Effect of Betaine, Serine and Folic Acid on Vascular Function in Healthy Volunteers

Wageningen Centre for Food Sciences

Status

Completed

Conditions

Healthy

Cardiovascular Diseases

Treatments

Procedure: supplementation with betaine, serine, and folic acid

Study type

Interventional

Funder types

Other

Identifiers

NCT00126347

P02.0470L

Details and patient eligibility

About

The purpose of this study is to determine whether reducing the increase in plasma homocysteine concentrations following an oral methionine load affects vascular function in healthy volunteers, irrespective of the homocysteine-lowering agent.

Full description

A high plasma homocysteine is a potential risk factor for cardiovascular disease and death. However, it remains uncertain whether homocysteine per se, low status of folate, or other factors related to methionine metabolism are involved in the pathogenesis of cardiovascular disease. Previous studies have shown that a high concentration of homocysteine in blood is related to an impaired vascular function in the arteries, an indicator of cardiovascular disease risk. Virtually all intervention trials used folic acid as a homocysteine-lowering agent, which may however affect vascular function through mechanisms not related to homocysteine. The researchers investigated whether reduction in homocysteine concentrations following a methionine load, via supplementation with serine, betaine or folic acid improves vascular function in healthy volunteers, in order to distinguish between effects of folic acid and of homocysteine-lowering per se.

Comparison: The effects of supplementation with serine, folic acid and betaine (all together with an oral methionine load) were compared to the effects of a placebo (together with a methionine load) on plasma homocysteine concentrations and on vascular function following methionine loading in healthy volunteers.

Sex

All

Ages

50 to 70 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

Apparently healthy
Women postmenopausal: two or more years after last menstruation. If the uterus was surgically removed, the women must be 55 years or older
Normal blood values for: hematology, total homocysteine, lipids, vitamin B6, vitamin B12, folic acid, liver enzymes, creatinine
Absence of protein and glucose in urine sample
Body mass index (BMI) between 18 and 30 kg/m2
Good ultrasound visibility of the brachial artery, judged by a sonographer.
Willing not to use supplements containing B-vitamins, antioxidant vitamins (A, beta-carotene, C and E) or n-3 fatty acids/fish oil supplements from screening day (>2 months before start of the study) until end of study
Willing not to be blood or plasmapherese donor from 4 weeks before the screening day, and 4 weeks before the start of the study until the end of study

Exclusion criteria

Any chronic or acute disease (e.g. diabetes, renal disease, inflammation)
Current, or history of cardiovascular disease
Hypertension
Medical history or surgical events know to interfere with the study
Fasting plasma total homocysteine > 26 micromol/L
Alcohol consumption: women >21 consumptions/week; men >28 consumptions/week
Weight loss or gain > 2 kg in the month prior to screening
Any special diet (prescribed, slimming, macrobiotic or total vegetarian. Sole exclusion of meat and fish from a otherwise 'normal' western diet is allowed).
Lactose intolerance
Use of supplements containing B-vitamins more than once weekly in the period from 3 months before the screening day
Participation in any other trial up to 3 months before this study
Use of medication known to interfere with the study outcome.