"Best Food to Counter the Effects of Air Pollution"
Outdoor air pollution may be the 9th leading cause of death and disability
in the world, responsible for millions of deaths from lung cancer,
emphysema, heart disease, stroke, and respiratory infection.
In the U.S., living in a polluted city was associated
with a 16, 27, and 28% increase in total, cardiovascular, and lung cancer death,
compared to living in a city with cleaner air.
Living in a city with polluted air may lead to up to a 75% increase
in the risk of a heart attack.
No one wants to be living in a traffic jam, but it's better than dying in a traffic jam.
In addition to causing deaths,
air pollution is also the cause of a number of health problems.
It may not only exacerbate asthma,
but also increase the risk of developing asthma in the first place.
These pollutants may trigger liver disease,
even increase the risk of diabetes.
Even when atmospheric pollutants are within legally established limits,
they can be harmful to health. So what can we do about it?
Paper after paper describing all the terrible things air pollution can do to us,
but most failed to mention public policy.
We're making great strides in demonstrating the harmful effects,
but public authorities are not using these data to reduce emissions,
as they might inconvenience the population
and therefore might not be politically acceptable.
To treat the cause, we need better vehicle inspections,
efficient public transport, bus lanes, bicycle lanes,
even urban tolls to help clean up the air.
While we're waiting for all that,
is there anything we can do to protect ourselves?
Well, our body naturally has detoxifying enzymes,
not only in our liver but lining our airways.
Studies showing that people born with less effective detox enzymes
have an exaggerated allergic response to diesel exhaust,
suggesting that these enzymes actively combat the inflammation
caused by pollutants in the air.
A significant part of the population has these substandard forms of the enzyme,
but either way, what can we do to boost the activity
of whichever detoxification enzymes we do have?
Well, if you remember, broccoli can dramatically boost the activity
of the detox enzymes in our liver, but what about our lungs?
Researchers fed some smokers a large stalk of broccoli every day for 10 days
to see if it would affect the level of inflammation within their bodies.
Why smokers? Because smoking
is so inflammatory that you can end up
with elevated C-reactive protein levels for up to 30 years after quitting,
and that inflammation can start almost immediately after we start smoking,
so it's critical to never start in the first place.
But if you do, you can cut your level of that inflammation biomarker, CRP,
nearly in half, after just 10 days eating a lot of broccoli.
Appears to cut inflammation in nonsmokers as well,
maybe explaining in part why eating more than two cups of broccoli,
cabbage, cauliflower, kale, or other cruciferous veggies a day
is associated with 20% reduced risk of dying,
compared to eating a third of a cup a day or less.
So what about air pollution?
We know the cruciferous compound is the most potent known inducer
of our detox enzymes.
And so most of the research has been its ability to fight cancer,
but here for the first time, they tried to see if it could combat
the pro-inflammatory impact of pollutants such as diesel exhaust.
They put some human lung lining cells in a Petri dish
and this is how many detox enzymes are produced.
Drip on some broccoli goodness and you get this many.
Yeah, but we don't inhale broccoli, we don't snort it; we eat it.
Can it still get into our lungs and help?
Yes, two days of broccoli sprout consumption,
then you suck some cells out of their nose,
and up to 100 times more detox enzyme expression
compared to eating a non-cruciferous vegetable, alfalfa sprouts.
Now, all we have to do is squirt some diesel exhaust up their nose,
which is what some UCLA researchers did,
an amount equal to daily rush hour exposure on a Los Angeles freeway.
Within six hours, the number of inflammatory cells in their nose
shot up and continued to rise.
But in the group that had been getting a broccoli sprout extract,
the inflammation went down and stayed down.
Since the dose in these studies is equivalent
to the consumption of 1 or 2 cups of broccoli,
their study demonstrates the potential preventive
and therapeutic potential of broccoli.
But if broccoli is so powerful at suppressing this inflammatory
immune response, might it interfere with normal immune function?
After all the battle with viruses like influenza can happen in the nose.
Let's drip some flu viruses
into the nostrils of broccoli sprout eaters and find out.
And what you get is the best of both worlds:
less inflammation, yet an improved immune response.
Eat alfalfa sprouts and you can get this kind of viral spike in your nose,
but after eating a package of broccoli sprouts every day,
our body is able to keep the virus in check,
potentially offering a safe, low-cost strategy
for reducing influenza risk among high risk populations.
So better immune function, yet less inflammation,
potentially reducing the impact of pollution on allergic disease
and asthma—at least for an enthusiastic broccoli consumer.
But what about cancer,
detoxifying air pollutants throughout the rest of our body?
We didn't know until now.
Off to China where they have some of the worst air pollution in the world.
And by day one, those getting the broccoli sprouts
were able to get rid of 60% more benzene from their bodies,
a rapid, highly durable elevation in the detoxification
of a known human carcinogen.
Now this was using broccoli sprouts, which are highly concentrated,
equivalent to about 5 cups of broccoli a day.
So we don't know how well more modest doses would work,
but if they do, eating broccoli could provide a frugal means
to attenuate the long-term health risks of air pollution.