Does Having Allergies Mean That You Have A Decreased Immunity?

iStock.com/PeopleImages
iStock.com/PeopleImages

Tirumalai Kamala:

No, allergy isn't a sign of decreased immunity. It is a specific type of immune dysregulation. Autoimmunity, inflammatory disorders such as IBS and IBD, and even cancer are examples of other types of immune dysregulation.

Quality and target of immune responses and not their strength is the core issue in allergy. Let's see how.

—Allergens—substances known to induce allergy—are common. Some such as house dust mite and pollen are even ubiquitous.
—Everyone is exposed to allergens yet only a relative handful are clinically diagnosed with allergy.
—Thus allergens don't inherently trigger allergy. They can but only in those predisposed to allergy, not in everyone.
—Each allergic person makes pathological immune responses to not all but to only one or a few structurally related allergens while the non-allergic don't.
—Those diagnosed with allergy aren't necessarily more susceptible to other diseases.

If the immune response of each allergic person is selectively distorted when responding to specific allergens, what makes someone allergic? Obviously a mix of genetic and environmental factors.

[The] thing is allergy prevalence has spiked in recent decades, especially in developed countries, [which is] too short a time period for purely genetic mutation-based changes to be the sole cause, since that would take multiple generations to have such a population-wide effect. That tilts the balance towards environmental change, but what specifically?

Starting in the 1960s, epidemiologists began reporting a link between infections and allergy—[the] more infections in childhood, [the] less the allergy risk [this is called hygiene hypothesis]. Back then, microbiota weren't even a consideration but now we have learned better, so the hygiene hypothesis has expanded to include them.

Essentially, the idea is that the current Western style of living that rapidly developed over the 20th century fundamentally and dramatically reduced lifetime, and, crucially, early life exposure to environmental microorganisms, many of which would have normally become part of an individual's gut microbiota after they were born.

How could gut microbiota composition changes lead to selective allergies in specific individuals? Genetic predisposition should be taken as a given. However, natural history suggests that such predisposition transitioned to a full fledged clinical condition much more rarely in times past.

Let's briefly consider how that equation might have fundamentally changed in recent times. Consider indoor sanitation, piped chlorinated water, C-sections, milk formula, ultra-processed foods, lack of regular contact with farm animals (as a surrogate for nature) and profligate, ubiquitous, even excessive use of antimicrobial products such as antibiotics, to name just a few important factors.

Though some of these were beneficial in their own way, epidemiological data now suggests that such innovations in living conditions also disrupted the intimate association with the natural world that had been the norm for human societies since time immemorial. In the process such dramatic changes appear to have profoundly reduced human gut microbiota diversity among many, mostly in developed countries.

Unbeknownst to us, an epidemic of absence*, as Moises Velasquez-Manoff evocatively puts it, has thus been invisibly taking place across many human societies over the 20th century in lock-step with specific changes in living standards.

Such sudden and profound reduction in gut microbiota diversity thus emerges as the trigger that flips the normally hidden predisposition in some into clinically overt allergy. Actual mechanics of the process remain the subject of active research.

We (my colleague and I) propose a novel predictive mechanism for how disruption of regulatory T cell** function serves as the decisive and non-negotiable link between loss of specific microbiota and inflammatory disorders such as allergies. Time (and supporting data) will tell if we are right.

* An Epidemic of Absence: A New Way of Understanding Allergies and Autoimmune Diseases Reprint, Moises Velasquez-Manoff

** a small indispensable subset of CD4+ T cells.

This post originally appeared on Quora. Click here to view.

Mental Floss's Three-Day Sale Includes Deals on Apple AirPods, Sony Wireless Headphones, and More

Apple
Apple

During this weekend's three-day sale on the Mental Floss Shop, you'll find deep discounts on products like AirPods, Martha Stewart’s bestselling pressure cooker, and more. Check out the best deals below.

1. Apple AirPods Pro; $219

Apple

You may not know it by looking at them, but these tiny earbuds by Apple offer HDR sound, 30 hours of noise cancellation, and powerful bass, all through Bluetooth connectivity. These trendy, sleek AirPods will even read your messages and allow you to share your audio with another set of AirPods nearby.

Buy it: The Mental Floss Shop

2. Sony Zx220bt Wireless On-Ear Bluetooth Headphones (Open Box - Like New); $35

Sony

For the listener who likes a traditional over-the-ear headphone, this set by Sony will give you all the same hands-free calling, extended battery power, and Bluetooth connectivity as their tiny earbud counterparts. They have a swivel folding design to make stashing them easy, a built-in microphone for voice commands and calls, and quality 1.18-inch dome drivers for dynamic sound quality.

Buy it: The Mental Floss Shop

3. Sony Xb650bt Wireless On-Ear Bluetooth Headphones; $46

Sony

This Sony headphone model stands out for its extra bass and the 30 hours of battery life you get with each charge. And in between your favorite tracks, you can take hands-free calls and go seamlessly back into the music.

Buy it: The Mental Floss Shop

4. Martha Stewart 8-quart Stainless-Steel Pressure Cooker; $65

Martha Stewart

If you’re thinking of taking the plunge and buying a new pressure cooker, this 8-quart model from Martha Stewart comes with 14 presets, a wire rack, a spoon, and a rice measuring cup to make delicious dinners using just one appliance.

Buy it: The Mental Floss Shop

5. Jashen V18 350w Cordless Vacuum Cleaner; $180

Jashen

If you're obsessive about cleanliness, it's time to lose the vacuum cord and opt for this untethered model from JASHEN. Touting a 4.3-star rating from Amazon, the JASHEN cordless vacuum features a brushless motor with strong suction, noise optimization, and a convenient wall mount for charging and storage.

Buy it: The Mental Floss Shop

6. Evachill Ev-500 Personal Air Conditioner; $65

Evachill

This EvaChill personal air conditioner is an eco-friendly way to cool yourself down in any room of the house. You can set it up at your work desk at home, and in just a few minutes, this portable cooling unit can drop the temperature by 59º. All you need to do is fill the water tank and plug in the USB cord.

Buy it: The Mental Floss Shop

7. Gourmia Gcm7800 Brewdini 5-Cup Cold Brew Coffee Maker; $120

Gourmia

The perfect cup of cold brew can take up to 12 hours to prepare, but this Gourmia Cold Brew Coffee Maker can do the job in just a couple of minutes. It has a strong suction that speeds up brew time while preserving flavor in up to five cups of delicious cold brew at a time.

Buy it: The Mental Floss Shop

8. Townew: The World's First Self-Sealing Trash Can; $90

Townew

Never deal with handling gross garbage again when you have this smart bin helping you in the kitchen. With one touch, the Townew will seal the full bag for easy removal. Once you grab the neatly sealed bag, the Townew will load in a new clean one on its own.

Buy it: The Mental Floss Shop

9. Light Smart Solar Powered Parking Sensor (Two-Pack); $155

FenSens

Parking sensors are amazing, but a lot of cars require a high trim to access them. You can easily upgrade your car—and parking skills—with this solar-powered parking sensor. It will give you audio and visual alerts through your phone for the perfect parking job every time.

Buy it: The Mental Floss Shop

10. Liz: The Smart Self-Cleaning Bottle With UV Sterilization; $46

Noerden

Reusable water bottles are convenient and eco-friendly, but they’re super inconvenient to get inside to clean. This smart water bottle will clean itself with UV sterilization to eliminate 99.9 percent of viruses and bacteria. That’s what makes it clean, but the single-tap lid for temperature, hydration reminders, and an anti-leak functionality are what make it smart.

Buy it: The Mental Floss Shop

Prices subject to change.

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links. If you haven't received your voucher or have a question about your order, contact the Mental Floss shop here.

Just How Clean Is the Air On an Airplane?

Air quality in airplane cabins has become a growing concern during the coronavirus pandemic.
Air quality in airplane cabins has become a growing concern during the coronavirus pandemic.
Leylanr/iStock via Getty Images

For millions of Americans and millions more abroad, the excitement of booking a flight has turned into concern. Being stuffed into an airplane cabin with hundreds of other people for hours at a time seems like a risk in light of the coronavirus continuing to be a threat to public health.

According to experts, plane travel is indeed a risk, and much of that risk has to do with social proximity. But the air itself might be cleaner than you think.

In a piece for Condé Nast Traveler, author William J. McGee writes that many airplanes have highly effective air cleaning systems that use high-efficiency particulate air, or HEPA, filtration to remove 99.97 percent of airborne contaminants, including viruses. (But not all. Some regional airlines may not have HEPA devices.) The clean air is pumped in through the ceiling and leaves below the window seats. The air is roughly 60 percent fresh and 40 percent filtered and recirculated constantly.

Would this impact how coronavirus or other germs may spread? Theoretically, yes. But the Centers for Disease Control and Prevention (CDC) and other health organizations caution that no air filtration system can make up for being seated within a few feet of an infected person. It’s entirely possible that their germs will make their way to you before the circulating air removes them. And filtration isn’t a factor when travelers are standing near each other in line to board the aircraft.

Viruses aren’t the only air quality concern onboard a plane. Fumes from engine oil, hydraulic fluid, exhaust, and other sources can travel into the cabin. Pesticide applications may also leave a lingering odor.

The bottom line? If you have to be stuck in an enclosed space with several strangers, an airplane cabin might be the safest way to go about it. But variables like infected passengers, mask habits, and proximity make it impossible for anyone to offer assurances about safety. If you have a desire or need to fly, wearing a mask and keeping as much distance as possible between yourself and other passengers is the best way to approach it.

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