It’s crazy when you think about all of the different kinds of food we eat.
We just swallow and hope it all works out for the best.
Well, it turns out there are better ways
to think about keeping our bodies humming healthfully along.
Welcome to Nutrition Facts.
I’m your host Dr. Michael Greger.
Feeling lousy?
Well, take two aspirin and call me in the morning.
Or not.
Today on the podcast, we take a closer look
at the health effects of regular aspirin use.
In our first story, we weigh daily aspirin use
against the risk of internal bleeding.
Salicylic acid, the active ingredient in aspirin,
has been used for thousands of years
as an anti-inflammatory pain killer in the form of willow tree bark extract,
which Hippocrates used to treat fever and to alleviate pain during childbirth.
It became trademarked as a drug in 1899, and remains to this day
probably the most commonly used drug in the world.
One of the reasons it remains so popular, despite the fact that
we have better painkillers now, is that it also acts as a blood thinner.
Millions of people now take aspirin on a daily basis to treat or prevent heart disease.
It all started back in 1953, with the publication of this landmark study
in the New England Journal of Medicine,
“Length of Life and Cause of Death in Rheumatoid Arthritis.”
The paper started out with the sentence,
“It has often been said that the way to live a long life is to acquire rheumatism.”
They found fewer deaths than expected from accidents,
which could be explained by the fact that people with arthritis probably aren’t out,
you know, going skiing, but also significantly fewer deaths from heart attacks.
Maybe it was all the aspirin they were taking for their joints
that was thinning their blood and preventing clots forming
in their coronary arteries.
And so, in the 1960s there were calls to study whether aspirin would
help those at risk for blood clots.
And in the 1970s, we got our wish,
studies suggesting regular aspirin intake protects against heart attacks.
Today, the official recommendation is that low-dose aspirin
is recommended for all patients with heart disease,
but in the general population, for those without a known history
of heart disease or stroke, daily aspirin is only recommended
when the heart disease benefits outweigh the risks of bleeding.
The bleeding complications associated with aspirin use may be considered
an underestimated hazard in clinical medical practice.
For those who’ve already had a heart attack, the risk–benefit analysis is clear.
If you took 10,000 patients, daily low-dose aspirin use would be expected to prevent
approximately 250 major vascular events, such as heart attacks, strokes, or,
the most major event of all, death.
But, that same aspirin would be expected to cause approximately
40 major extracranial bleeding events,
meaning bleeding so bad you have to be hospitalized.
Thus, the net benefit of aspirin for secondary prevention,
meaning like preventing your second heart attack,
would substantially exceed the bleeding hazard.
For every 6 major vascular events prevented,
only about 1 major bleeding event would occur;
so, the value of aspirin for secondary prevention is not disputed.
But, if you instead took 10,000 patients who never had a heart attack or stroke—
yet, and tried to use aspirin to prevent clots in the first place,
so-called primary prevention, daily low-dose aspirin would only be expected
to prevent 7 major vascular events, at the cost of causing a hemorrhagic stroke,
bleeding within the brain, along with 3 other major extracranial bleeding events.
So then, the benefits are only like 2 to 1, which is a little too close for comfort,
which is why the new European guidelines do not recommend aspirin
for the general population,
especially given the additional risk of aspirin causing smaller bleeds
within the brain as well.
If only there were safe, simple, side effect-free solution…
and there is.
Ornish and Esselstyn proved that even advanced crippling heart disease
could not only just be prevented and treated but reversed with a plant-based diet,
centered around grains, beans, vegetables, and fruits,
with nuts and seeds treated as condiments,
and no oils, dairy, meat, poultry, or fish.
Bill Castelli, long-time director of the longest running
epidemiological study in the world— the famous Framingham Heart Study,
was once asked what he would do to reverse
the coronary artery disease epidemic if he were omnipotent.
His answer?
“Have the public eat the diet [of the rural Chinese] as described by Dr. T. Colin Campbell.”
In other words, he told PBS, "If Americans ate healthy enough, the whole
heart disease epidemic would disappear,”
though Esselstyn clarifies, we’re not just talking about vegetarianism.
“This new paradigm” of heart disease reversal means “exclusively plant-based nutrition.”
Next up, we discover how the aspirin compounds naturally found in plant foods
may help explain the lower cancer rates among those eating plant-based diets.
In people without a personal history of cardiovascular disease,
the risks of aspirin may outweigh the benefits,
but aspirin may have additional benefits as well.
We have long recognized the preventative role of daily aspirin
for patients with heart disease;
however, it now appears we can now hatch two birds from one egg.
Daily low dose aspirin may also help prevent certain
forms of cancer as well.
An analysis of 8 different studies involving more than 25,000 people
the authors found a 20% decrease in risk of death from cancer among those
randomized to a daily aspirin.
You know the search for effective and safe treatments for cancer
remains an enormous and burdensome challenge.
If only we could just stop cancer in its tracks—prevent
it before it strikes.
Well, perhaps we can with this plant phytonutrient,
salicylic acid, found in aspirin.
How does it affect cancer?
Well, the Nobel Prize in Medicine went to the team that discovered how aspirin works.
Enzymes named COX, cyclooxygenase,
take the proinflammatory omega-6 fatty acid arachidonic acid that our body makes—
or we get directly in our diet from mainly chicken and eggs,
our enzymes take the arachidonic acid and turn it
into inflammatory mediators, like thromboxane,
which produces thrombosis, clots, and prostaglandins,
which cause inflammation.
Aspirin suppresses these enzymes, though; so, less thromboxane means fewer clots,
and less prostaglandin means less pain, swelling, and fever.
But prostaglandins can also dilate the lymphatic vessels inside tumors,
allowing cancer cells to spread.
So, one of the ways cancer tries to kill us is by boosting COX activity.
That’s one of the ways we think aspirin can help prevent cancer,
by counteracting tumor attempts to pry open the lymphatic bars on its cage
and spread throughout the body, because the reduction in mortality due to
some cancers occurred within 2 to 3 years after aspirin was started.
That seems too quick to be accounted for by an effect only on the genesis formation of cancer.
Cancer can take decades to develop;
so, the only way aspirin could save us that fast is by suppressing the growth
and spread of tumors that already exist.
Aspirin appeared to cut the risk of metastases in half,
particularly for adenocarcinomas, like colon cancer.
So now, what about everyone taking a daily baby aspirin?
Previous risk/benefit analyses did not consider the effects of aspirin on cancer,
instead just balancing cardiovascular benefits with bleeding risks.
But these new cancer findings may change things.
If this was just a reduction of colon cancer risk,
then the benefits might not outweigh the harms for the general public,
but now we have evidence that it works against other cancers, too.
Even a 10% reduction in overall cancer incidence could
tip the balance in favor of benefits versus risks.
How does the cancer benefit compare?
As we saw before, using aspirin in healthy people just for cardiovascular protection
is kind of a wash.
By contrast, the cancer prevention rates might save twice as many lives;
and so, the benefits may outweigh the risks.
If you put it all together, heart attacks, strokes, cancer, and bleeding,
aspirin comes out looking protective overall, potentially extending our lifespan.
Yes, higher risk of major bleeding even on low dose aspirin,
but fewer heart attacks, clotting strokes, and cancers;
so, aspirin may be beneficial overall.
Note these age categories only go up to 74 years old, though.
That’s because the risk of bleeding on aspirin increases steeply with age;
and so, may tip the balance the other way.
But in younger folks, these data certainly have the research community buzzing.
The emerging evidence on aspirin’s cancer protection
highlights an exciting time for cancer prevention.
In light of low-dose aspirin’s ability to reduce mortality from both vascular events
and cancer to a very notable degree, it is tempting to recommend
low-dose aspirin for nearly everybody.
However, aspirin pills, even in low doses, have a propensity to damage
the lining of our stomach and intestines and increase the risk
for gastrointestinal bleeding;
this fact may constrain health authorities from recommending aspirin
for the general population.
Recent meta-analyses estimate that just a single year of low-dose aspirin therapy
will induce major gastrointestinal bleeding in one out of 833 people.
If only there was a way to get the benefits, without the risks.
Those who remember this video, already know the answer.
The aspirin phytonutrient isn’t just found in willow trees,
but throughout the plant kingdom.
This explains why the active ingredient in aspirin is found normally in the
bloodstream even in people not taking any aspirin.
Then, drink just one fruit smoothie, and within an hour and a half, your levels rise.
But, as you can see, one smoothie ain’t going to do it;
you have to regularly eat daily fruit and vegetable consumption.
Are these kinds of aspirin levels sufficient to suppress the expression
of that inflammatory enzyme implicated in cancer growth and spread?
Using umbilical cords and foreskin cells—where else are you going to get human tissue?—
they found that even those low levels caused by smoothie consumption
significantly suppressed the expression of that inflammatory enzyme on a genetic level.
Well, if this aspirin phytonutrient is made by plants, we might expect plant-eaters
to have higher levels, and indeed, not only did they find
higher blood levels in vegetarians,
there was an overlap with people taking aspirin pills.
Some vegetarians had the same level in their blood as people actually taking aspirin.
Vegetarians pee out as much of the active metabolite of aspirin as aspirin users do,
just because they’re eating so many fruits and vegetables.
Because the anti-inflammatory action of aspirin is probably the result of
this active ingredient in aspirin, salicylic acid, and the concentrations of salicylic acid
seen in vegetarians have been shown to inhibit that inflammatory COX enzyme in vitro,
it’s plausible that dietary salicylates may contribute to
the beneficial effects of a vegetarian diet,
although it seems unlikely that most omnivores would be able to achieve
sufficient dietary intake of salicylates to have a therapeutic effect.
They can certainly eat more fruit and veggies too.
With effectively all that aspirin flowing through their systems,
plant-eaters must have high ulcer rates, right? Aspirin can just chew through our gut.
But no, vegetarians appear to have a significantly lower risk of ulcers,
for both men and women.
So, for the general population, by eating plants instead of taking aspirin,
we may not just get the benefits without the risks,
we get the benefits—with benefits!
How is that possible?
Because in plants, the salicylic acid may come naturally pre-packaged
with gut-protective nutrients.
For example, nitric oxide from dietary nitrates exerts stomach protective effects
by boosting blood flow and protective mucus production in the lining of the stomach,
effects which demonstrably oppose the pro-ulcerative impact of aspirin.
Dark green leafy vegetables are among the richest dietary sources of nitrate,
but of course, the researchers go on to say that
“Since it may be unrealistic to expect people to eat ample servings” of greens “every day,"
we should just give people pills with their
pills, right? Nitrate pills with their aspirin pills.
But, why not just eat our greens?
People who’ve had a heart attack should follow their physician’s advice,
which probably includes taking aspirin every day, but what about everyone else?
I think everyone should take aspirin— but, in produce, not pill form.
Finally today, we ask should the active ingredient in aspirin
be considered an essential vitamin?
The results of the recent aspirin meta-analyses suggesting
a reduction of cancer mortality by about a third
in subjects taking daily low-dose aspirin can justly be called astounding.
Yet the protection from "Western" cancers enjoyed by those
eating more traditional plant- centered diets is even more dramatic.
Before the Westernization of their diets,
animal products made up only about 5% or less of the Japanese diet.
Note that age-adjusted death rates from cancers of the colon, prostate, breast,
and ovary were on the order of 5 to 10 times lower in Japan than in the US,
with mortality from pancreatic cancer, leukemias, and lymphomas
three- to four-fold lower.
But this phenomenon was by no means isolated to Japan.
Western cancers were likewise comparatively rare
in other societies where people ate plant-based diets.
The cancer protection afforded by lifelong consumption of a plant-based diet,
in conjunction with leanness and insulin sensitivity
that tends to come along with it may be very substantial indeed.
Therefore, a lifestyle protocol for minimizing cancer risk
may include a whole-food plant-based diet.
Now if part of this cancer protection arises
out of the aspirin phytonutrients in plants,
are there any plants in particular that are packed with salicylates?
Though salicyclic acid, the main active ingredient in aspirin,
is ubiquitously present in fruits and vegetables,
herbs and spices contain the highest concentrations.
Chili powder, paprika, turmeric have a lot, but cumin is like 1% aspirin by weight.
Eating a teaspoon of cumin is like taking a baby aspirin.
Consequently, populations that incorporate substantial amounts
of spices in foods may have markedly higher daily intakes of salicylates.
Indeed, it's been suggested that the low incidence of colorectal cancer
among Indian populations may be ascribed in part
to high exposure to dietary salicylates throughout life from spice consumption.
The population in rural India has one of the lowest rates of colorectal cancer
in the world, and they have a diet that could be extremely rich
in salicylic acid, given the substantial amounts of plant foods
flavored with large quantities of herbs and spices.
Some have proposed it's the curcumin in the spice turmeric,
but maybe it's the salicylic acid in cumin.
And the spicier, the better.
A spicy veggie vindaloo may have four times
the salicylates of a milder Madras-style veggie dish.
One meal and you get a spike in your bloodstream like you just took an aspirin.
So eating flavor-filled vegetarian meals, with herbs and spices,
may be more chemoprotective, meaning more preventive against cancer
than just regular, more bland vegetarian meals.
We may also want to eat organic.
Because salicylic acid is a defense hormone of plants,
the concentration is increased when plants become stressed,
like when plants are bitten by bugs, unlike pesticide-laden plants.
And indeed, soups made from organic vegetables
were found to have nearly 6 times more salicylic acid
than soups prepared from conventionally grown ingredients.
We should also choose whole foods.
Whole grain breads, which are high in salicylic acid,
contain about 100 times more phytochemicals than white bread,
800 perhaps, compared to 8.
That does raise the question, though, what about the other 799?
Interest in the potential beneficial effects of dietary salicylates has risen, in part,
because of the extensive literature on the disease-preventative effects of aspirin.
However, it should not be forgotten that plant products, found to contain
salicylic acid, are generally rich sources of a whole long list
of other phytonutrients, many of which have
marked anti-inflammatory and antioxidant activity as well.
Their potential protective effects should therefore not be overlooked.
In this context, the importance of dietary salicylic acid
should not perhaps be over emphasized.
Indeed, some believe that "salicylic acid deficiency"
has such important public health implications that it should be classed
as an essential vitamin, namely "Vitamin S,"
but what they're really saying is that we should all just have to eat a lot of plants.
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