Literature Review: Pregnant and breastfeeding ... - Eat For Health

Reference Koebnick 2004Dietary patterns Vegetarian diet: no meat or meat products; plant based diet (high consumption of raw vegetables (> 100 g/d), preference for wholegrain products (ratioof refined grain products/wholegrain products < 0.95))Low meat diet: limited meat consumption (meat < 300 g/week and meat products < 105 g/week); plant based diet (high consumption of raw vegetables(> 100 g/d), preference for wholegrain products (ratio of refined grain products/wholegrain products < 0.95))Western diet (control group): similar to diet of average German population (mainly refined grain products (ratio of refined grain products/wholegrainproducts > 1.05) and > 300 g meat and 105 g meat products per week and < 100g unheated vegetables per dayStudy typeProspective cohort (3 concurrent comparisons)Level of evidence II (aetiology)SettingErlangen, GermanyFundingEden Foundation, Stoll VITA Foundation, GermanyParticipants109 healthy pregnant women with less than 4 prior pregnancies at any stage of pregnancy (recruited by advertisements in health magazines and bygynaecologists from 1995 to 1997);Participants in the vegetarian and low meat diet groups could not have changed their diet substantially for at least three years; participants in the controlgroup were only included if they did not follow any special dietBaseline comparisons Vegetarians and low meat eaters had lower prepregnancy BMIs than the control groupSee Confounding belowTimingFFQ when recruited, recording usual dietary intake before pregnancy;Information on dietary intake and blood samples were collected at 9-12 weeks, 20-22 weeks, and 36-38 weeks gestationComparison Vegetarian (ovo-lacto) diet: n = 27Low meat diet: n = 43Western diet (control group): n = 39OutcomesMaternal B-12 concentrationsResultsSerum B-12 concentrations, pmol/L (medians with 25 th and 75 th percentiles)Trimester ovo-lacto vegetarian Low meat diet Western diet1 179 (100-317); n=16 209 (160-293); n=29 249 (201-310); n=312 176 (102-271); n=25 215 (151-269); n=42 238 (190-305); n=393 127 (90-184); n=19 164 (125-208); n=34 169 (141-213); n=38Ovo-lacto vegetarian versus western diet: p < 0.001Low meat versus western diet: p = 0.05FollowupConfoundingRisk of biasRelevanceOther commentsLow serum vitamin B-12 in at least trimester (with western diet group as reference):Ovo-lacto vegetarian diet: OR 3.9 95% CI 1.9 to 6.1Low meat diet: OR 1.8 95% CI 1.0 to 3.9To birthAdjusted for supplemental vitamin B-12,maternal age and first, second or third trimesterLow-moderate risk of bias: risk of selection bias from advertising in health magazines; reasons for missing B-12 measurements not reportedLikely to be similar to Australian women; perhaps higher use of supplements in GermanyOther possible confounders e.g. from choosing a vegetarian lifestyleB-12 status is a risk factor for neural tube defectsPregnancy and Breastfeeding Dietary Patterns39