It’s the Olive Oil: Mediterranean Diet Lowers Risk of Heart Attack and Stroke

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The Mediterranean diet is a well-known weapon in the fight against heart disease, but exactly how effective is it?

To find out, researchers led by Dr. Ramón Estruch, from the Department of Internal Medicine at the Hospital Clinic of Barcelona, put the Mediterranean diet to the test against a low-fat diet. They followed participants to track rates of heart attack, stroke and heart-disease-related death. After nearly five years, the results were so striking for one group that the study was stopped early, according to research published online by the New England Journal of Medicine.

The group that showed the least heart problems and lowest rate of heart disease deaths? Those who ate a Mediterranean diet high in extra-virgin olive oil. Coming in at a close second were participants who ate a Mediterranean diet high in nuts. Compared with those eating the low-fat diet, the extra-virgin-olive-oil group showed a 30% lower risk of having a heart attack, stroke or dying of heart disease after five years, while those consuming the Mediterranean diet with more nuts showed a 28% lower risk of these outcomes.

(MORE: Mediterranean Diet Linked to Lower Child-Asthma Risk)

“We think the strength of this study comes from the fact that we measured hard outcomes and not just blood pressure or changes in cholesterol levels,” says Estruch. “We really believe the Mediterranean diet lowers incidence of [heart attack], stroke and cardiovascular deaths.”

Previous studies have linked Mediterranean diets to fewer heart attacks and deaths from heart disease, but most of those have correlated people’s recall of their diet with heart-disease outcomes rather than randomly assigning participants to eat specific diets and then following them for heart-disease risk, as Estruch and his colleagues did.

In the study, the participants in the Mediterranean diet groups agreed to replace red meat with white meat like chicken and eat three or more servings of fish each week, along with three or more servings of fruit and two or more servings of vegetables a day. The extra-virgin-olive-oil group also consumed more than four tablespoons of the oil a day, replacing regular olive oil with the extra-virgin variety, which contains more potentially heart-healthy compounds like polyphenols and vitamin-E tocopherols — which can lower levels of inflammatory factors that contribute to heart disease — in addition to oleic acids, which are lower in the saturated fat that can build up in blood vessels. The group that consumed more nuts was asked to eat a combination of 30 g of walnuts, almonds and hazelnuts every day. These groups were also asked to stay away from sodas and red meats. The participants eating the low-fat diet ate three or more servings of fish or seafood a week and the same amount of fruit and vegetables as the Mediterranean diet groups. They were discouraged from consuming more than two tablespoons of vegetable oils, including olive oil, each day.

(MORE: Can Olive Oil Help Prevent Stroke?)

To ensure that other factors that could affect heart-disease rates were not playing a role, the researchers also adjusted for the total amount of calories the groups were eating, since obesity can be a major contributor to heart attack and stroke. Even after making these adjustments, however, the olive-oil group showed statistically significant drops in heart-disease risk. And because the three groups were randomly assigned to their diets, Estruch says that factors like the amount of exercise the participants did, or the medications they took, would be about the same in all three groups, and thus affect all participants equally.

Estruch says that the study has some limitations, most notably that the low-fat diet group may not have had as intense an intervention during the first part of the study as the Mediterranean groups did, potentially biasing the results in favor of the Mediterranean diet. Some volunteers also dropped out, most of whom had higher body mass index on average, which may also skew the results toward a beneficial effect of the Mediterranean diet, since the individuals who remained might have been more motivated to take care of their hearts to begin with.

Still, the findings add to the body of evidence that suggests the Mediterranean diet can play an important role in protecting the heart, and should guide doctors and patients who want to avoid heart disease toward eating the foods that can help them the most.

54 comments
RichardWilson2
RichardWilson2

The study has too many faults to be even considered near scientific. How much fat was considered low fat?   What kind of oil/fat did they consume?  How much fruits and vegetables did the low fat folks consume and how much animal products?

If the Med Diet is so great why are there so many overweight and a high rate of heart disease?

Well over 50% of extra virgin oil is fake, did they check the oil consumed? 

JacquelineBrown
JacquelineBrown

My understanding of the Med diet is that it's these things working in concert with each other -- MUFAs, PUFAs, Omega 3s, and phytonutrients (http://www.womentowomen.com/healthynutrition/mediterraneandiet.aspx). What would happen if you raised both nuts and olive oil? Would they cancel out the benefits, or increase them even more? I am glad to see this study because it has seemed in recent years that the Med diet was being eschewed in favor or other fad diets. 

javierlle
javierlle

@teresadefresa @TIMEHealthland @juanpantera Red, red wine, go to my head

GeyoOo
GeyoOo

@jadedjad @christellear1 ijbareeee lol

NYY1B23
NYY1B23

@crystalbowersox Spot on Crystal.

cmoraza
cmoraza

@boochanco Sige hic, ...I'll increase my red wine consumption...hic!

rolopretto
rolopretto

“@TIME: The Mediterranean diet: A strikingly effective tool against heart disease | http://t.co/LpbtuWTAUN (via @TIMEHealthland)” Enjoy it

sidkarker
sidkarker

@TIME my family had this diet for hundred of years yet heart disease is common. What you cook your food with is what really counts.

shecyclesnbi
shecyclesnbi

@coldtusker well I do love Italian food, and recently learned how to make fresh pasta...

CrimsonCues
CrimsonCues

@TIME @TIMEHealthland You had me at Mediterranean. Why diet?

raionnomachi
raionnomachi

Idk i always just found the take away from these to be: eat less crap and you may just be healthier XD

Tbiosensors
Tbiosensors

@DrAlexConcorde Excellent, love nuts and olive oil!

allthingsconsidered
allthingsconsidered

Actually, first, there are MANY other factors in lowering risk.  Secondly, ANY unsaturated oil will bring the same results.

yugs
yugs

“@TIME: All about olive oil: A Mediterranean diet lowers risk of heart disease | http://t.co/v3cN6TXeDQ (via @TIMEHealthland)”

derekpag
derekpag

“@TIME: All about olive oil: A Mediterranean diet lowers risk of heart disease | http://t.co/JZ4SgGNjjJ (via @TIMEHealthland)” @anialeeswan

rentpayer
rentpayer

@TIME @TIMEHealthland you need a stomach made from steel otherwise u will get some heartburn that only 1 kilo of Tums will help

Beatever
Beatever

@mcbrando grappig, was net iets gelijkaardigs aan het lezen

coldtusker
coldtusker

@shecyclesnbi Erm, I enjoy pasta too...

coldtusker
coldtusker

@shecyclesnbi Note Northern Italian cuisine is quite different from Southern Italian cuisine...

coldtusker
coldtusker

@shecyclesnbi Italian is different from Greek... though enough similarities, eh?

mcbrando
mcbrando

@Beatever nou, van een 'influencing' gesproken dan ;-)

ay1m
ay1m

@coldtusker @shecyclesnbi Pasta is Cucina Povera. Non? :-)

ay1m
ay1m

@coldtusker Is there a chance that would have been the pasta teacher? 2 and 2 is definitely coming to four. @shecyclesnbi

coldtusker
coldtusker

@shecyclesnbi Sigh, let me stay in my lane... Wake up early? Drink water not beer? ... Greek boy all yours! @ay1m

shecyclesnbi
shecyclesnbi

@coldtusker Wake up early, drink lots of water... when you get here there'll be a tall pitcher of horrible tasting re-hydrating drink @ay1m

coldtusker
coldtusker

@shecyclesnbi Headline: "Chap dies of dehydration & hypoglycemia while cycling..." @ay1m

shecyclesnbi
shecyclesnbi

@ay1m yes. With proof that you actually cycled the distance... @coldtusker

ay1m
ay1m

@shecyclesnbi Errm, there is an elephant in the room.. or rather.. one hoping to enter the room. :-) @coldtusker

shecyclesnbi
shecyclesnbi

@ay1m I had no idea it was so easy to make fresh pasta until I took the lesson. Don't know if Greeks eat pasta? @coldtusker

ay1m
ay1m

@coldtusker I guess it will only be, if you promise to show up on a bike. @shecyclesnbi

coldtusker
coldtusker

@ay1m Getting an invitation from @shecyclesnbi to try her pasta is...

ay1m
ay1m

@shecyclesnbi Origins.. :-) The good thing about pasta is it goes with anything. If you can make your own.. you rock. @coldtusker

shecyclesnbi
shecyclesnbi

@ay1m Cucina Povera = peasant cooking... Not any more. It's now about simple cooking @coldtusker