March 4, 2019
THE NUTRITIONAL STUDIES
INTRO
We know that the foods that we consume affect our intestinal microbiome, our immune system and therefore have a significant effect on inflammation. Is this knowledge translatable to asthma? Let us look specifically at nutrition as it relates to Asthma. Are there specific diet studies available that lead us toward a unified diet for better asthma health?
Can we make good recommendations for our patients on a macronutrient basis with fats, carbohydrates and protein ratios and types. Do we have data to support certain micronutrient needs in asthma and how a diet could provide these nutrients? How much can we trust the data?
There are true and legitimate reasons why nutritional studies are difficult to use.
• A single macronutrient or micronutrient study doesn't reflect normal life as we consume food stuffs synergistically
• It is hard to adequately power a nutritional study to show statistical significance
• Animal studies are unlikely to reflect human reactions
• GWAS,genome wide association studies, data is showing how genetically and metabalomically unique humans are, making it difficult to draw conclusions
• Patient compliance with diet interventions is notoriously poor begging the question that if compliance is good in a study was the patient already on a different path than the average American
Knowing that the above statements are likely true, we will press on with the data as it is because we have no better options.
Let us start by defining the large macro type diets. The three main dietary types that have been reasonably well studied in human disease are: DASH(dietary approaches to stop hypertension), Mediterranean and Western or otherwise known as SAD, the standard American diet. .
Many people are looking at the Keto diet and the Paleo diet for help these days, however, they have some data in relation to neurological disease and cancer, but no data that I can translate to asthma and allergy.
The three main diets:
The DASH diet is based on eating lots of vegetables, fruits and whole grains. Fish, poultry, legumes, nuts, seeds and vegetable oils are a large part of the diet. It is very limited in refined and processed carbohydrate foods. It is low in saturated fats. It is well studied and has shown significant benefit in reducing hypertension and cardiovascular disease.(Siervo et. al. 2015)(Saneei et. al. 2014)
The Mediterranean diet is based on the foods eaten in the Mediterranean region. It is filled with vegetables, fruits, legumes, whole grains, olive oil, fish and full fat dairy products. It is lower in non-fish meats and processed foods of all types. Its prominent benefit, which is highly touted by Integrative Medicine Physicians, is the beneficial load of antioxidant vegetables and fruits along with a healthy balanced fat profile and limited refined pro-inflammatory carbohydrates.
The Western SAD diet is popular in the United States and is composed of large volumes of highly processed flour and sugar-based foods, red and processed meats, sugar beverages, dairy, eggs and poultry. It is largely a convenience and taste-based diet that our American population thoroughly enjoys. Unfortunately, it is highly associated with inflammation and chronic disease in humans.
Now that we have defined them, we can begin to dissect the studies and see if we can come to a conclusion for asthma sufferers on what or what not to eat.
The story continues next week,
Dr. M
Siervo British J Nutrition Article
Saneei Nutrition Metab Card Dis Article
