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Mostrando entradas con la etiqueta Supplements. Mostrar todas las entradas

miércoles, 10 de abril de 2019

Probióticos: ¿sí o no?

El acceso a y uso de probióticos está cada vez más extendido. No solo se venden como suplementos en las farmacias, si no que también lo vemos anunciado en variedad de productos como yogures, té kombucha, miso, kéfir, etc.
Imagen de Bruno Glätsch en Pixabay 

Para aquellos que no sepan de lo que estoy hablando, los probióticos son microorganismos vivos que pueden, potencialmente, aportar beneficios para la salud de aquellos que los consumen (1). Según la Organización Mundial de Gastroenterología, estrictamente hablando, solo se les debería llamar probióticos a aquellos productos que han demostrado, en estudios, producir este efecto beneficioso. 

En general, se supone que al introducir especies de bacterias beneficiosas para el organismo, nos podríamos beneficiar de, por ejemplo, menor incidencia de diarrea tras el uso de antibióticos, ya que éstos matarían tanto a las bacterias dañinas como a las "buenas" que tenemos en el intestino. Sobre el papel tiene sentido, pero en la realidad no ha habido tanto éxito aplicándolo. Por ejemplo, hay estudios (2) que no han encontrado un efecto consistente tras el consumo de yogur para prevenir la diarrea asociada al consumo de antibióticos, e incluso este estudio (3) mostró cómo algunas personas suplementadas con probióticos presentaban un retraso en la recuperación de la flora intestinal tras el uso de antibióticos, comparados con aquellos que tomaron un placebo. Curiosamente, lo que sí que demostró tener un efecto positivo fue el transplante fecal autólogo, que es básicamente la reintroducción de las heces del paciente en sí mismo. 

También se ha sugerido que los probióticos estimulan, modulan y regulan la respuesta inmunitaria del huésped (4) y que podrían jugar un papel importante en la regulación de la inflamación en enfermedades inflamatorias intestinales (5). Incluso jugaría un papel importante en la dermatitis atópica (6).

Sin embargo, existen varios "problemillas" con los probióticos. Para empezar, al ser un suplemento alimentario, no está regulado de la misma manera que los medicamentos, con lo que podría contener especies de bacterias que "no nos interesan" y que podrían ser dañinas (7). También ha habido casos en los que los efectos asociados a estos "suplementos" o probióticos no han podido demostrarse cuando se le ha pedido a la compañía en cuestión que presente los hallazgos o las pruebas que demuestran que en realidad sí que se produce un efecto beneficioso. Este es el caso del Activia de Danone o del L.Casei (8). Básicamente le vinieron a decir a Danone que hasta que no pruebe que el activia te regula el tránsito intestinal y que el Actimel te protege de resfriados (por los probióticos que contiene), pues que no puede decir que sus productos te curan nada de nada. También existe el problema de que el probiótico tiene que atravesar en estómago, con sus ácidos gástricos correspondientes, con lo que las cepas tienen que estar protegidas de tal manera que consigan llegar al intestino. Y luego, una vez allí, tienen que sobrevivir y colonizarlo. 

Y la realidad es que, ahora mismo, no hay suficientes estudios que garanticen que a nivel poblacional sea beneficioso el uso indiscriminado de probióticos. De hecho, hace tan solo unos días, se ha presentado en la reunión anual del American Association for Cancer Research, un abstract que mostraba como en pacientes con melanoma, tomar suplementos probióticos se asociaba con una posibilidad 70% menor de respuesta al tratamiento de inmunoterapia contra ciertos tipos de cáncer. 

La flora intestinal es muy personal, y cada uno tenemos diferentes microorganismos que pueden responder de manera distinta a la suplementación con probióticos. Sí que es un área que promete y que creo que va a tener mucha importancia en los próximos años, aunque los datos parecen apuntar a que los probióticos deberán ser diseñados de forma personal, y que no va a ser algo de que "un probiótico nos vale a todos para todo". También los transplantes fecales (que ya se realizan en España) están cobrando más importancia, ya que en vez de introducir un número limitado de especies, estamos introduciendo un ecosistema completo. 

También mencionar que aunque sí que se ha demostrado su eficacia en casos aislados (9),  existe mucha publicidad dudosa al respecto, como el Probiota Histaminx, cuyos estudios asociados a la eficacia no he conseguido encontrar, cepas de probióticos de farmacia como Lactibiane, que tampoco tiene estudios para demostrar la eficacia (en su estudio no consiguieron probar eficacia en aliviar los síntomas del Intestino Irritable (10): Lactibiane Référence was not superior to the placebo in relieving symptoms of IBS (42.6 % vs 42.3 % improvement).

Muchos de estos probióticos parece que podrían tener efecto. Sin embargo nos hemos liado a crear productos con probióticos sin todavía entender completamente el mecanismo de actuación ni tampoco la complejidad del microbioma intestinal.

Lo cierto es que se necesitan muchos más estudios para conocer qué bacterias, qué cepas dentro de esas bacterias, en qué cantidades, durante cuando tiempo y para qué condiciones/enfermedades los deberíamos tomar. Y, aunque el consejo general solía ser "bueno, tómatelo, daño no te va a hacer y a lo mejor te va bien", cada vez hay más evidencia disponible de que no es cierto y sí podría tener un efecto nocivo.

Parece que además de probióticos y prebióticos hay un tercero que se ha unido a la fiesta, los postbioticos, pero ya hablaremos de ellos más adelante. 


Referencias
1. http://www.worldgastroenterology.org/guidelines/global-guidelines/probiotics-and-prebiotics
2. https://www.sciencedirect.com/science/article/pii/S0899900714005139?via%3Dihub
3. https://www.cell.com/cell/fulltext/S0092-8674(18)31108-5
4. https://genomemedicine.biomedcentral.com/articles/10.1186/s13073-016-0300-5
5. http://www.jimmunol.org/content/196/10/4311.short
6. https://www.ncbi.nlm.nih.gov/pubmed/29117309
7.https://www.consumerreports.org/vitamins-supplements/supplements-can-make-you-sick/
8. https://www.ftc.gov/news-events/press-releases/2010/12/dannon-agrees-drop-exaggerated-health-claims-activia-yogurt
9.https://www.nature.com/articles/nature23480
10. https://www.medecine-nutrition.org/articles/mnut/abs/2007/04/mnut2007434p157/mnut2007434p157.html






miércoles, 13 de junio de 2018

¿Mejora nuestra salud articular si ingerimos alguno de los famosos suplementos de colágeno que tan de moda están?

Artículo brillante del compañero José Manuel López Nicolás, profesor titular de Bioquímica y Biología Molecular de la Universidad de Murcia, acreditado a Catedrático y Miembro del Comité Científico de la Agencia Española de Seguridad Alimentaria.

El máximo organismo en materia de alimentación, la Autoridad Europea de Seguridad Alimentaria, ha sido contundente. Según su Panel de Expertos en Nutrición, Alergias y Dietéticos no existe relación causa/efecto entre el consumo de colágeno y el mantenimiento de las articulaciones.

Aquí os dejo el análisis científico y explicación de esto. Merece la pena leerlo y como siempre decimos, ser consumidores informados

jueves, 17 de mayo de 2018

Vitamina D y su relación con las caídas en ancianos

Hoy vamos a hablar de un estudio caso-control llamado Vitamin D and the Mechanisms, Circumstances and Consequences of Falls in Older Adults: A Case-Control Study.

Aunque obviamente hace falta más de un estudio para establecer conclusiones, me parece interesante las observaciones que han hecho, que se acercan mucho a las que ya comentábamos hace un par de año por aquí. 

En este estudio cogieron a 216 pacientes del ala de geriatría de un hospital y tras observar que no había diferencias en los niveles basales de vitamina D y de ajustar por factores de confusión llegaron a dos conclusiones:
  1. La deficiencia de vitamina D estaba asociada con caídas en los ancianos.
  2. Los ancianos que presentaban deficiencia de vitamina D tenían mayor prevalencia de hipotensión ortostática, lo que sugeriría que la vitamina D puede influir en las condiciones que predisponen a las caídas en lugar de la caída en sí misma.
Aún queda mucho que investigar, pero parece que la vitamina D está involucrada en numerosos procesos metabólicos (justo acabo de leer un estudio sobre su deficiencia y suplementación en quemados, pero eso ya para otra vez) y que su deficiencia es cada vez más común.

miércoles, 20 de septiembre de 2017

An Introduction to Periodised Nutrition

If you regularly read articles about training or subscribe to any of the millions of training magazines, you will almost certainly be familiar with the term “periodised training”. Basically, it means instead of doing the same thing day in day out, you plan your training sessions to ensure you reach your optimal state of fitness for your given sport at the right time. As with most ideas regarding training it has been tweaked over the years and now we have versions such as, inverse periodisation, block periodisation so on and so on, but the idea remains the same, plan your training.

When people ask me how much carbs/protein/fat they should eat I always answer, “it depends on your training”. Initially they think I have given them a rather vague and unhelpful answer, but once I explain that their nutrition should match their training and go into detail they understand why I gave that answer.
This is the concept of periodised nutrition, depending on the type/duration/intensity of your training regime determines what you should eat. This is one of my main arguments against the LCHF craze, if during your training regime you have any periods of high intensity training or races, then chronically following a low carb diet will not be of much help. Of course, the opposite is true. If you are not doing any kind of intense or long duration training then a high carbohydrate diet is not necessary.

A good example would be somebody training for an Ironman, whilst the event is still several months away and they are wanting to optimise their fat utilisation capacity, they will most likely be doing sessions of fasted training or sessions of fairly low intensity. At this point, I would recommend a diet low in carbs with higher fat. Once they got nearer to race day and the intensity of training increased, I would increase the amount of carbohydrate in their diet. And of course, for the event itself, ensuring they take on plenty of carbohydrate will be vital.
In summary, your diet should provide fuel for your training and your recovery, the more intense your training is the more you will need carbohydrate in your diet.

Over the next few months we will be looking in-depth at different strategies of periodised nutrition, but in the meantime any questions or comments leave below or contact www.gabinetederueda.es

lunes, 18 de septiembre de 2017

Amino Acidos Ramificados: ¿Merecen la pena?

Los aminoácidos ramificados (también conocidos como BCAAs) son uno de los suplementos más populares, quizá más que la creatina. Siempre se ha dicho que los BCAAs son imprescindibles para los aficionados de entrenamiento de fuerza y resistencia, porque al parecer los BCAAs provocan un estado de anabolismo o impiden un estado de catabolismo.
Mientras la creatina tiene décadas de apoyo científico, ¿podemos decir lo mismo sobre los BCAAs?
En este post resumimos el artículo de Robert Wolfe de la publicación Journal of the International Society of Sports Nutrition. Te dejamos el original aquí (en inglés), te recomendamos que leas, aquí abajo tienes los puntos claves. 

Antes de que empecemos a repasar la evidencia, vamos a repasar brevemente qué son los aminoácidos. Hay en total 20 aminoácidos, 9 son esenciales y 11 no esenciales. Esencial quiere decir que nuestro cuerpo no los puede construir y tenemos que obtenerlos través de la dieta. De los 9 aminoácidos esenciales (AAE) 3 de ellos se llaman los amino ácidos ramificados o “branched chain” (BCAAs) son: leucina, isoleucina y valina. Las proteínas musculares están en un estado continuo de rotación, es decir, que siempre hay síntesis de proteínas musculares (SPM) y descomposición de proteínas musculares (DPM). Hay un estado de anabolismo cuando hay más síntesis que descomposición, y cuando pasa lo contrario lo llamamos estado de catabolismo. Se puede alcanzar un estado de anabolismo al aumentar SPM o al inhibir DPM, pero para la SPM hacen falta todos los aminoácidos.


La evidencia

  • En los estudios que demuestran un efecto positivo de la SPM los sujetos son ratas. Los estudios de músculos en ratas tienen casi ninguna relación con los estudios de músculos de los humanos.
  • En estos estudios, los BCAAs que les dieron a las ratas fue por la vía intravenosa, no vía oral, un método poco práctico en realidad.
  • En los estudios con sujetos humanos, también les dieron los BCAA por la vía intravenosa, pero esta vez hubo una disminución de la SPM.
  • En los estudios de humanos hubo también una disminución de descomposición (DPM) pero los sujetos se quedaron en un estado de catabolismo.  

Actualmente la evidencia sugiere que los BCAAs solos (sin otras proteínas, carbohidratos etc.) reducen la rotación de las proteínas musculares (síntesis y descomposición). El autor nos advierte que una reducción en la rotación de las proteínas musculares puede tener un efecto negativo en el esfuerzo del músculo debido a una reducción en la construcción de nuevas fibras musculares.
La evidencia actual indica que los BCAA (particularmente leucina) aumentan la señal de SPM, sin embargo, una señal más potente no significa más SPM si todos los AAE no están presente. Es como intentar arrancar un coche sin combustible.
Para conseguir la SPM necesitamos todos los aminoácidos. Después de una comida con proteínas, nuestro cuerpo puede utilizar los AAE de la comida, pero entre comidas, en el estado post-absortivo, la única fuente de AAE es a partir de la descomposición de las proteínas musculares, por eso la proteína del músculo está siempre en un estado de rotación.
Si tomamos una dosis de BCAA muy grande sí reducimos DPM, pero eso significa que estamos reduciendo la cantidad disponible de AAE, por lo que como resultado también reducimos la SPM.


El lado bueno (más o menos)

Con una señal de SPM aumentada gracias a los BCAA puede que, en combinación con una comida rica en proteína, el efecto de la proteína resulte aumentado. Un estudio ha demostrado que una dosis de 5g de BCAA en combinación con 6.25g de proteína de suero tenían el mismo efecto en la SPM que 25g de proteína de suero solo.  
Aunque esto es interesante, si pensamos en el precio de los BCAA en comparación con el precio de proteína de suero o mejor todavía, COMIDA, ¿merecen la pena los BCAA? Recuerda que más no es necesariamente mejor, si añades más BCAA a tu batido de proteínas no significa aún más SPM.
Otro punto a recordar, como decimos en nuestro blog de BCAA e inmunidad, es que los BCAA compiten por el mismo sitio de absorción y normalmente el aminoácido en mayor cantidad (casi siempre leucina) es absorbido a costa de los otros dos. 

Conclusión

No solo hay una falta de evidencia que demuestra un efecto anabólico de los BCAA solos. El autor concluye que sin la presencia de una fuente de AAE (a través la comida o de la DPM), no es posible para los BCAA aumentar la síntesis de las proteínas de musculares. Nuestro consejo es: olvídate de los BCAA y asegúrate de que tu dieta tiene una buena cantidad de proteínas de fuentes animales y vegetales.     

Si quieres saber más sobre nutrición deportiva visita nuestra web. www.gabinetederueda.es   

lunes, 11 de septiembre de 2017

BCAAs: Are they really worth it?

Branched chain amino acids (BCAAs) are in some way the creatine of the 21st century, what I mean by that is, that they have become the “go to” supplement for every gym goer. Strength and endurance enthusiasts alike are sold the idea that BCAAs are an essential component of their nutrition regime because they supposedly induce an anabolic/avoid a catabolic state in humans.
Whereas creatine now has decades of convincing research behind it, can we really say the same about BCAAs?
This post will summarise the recent review by Robert Wolfe in the Journal of the International Society of Sports Nutrition. I strongly recommend that you read the full paper (link here) after you have read the main points below.

First, a quick recap on amino acids. There are 20 amino acids in total, 9 are essential and 11 are non-essential. The term “essential” means that the body cannot synthesise these amino acids so we must obtain them from food. Of the 9 essential amino acids (EEAs) 3 of these are called the branched chain amino acids (BCAAs) these are, leucine, isoleucine and valine. 
Muscle protein is in a continued state of turnover, meaning proteins are constantly being broken down and synthesised (built up). The term anabolic state refers to when muscle protein synthesis (MPS) is greater than muscle protein breakdown (MPB), in other words, our muscle tissue is being built up as opposed to being broken down. When muscle protein breakdown is greater than synthesis this is known as a catabolic state. The anabolic state can be achieved by either increasing muscle protein synthesis or by reducing muscle protein breakdown. For MPS to be greater than MPB all 20 amino acids must be present.

We are sold BCAAs under the premise that they stimulate muscle protein synthesis and so we can avoid the dreaded catabolic state. But what does the actual evidence say?


The Evidence 

  • The studies that show an increase in MPS after ingestion BCAAs were conducted on rats. Muscle protein studies on rats have little if any relevance to humans.
  • These studies also administered the BCAAs intravenously as opposed to orally
  • Studies on humans, (who also administered the BCAAs intravenously), actually showed a decrease in MPS
  • The human studies also demonstrated a decrease in muscle protein breakdown but overall net effect was that the subjects remained in a catabolic state. 

When all the evidence is considered, it appears that taking BCAAs alone reduces protein turnover (synthesis and breakdown). The author points out that this may have a negative effect on muscle strength due to a reduction in new muscle fibre construction.
Current evidence suggests that BCAAs (in particular leucine) increase the “signal” for MPS, however an increased signal will not lead to increased MPS if the other EAAs are not available. Think of it as turning the key in the ignition, without fuel the engine won’t start.
In order for MPS to occur all amino acids must be available. After a meal containing sufficient protein, MPS is achievable because the EAAs will be taken from the ingested food. However, in the post-absorptive state (in between meals) the only source of EEAs is from the breakdown of muscle protein. This is why muscle is in a constant state of turn over.
If we take a huge dose of BCAAs we reduce MPB, however, by reducing MPB we reduce the amount of EEAs available for MPS so in turn, both MPS and MPB are reduced.

The Good News (kind of) 

With an increase in anabolic signalling through BCAAs, it appears that it can increase the effect of a protein meal. One study demonstrated that 5g of BCAAs added to 6.25g of whey protein had the same effect on MPS as 25g of whey protein alone.
While this may seem interesting, when you weigh up the cost of BCAAs against the cost of whey protein or (shock horror) real food, are they really worth it? Remember the golden rule, more is not always better, so adding even more BCAAs to your shake will not have a greater effect on MPS.
Another point to remember is, as we mentioned in our amino acids and immune system post, the BCAAs compete for the same site of absorption so when taken in a large dose the amino acid in the greatest concentration (usually leucine) will be absorbed at the expense of the others. 

Conclusion 

Not only is there a lack firm evidence to demonstrate an anabolic effect of taking BCAAs alone, the author concludes that without a supply of essential amino acids (either through food or muscle protein breakdown) it is not possible for BCAAs alone to increase muscle protein synthesis. Our advice as always is ensure you have a diet rich in high quality protein before starting to consider supplements. 

For more info please see www.gabinetederueda.es 

jueves, 6 de julio de 2017

Energy Bar Recipe

Finding an energy bar that tastes good and is not full of rubbish has always been a huge challenge. I'm sure that I am not the only person who has ordered a large batch of energy bars for a cycling or training trip and then during a long ride as you unwrap probably the 20th bar you think "God! I am sick of this flavour!"

Taste fatigue is detrimental to both moral and performance. It may sound obvious but if don't like the flavour of something or you are sick to death of it, you will not eat it, which eventually leads to your performance suffering through lack of energy.
The finished article. 
Through years of trying several different brands of energy bars I have found that I really want them to taste like actual food and not a bunch of chemicals and flavourings. Eventually I decided to experiment with making my own bars.

The advantages of making your own bars are, you know exactly what is going into them, you can experiment with several flavours without having to buy lots of different types of bar, and generally speaking the cost of the ingredients will be cheaper than buying a box of energy bars from a well known brand.
I have always found that the energy bars you buy are very sweet so after 2 or 3  I get really sick of the flavour, especially if I am on a very long ride where I will be taking gels and sports drinks as well. By the end of the ride I am dying for something savoury!
With this recipe I have tried to find the right balance between carbohydrate for energy but not being too sweet. The great thing is that the recipe is pretty flexible so you can add or take away ingredients as you pplease to suit your taste preference. The only 3 ingredients that are essential are oil, oats and honey. This is the recipe to the bars I am currently taking out with me.

Ingredients:
100mls oil. (I use sunflower oil just for the fact it doesn't really taste of anything, I have tried both coconut and olive oil and find the flavour overpowers the rest of the ingredients.)
225g of oats
210mls Honey (The reason I put mls here instead of grams is that I use a protein powder scoop to measure my honey, 210 mls is 3 big scoops or around 300g. Yes that is a lot of honey but these are energy bars for long days in the saddle.) 

The ingredients above form the base of the bars and should be included in whatever batch you make. With the following you can be pretty flexible and change depending on your preferences.

40g Almonds (chopped)
10-12 Dates (chopped) 
2-3 tablespoons of peanut butter (this takes a bit of the sweetness away from the honey and dates, make sure you use a brand of peanut butter that isn't full of palm oil and sugar. I use bulkpowders 100% peanut butter.)
30g 100% cocoa grated or in powder (again this takes the edge off the sweetness and gives the bars a nice chocolate hint)


Here is a picture of all the ingredients. 














Melted Honey

Method 


  • Preheat oven to 180C 
  • Place the oil in a saucepan and put on a low-medium heat (my electric hob is numbered 1-6 and I usually use 3) 
  • Add the honey and stir continuously until it has melted
  • Add the peanut butter and also stir until melted 
  • Once the both the peanut butter and honey have melted you can start to add your other ingredients and give them a good stir so they are totally covered by the mixture
  • Now you can start adding the oats. Add them a small amount at a time and make sure you keep stirring to get all the oats covered in the mixture. As you add more oats it will start to get thick and difficult to stir. At this point also add the cocoa. 
  • Transfer the mixture into a cake tin and place in the preheated oven for between 15-18 mins depending on how gooey you want your flapjacks. I usually take them out around 15 minutes.
  • Leave to cool. This may sound obvious but if you try and cut the flapjacks now they will just fall apart, I usually leave them overnight. 
  • Cut them up into sizes of your preference, I have recently started to cut them into smaller pieces as I have found it easier to eat in one go as opposed to taking a bite then putting it back in your pocket whist moving.



Adding the almonds and dates into the mixture  
Adding the oats 

Nutritional Info if you divide the finished block into 8 bars each bar contains 

  • Kcals 324
  • Carbohydrates 59g 
  • Sugar 36g
  • Fat 6g
  • Protein 6g  

For long endurance events, the magic number in terms of carbohydrate is 60g/hr which means one of these bars an hour should do the trick in meeting your carb needs. 

If you try this recipe please let us know in the comments section how you get on, or you make any tweaks 


http://gabinetederueda.es/ 







viernes, 28 de abril de 2017

Excercise, Macronutrients and immunology part III Protein and Amino Acids

As the debate about fat and carbohydrate rages on, I think everybody can agree that protein is essential. Even the moderately active individual needs to have a higher than recommended protein intake. This is the final article that summarises the latest evidence on the role of the macronutrients in exercise and immunology (click here and here to read the previous two articles). The article will not look at protein as a whole but on the amino acids that have been researched the most in terms of their effect on the immune system post exercise. These amino acids are the branched chain amino acids (BCAA) and glutamine. Remember that if you want to read about this topic in more detail please consult the Exercise and Immunology review1.

The branched chain amino acids (leucine, isoleucine and valine) are probably one of the most popular sports nutrition supplements, especially among people who regularly lift weights. During long bouts of exercise the BCAAs are utilised by the working muscles and this causes the plasma concentration of BCAA to fall. Apart from being used for energy, the metabolism of BCAA produces nitrogen which is used for glutamine synthesis. During exercise, a reduction in plasma glutamine has been observed which has been linked to exercise-induced immunodepression. 
It was suggested that BCAA intake could indirectly influence immune response by increasing glutamine synthesis. As we all know, just because something sounds good in theory doesn’t mean it will work in practice. Despite the fact that supplementing with BCAA during exercise did indeed increase both plasma and muscle concentrations, this did not lead to an increase in plasma glutamine. 
There is some evidence that chronic supplementation of BCAA can prevent the decrease in plasma glutamine and other markers of exercise-induced immunodepression.
BCAA, in particular leucine, may have a direct effect on the immune system through their effect on the mTor signalling pathway. mTor stimulates muscle protein synthesis and activates cytokine and antibody production. Again, somewhat predictably, the evidence is lacking and what data there is indicates that BCAA has a greater involvement in muscle protein synthesis as opposed to immune function.

The authors conclude that there is some evidence that BCAA can reduce exercise-induced immunodepression but not enough to recommend its use for athletes in the context of immune function.

It is worth remembering that the BCAA use the same transporter during digestion and that when they are taken in large amounts (for example as a supplement) the amino acid that is in the highest concentration (usually leucine) is absorbed at the expense of the other two2. Therefore, I would suggest that BCAA supplementation in general may not be as advantageous as diet rich in high quality proteins.

Moving away from BCAA as a precursor to glutamine and to glutamine itself. Glutamine is the most abundant amino acid in the body and was originally thought to be non-essential. However, during times of stress to the body the requirement increases so it has been renamed conditionally essential. It is synthesised, stored and released mainly in the skeletal muscle, and among the numerous cells that utilise it are the immune cells, such as, macrophages, neutrophils and lymphocytes. As mentioned before, prolonged exercise results in a decrease in plasma glutamine concentration, a decrease in immune function is simultaneously observed.

As with BCAA supplementation, the rationale is sound but disappointingly, the results from studies of glutamine supplementation do not live up to the expectation.
In conclusion, while there are some encouraging signs that BCAA and glutamine may influence immune function, the evidence is not currently strong enough to promote the supplementation of either. As I stated before, what is essential is that you have a diet rich in high quality protein. 
Before even considering supplementation of any kind you should always evaluate the quality of your diet and address any issues. If you would like to know more about our sports nutrition packages please contact us on info@gabinetederueda.es 

References 
1.Berman S et al. (2017) Immunonutrition and Exercise Consensus Statement. Exercise and Immunology Review: Vol 23
2. Gropper, S.S & Smith, (2013) J.L Advanced Nutrition and Human Metabolism 6th Edition. Wadsworth Cengage Learning 

miércoles, 29 de marzo de 2017

Macronutrients, Exercise and Immunology Part 2: Lipids

As was discussed part 1, exercise can depress the function of the immune system. Supplementing with carbohydrate during exercise has been shown to blunt this response therefore the immune system can function better than if no supplementation had taken place. In this post, we will be looking at the role of fatty acids in exercise and immune function.


As with carbohydrate, the main role of fatty acids is a source of energy. As well as energy, certain fatty acids are involved in inflammation and immune responses. A dialogue that is probably very familiar to all of us is that Omega-6 fatty acids are pro-inflammatory and Omega-3 anti-inflammatory and that our modern diet has too much Omega-6 and not enough Omega-3. Just a quick google search of either Omega-3 or 6 will result in many nutrition “experts” giving advice on how to improve the ratio of the fatty acids in the diet. 


The Omega-6 linoleic acid is termed an essential fatty acid because, as with essential amino acids, it cannot be synthesised by the body and therefore must be obtained through the diet. Nuts, seeds and vegetable oils are rich sources of linoleic acid1. Once in the body, linoleic acid can be converted to another Omega-6 fatty acid arachidonic acid, this fatty acid is a pre-cursor to inflammatory mediators known as prostaglandins and leukotrienes. These two mediators are involved in inflammatory (and allergic) reactions, hence the belief that a diet rich in Omega-6 can lead to problems associated with chronic inflammation. Despite their role in inflammation, the authors of the exercise and immunology review2 state that currently there is no strong evidence to support the claims that altering your Omega-6 intake will affect inflammation. In terms of the role of Omega-6 in exercise and the immune system, the same authors state that there is very little research in this area.


Moving on to the Omega-3 fatty acids EPA and DHA, the anti-inflammatory actions of these fatty acids, taken as either a fish oil supplement or as oily fish, are well documented. EPA and DHA can be easily assimilated into cell membranes at the expense of the Omega-6 arachidonic acid, which of course leads to less production of the prostaglandins and leukotrienes. They are also involved in the production of mediators that resolve inflammation, enhance immune function and regulate key signalling events within immune cells such as T-cells and B-cells.

Unlike with Omega-6, the role of Omega-3 within exercise is a well-researched topic. However, (there is always a however) it is difficult to draw any firm conclusions from the published research. A large difference in doses used, (1g – 4g/day), the populations studied (untrained or elite athletes) and length of time of the studies (one week to several months) have made it difficult to say with confidence that Xg of Omega-3 taken per day will help you decrease exercise induced immunodepression. Supplementing with Omega-3 appears to decrease post exercise muscle soreness and exercise induced inflammation in untrained individuals but the evidence in trained and elite individuals is less convincing. The conclusion of the authors of the Exercise and Immunology Review is that more research is needed in this area.


So, what conclusions if any can we draw from this information? Regardless of its role in exercise Omega-3 fatty acids have numerous health benefits, so I would recommend that our diet has sufficient Omega-3 in it, either by ensuring we eat 1-2 portions of oily fish per week, or if you do not eat fish, take a fish oil supplement. At this moment in time I would avoid taking large doses of Omega-3 either before or during exercise until there is stronger evidence supporting the claim that it has a beneficial effect in this area. 

If you want any more information on diet, exercise and the immune system please get in touch via wayne@gabinetederueda.es 
 
References

1. http://nutritiondata.self.com/foods-000141000000000000000-w.html   
2. Berman S et al. (2017) Immunonutrition and Exercise Consensus Statement. Exercise and Immunology Review: Vol 23