Dr. Kari Nadeau of the Sean N. Parker Center for Allergy & Asthma Research on The Food Allergy Epidemic – The After on Podcast with Rob Reid

Check out the After On Podcast Episode Page & Show Notes

Key Takeaways

  • Background and Important Stats
    • The percentage of the population (across the globe) with a food allergy is doubling every 10 years 
    • The most common food allergens are as follows:
      • Egg, milk, peanut, cashew, walnut, shrimp, wheat, and seeds
    • 50% of adults report not having their specific food allergy during childhood
      • “The fact that adults are now developing food allergies for the first time says something about the environment”
    • 10% of adults in the United States have a food allergy
    • Food allergy care costs the U.S. ~$24 billion annually
  • The Importance of Epinephrine Pens
    • The only known treatment for an anaphylactic reaction is an injectable epinephrine device
    • EVERYONE with a food allergy should carry an epinephrine pen (and probably 2, just in case the first doesn’t work or you need a second dose)
    • Just as employees in schools, restaurants and other public facilities require training in the Heimlich maneuver, how to use a fire extinguisher etc., employees should also be trained in how to use and administer an epinephrine dosing
    • Epinephrine pens should be in the rescue administration kits at all restaurants, schools, universities, and public sports events 
  • The Allergic Reaction Explained
    • Immunoglobulin G (IgG) antibodies are molecules in our blood that act like a big claw – they bind to a virus, bacterial, or fungal particle and say, “Wait a minute, you’re not supposed to be here”
      • They then digest the bacteria/virus/fungal particle through a process known as endocytosis
    • There’s also IgE
      • IgE molecules basically work the same way as IgG, but confuses things like peanut/shrimp/cashew proteins (or other allergens) as the bad guy
    • What happens once IgE binds to an allergen?
      • The complex then binds to and is recognized by allergy cells (masts cell, eosinophils, or basophils
      • The complex then releases histamines and other inflammatory chemicals
        • This causes our blood capillaries to leak fluid, causing rapid swelling which leads to itching and redness
  • What’s causing the rise in food allergies?
    • It’s thought to be a combination of environmental and other factors related to the increase in personal hygiene, more specifically the 5 Ds:
      • Dirt
        • Maybe people are “too clean” and our immune systems need more exposure to certain types of bacteria
      • Dogs
        • Perhaps humans were meant to be raised in closer proximity to animals
      • Dry Skin
        • Maybe the use of detergents with washing clothes is leading to the breakdown of skin in infants more than it should be
      • Vitamin D
        • It’s thought that low vitamin D levels contribute to the rise in food allergies
      • Diet
        • In infancy, children should eat a diverse array of foods and be exposed to as many common allergens as possible

Intro

The Sean N. Parker Center for Allergy & Asthma Research

  • Sean Parker, most known for his work in the early days of Facebook and Napster, also started the Parker Institute for Cancer Immunotherapy (PICI)
  • Sean himself suffers from quite a few life threatening allergies
    • “It’s a very scary disease to be eating out in a restaurant, and even though you’ve told someone you have X, Y, or Z food allergy, there can still be remnants of that food in your dish”
    • Sean has had a dozen+ fatal food reactions that have brought him to the emergency room
    • Wanting to help the cause, Sean helped establish the center with a large donation  in 2015
  • The center now has 60 full-time employees
  • What does the center do?
    • They study the immune system and how it relates to allergies and asthma in a laboratory setting, and then analyze that data through a field known as computational biology
  • Something Kari stresses – community-based participation and understanding the needs of the public
    • “We need to ask people who are suffering from diseases what they’re issues are. What do they want to see in the next 5-10 years?”

The Food Allergy Epidemic

  • “This is plaguing all of us as to why the rate of food allergies is increasing and to what extent this increase is increasing”
  • What are the hypotheses for why this is occurring?
    • “We really think this is truly increasing in our population due to biology, due to something in our external environments”
    • Genetics may also play a role
  • The timeline 
    • The rise of food allergies started in the 1940s (~0.1% of the population had an allergy to some type of food)
    • In the 1970s, ~0.4% of the population had a good allergy
    • The rate of food allergies was stable for a few decades
    • BUT – in the 1990s, there was another rise (~0.8% of the population had a food allergy)
    • It gets worse:
      • An epidemiology study from 2011 showed that ~8% of the population under the age of 21 had a food allergy 
        • From 1940, this is a jump of 8000%
      • In Australia, 1 out of 8 children have a food allergy
    • And worse…
      • The percentage of the population (across the globe) with a food allergy is doubling every 10 years 
        • This includes the rising rates in countries like Brazil, China, and South Africa
    • Contrast this – most public health indicators have been improving over the past decade

The Different Types of Food Allergens

  • Each country has its own cost common allergens, but in general the following are most prevalent:
    • Egg, milk, peanut, cashew, walnut, shrimp, wheat (to some extent), and seeds
  • What about soy?
    • Soy falls under the peanut category – “But I myself have not seen a lot of soy allergies”
  • What about fruit?
    • Most of the time, the proteins in fruit get digested so quickly that they don’t create bad reactions
      • But sometimes people can bite into something like an apple or pear and get a slight tingling in their throat – this is known as Oral Allergy Syndrome
    • Fruit sensitivities:
      • Sometimes people can get bloated from certain fruits, or develop a rash around their mouth 
        • But this is often due to the acidity of the fruit – not an allergy
      • This might also manifest itself through a headache

The Difference Between a Food Sensitivity and a Food Allergy

  • With an allergy, the immune system is involved
    • Every time you get a dose of whatever food you’re allergic too, you’ll experience a very defined allergic response
      • Histamine pathways are activated which creates a variety of symptoms – swelling, rashes that itch, itchy eyes, a runny nose, wheezing, and sometimes blood pressure changes, vomiting, or abdominal pain within 2-3 hours 
    • The worst cases of allergen exposure lead to anaphylaxis (essentially a life-threatening allergic reaction)
  • With food sensitivities, you’re more likely to experience bloating or headaches
    • There is no immune system involvement
  • An example – a gluten sensitivity vs. developing full-on Celiac disease
    • With Celiac disease, there’s an autoimmune attack on your own gut because of the gluten you consume
  • What about intolerances?
    • They’re a subset of a sensitivity
    • With lactose intolerance – people lack a certain enzyme necessary to chew up a certain sugar that’s in milk

The Role of Genetics in Food Allergies

  • In some populations, lactose intolerance is the norm (caused by genetics)
  • With food allergies, it’s a different story:
    • ~75% of the cases of new onset food allergies don’t have any family history whatsoever

Adult-Onset Food Allergies

  • The latest sets of data show that if you have a food allergy as a child, you have a 50% chance of losing that allergy by adulthood
    • Previously, this number was thought to be ~80%
  • Findings from a recent study published in January:
    • 50% of adults report not having their specific food allergy during childhood
      • “The fact that adults are now developing food allergies for the first time says something about the environment. Their genetics are the same, they’re the same person!”
    • 10% of adults in the United States have a food allergy
      • “I think that could perhaps be reflective of the fact that less and less people are growing out of their food allergies, but in addition, more and more adults are getting food allergies for the first time”

The Financial Side of The Food Allergy Epidemic

  • “It’s really becoming a disabling disease on all fronts”
    • Food allergy care costs the U.S. ~$24 billion annually (the bulk of this cost comes from emergency room visits and the specialty foods some people have to buy)

Epinephrine Pens

  • The only known treatment for an anaphylactic reaction is an injectable epinephrine device
    • Epinephrine works very quickly (within seconds to minutes) to stop the leakage of histamine released by the body’s immune cells
    • “But it only works if there’s not enough destruction that’s already happened”
      • Ideally, you should be using it within the first minute after developing wheezing, dizziness, or you start vomiting
  • EVERYONE with a food allergy should carry an epinephrine pen (and probably 2, just in case the first doesn’t work or you need a second dose)
    • “Even if one person isn’t carrying it or doesn’t get access to one, that’s one person too many”
  • Some stats to show why every school and restaurant should carry epinephrine pens:
    • While Barack Obama was President, he signed the School Access to Emergency Epinephrine Act, which allowed schools to carry epinephrine pens (but didn’t require them to do so)
      • In the state of California alone, 300,000 first-case allergic reactions occur each year
    • 90,000 food allergy events occur in California restaurants alone each year
  • Key Points
    • For these reasons, just as employees in schools, restaurants and other public facilities require training in the Heimlich maneuver, how to use a fire extinguisher etc., employees should also be trained in how to use and administer an epinephrine dosing
      • Why does every restaurant have a fire extinguisher present but not an epinephrine pen?
    • Epinephrine pens should be in the rescue administration kits at all restaurants, schools, universities, and public sports events 

The Immune System and Antibodies

  • Immunoglobulins are antibodies found in our blood. There are different types:
    • The most prevalent – Immunoglobulin G (IgG) antibodies
      • Think of IgG antibodies like a big claw – they bind to a virus, bacterial, or fungal particle and say, “Wait a minute, you’re not supposed to be here”
        • It then digests the bacteria/virus/fungal particle through a process known as endocytosis
      • IgGs are hyper-specialized
        • Think – it’s like a claw that’s shaped according to whatever it’s going to bind to
      • Some IgGs just float though the blood
      • Other IgG antibodies are attached to B cells, macrophages, and other immune cells
    • There’s also IgA, IgD, IgE, and IgM antibodies
      • The number of IgG antibodies is usually 100-1,000x greater than the number of IgE antibodies
  • Let’s get more specific with an example:
    • Once you get something like chicken pox (or the vaccine for it) – you now have chicken pox IgG antibodies within your body which fight off the virus for the foreseeable future (so you’re immune to it)

The Allergic Reaction and IgE

  • Here’s where IgE comes in…
    • IgEs used to be more important years ago, as they bind to things like parasites (which aren’t all that common anymore)
    • It basically works the same way as IgG, but it confuses things like peanut/shrimp/cashew proteins (or other allergens) as the bad guy
      • Note – you can have IgE antibodies which bind to certain foods, and you still won’t be allergic to them 
    • As you are exposed to allergens in small doses (like getting peanut dust on your skin if you’re allergic to peanuts), over time your IgE antibodies to that allergen increase in number
      • Why does this happen? – On a simple level, your IgE antibodies think they’re helping you (think evolutionarily – they used to bind/engulf parasites)

What happens once IgE binds to an allergen?

  • The complex then binds to and is recognized by allergy cells (masts cell, eosinophils, or basophils
  • The complex (specifically the allergy cell) then releases histamines and other chemicals (which evolutionarily speaking, were probably once helpful at killing parasites)
    • These chemicals cause our body to make excess mucus
    • This also causes our blood capillaries to leak fluid, causing rapid swelling which leads to itching and redness
  • When this occurs, the body’s production of interleukin-4 (IL-4) also increases
    • It’s a cascading reaction because IL-4 binds to the body’s immune cells (B and T cells), which in turn causes them to make more IgE
  • Here’s where things get interesting…
    • As described, sporadic exposure to an allergen is harmful and causes the body to actually make more IgE
    • But acute, daily exposure actually seems to dampen the body’s immune response
      • This is essentially what an allergy shot is
  • With IgE and environmental allergies (like pollen), the same allergic reaction cascade takes places
  • Important points:
    • You can have high amounts of IgE, but they don’t really bind to anything specifically
    • Certain people also have IgEs for things like peanut and shrimp, but when they eat them they don’t experience an adverse reaction

The Multifactoral Nature of Food Allergies

  • When people with food allergies are examined, 40% of those people have more than one type of food allergy
  • People with food allergies often have other allergic diseases (asthma, eczema, major allergies to bee stings, etc.)
    • 70% of people who come to the Stanford center for allergic research trials have other allergies

What’s causing the rise in food allergies?

  • The increase in personal hygiene, more specifically the 5 Ds
    • Dirt
      • Maybe people are “too clean” and our immune systems need more exposure to certain types of bacteria
    • Dogs
      • Perhaps humans were meant to be raised in closer proximity to animals
      • It’s thought that exposure to dogs early on in life decreases the risk of developing allergies down the line
    • Dry Skin
      • Maybe the use of detergents with washing clothes is leading to the breakdown of skin in infants more than it should be
    • Vitamin D
      • It’s thought that low vitamin D levels contribute to the rise in food allergies
    • Diet
      • In infancy, children should eat a diverse array of foods
        • International guidelines (and general consensus) used to dictate that infants shouldn’t be exposed to common food allergens (like peanuts, shrimp, and eggs) until 2-3 years of age – but this couldn’t be further from the truth
          • Instead, you should expose your child as early as possible to these types of foods
      • Perhaps the lack of fiber people eat as they age hurts the microbiome, which in turn leads to the development of certain allergies

Epigenetics

  • This is the field of research as to how our genes/DNA are essentially turned on/off
    • Much of this is influenced by our environment
      • AND – once a gene is switched on/off by the environment, that switch can then be passed down to offspring
      • For example – having a parent, or even a grandparent who smoked is a risk factor for developing a food allergy
  • Let’s dive deeper:
    • It’s been found that if women received allergen immunotherapy (allergy shots) while pregnant, their babies had a reduced risk of developing a food allergy
    • Women who receive allergen immunotherapy before even becoming pregnant – their children have a lower risk of developing a food allergy
    • Smoking can induce allergy genes which can be passed to offspring
      • It can also turn off certain genes that protect against food allergies

Oral Immunotherapy (OIT)

  • This therapy involves increasing exposure to food allergens by ingesting small doses daily
    • With milk, for example, you might start out by consuming a very, very small amount (milligrams) and then titrate up over time to about 1,000 grams (aka a maintenance dose) – done every day
      • This trains the immune system, and over time, the threshold for reactivity is increased
      • Check out this study done at Johns Hopkins for more info. about milk immunotherapy
  • There’s also something called epicutaneous immunotherapy (EPIT) which is similar to OIT, except done through skin exposure, as well as sublingual immunotherapy (SLIT)
  • DO NOT do this at home – go to a clinic (there are ~100 in the U.S. currently)
    • Caveat – this is an emerging field and the FDA hasn’t approved anything related to this yet
    • How does it work?
      • You got to the clinic about every 2 weeks to updose
      • The first dose is very, very tiny (~a millionth of a peanut – a peanut weighs about 300 mg)
    • Some clinics do what’s called a food challenge on the first day, which is a term for exposing increased allergen doses to find your allergic threshold

XOLAIR (omalizumab)

  • What is it? -It’s an “anti-IgE” (anti-IgE monoclonal antibody)- it stops its action
    • It’s the only ant-IgE molecule that’s currently on the market
    • XOLAIR has been commonly used in conjunction with allergen/environmental immunotherapy (for environmental allergens like grasses, dogs, and cats)
  • It’s a shot
  • It can be taken in conjunction with OIT to make it safer and accelerate your path to a higher allergic response threshold

Some Studies

  • Kari and her team have published a Phase 2 study related to OIT and XOLAIR
    • What were the results? – “The majority of people with multiple food allergies did great and they were able to consume up to two grams within 9 months”`
      • 2 grams is equivalent to a tablespoon of peanut butter

What’s next in the field of food allergy research?

  • A lot of the newer research involves examining biomarkers in saliva that might be used to:
    • Predict a food allergy
    • Predict someone getting better from food allergy therapy
    • Examine which types of food someone is allergic to
  • Small food allergy diagnostic chips are being developed – all they’d need is a drop or two of blood
    • Through examining for the presence of certain biomarkers in the blood, you’d be able to tell whether someone has a food/drug allergy
  • “We’re getting to a stage where hopefully biomarkers will supplant food challenges”
    • Remember – food challenges involve dosing someone with ever increasing amounts of an allergen, or a variety of different allergens, to see what they’re allergic too/and their allergic reaction thresholds
  • “In the era of personalized medicine, you should be able to take out your smartphone and put a chip into it and determine if you’re allergic to X, Y, or Z. This is what people deserve. This is the era of personalized medicine we should be aiming towards – not having to have people go through a food challenge and risk their life in a doctor’s office.”
  • Vaccines:
    • Vaccines  are nearly on the market to treat and prevent peanut allergy
    • Another vaccine company is developing peptide-based vaccine which would create tolerance to certain allergens over time, essentially replacing OIT
  • Check out all the clinical trials going on in the food allergy field here 

What’s the moonshot of food allergy research?

  • Cure someone of all their allergies ASAP (ideally in as little as a day or two)

The Big Unanswered Questions

  • Why do some people lose their food allergies over time? What’s going in their immune systems?
  • Why do some people have no food allergies (or environmental allergies)? Why are they protected? What’s happening in their immune systems?
    • How can we then induce this protection in other people?

These notes were edited by RoRoPa Editing Services

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