"Using the Produce Aisle to Boost Immune Function"
What we eat, or don’t eat,
can affect our immune system.
This study was conducted to determine the effect
of the consumption of brightly colored vegetables
on the immune system.
The first two weeks basically no fruits and veggies,
then two weeks drinking a cup and a half of tomato juice every day,
then carrot juice, then spinach powder.
This is a graph of a marker of immune function
over those eight weeks.
Within just two weeks of a fruit and veggie deficient diet,
immune function plummets,
but just a cup and a half of tomato juice
can bring us back from the ashes.
Not 5 servings a day, just that tall glass of tomato juice,
but the carrot juice alone didn’t seem to work as well,
nor did the the powder equivalent of about one serving of spinach.
This says to me 2 things—
1. How remarkably we can affect our immune function
with simple dietary decisions, and
2. not all veggies are alike.
Though this study was repeated looking at other immune markers
and the tomato versus carrot appeared more evenly matched.
there is one family of vegetables
we definitely don't want to miss out on.
Inflammation, leaky gut,
all because of an absence of AHR ligands.
In other words, an absence of cruciferous vegetables in our diet:
cabbage, collards, cauliflower, kale, Brussels sprouts, broccoli.
So do people who eat healthier actually get sick less?
Those who eat more fruits and vegetables
appear to have lower risk
of getting an upper respiratory tract infection like the common cold
whether they’re otherwise vegetarian or not.
Even just one added apple a day
may help keep the doctor away.
The common cold is so innocuous, though.
Why not test against something stronger?
One can also look at more serious
respiratory infections like influenza.
Looking at the relationship between various risk factors
and influenza-related hospitalizations in the United States,
they found that a 5% increase in the prevalence of obesity
was bad, associated with a 6% increased hospitalization rate,
but physical inactivity was worse: 7%.
But just that tiny bump in the rates
of low fruit and vegetable consumption
may increase flu-related hospitalization rates even more.
And the common cold isn’t always innocuous.
A common cold during the first trimester of pregnancy
is associated with a number of birth defects
including one of the worst,
anencephaly,
a fatal malformation of the brain.
More recent data suggests it’s the fever,
as anti-fever drugs appeared able to prevent
the possible birth defect causing effect of the common cold,
but even better, to not get sick in the first place.
A thousand women and their diets were followed
before and during pregnancy,
and women who consumed more fruits and vegetables
had a moderate reduction in risk
of upper respiratory tract infection during pregnancy,
and this benefit appears to be derived from both
fruits and vegetables instead of either alone.
Whole fruits and vegetables provide a natural balance
of all sorts of things that may improve our immune function
in a complementary, combined or synergistic manner
that could account for the protective effect
observed from high consumption
of both fruits and vegetables.
Or maybe that’s the only way they got enough.
The women who appeared protected in this study
were eating nearly 9 servings of fruits and vegetables a day,
compared with only 5 servings of fruits, or four of veggies.
That may fulfill some arbitrary five or six a day minimum,
but may be insufficient for effective immunity.
For example in that famous study I profiled previously,
elderly individuals randomized into a five a day group
did have an improved antibody response to their pneumonia vaccination,
compared to just two servings of fruits and vegetables a day—
an 80% increase, but only about 30% reached
their target levels- 12 out of 40.
Six times better than the two-a-day group,
but maybe eight, nine, or ten a day would have worked better.