By clicking “Accept”, you agree to the storing of cookies on your device to enhance site navigation, analyse site usage, and assist in our marketing efforts. View our Privacy Policy for more information.
Coffee & Health
Other coffee & health research

Association of maternal pre-pregnancy dietary intake with adverse maternal and neonatal outcomes: A systematic review and meta-analysis of prospective studies

Y Cui et al, 2021.
Critical Reviews in Food Science and Nutrition, published online.
October 19, 2021



We conducted a 2-sample Mendelian randomization study to assess the associations of cardiometabolic, lifestyle, and nutritional factors with varicose veins.

Methods and Results

Independent single-nucleotide polymorphisms associated with height (positive control), body mass index, type 2 diabetes, diastolic and systolic blood pressure, smoking, alcohol and coffee consumption, 7 circulating vitamins (A, B6, B9, B12, C, 25-hydroxyvitamin D, and E), and 5 circulating minerals (calcium, iron, magnesium, selenium, and zinc) at the genome-wide significance level were used as instrumental variables. Summary-level data for the genetic associations with varicose veins were obtained from the UK Biobank (8763 cases and 352 431 noncases) and the FinnGen consortium (13 928 cases and 153 951 noncases). Genetically predicted higher height, body mass index, smoking, and circulating iron levels were associated with an increased risk of varicose veins. The odds ratios (ORs) per 1-SD increase in the exposure were 1.34 (95% CI, 1.25-1.43) for height, 1.39 (95% CI, 1.27-1.52) for body mass index, 1.12 (95% CI, 1.04-1.22) for the prevalence of smoking initiation, and 1.24 (95% CI, 1.16-1.33) for iron. Higher genetically predicted systolic blood pressure and circulating calcium and zinc levels were associated with a reduced risk of varicose veins, whereas the association for systolic blood pressure did not persist after adjustment for genetically predicted height. The OR was 0.75 (95% CI, 0.62-0.92) per 1-SD increase in calcium levels and 0.97 (95% CI, 0.95-0.98) for zinc.


This study identified several modifiable risk factors for varicose veins.

More research

All research