Consumption of wheat aleurone-rich foods increases fasting plasma betaine and modestly decreases fasting homocysteine and LDL-cholesterol in adults.
There is strong evidence that whole-grain foods protect against heart disease. Although underlying mechanisms and components are unclear, betaine, found at high levels in wheat aleurone, may play a role. We evaluated the effects of a diet high in wheat aleurone on plasma betaine and related measures. In a parallel, single-blinded intervention study, 79 healthy participants (aged 45-65 y, BMI ≥ 25 kg/m(2)) incorporated either aleurone-rich cereal products (27 g/d aleurone) or control products balanced for fiber and macronutrients into their habitual diets for 4 wk. Fasting blood samples were taken at baseline and postintervention (4 wk) from participants. Compared with the control, the aleurone products provided an additional 279 mg/d betaine and resulted in higher plasma betaine (P < 0.001; intervention effect size: 5.2 μmol/L) and lower plasma total homocysteine (tHcy) (P = 0.010; -0.7 μmol/L). Plasma dimethylglycine and methionine, which are products of betaine-mediated homocysteine remethylation, were also higher (P < 0.001; P = 0.027) relative to control. There were no significant effects on plasma choline or B vitamins (folate, riboflavin, and vitamin B-6). However, LDL cholesterol was lower than in the control group (P = 0.037). We conclude that incorporating aleurone-rich products into the habitual diet for 4 wk significantly increases plasma betaine concentrations and lowers tHcy, which is attributable to enhanced betaine-homocysteine methyltransferase-mediated remethylation of homocysteine. Although this supports a role for betaine in the protective effects of whole grains, concomitant decreases in LDL suggest more than one component or mechanism may be responsible.
Price
Ruth K
RK
Northern Ireland Centre for Food and Health, University of Ulster, Coleraine, UK.
Keaveney
Edel M
EM
Hamill
Lesley L
LL
Wallace
Julie M W
JM
Ward
Mary
M
Ueland
Per M
PM
McNulty
Helene
H
Strain
J J
JJ
Parker
Michael J
MJ
Welch
Robert W
RW
D000328:Adult; D000368:Aged; D001622:Betaine / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D005215:Fasting; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D010919:Placebos; D016037:Single-Blind Method; D014908:Triticum / Q000737:chemistry*
D008078:Cholesterol, LDL; D010919:Placebos; D006710:Homocysteine; D001622:Betaine