New science reveals risk behind saturated fats

A diet high in cream, cheese and other saturated fat rich foods can
influence the uptake of bad cholesterol to the arteries, confirms
new research.

Scientists are already aware that a diet high in saturated fat increases plasma cholesterol levels (LDL levels) and atherosclerosis. But it was not known how dietary fats directly affect uptake of LDL cholesterol ester, and whether selective uptake was a factor.

While we need some fat in our diet, because it helps the body absorb some vitamins, is a good source of energy and a source of the essential fatty acids that the body can not make itself, having too much saturated fat can increase the amount of cholesterol in the blood, which increases the chance of developing heart disease.

Saturated fats are found in a wide variety of foods, including :meat products, meat pies, sausages; hard cheese; butter and lard; pastry; cakes and biscuits; cream, soured cream and crème fraîche; coconut oil, coconut cream or palm oil.

Scientists at Columbia University in the US now suggest that diet can influence delivery of LDL cholesterol ester to arteries via selective uptake, affecting cholesterol depostion and atherogenesis.

Selective uptake is a process whereby LDL cholesterol esters can be delivered to cell independent of the full LDL molecule.

For the study, mice that are relatively atherosclerosis resistant (C57BL/6) or susceptible to atherosclerosis (apoE-/-) were fed a chow or a saturated fat diet and then injected with double radiolabelled or fluorescent-labelled human LDL, to independently trace LDL-CE core and whole-particle uptake, respectively.

"Our results show that a SAT [saturated-fat] diet increased contributions of selective uptake to total arterial LDL- cholesteryl ester delivery in C57BL/6 and apoE-/- mice," report the researchers.

The saturated fat-rich diet increased plasma fatty acid and cholesterol levels.

These studies suggest that arterial LDL-CE delivery via SU [selective uptake] can be an important mechanism in vivo, and that dietary influences on arterial LPL levels and atherogenesis modulate arterial LDL-CE delivery, cholesterol deposition, and SU, they conclude.

Full findings are posted in the Journal of Clinical Nutrition, published online on 21 July.