Scientific Opinion on the substantiation of health claims related to betaine
and contribution to normal homocysteine metabolism (ID 4325) pursuant
to Article 13(1) of Regulation (EC) No 1924/2006[sup]1[/sup]
EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA)2, 3
European Food Safety Authority (EFSA), Parma, Italy
1. Charakterystyka żywności / składnika
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Betaina przyczynia się do prawidłowego metabolizmu homocysteiny
The food constituent that is the subject of the health claim is betaine.
Betaine, i.e. N,N,N-trimethylglycine, is formed by oxidation of choline in mammals including humans, and can also be found in food. Dietary intakes of betaine range approximately from 0.5 to 2 g per day. Betaine is measurable in foods by established methods.
The Panel considers that the food constituent, betaine, which is the subject of the health claim, is sufficiently characterised.
3. Naukowe uzasadnienia wpływu na zdrowie człowieka - Udział w prawidłowym metabolizmie homocysteiny
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Betaina przyczynia się do prawidłowego metabolizmu homocysteiny
Most of the references provided in the consolidated list were narrative reviews or textbooks that did not provide original scientific data that could be used to substantiate the claimed effect. One meta-analysis was not related to betaine. The Panel considers that no conclusions can be drawn from these references for the scientific substantiation of the claimed effect.
It is well established that betaine can act as a methyl donor in the remethylation of homocysteine in the liver by the enzyme betaine-homocysteine methyltransferase.
In a randomised, double-blind, placebo-controlled intervention study, 42 obese subjects (28 women) treated with a hypocaloric diet were randomly assigned to a betaine-supplemented group (6 g/day) or a control group given placebo for 12 weeks after a 4-week run-in period aiming at energy balance (Schwab et al., 2002). Plasma homocysteine concentrations significantly decreased in the betaine group compared to placebo (p=0.030 for the interaction of time and treatment). Total and LDL-cholesterol concentrations significantly increased in the betaine group compared to placebo (p=0.009 and p=0.011 for the interaction of time and treatment, respectively). No significant differences were observed between groups with respect to changes in body weight or body fat.
Olthof et al. (2003) investigated the effect of betaine supplementation in the range of dietary intakes on fasting and post-methionine-loading plasma homocysteine concentrations in a double-blind, placebo-controlled, randomised intervention. Four groups of 19 healthy subjects with the highest
plasma total homocysteine concentrations (range 8.4 to 22.2 mol/L) among the 132 subjects screened (but within the normal range) consumed either 0.75 g of betaine (plus 2.25 g of placebo), 1.5 g of betaine (plus 1.5 g of placebo), 3 g of betaine or 3 g of placebo twice daily (at breakfast and evening meal) dissolved in a glass of water. Daily doses of anhydrous betaine were 0, 1.5, 3 and 6 g in the four intervention groups, respectively. A methionine-loading test was performed during the run-in period (day 3), on day 1 of betaine supplementation, and after 2 and 6 weeks of betaine supplementation. Blood samples were collected at these time points after an overnight fast and six hours after the methionine load. Fasting plasma concentrations of homocysteine after 6 weeks of daily betaine intakes of 1.5, 3 and 6 g were 12 % (p<0.01), 15 % (p<0.002) and 20 % (p<0.0001) lower than in the placebo group, respectively. The increase in plasma homocysteine concentrations after the methionine-loading on the first day of betaine supplementation with 1.5, 3 and 6 g of betaine per day was 16 % (p<0.06), 23 % (p<0.008) and 35 % (p<0.0002) lower than in the placebo group, respectively, and after 6 weeks of supplementation it was 23 % (p<0.02), 30 % (p<0.003) and 40 % (p<0.0002) lower than in the placebo group, respectively.
A randomised, double-blind, cross-over intervention in humans was designed to assess the pharmacokinetics of orally administered betaine and its acute effect on plasma homocysteine concentrations (Schwab et al., 2006). A total of 10 normal weight volunteers (three females) received betaine at doses of 1, 3 and 6 g on single occasions seven days apart mixed with 150 mL of orange juice after a 12 h overnight fast. A significant, dose-dependant, inverse relationship was observed between the intake of betaine and blood concentrations of homocysteine. The Panel notes that no conclusions can be drawn from this study on the sustained effects of betaine consumption on blood homocysteine concentrations, but that it supports the findings observed in the longer term studies described above.
The Panel notes that whereas doses of 6 g per day of betaine appear to increase total and LDL-cholesterol concentrations in the blood (Olthof et al., 2005; Schwab et al., 2002), this effect does
not appear to be significant at lower daily doses ( 4 g per day) (Olthof et al., 2005; Schwab et al., 2010).
In weighing the evidence, the Panel took into account that betaine can act as a methyl donor in the remethylation of homocysteine in the liver by the enzyme betaine-homocysteine methyltransferase, and that human intervention studies consistently show a significant decrease in plasma concentrations of homocysteine following betaine administration.
The Panel concludes that a cause and effect relationship has been established between the consumption of betaine and contribution to normal homocysteine metabolism.
