Hello and welcome to the Nutrition Facts podcast. I’m your host, Dr. Michael Greger.
Now, I know I’m known for explaining how not to do certain things (just look at my books, How Not to Die, the one I’m working on right now–How Not to Diet), but what I actually have to share with you is quite positive and boils down to this: What’s the best way to live a healthy life? Here, are some answers.
There are certain times of the year when most people would give just about anything not to be sneezing all the time. Well, as it turns out, a healthy plant-based diet may reduce the risk of a variety of allergic-type reactions. Today, we’re going to talk about that diet and the many ways you can make your life a little easier.
Our immune response against a foreign molecule present in animal products may play a role in some allergic, autoimmune, and inflammatory disorders. This reaction is thought to underlie tick bite-triggered meat allergies. Here’s the story.
In the beginning, Aristotle defined two forms of life on planet earth: plants and animals. Two thousand years later, the light microscope was invented, and we discovered tiny, one-celled organisms, like amoebas. Then, the electron microscope was invented, and we were better able to characterize bacteria. Finally, in 1969, biologists recognized fungi as a separate category, and we’ve had at least five kingdoms of life ever since.
In my video Higher Quality May Mean Higher Risk, I talk about the potential downsides of consuming proteins from within our own kingdom, because of the impact our fellow animal proteins can have on boosting our liver’s production of a cancer-promoting hormone called IGF-1.
In Eating Outside Our Kingdom, I talked about other potential advantages of preferably dipping into the plant and mushroom kingdoms for dinner, not only from a food safety perspective—we’re more likely to get infected by animal pathogens than Dutch elm disease, but because of the potential for cross-reactivity between animal and human proteins. And so, there may be less potential to trigger an autoimmune reaction—like the degenerative brain disease I talked about in that other video. Same concept with animal proteins triggering inflammatory arthritis. In attacking some foreign animal meat protein, some of our own similarly composed tissues may get caught in the crossfire.
And, it’s not just proteins. If you remember the Neu5Gc story, there’s this sialic acid in other animals that may cause inflammation in our arteries, and help breast tumors and other human cancers grow.
Well, now, there’s a new twist has been added to the story. The reason NeuGc triggers inflammation is because humans lost the ability to make it two million years ago. And so, when our body is exposed to it through animal products, it’s treated as a foreign invader. Well, there’s another oligosaccharide, called alpha-gal, that we, chimps, and apes lost the ability to make twenty million years ago—but it’s still made by a variety of animals, including many animals we eat.
Anti-gal antibodies may be “involved in a number of detrimental processes [which] may result in allergic, autoimmune, and ‘autoimmune like’ [diseases]”—such as autoimmune thyroid disorders. And, you can even find antibodies to this stuff in atherosclerotic plaques in people’s necks. But, those are all mostly speculative risks. We do know alpha-gal is “a major obstacle” to transplanting pig organs into people—like kidneys—because our bodies reject alpha-gal as foreign. It’s considered “the major target for human anti-pig antibodies.”
It’s interesting; if you look at those who abstain from pork (for whatever reason), they have “fewer swine-specific” white cells in their bloodstream—speculating that “oral intake of pork” could ferry swine molecules into the bloodstream via “gut-infiltrating lymphocytes…to prime [the] immune response.”
So, we can have an allergic reaction to eating the kidneys too, but such severe meat allergies were considered rare—until an unusual report surfaced. “[F]irst described in 2009, the report included details on 24 cases of meat allergies triggered by tick bites. Within a year, it was obvious that the cases should be counted in [the] hundreds rather than dozens. By 2012, it was clear that there [were] thousands of cases across a large area of the southern and eastern US,” and now “present in several countries” around the world.
The lone star tick, so called because females have a white spot on their back. They’re famous for causing Masters’ disease, a Lyme-disease like syndrome, also known as STARI, southern tick-associated rash illness. But, thanks to the lone star tick “steadily expanding its range,” it’s not necessarily just so southern anymore.
Okay, but what is “the relevance of tick bites to the production” of anti-meat antibodies to alpha-gal—these allergic antibodies? Good question. What we know is you get bit by one of these ticks, and you can develop an allergy to meat. This appears to be “the first example of a response to an [external parasite] giving rise to an important form of food allergy”—either because there’s something in the tick saliva that’s cross-reacting with the alpha-gal, or, because the tick is, like, injecting you with animal allergens from its last meal.
Here’s a fascinating story featuring a randomized, placebo-controlled, double-blind study of a 5-cents-a-day food for ragweed allergy sufferers.
“[A] great deal is asked of [our] immune system. On one hand, it has “to respond rapidly and violently to invaders, but at the same time limits both the…response and the collateral damage to the host.” Anaphylactic shock, like when someone with a peanut allergy drops dead after eating a peanut, is an example of an overactive immune response. The flipside is an underactive immune response, which can put you at risk for infection.
If you suffer some severe trauma, for example, it’s not enough to get to a level 1 trauma center. Death related to sepsis, blood infection, is still a major problem. And, a major factor is the depression of our immune system caused by the stress of the trauma. So, what these researchers did was to try to stimulate immune function in trauma victims by injecting them with beta glucan, a type of fiber found in yeast—mostly car crash victims, but also gunshots and stab wounds. And, not only did the beta-glucan group suffer less sepsis overall, they had five times fewer complications, and no deaths—compared to nearly one in three dying in the control group.
I’ve talked about the role of oral beta glucans in the form of nutritional yeast to boost immune function in adults and children. But if it’s so immunostimulatory, then might it increase inflammation, worsen allergies?
Actually, dietary yeast may offer the best of both worlds, possessing both anti-inflammatory as well as antimicrobial activities. On one hand, activating the immune system to prevent infections; “on the other hand,…capable of reducing…inflammatory reaction…” Given their best-of-both-worlds nature, enhancing immune defense while “simultaneously down-regulat[ing] inflammations, beta…glucan[s are suggested as a replacement] for immunosuppres[ant] drugs to treat inflammatory diseases,” like inflammatory bowel disease. Turns out that’s a bad idea for Crohn’s disease, since it can make things worse. Same with another disease called hidradenitis suppurativa. But what about allergies, like hay fever?
They did a “nasal provocation test” with tree pollen, and then siphoned off some mucus, and those that had been taking beta glucans had lower levels of some inflammatory compounds (or should I say inphlegmatory compounds). And, based just on that, they suggested it might help people with hay fever. But you don’t know—until you put it to the test.
A “randomized, placebo-controlled, double-blind study compared the effects of daily supplementation” for a month with about a teaspoon of nutritional yeast worth of beta glucans versus placebo on the “physical and psychological health…of self-described ‘moderate’ ragweed allergy sufferers.” The ragweed family is one of the leading causes of hay fever. Give people a placebo and nothing much happens. But, in the beta-glucan group, a significant drop in symptoms and symptom severity. Fewer runny noses, fewer itchy eyes, and fewer sleep problems. So, no wonder: less tension, depression, anger, fatigue, and confusion, and more vigor. So, improved allergy symptoms, overall physical health, and emotional well-being with the beta glucans found in a single teaspoon of nutritional yeast, which would cost about five cents a day.
Randomized double-blind controlled trials suggest excluding certain foods, such as eggs and chicken, can significantly improve atopic dermatitis, also known as eczema.
Eczema, “is a chronic inflammatory skin disease”; in fact, the leading cause of healthy years of life lost due to common skin diseases, because it’s just so common—affecting about a fifth of us. And, it’s not just an itchy rash; it’s associated with other diseases, too. Yes, it can be itchy, exhausting, embarrassing, but in kids, may increase risk for ADHD—though that may just be from the sleep deprivation. And, in adults, may increase the risk of major depression. And, it’s on the rise.
There are drugs for it; of course, there are always drugs. Steroids are the first-line therapy, but then there are immunosuppressants as well, with more in the drug pipeline. You know the medical profession is desperate when they’re forced to go back to the basics, and start applying leeches to people.
Previously, I talked about the safety and efficacy of other, more natural treatments. But, what about diet? Our story begins in 1920, a year doctors were realizing how good this oxygen stuff was—though maybe not as good as injecting people with mercury. But, a researcher at Johns Hopkins reported a number of cases in which, “[b]y omitting eggs, meat[s], and milk from the diet, [patients’] eczema improved.” Who’s going to profit off of that, though? No wonder it took 58 years before it was put to the test.
Figuring eggs and milk were the two foods most likely involved in eczema, they excluded them— and chicken and beef, since it may just be chicken and cow proteins more generally—in a randomized, double-blind, controlled trial swapping in soy milk instead. And…70% of the patients improved. One person got worse on the no-egg, no-chicken, no-milk, no-beef diet, but almost everyone else got better. So, the researchers conclude that for many kids, avoiding those foods may “induce a clinical improvement.” And interestingly, it didn’t seem to depend on whether allergy tests showed that they were allergic to milk and eggs. Either way, they tended to get better, regardless.
You can do randomized, double-blind, food challenges, where you like give kids with eczema various foods in opaque capsules—like one with egg powder, one with wheat powder, etc. And egg was found “by far [to be] the most…offending food.” For example, in this study, where they just cut out the eggs, dramatic improvements were documented for both the amount of skin involvement and the severity of the eczema lesions, after removing eggs from the diet.
But, in about 90% of cases, the mom had no idea that eggs were a problem. Why? Because it wasn’t like they were eating scrambled eggs or something. Almost all the egg exposure was hidden; they were exposed to hidden egg products in like packaged foods. So, they had no idea why their eczema was so bad—until this study, where they removed all eggs and egg products from their diets.
Eggs are evidently “the most frequent cause of food…sensitivity in children.” Out of hundreds of kids with eczema tested, “egg allergy was documented in two thirds” of those with sensitivities. In fact, a child having a blood reaction to egg-white proteins appears to be one of the best laboratory tests for predicting future allergic diseases in general. It appears to be the ovomucoid protein within egg white that seems to be causing most of the mischief.
About 40% of kids with eczema have some form of food allergy. And, the more food allergies they have, the more likely it appears they’re going to suffer from eczema— and, make it worse. Those who react to cow’s milk protein are significantly more likely to suffer severe eczema, showing the important role cow’s milk proteins may play “in the induction and increased severity of eczema in children.”
Often, parents switch from cow’s milk to goat’s milk, in an attempt to improve their children’s eczema. But goat’s milk should never be given to kids with cow’s milk allergy, because they often cross-react with one another, which has been confirmed with double-blind, placebo-controlled food challenges.
Ass milk, on the other hand, is a different story. Switching kids to donkey milk improved their eczema, and, for that matter, horse’s milk might, as well.
To see any graphs, charts, graphics, images or studies mentioned here, please go to the Nutrition Facts podcast landing page. There, you’ll find all the detailed information you need – plus links to all of the sources we cite for each of these topics.
Be sure to check out my new How Not to Die Cookbook. It’s beautifully designed, with more than 120 recipes for delicious, plant-based meals, snacks and beverages. All the proceeds from the sales of all my books all go to charity. I just want you to be healthier.
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Thanks for listening to Nutrition Facts. I’m Dr. Michael Greger.
This is just an approximation of the audio content, contributed by Allyson Burnett.