no es el caso. 

Finalmente, en la mayoría de los análisis ahora nos encontramos con el Índice de Riesgo aterogénico, que no es más que el colesterol total, dividido por el HDL. Lo normal es tenerlo por debajo de 4, y por encima significa riesgo aumentado de padecer enfermedad cardiovascular, aunque para la evaluación de éste está más aceptado la herramienta Qrisk (2).

1. Berglund L, Brunzell JD, Goldberg AC, et al. Evaluation and treatment of hypertriglyceridemia: an Endocrine Society clinical practice guideline [published correction appears in J Clin Endocrinol Metab. 2015 Dec;100(12):4685]. J Clin Endocrinol Metab. 2012;97(9):2969–2989. doi:10.1210/jc.2011-3213

2. Qrisk. www.QRisk.org