Preserving Immune Function in Athletes with Nutritional Yeast

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

“Moderate exercise improves immunity and decreases illness rates. By far, the most important finding that has emerged from exercise immunology studies [during] the past 2 decades is that positive immune changes take place during each bout of moderate physical activity.” Over time, this translates to fewer days of sickness with the common cold and other [upper respiratory infections].” We’re talking a “25% to 50% reduction in sick days.” Name one drug or supplement that can do that.

And, it doesn’t take much. Let kids run around for just six minutes, and you can boost the numbers of immune cells circulating in their bloodstream by more than a third.

At the other end of the life cycle, exercise may help prevent age-related immune decline. Sedentary women in their 70s may have a 50% chance of getting an upper respiratory illness during the fall season every year, but walk a half-hour a day, and your risk is down to 20%. The runners in the group got it under 10. That’s like a five times better immune system.

Now, while “[r]egular physical activity improves immune function and lowers [upper respiratory infection] risk,…sustained and intense exertion [may have] the opposite effect”—forming a so-called J-shaped curve relationship. As you go from inactive to active, your infection risk declines, but hardcore athletes that overtrain may actually put excessive stress on their bodies, and increase their risk of infection. Then, you could lose training days; your performance could suffer. So, what can you do? Well, traditional sports medicine doesn’t appear to have much to offer, advising athletes to you know, don’t pick your nose, avoid sick people, and get a flu shot.

A new study, though, found that one can better maintain one’s level of circulating white blood cells after exhaustive exercise by consuming a special type of fiber found in baker’s, brewer’s and nutritional yeast. Brewer’s yeast is bitter, but nutritional yeast has a nice cheesy flavor. I use it mostly to sprinkle on popcorn. Anyway, normally two hours after cycling-your-brains-out, you can experience a dip in circulating monocytes—one of our first line of defense white blood cells. But, those who had been eating the equivalent of less than 3/4 of a teaspoon a day of nutritional yeast ended up even better than when they started, after strenuous exercise. But, does this increase in immune cells translate into fewer illnesses? Well, let’s try it on some marathon runners.

In the weeks following the Carlsbad Marathon, this is how many runners reported experiencing upper respiratory tract infection symptoms, taking a placebo. But, if instead, they had the equivalent of a daily spoonful of nutritional yeast, they cut their rates in half.

What’s even more remarkable is that they felt better. Asked how they felt on a scale of one to ten, people taking the sugar pills were like, okay, down around four or five. But, those taking identical-looking capsules of the fiber found in nutritional yeast were up at like six or seven. Evidently, elite athletes tend to normally experience deterioration in mood state during intense training periods, and before and after a marathon race. But, sprinkle a little spoonful of nutritional yeast, and you may feel less tense, less fatigued, less confused—even less angry, and my favorite, significantly more vigor!

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Image thanks to ivymushbowl via flickr. Thanks to Ellen Reid for her Keynote help.

• beta-glucano
• cognición
• ejercicio
• envejecimiento
• estado de ánimo
• estrés
• fatiga
• fibra
• función inmune
• infecciones respiratorias
• levadura
• levadura de cerveza
• levadura nutricional
• niñez
• resfriado común
• vacunas contra la gripe