July 31, 2023
Asthma, Allergies and Nutrition Part IV - The Story
Micronutrients
Zinc
Zinc is a mineral involved in over 100 enzymatic reactions in the body! It is necessary in adequate levels for cellular metabolism and is critical for the function of our immune system, our skin and our gut lining. At the cellular level, zinc is necessary for protein synthesis, DNA synthesis and cellular repair in wound healing.
Some common symptoms and diseases related to insufficient zinc include: recurrent infections, chronic mild diarrhea and diaper rashes, worsening atopic diseases like eczema and asthma.
As it relates to asthma, the data is mixed. Zinc is necessary for proper immune function and likely has a role in asthma by preventing infectious etiologies from triggering an asthma flair. Inadequacies of serum zinc volume can lead to imbalances of immune function including macrophage activity and T helper cell function in allergic asthmatics.
I could not find any solid data supporting zinc having a direct role in asthma pathophysiology. However, as asthma is often triggered by infections, preventing an asthmatic sufferer from getting sick frequently makes complete sense.
Food sources of zinc: Oysters are the bounty with 74mg per serving. Meats, fish, beans, nuts and dairy contain 7 mg or less per serving. Increase daily amounts of zinc containing foods to help the immune system stay in balance. Taking a zinc supplement also has value based on serum red blood cell zinc levels.
Magnesium
Magnesium is a mineral and major cofactor in over 300 enzymatic reactions in the body! It is necessary in adequate levels for energy production, insulin function, protein synthesis and blood pressure regulation and muscle/nerve function. That is every major system in the body!
Magnesium is located about half in our bones and the other half in tissues. Our blood has less than 1%. Our kidneys keep the blood level of magnesium in tight control.
Insufficiency and deficiency occurs primarily in people with highly processed diets and gastroenterological disorders. Medicines like antacid proton pump inhibitors, certain antibiotics and diuretics will lower magnesium levels.
Magnesium deficiency causes problems with lung function as well as lowering the levels of circulating vitamin D which in turn affects immune function and infectious disease risk. Much like a low zinc level, magnesium and vitamin D are necessary to prevent infections that trigger an asthma flair. However, magnesium has the added benefit of relaxing pulmonary smooth muscles.
We use it frequently in the emergency setting to save a life when someone is dying from a severe asthma attack.
It is obvious that this mineral is insanely important to us! Where can we get it? The best HEALTHY sources of mag are spinach, nuts, beans, oatmeal, avocado, soy, potato and banana. Fish, chicken and beef have reasonable amounts as well.
In order to absorb magnesium well, you need vitamin D and B6 as well as selenium and the amino acid taurine. This of course happens naturally when we eat vegetables, fruits and get adequate sun exposure.
Take home point: if you feel mentally or physically tight, you are likely low in magnesium. Load up the nuts, organic spinach, salmon, organic soy and beans. If that does not work, take magnesium supplements like magnesium taurate or glycinate in doses as recommended by your provider.
Vitamin D
Why is Vitamin D so important for Asthma and allergies?
Vitamin D along with vitamin A and commensal gut bacteria promote the maturation of the immune system's police called T regulator cells via the gene FOXP3. Vitamin D is arguably the most important micronutrient for human health and asthma. It is one of the four fat soluble vitamins and has the added benefit of being naturally synthesized by our skin via exposure to the sun's UVB rays and stored for months in fat.
The big issue surrounding vitamin D and asthma is that humans are avoiding the sun and spending too much time indoor. We are not synthesizing adequate amounts of natural vitamin D in our skin and this is putting downward pressure on our immune system in a negative way. The T regulator cells are critical for dampening inflammation and immune activity post pathogen killing. Unchecked or excess inflammation becomes the main driver of asthmatic disease decline.
In the most recent published literature, vitamin D appears to reduce the number and severity of exacerbations requiring oral steroid use and emergency room visits for asthma and infectious diseases. (Jolliffe et. al. 2017)(Riverin et. al.2015)(Pojsupap et. al. 2015)(Bergman et. al. 2013)(Martineau et. al. 2016)(many more studies...)
Read to the end for a nice high end summary from Dr. Pfeffer. I am in the middle of a deep dive into the field of immunology and all of the posited mechanisms for the beneficial effects of vitamin D in human disease, especially asthma, make me wish everyone could and would get tested for D insufficiency.
The current general health recommendations are to avoid the sun because of skin cancer risks. These recommendations are unhelpful. The goal of skin cancer prevention should be to avoid sunburns which are a noted risk factor for cancer. Exposure to 15 to 30 minutes of direct sun a day without sunscreen has never been shown in any way to be dangerous, however, the beneficial effects on Vitamin D levels are well known during this brief exposure at peak day sun. (Nair et. al. 2012)
Aside from sun exposure, where can we get vitamin D? Food and supplements. Food sources of Vitamin D are dairy, fish, eggs, mushrooms and fortified foods like orange juice and cereals. A diet that includes oily fish like roughly 3 ounces of salmon will provide 400IU of Vitamin D.
Some other caveats are to remember that your skin color dictates how fast you can make D. Darker skin = more time to generate adequate D and lighter skin is the converse. Between the months of November and April, it is quite difficult for most individuals to generate adequate D from the sun in the mid to northern United States. Dark skin color is an advantage for preventing skin cancer, but a disadvantage for developing vitamin D.
From a supplement perspective, I do not recommend taking higher doses of vitamin D without blood level monitoring. Over consumption of vitamin D can be toxic as it is fat soluble and can accumulate in our fat cells. Symptoms and findings of toxicity include hypercalcemia, bone pain, kidney stones, calcium deposits in the body. Diseases that could increase the risk of toxicity include: sarcoidosis, hyperparathyroidism, tuberculosis, lymphoma and other cancers. There is only one way to be sure that you are not in the toxic range and that is to test 25 OH vitamin D blood levels.
Children that are at increased risk for insufficiency or deficiency of vitamin D have: sun avoidance behavior, issues with intestinal fat malabsorption (vitamin D is a fat soluble vitamin like D/E/K), intestinal dysbiosis, inflammatory bowel disease, eating disorders, celiac disease and disorders of bile production or pancreatic enzyme production, chronic kidney disease and magnesium deficiency.
Omega 3 and 6 Fatty Acids
Fish oil, flax oil, wild caught fish, kelp, grass fed meats are all the rage now for health conscious consumers. There is good reason for this shift in consumerism. These foods are all loaded with health promoting omega three fats. On the other hand, seed and vegetable oils are the major source of omega six fatty acids. Omega three and six fatty acids are a type of fat called polyunsaturated fatty acid(PUFA) which in chemistry terms means that there are at least two or more double bonds located on the carbon chain. This piece of information is important because this chemical structure makes it more unstable when exposed to heat, oxygen or chemicals, which in turn can on occasion make the fatty acid unhealthy.
Mechanistically, omega three and six fats are used by the body in cell membranes and as a precursor for a chemical pathway called prostaglandins which are pro and anti inflammatory chemicals released during injury, infection and repair. It is commonly understood that omega three fats are the precursor foods for the anti-inflammatory cascade while omega six fats are on the other side of the equation promoting inflammation. They share a set of enzymes in their conversion to their beneficial end products and are both necessary in moderation.
During my training in Arizona with Dr. Weil, we were taught that historically, it was believed that humans consumed roughly a 3:1 ratio of omega 6:3 fats. Currently, it is more akin to 30:1 based on the voluminous rise in processed foods with seed and vegetable oils. Based on this change in substrate ratios, we would assume that the flood of omega six fats would push the prostaglandins equation toward increased inflammation.
Based on the mechanisms and natural logic, it would seem prudent that following the older paradigm of a 3:1 ratio of PUFA's would hold benefit for reducing inflammation in asthmatics. However, the data regarding asthma and supplementing PUFA's is mixed at best. Dr. Julia's Nature Reviews article has a nice summary of the effects at the biochemical level for inflammation.
In two recent reviews of the current data, supplementation with fish oil/omega three fats was neutral in benefit. (Muley et. al. 2015)(Kwok et. al. 2017)
Boiling it all down: I resolve to follow the fish. Humans for thousands of years ate more fish and less to no omega 6 oils. It is highly likely that a 3:1 ratio of 6:3 PUFA's is more in line with human physiology. Mechanistically, this makes complete sense.
I recommend that all of my asthmatic patients reduce the volume of processed food which is the major human source of refined omega 6 oils. I further recommend that asthmatic children eat more small oily fish like mackerel, sardines, salmon. Taking fish oil as a supplement is safe and may turn out to be helpful although that remains to be seen.
Balancing the PUFA ratio is key in my mind.
The story continues next week,
Dr. M
Julia Nature Reviews Immunology Article
Jolliffe Lancet Respiratory Medicine Article
Pojsupap Journal of Asthma Article
Martineau Cochrane Review Article
Nair Journal of Pharmacologic Pharmacotherapy Article
Linus Pauling Institute Vitamin D
Mao Respiratory Medicine Article
Dierichs European Journal of Nutrition Article
Rosenkranz European Journal of Nutrition Article
Shaikh Pulmonary Medicine Article
Schwalfenberg Scientifica Article
Somashekar Archives of Asthma, Allergy and Immun Article
"There is increasing interest in the therapeutic utility of vitamin D in asthma, which is supported by a significant body of evidence on epidemiologic associations between vitamin D insufficiency and worse asthma control. In support of a causal relationship, vitamin D beneficially modulates diverse immunologic pathways in heterogeneous asthma endotypes, regulating the actions of
lymphocytes, mast cells, antigen-presenting cells, and structural cells to dampen excessive inflammatory responses. Allergic asthma is characterized by a failure of immune tolerance and the development of pathologic responses to inhaled aeroallergens, and vitamin D has been extensively shown to support immune regulation. Alarmin cytokines are increasingly implicated in nonallergic eosinophilic inflammation, which vitamin D also regulates.
Steroid resistance and pathologic interleukin (IL)-17 responses are features of severe asthma, and vitamin D beneficially enhances the response to steroids in these individuals. Additionally, vitamin D enhances antimicrobialpathways, which is of relevance to infection-precipitated asthma exacerbations. These mechanisms support a role for vitamin D as secondary prevention to reduce exacerbations and inflammation in asthma. Similar mechanisms, and effects on fetal lung development, likely underlie a primary prevention therapeutic role in pregnancy for vitamin D to reduce the development of asthma in children." (Pfeffer et. al. 2018)
