 There's lots of products that promise to boost our immune system. And who wouldn't want that? Well, there's millions of people with autoimmune diseases, inflammatory diseases, and allergies. Millions of people whose immune systems may already be a bit too active. I try to make sufferers of seasonal allergies feel better by explaining that having an overactive immune system is not all bad. Individuals with allergies have a decreased risk for cancer, compared with the general population. Yes, your immune system may be in such overdrive it's attacking things left and right like tree pollen, but that heightened state of alert might also help bring down some budding tumors in the body. So it's tricky. We want to boost the part of the immune system that fights infection, while down-regulating the part that results in chronic inflammation. And mushrooms may fit the bill. There are thousands of edible mushrooms. There are only about 100 are cultivated commercially. But 10 of those, really, on an industrial scale. And I do mean industrial, rising to over 20 million tons. And for good reason. They accelerate immunoglobulin A secretion. Let me explain. Though skin is considered our largest organ, we actually interface with the outside world more through our mucus membranes that line our mouth, our entire digestive tract, our reproductive and urinary systems, inside the breast glands, on our eyeballs, occupying our largest body surface area. Our gut alone covers more area than a tennis court, and much of it is only one cell thick. One microscopic layer is all that separates us from all the toxins, viruses, and bacteria out there, and so we need one heck of a first-line defense. And that defense is called IGA, Immunoglobulin A. Immunoglobulin means antibody. These are our Type A antibodies. Dietary intake may improve mucosal immunity by accelerating IGA secretion, but no studies have ever been conducted on mushrooms until now. So they had half people eat their normal diet, half eat their normal diet, plus cooked white button mushrooms every day for a week. Then, using the passive dribble method for collecting saliva, they just measured the amount of IGA. They were pumping out. No change in the control group, but after a week of mushrooms, IGA secretion jumped 50% and even stayed up there for a week after they stopped eating the mushrooms. This study has shown for the first time that dietary intake of white button mushrooms, just regular white mushrooms, about a cup a day, resulted in higher IGA secretion. And the elevated secretion remained stable into week two, but then fell back to baseline. So this suggests that in arresting or slowing the decrease in IGA in individuals such as the elderly or those of the immune compromise, a continuous daily intake of mushrooms may be necessary to maintain an increased IGA secretion, meaning you can't just eat mushrooms once and expect to be productive forever. You have to make them part of your regular diet. But if you continue to churn out 50% more antibodies, might that contribute to chronic inflammation, which is implicating the development of a variety of diseases? No, in fact, mushrooms appear to have an anti-inflammatory capacity in vitro, suggesting that they could be regarded as a potential source of natural anti-inflammatory agents. For example, here's an inflammatory response, without mushrooms and with mushrooms, both white and a few other varieties. They think it might be the phytonutrient pyrogallol found in a variety of mushrooms, as well as in our old friend amla, Indian gooseberries, that similarly appear to reduce inflammation while at the same time boosting immune and anti-cancer function.