Podcast: Preventing Allergies with Diet

We have lots of choices to make about our diet, add to that doing the right thing when it comes to treating a chronic disease, fighting a virus, or losing weight. And suddenly, our nutrition choices can seem almost overwhelming. Well, I'm here to help. Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Orton. Diet may be one of the most powerful tools for calming an overactive immune system. In our first story, we look at the best diet for people who suffer from ragweed allergies. 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 dropped dead after eating a peanut, is an example of an overactive immune response. The flip side 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 have 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 anti-microbial activities. On one hand, activating the immune system to prevent infections, on the other hand, capable of reducing inflammatory reactions. Given their best-of-both-worlds nature, enhancing immune defense while simultaneously down-regulating inflammations, beta-glucans are suggested as a replacement for immunosuppressant drugs to treat inflammatory diseases like inflammatory bowel disease. It 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, inflammatory compounds. And based on just that, they suggest 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, and 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. In our next story, we look at the rising incidence of tick-bite-induced meat allergies. Tick-bite-induced meat allergies are really unlike any other food allergy we know. The most interesting feature of the reaction may be the first symptom can occur hours after eating meat, normally you have an allergic reaction to a bee sting or something, and it happens within minutes. But with this, you could eat a piece of bacon for breakfast, and your throat doesn't start closing off until the afternoon, and so you blame lunch, or doctors just call it spontaneous, or idiopathic anaphylaxis. Idiopathic is just doctor speak for we have no idea what the cause is. The delay is because the alpha-gal is thought to be absorbed along with the fat in the meat, given that the allergic reaction occurs 4 to 5 hours after meat ingestion, corresponding to the peak absorption time of the fat from the digestive tract. What makes it even more difficult to diagnose is that the majority of victims experience only occasional overt reactions, despite regular meat consumption. Fattier meats like pork rinds may provoke episodes more consistently and severely, but still, it's not like it happens every time. And it's on the rise. Ten years ago, we didn't even know the thing existed, but now in tick-ridden states, as many as 20% of the population have these anti-meat allergic antibodies, and more and more people are coming in affected. Though probably no more than 10% who test positive go on to experience hives or serious allergic reactions to meat. We're also seeing it more and more in kids, researchers in Virginia finding it not uncommonly, though identification of these cases may not be straightforward. Unlike in adults, who frequently present with systemic reactions, the majority of children with this syndrome present with just skin manifestations, such as hives. It doesn't mean it's not serious. In fact, nearly half the kids end up in the ER, and about 1 in 12 need to be hospitalized. Up to a quarter of the population breaks out in hives at some point in their lives, but some children can be affected for weeks or months, and it can be triggered by infections, foods, drugs, parasites, autoimmune. But in a large subset of cases, we don't know what the trigger is, and so we call it chronic idiopathic urticaria. It's a common thing pediatricians see, and the only cure is avoiding and eliminating whatever is triggering it. But in three quarters of the cases, we have no clue. But now we know that many children who have been diagnosed with mysterious hives or allergic reactions, and may have been specifically told that the reactions were not a result of food allergy, may have actually been suffering from anti-gal meat allergies. Given the serious nature of the reactions, and the rising frequency of allergic swelling and hives across all age groups, this underscores the importance of identifying what's going on, and clearly physicians should keep this new diagnosis in mind. Allergies to meat might be more common than previously thought. Two percent would mean millions of people. But just to put it in context, Americans are much more likely to suffer an anaphylactic reaction due to seafood, tick bite or not, no matter where they live. A national survey of emergency rooms found shellfish was by far the most frequently implicated food, and unlike many other allergies, kids don't tend to outgrow fish and shellfish allergies. And many fish allergies are actually allergies not to the fish, but to worms within the fish, like Anisakis. Exposure to these parasites, living or dead in fish, is a widespread problem. In fact, you can even have an allergic reaction to the parasitic fishworm eating chickens that were fed on fish meal. This is one of the ways someone who's allergic to fish could get triggered by just eating chicken. It reminds me of pork cat syndrome, where your mouth can get all itchy eating bacon in people with cat allergies, because of an allergic cross-reaction between cat skin and pig blood proteins. Anisakis worms are found particularly in cod, anchovies, and squid, and can also cause chronic hives and intractable chronic itching. Because of these worms, researchers recommend that people stop eating all seafood sushi altogether, because besides inducing allergenic reactions, the worms may cause a leaky gut syndrome, which often is unrecognized and can predispose to other more important pathologies than just being itchy all over. Finally today, we discover the anti-allergy properties of onions. Onions are potentially a good source of antioxidants, though interestingly, the antioxidants are concentrated in the outer layers immediately under the papery peel. Unfortunately, most consumers discard these most nutrient-rich outermost layers, thus losing a valuable part. Here are some numbers. More than 10 times more antioxidants in the outer layer of white onions compared to the core. Yellow onions in general have more antioxidants than white, and red onions beat them both, based on three different antioxidant testing methods. That's why I always try to buy red. Though red onions are indeed slightly better, yellow or white onions are no slouches, containing considerable levels of antioxidant activity. So, nutritious, sure, but are there any particular clinical benefits to onion consumption? There are grammatically challenged titles in the medical literature purporting all sorts of miraculous benefits, but what do they base these claims on? For example, here's a review purporting to have evidence that testosterone in males are enhanced by onions, but the researchers were talking about studies like this on the effects of onion juice on testicular torsion in rats. Who cares what happens after a rat testicle is rotated 720 degrees counterclockwise, except, of course, the rat. You don't know what happens in people until you put human testes to the test, and onion extracts don't appear to work. OK, what about bone health? Evidently, older white women who consumed onions at least once a day had an overall bone density that was 5% greater than individuals who consumed onions no more than once a month. 5% might not sound like a lot, but that improvement in bone density could potentially translate into decreasing the risk of hip fracture by more than 20% if, indeed, it was cause and effect. Daily administration of onion did cause a big bump in bone density. This opens the possibility for a low-cost, safe, and effective nutritional approach to osteoporosis, you guessed it, in the rat. Another rodent study. Rats. But finally, here we go. Tremendous strides have been made in treating osteoporosis with drugs, but they have the potential for serious adverse side effects, so scientists have drawn their attention to natural remedies. So, let's randomize people to drink… onion juice, or placebo onion juice. I don't know what sounds worse, sugary onion juice, or fake sugary onion juice. And, as if drinking onion juice wasn't bad enough, it was all for nothing. It didn't even work. What about the anti-allergy activities of shallots, and any therapeutic effects on helping allergic runny noses? Sixteen such patients were randomized equally into an antihistamine group, or a group that got antihistamines, plus some capsules containing dried shallot powder. It looked like the shallot group did better, but there was actually no statistically significant difference in total symptoms between the two groups, so another hashtag onion fail. There has to be something onions can do. What about testing the effects of fresh yellow onion consumption on breast cancer patients to try to decrease the toxic effects of a chemotherapy drug called doxorubicin? Unfortunately, no significant benefit found on decreasing damage to the liver or heart, but here we go. Finally, a clinical benefit to onions. The consumption of fresh yellow onion ameliorates the high blood sugars and insulin resistance in breast cancer patients during doxorubicin-based chemotherapy. Doxorubicin isn't just toxic to the liver and heart, it may also contribute to insulin resistance. So, let's do a randomized, triple-blind, controlled clinical trial, randomizing patients to like a whole onion a day, or a third of an onion a day. What happened? The high-onion group experienced a significant decrease in blood sugars and insulin resistance compared to the low-onion group. They went up in the low-onion group, but down in the high-onion group. So, make onions your friend. What's the worst that can happen? A little onion breath and be-go? Probably the least of your worries if you have cancer on chemotherapy. Visit NutritionFacts.org slash audio to see all the podcast episodes with descriptions that include links to their associated videos, sources cited, and other details are available on each video's page. Information about my books, How Not to Die, How Not to Diet, and How Not to Age is all at NutritionFacts.org slash books, including some of the newer titles, including Lowering LDL Cholesterol Naturally with Food. All proceeds from all book sales that I get go to charity, and I've got a new book in the publication pipeline, How Not to Hurt. It's going to be available December 15th of this year, 2026. And don't forget to sign up for our free newsletter at NutritionFacts.org slash subscribe to stay updated on the latest bite-sized videos and articles. NutritionFacts.org is a science-based nonprofit, and everything on the website is free. There are no ads, no corporate sponsorship, no kickbacks, strictly non-commercial, not selling anything. Just put it up as a public service, as a labor of love, as a tribute to my grandmother, whose own life was saved with evidence-based nutrition. Thanks for listening.