Soybean amplifies the hypohomocysteinemic effect of betaine and improves its hypercholesterolemic effect.
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
betaine | decrease | plasma Hcy concentration | rats fed the casein-based diet | - | decreased | #1 |
betaine | decrease | plasma Hcy concentration | rats fed the SB-based diet | - | decreased | #2 |
betaine | decrease | plasma Hcy concentration | rats fed the SPI-based diet | - | decreased | #3 |
SB-based diet | decrease | betaine-induced elevation of plasma cholesterol | rats | - | decreased | #4 |
SPI-based diet | no change | betaine-induced elevation of plasma cholesterol | rats | - | was not decreased | #5 |
soy lecithin (SL) | no change | increased concentration of plasma cholesterol by betaine feeding | rats fed the SPI-based diet | - | was not prevented | #6 |
soybean fiber (SF) | no change | increased concentration of plasma cholesterol by betaine feeding | rats fed the SPI-based diet | - | was not prevented | #7 |
combination of SL and SF | decrease | increased concentration of plasma cholesterol by betaine feeding | rats fed the SPI-based diet | - | was prevented | #8 |
combination of SL and SF | increase | fecal excretion of bile acids | rats fed the SPI-based diet | - | was associated with increased | #9 |
We examined whether soybean (SB) and soy protein isolate (SPI) can prevent the betaine-induced elevation of plasma cholesterol as well as maintain the betaine-induced reduction of plasma Hcy concentration. Rats were fed casein-, SB-, or SPI-based diet with or without betaine; SPI-based diet with betaine containing soybean fiber (SF) or soy lecithin (SL) or the combination of SF and SL. Plasma Hcy concentration was decreased by feeding betaine to rats fed the casein-, SB-, and SPI-based diets. Betaine-induced elevation of plasma cholesterol was decreased by feeding the SB-based diet compared with the casein-based diet, but was not decreased by feeding the SPI-based diet. In rats fed the SPI-based diet, the increased concentration of plasma cholesterol by betaine feeding was not prevented by independent addition of SL or SF, but was prevented by a combination of SL and SF, and was associated with increased fecal excretion of bile acids.