Grapefruit pectin reduces cholesterol.

Grapefruit pectin reduces cholesterol

Researchers at the University of Florida in Gainesville reportthat about three tablespoons of grapefruit pectin a day--either in capsule form or as a nontoxic dietary additive--can lower blood-cholesterol levels an average of almost 8 percent. This reduction "is quite significant,' explains James Cerda, who directed the study, since "a 1 percent drop in cholesterol causes about a 2 percent drop in the risk of heart disease.'

Pectins are the main structural substances binding adjacentcell walls in plants. Especially prevalent in the rinds and fleshy parts of citrus and other fruits, they are often used as binders in jams and jellies. For 16 weeks, volunteers with high serum-cholesterol levels consumed unidentified capsules with each of their three major meals daily. Roughly half the 27 subjects got capsules containing a placebo; the others got capsules containing pure grapefruit pectin. Eight weeks into the experiment, each group was switched to the opposite capsule.

Although the average blood-cholesterol reduction for thoseon the pectin was 7.6 percent, levels in some dropped by as much as 19 percent. Moreover, 13 participants experienced a drop of more than 10 percent in low-density lipoprotein (LDL) levels while taking the pectin-capsule supplements. No one is sure what a reduction in LDLs--sometimes called the "bad' lipoproteins--heralds, Cerda says, "but this kind of drop can't hurt you, and most scientists would interpret such a drop as very favorable.'

Recently, Agriculture Department scientists reported thatvegetable pectins, like those in carrots, appear capable of comparable cholesterol lowering (SN: 6/27/87, p.409). However, Peter D. Hoagland, one of that study's authors, told SCIENCE NEWS it is unlikely that the pectins in these two studies would lower cholesterol in the same way. First, carrot and grapefruit pectins differ. Cerda's previous work suggests that the different effects may be due in part to the fact that grapefuit pectins contain more methyl (CH4) groups than do carrot pectins. Second, in Hoagland's study, the pectins used calcium to bind with bile acids as a route to lower cholesterol. Cerda's study, however, involved pure pectins and required no calcium to achieve similar ends.