Olive Oil May Protect Against StrokeJune 17, 2011 — A diet rich in olive oil may reduce the risk for stroke in older adults, new research suggests.
In roughly 7600 elderly adults, higher olive oil
consumption at baseline was associated with a lower incidence of stroke
over roughly the next 5 years, after controlling for numerous
confounding factors, including lifestyle and nutritional factors, stroke
risk factors, and blood lipids.
Cecilia Samieri, PhD, from University of Bordeaux
and the National Institute of Health and Medical Research (INSERM) in
Bordeaux, France, reported their findings online June 15 in
Neurology.
"The high prevalence of stroke in older subjects
emphasizes the need for primary and secondary prevention in this age
group," they conclude. "Showing a strong association between intensive
olive oil use and lower stroke incidence, our study suggests a novel
approach of dietary recommendations to prevent stroke occurrence in
elderly populations."
But the authors of a linked commentary caution
against jumping to any conclusions, noting that the putative health
benefits of olive oil, and a Mediterranean-style diet, are complex.
The Three-City Study Dr. Samieri and colleagues examined the
association between olive oil intake and stroke incidence in 7625 people
aged 65 and older from Bordeaux, Dijon, and Montpellier, France. They
are enrolled in the ongoing, population-based French Three-City Study,
which is looking at vascular risk factors for dementia.
At baseline, 1738 (22.8%) participants reported
no olive oil use, 3052 (40.0%) reported moderate olive oil use, and 2835
(37.2%) reported intensive olive oil use.
The authors note that moderate and intensive
olive oil users (relative to nonusers) were younger than nonusers; they
also had lower values or frequencies for several stroke risk factors,
weighed less, had lower triglycerides and lower total/high-density
lipoprotein cholesterol ratio. They were also more apt to be regular
exercisers and ate fish, fruits, and vegetables and omega-3–rich oils
more often than nonusers.
Over a median of 5.25 years, 148 incident strokes were recorded (115 ischemic, 28 hemorrhagic, 5 undetermined).
After adjusting for sociodemographic and dietary
variables, physical activity, body mass index, and risk factors for
stroke, the researchers observed a lower incidence of stroke with higher
olive oil use (
P for trend = .02). Compared with participants
who did not use olive oil, those with intensive use had a 41% lower risk
for stroke. No other dietary variable was significantly associated with
stroke incidence.
Multivariate Association Between Olive Oil Use and 6-Year Incident Stroke Olive Oil Use | Hazard Ratio (95% CI)* | P Value |
None | Reference | |
Moderate (with cooking or dressing) | 0.80 (0.53 - 1.20) | 28 |
Intensive (both cooking + dressing) | 0.59 (0.37 - 0.94) | .03 |
*Fully adjusted model.
CI = confidence interval The researchers also examined the association
between plasma oleic acid and stroke incidence in a subgroup of 1245
participants. In this group, there were 27 incident strokes during a
median follow-up of 5 years, including 20 ischemic and 7 hemorrhagic
strokes.
After adjustment for a wide variety of
potentially confounding factors, compared to those in the first tertile
of plasma oleic acid, those in the third tertile had a 73% reduction in
stroke risk (hazard ratio, 0.27; 95% CI, 0.08 - 0.90;
P = .03).
However, in the fully adjusted model using
"component analysis" of total saturated fatty acids, total omega-3 fatty
acids, and other dietary factors, the intensity of the association
between plasma oleic acid and stroke was reduced (hazard ratio, 0.25;
95% CI, 0.08 - 0.86;
P = .03).
One limitation of the study, Dr. Samieri and
colleagues say, is not being able to distinguish between the different
types of oil olive consumed. They also say the validity of plasma oleic
acid as an indirect marker of olive oil consumption remains to be
evaluated.
Olive Oil Pertinent to Neurologic Disease Too? In their commentary, Nikolaos Scarmeas, MD, from
Columbia University Medical Center in New York, New York, and Luc
Dauchet, MD, PhD, from Institut Pasteur de Lille in France, comment on
the study and the state of research on this topic.
They make the point that exploration of the
relation of the Mediterranean-type diet with neurologic diseases has
started "only very recently and has suggested potentially beneficial
associations for Alzheimer's disease, mild cognitive impairment,
cognitive decline, essential tremor, Parkinson disease, and stroke."
Although the current study suggests a protective
effect of olive oil in stroke, the authors caution against drawing any
firm conclusions from this study, until the observations "withstand the
trial of randomized intervention."
They point out that covariate adjustment "can
never be complete." Additionally, other potentially beneficial effects
of olive oil, not considered in the analyses, may be mediating the
association.
They also note that olive oil is not consumed in
isolation but with a whole host of potentially healthy foods. "To add
further to the complexity, the potentially beneficial biological
elements of olive oil are not clear."
Dr. Samieri received support from Institut
Carnot LISA (Lipides pour l'Industrie et la Sante [Lipids for Industry,
Safety and Health]). A complete list of disclosures for the other
authors can be found with the original article. Dr. Scarmeas receives
research support from the National Institutes of Health/National
Institute on Aging and the Alzheimer's Association. Dr. Dauchet has
disclosed no relevant financial relationships.
Extra Virginity: The Sublime and Scandalous World of Olive OilThe sacred history and profane present of a substance long seen as the essence of health and civilization.For
millennia, fresh olive oil has been one of life's necessities-not just
as food but also as medicine, a beauty aid, and a vital element of
religious ritual. Today's researchers are continuing to confirm the
remarkable, life-giving properties of true extra-virgin, and
"extra-virgin Italian" has become the highest standard of quality.
But what if this symbol of purity has become deeply corrupt? Starting with an explosive article in
The New Yorker,
Tom Mueller has become the world's expert on olive oil and olive oil
fraud-a story of globalization, deception, and crime in the food
industry from ancient times to the present, and a powerful indictment of
today's lax protections against fake and even toxic food products in
the United States. A rich and deliciously readable narrative,
Extra Virginity is also an inspiring account of the artisanal producers, chemical
analysts, chefs, and food activists who are defending the extraordinary
oils that truly deserve the name "extra-virgin." 25 black-and-white
illustrations
GET IT HERE
Order now and save $10.38
(40%)
Search inside this book
HERE.