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Hogere bloeddruk door herhaaldelijk gebruik van meeste oliën
om te bakken.
Deskundigen zeggen al langer dat van verschillende soorten
oliën om te bakken de een beter is dan de andere. Uit een Spaans onderzoek
blijkt nu dat alle oliën, met uitzondering van olijfolie bij herhaaldelijk
gebruik hogere bloeddruk veroorzaken. De gezonde voordelen van olijfolie worden
wel steeds minder bij herhaaldelijk gebruik.
Experts say that different
types of cooking oils are better for you than others, and a new study suggests
that the number of times you reuse cooking oils can also affect your health.
Spanish researchers found that
people whose kitchens contained any type of oil that had been reused many times
over were more likely to have high blood pressure than people whose cooking oils
were changed more frequently.
People who ate foods cooked
with sunflower oil also showed a higher risk of high blood pressure, while
consuming more olive oil appeared to protect people from high blood pressure.
Based on the findings, study
author Dr. Federico Soriguer of the Hospital Civil Plaza in Malaga recommends
that people cook with olive oil whenever possible, and discard any oils after
using them up to two or three times.
Although olive oil is
generally considered to be a healthy addition to meals, the findings suggest
that repeatedly reusing the oil may invalidate its favorable effects on health,
told Soriguer.
Many of the study participants
consumed the so- called Mediterranean diet, which features liberal use of olive
oil and has been linked with numerous health benefits.
Soriguer explained that
followers of the Mediterranean diet often use an "oil bath," or deep
fryer, to fry foods. However, when the same pot of oil is repeatedly reheated,
the oils begin to degrade, releasing substances known as polymers and polar
compounds that can become absorbed by food.
To measure the effects of
repeated use of cooking oils, Soriguer and his team measured levels of polymers
and polar compounds from oil samples taken directly from the kitchens of 538
adults.
The more polar compounds and
polymers present in oil samples taken from a participant's house -- a sign the
oil had been reused repeatedly -- the more likely it was that participant had
high blood pressure.
However, people whose blood
samples contained a relatively high concentration of fats predominantly found in
olive oil were less likely than others to have high blood pressure, Soriguer and
his team report in the American Journal of Clinical Nutrition.
Olive oil that had been
repeatedly reused tended to show a lower concentration of polymers and polar
compounds than other types of oil, suggesting that olive oil degrades more
slowly than other types, Soriguer explained.
He added that although the
Mediterranean diet features heavy use of olive oil, its rising cost is inducing
some followers to substitute other types of oil, or to use a mixture.
Soriguer noted that his
findings have induced him to make a personal change. "I have removed the
fryer out of my house," he revealed.
SOURCE: American Journal of Clinical Nutrition, 2004