Verzadigd en onverzadigde vetzuren en hart- en vaatziekte?*
Vis blijkt de beste vetzuren te leveren tegen hart- en vaatziektes, de meervoudige onverzadigde omega-3 vetzuren. Althans dat blijkt uit een muizenstudie. Na de omega-3 komen de omega-6 vetzuren, dan de verzadigde en daarna pas de enkelvoudig onverzadigde.
Fish,
Seafood Better Than Olive Oil, Nuts Against Heart Disease
Researchers have found that a diet rich in
fish, seafood, and grains -- also called polyunsaturated fats -- is better at
preventing heart disease than a diet containing olive oil, nuts, and avocados --
called monounsaturated fats. Although both types of fats are healthy, people
should probably include more of the first than the second in their diet to keep
a healthy heart, the scientists say.
Too much cholesterol has long been linked to increasing risks of developing
heart disease, but it has been less clear how the various dietary fats --
saturated, monounsaturated and polyunsaturated -- make people susceptible to the
disease.
Lawrence L. Rudel and colleagues developed a method to determine the effects of
the three types of dietary fats on acyl-coenzyme A, a key molecule involved in
the metabolism of fatty acids. The scientists found that mice fed diets high in
saturated and monounsaturated fat showed an increase in acyl-coenzyme A compared
to mice fed a diet enriched in polyunsaturated fat. These results suggest that
polyunsaturated fat is a more suitable replacement than monounsaturated fat for
dietary saturated fat, the scientists concluded.
Article: Monounsaturated fatty acyl-CoA is predictive of atherosclerosis in
human ApoB100 transgenic, LDLr -/- mice
Thomas A. Bell III, Martha D. Wilson, Kathryn Kelley, Janet K. Sawyer, and
Lawrence L. Rudel
Published in the Journal of Lipid Research (Vol. 48, No. 5)
ACAT2,
the enzyme responsible for the formation of cholesteryl esters
incorporated into apolipoprotein B-containing lipoproteins by the
small intestine and liver, forms predominantly cholesteryl oleate
from acyl-CoA and free cholesterol. The accumulation of cholesteryl
oleate in plasma lipoproteins has been found to be predictive of
atherosclerosis. Accordingly, a method was developed in which fatty
acyl-CoA subspecies could be extracted from mouse liver and
quantified. Analyses were performed on liver tissue from mice fed one
of four diets enriched with one particular type of dietary fatty
acid: saturated, monounsaturated, n-3 polyunsaturated, or n-6
polyunsaturated. We found that the hepatic fatty acyl-CoA pools
reflected the fatty acid composition of the diet fed. The highest
percentage of fatty acyl-CoAs across all diet groups was in
monoacyl-CoAs, and values were 36% and 46% for the n-3 and n-6
polyunsaturated diet groups and 55% and 62% in the saturated and
monounsaturated diet groups, respectively. The percentage of hepatic
acyl-CoA as oleoyl-CoA was also highly correlated to liver
cholesteryl ester, plasma cholesterol, LDL molecular weight, and
atherosclerosis extent. These data suggest that replacing
monounsaturated with polyunsaturated fat can benefit coronary heart
disease by reducing the availability of oleoyl-CoA in the substrate
pool of hepatic ACAT2, thereby reducing cholesteryl oleate secretion
and accumulation in plasma lipoproteins.
The American Society for Biochemistry and Molecular Biology is a nonprofit
scientific and educational organization with over 11,900 members in the United
States and internationally. Most members teach and conduct research at colleges
and universities. Others conduct research in various government laboratories,
nonprofit research institutions and industry. The Society's student members
attend undergraduate or graduate institutions.
Founded in 1906, the Society is based in Bethesda, Maryland, on the campus of
the Federation of American Societies for Experimental Biology. The Society's
purpose is to advance the science of biochemistry and molecular biology through
publication of the Journal of Biological Chemistry, the Journal of
Lipid Research, and Molecular and Cellular Proteomics, organization
of scientific meetings, advocacy for funding of basic research and education,
support of science education at all levels, and promoting the diversity of
individuals entering the scientific work force.
(Juni 2007) (Opm.
In de praktijk zit in gezonde voeding een combinatie van de
verschillende vetzuren met inderdaad een beetje
verzadigd en enkelvoudig onverzadigd en het meest de meervoudig onverzadigde,
doch wel in gelijke verhouding omega-3 en omega-6)