This is a graph of mortality versus coffee consumption,
suggesting coffee drinkers live longer than non-coffee drinkers.
This may be because coffee mayhave beneficial effects on inflammation,
lung function, insulin sensitivity, and depression.
This may be in part because
of a class of polyphenol phytonutrients
found in coffee beans called chlorogenic acids,
proven to have favorable effects with studies
like these where they just give it alone in pill form
and can show beneficial effects,
such as acute blood pressure-lowering activity,
dropping the top and bottom blood pressure numbers within hours of consumption.
OK, so which coffee has the most?
We know how to choose the reddest tomato,
the deepest orange sweet potato,
since many of the plant pigments are the antioxidants themselves.
How do you choose the healthiest coffee?
More than a hundred coffees were tested,
and different coffees had different caffeine levels,
but the chlorogenic acid levels varied by more than 30-fold.
As a consequence, coffee selectionmay have a large influence
on the potential health potential of coffee intake.
这些研究显示 一杯咖啡可能富含营养素 也可能没什么营养素
So all those studies that show that one cup of coffee does this or that,
what does that even mean when coffee can vary so greatly？
Interestingly, the major contributor to the wide range
was the coffee purchased from Starbucks,
which had an extremely low chlorogenic acid content,
averaging 10 times lower than the others.
Maybe it’s because they roast their beans too dark.
The more you roast, the less there is.
They appear to be partiallydestroyed by roasting.
Caffeine is pretty stable,
but a dark roast may wipe out nearly 90 %
of the chlorogenic acidcontent of the beans.
The difference between a mediumlight roast and a medium roast
was not enough though to make a difference
in total antioxidant status
in people’s bloodstreamsafter drinking them;
they both gave aboutthe same boost.
Other factors, such as howyou prepare it or decaffeination,
don’t appear to have a major effect.
What about adding milk?
Long-time fans may rememberthis ancient video,
where the addition of milk was shown to
prevent the protective effects of tea on artery function.
Drink black tea and you geta significant improvement
in vascular function within hours,
whereas addition of milk completelyblunted the effects of tea.
Here’s the big boost in arteryfunction you get drinking tea,
but drink the same amount of tea with milk
and it’s like you never drank the tea at all.
They think it’s the casein to blame,
one of the milk proteins binding up the tea phytonutrients. Bottom-line,
this finding that the tea-induced improvement in vascular function
is completely attenuated after additionof milk may have broad implications
on the mode of tea preparationand consumption.
In other words,
maybe we should not add milk to tea or put cream on our berries.
It appears to have the same effect on berry phytonutrients, or chocolate.
Check this out.
Eat milk chocolate,and nothing much happens
to the antioxidant powerof your bloodstream.
But eat dark chocolate and get a nice spike within an hour of consumption. Yeah,
but is that just becausethe milk in milk chocolate
crowds out some of theantioxidant-rich cocoa?
Milk chocolate mayonly be like 20% cocoa,
whereas a good dark chocolate may be like 70 % or more cocoa solids. No,
it’s not just that.
Here’s how much of thiscocoa phytonutrient
you get into your bloodstream eating dark chocolate compared to milk chocolate.
But eat that same amountof dark chocolate
with a glass of milk andit blocks about half. OK,
that’s cocoa beans;what about coffee beans?
When milk was added to the coffee
in like a test tube,
antioxidant activity decreased by more than half
with just a splash of milk,
and down like 95 % in latte or something with lots of milk. OK,
but what happens
in a test tube doesn’t necessarily happen in a person.
I mean, you don’t know until you put it to the test.
And indeed, over the course
of a day significantly fewer chlorogenic acids
made it into people’s bloodstreamsdrinking coffee with milk
compared to black, cuttingabsorption by more than half.
What about soymilk?
In a test tube,
coffee phytonutrients do appear to bind not only to dairy proteins
but also egg and soy proteins.
You can see how they didthis computer modeling
showing how these coffee compounds can dock
inside the nooks and crannies
of dairy, egg white, and soy proteins,
but what happens in a testtube or a computer simulation
doesn’t necessarilyhappen in a person.
Eggs haven’t been put to the test,
so you don’t know if having omelets
with your black coffeecould impair absorption,
and neither has soymilk until now. Yeah,
无论如何 相比牛奶 豆浆有一些固有的好处
either way soymilk has someinherent benefits over cow’s milk,
but does it have the samenutrient blocking effects?
And the answer is no.
No significant difference in theabsorption of coffee phytonutrients
drinking coffee black or with soymilk.
What seemed to be happeningis that the soy proteins
do initially bind the coffee compoundsup in the small intestine,
but then your good bacteria can release them
so they can be
absorbed down in the lower intestine.
So considering the reversible nature of binding
as opposed to the dairy proteins,
it seems not to be as relevant as to
whether or not you add soy milk.