"Benefits of Blueberries for Artery Function"
A single serving of blueberries can help mediate the arterial dysfunction
induced by smoking a cigarette.
They investigated the effect
of a single serving of frozen blueberries on young smokers.
Smoke a single cigarette, and the ability of your arteries to relax
naturally drops 25% within two hours.
But eat 2 cups of blueberries a hundred minutes before,
and that same cigarette causes less than half the damage,
demonstrating that a single big serving of frozen blueberries
could counteract the artery dysfunction induced by smoking.
However, of course, it should be noted that blueberry consumption
cannot be considered a means
of preventing health consequences due to smoking;
this can only be realized by stopping smoking
or even better, not smoking in the first place.
Two cups of blueberries is a lot, though.
Yeah, you could easily chug those down in a smoothie,
but what's like the minimum dose?
We didn't know until a group of British researchers decided to put it to the test.
To enable them to do a double-blind study,
they had to create a placebo control fake blueberry drink.
So they used a freeze-dried wild blueberry powder
to give people the equivalent
of three-quarters of a cup of fresh blueberries,
one and a half cups, one and three-quarters,
about 3 cups, or 4 cups.
They concluded blueberry intake
acutely improves artery function in an intake-dependent manner.
OK, so what's the optimal intake?
After the placebo, nothing happens.
But after eating one and three-quarter cup's worth of blueberries,
a big spike in artery function improvement within just one hour of consumption.
And that seems to be where the effect maxes out.
Less than a cup is good, but between 1 and 2 cups seems better,
with no benefit going beyond that in a single meal.
Can you cook them?
What if you put them in a blueberry pie or something?
The same remarkable improvement in artery function
baked into a bun, just spiking an hour later,
since solid food passes more slowly through your stomach.
And then if you eat blueberries week after week, you get chronic benefits, too,
in terms of reduced artery stiffness and a boost in your natural killer cells,
which are one of your body's natural first lines
of defense against viral infections and cancer.
But wait a second, how can blueberries have all these amazing effects,
if the anthocyanins, the blue pigments in blueberries purported to be
the active ingredients, hardly even make it into our system?
Women were given more than a cup of blueberries to eat,
and they couldn't find hardly any in their bloodstream or flowing through their urine.
Here's what's called a chromatogram,
with the spikes showing all the little anthocyanin peaks in blueberries.
Here's your blood before eating blueberries: obviously no signs of the pigments.
After one hour, you start to see them appear,
and a few hours after that they become a bit more distinct,
but, all in all, just a few billionths of a gram per milliliter show up.
So either anthocyanins are extremely potent,
and therefore active at low parts-per-billion blood concentrations
or somehow their bioavailability has been underestimated.
So researchers decided to radioactively tag them and trace them throughout the body.
What happens is that blueberry pigments are metabolized
by our liver and our microbiome, the good bacteria in our gut,
into these active metabolites that are then what's absorbed into our system.
So it's kind of a team effort to benefit from berries.
And that would solve this mystery as well.
Anyone notice this second spike in benefit over here at 6 hours?
How does that make sense?
Well, some of the metabolites peak in the bloodstream within an hour,
but others ramp up more slowly,
especially if the berries have to make it all the way down to the colon.
And it's not just spikes at 1 hour and 6 hours.
If you track them out even further, some go up even more.
So like a day later you may still be experiencing berry benefits
as our gut bacteria continue to churn out goodies
that get absorbed back into our system, feeding us as we feed them.
Eating blueberries can so feed our good bacteria
that it's like taking a natural probiotic, a win-win all around.