"Nutritional Yeast to Prevent the Common Cold"
Natural immunomodulators,
something that can help regulate our immune system
without side-effects,
has been sought for centuries,
and all the while they’ve been sitting in the produce aisle.
Plants produce thousands of active compounds,
many of which modulate our immune system,
enough to protect us from infection.
But we can’t forget the fungi.
Mushrooms have used for centuries as folk remedies,
and for good reasons—
some have been shown to boost immune function as well.
So much so, a type of fiber found in shiitake mushrooms
is approved for use as adjunct chemotherapy,
injected intravenously to help treat
a variety of cancers by rallying our immune defenses.
More than 6,000 papers have been published
on these so-called beta glucans,
but almost all of the data about preventing infections
had come from petri dish or lab animal studies,
until a few years ago
when a series of experiments on athletes
showed beneficial effects.
But that was in like marathon runners.
What about the rest of us?
We didn’t know until now.
Beta glucan fiber found in baker’s, brewer’s and nutritional yeast
helps to maintain our body’s defense
against pathogens even in nonathletes
according to this a double-blind, randomized, placebo-controlled trial.
Reducing the recurrence of infections
with the common cold by 25%
in those that ate the equivalent of about a spoonful
of nutritional yeast a day,
and had fewer cold-related sleeping difficulties
if they did get sick.
What about half a spoonful a day’s worth?
Still worked!
Big drop in common cold incidence
and a reduction in symptoms as well.
Why though?
This study found that not only
were upper respiratory infection symptoms diminished,
but that mood states appeared to be improved
like a significant boost in feelings of “vigor”.
So they suggest that maybe the yeast fiber
is able to counteract the negative effects
of stress on the immune system.
In terms of side-effects,
two folks reported stomachaches,
but they were both in the placebo group.
Unlike antibiotics and antivirals,
which are designed to kill the pathogen directly,
these yeast compounds instead appear
to work by stimulating our immune defenses,
and as such don’t share
the same antibiotic side effects.
They stimulate our immune defenses presumably
because our body recognizes them as foreign.
But if it’s treated like an invader,
might it trigger an inflammatory response?
Turns out it may actually have
an anti-inflammatory effect,
suggesting nutritional yeast
may offer the best of both worlds,
boosting the infection fighting side of the immune system
while suppressing the inflammatory component.
So oral intake can be considered safe and effective.
Note they said oral intake, though.
I would not recommend injecting nutritional yeast into your veins
no matter how much you like the stuff.
Yeast is high in purines, so those with gout,
uric acid, kidney stones, and new organ transplant recipients
may want to keep their intake
to less than a teaspoon a day,
but for everyone else, is there any downside?
Well if you look at some packages of nutritional yeast,
in California some are slapped with prop 65 warning stickers
suggesting there’s something in it exceeding cancer
or birth defect safety limits.
I called around to the companies
and it turns out the problem is lead.
California state law says a product cannot contain
more than half of a microgram of lead per daily serving.
So I contacted the six brands I knew about
and asked them how much lead was in their products.
KAL originally said “<5 ppm,”
but when we called back they said “<3 ppm,”
but even if it’s 3,
that translates into less than 45 micrograms per serving,
nearly a 100 times more than the California limit.
But perhaps better than Bob’s Red Mill or Frontier Coop,
who evidently didn't test at all.
But at least they got back to me.
Redstar brand failed to respond
to multiple attempts to contact them.
Now Foods said "of course we test for lead"...that’s nice,
and claim that at least their recent batches
meet the less than a half a microgram California standard.
Unfortunately, despite repeated requests
they did not provide me with documentation
to substantiate those numbers.
My favorite response was from Bragg’s
who sent me the analysis certificate from the lab
showing less than 0.01 ppm,
which means at most less than half the California standard,
which I believe is the most stringent in the world.
To put the numbers in context,
in determining how much lead
manufacturers can put into candy
likely to be frequently consumed by small children,
the Food and Drug Administration would allow like
2 micrograms a day in the form of lollipops,
but as far as I’m concerned the less lead the better.