Potential effects of a sugar-sweetened beverages tax on socioeconomic inequalities in health

Background

Sugar-Sweetened Beverages (SSBs) taxes have been implemented in several countries, however, little is known on how an SSBs tax may impact on low and high socioeconomic groups differently. Therefore, the aim of this study was to gain insight into the perceptions of different stakeholder groups in the Netherlands on (1) the contribution of an SSBs tax to socioeconomic inequalities in diet and health and (2) the mechanisms via which an SSBs tax may influence these inequalities.

Methods

Semi-structured interviews were held in the Netherlands in March-May 2019 with 27 participants from the following stakeholder groups: health and consumer organisations, health professional associations, advisory bodies, scientists, trade organisations, policy makers, and politicians. Interview transcripts were analysed following a thematic content approach.

Results

Participants from all stakeholder groups indicated that an SSBs tax would have a larger impact on the budget and SSB consumption of lower socioeconomic groups. With that, an SSBs tax could have larger health benefits among lower socioeconomic groups as a result of cutting down on SSBs. A few participants - from science and a health professional association - discussed possible unwanted effects of an SSBs tax (e.g. lower socioeconomic groups may compensate their lower SSB consumption with other unhealthy behaviour). Some participants emphasised that an SSB tax should only be introduced when accompanied by other measures (e.g. educational efforts, offering healthy alternatives).

Conclusions

Our results imply that most stakeholders agree that an SSBs tax could contribute to a reduction of socioeconomic inequalities in diet and health. However, in order to be effective and to prevent that an SSBs tax leads to a widening of inequalities, it is important to carefully monitor behavioural changes of socioeconomic groups in response to an SSBs tax, and to implement an SSBs tax as part of a comprehensive policy approach.

Key messages

An SSBs tax could contribute to a reduction of socioeconomic inequalities in health, according to Dutch stakeholders. It is important to carefully monitor behavioural changes of socioeconomic groups in response to an SSBs tax, and to implement an SSBs tax as part of a comprehensive policy approach.

Public acceptability of a sugar-sweetened beverages tax and its associated factors in the Netherlands

Background

Public acceptability of a sugar-sweetened beverages (SSBs) tax is important for governments in the decision-making process. Therefore, the aim of the present study was to investigate the level of public acceptability of an SSBs tax and its associated factors.

Methods

Dutch adults representative of the Dutch population for age, sex, educational level and location (n = 500) completed an online self-administered questionnaire. The acceptability of an SSBs tax was measured on a 7-point Likert scale. Associations between acceptability and sociodemographic factors, body mass index, SSB consumption, and beliefs about effectiveness (9 items, e.g. 'An SSBs tax would reduce people's SSB consumption'), appropriateness (7 items), socioeconomic and economic benefit (5 items), implementation (1 item) and trust (3 items) were assessed using multivariable linear regression analyses.

Results

Of the participants, 40% supported and 43% opposed an SSBs tax in general. Moreover, 42% supported (43% opposed) an SSBs tax as a strategy to reduce overweight and 55% supported (32% opposed) an SSBs tax if revenue is used for health initiatives. Participants with a low educational level (B=-0.82;95%CI = [-1.31,-0.32]), overweight (B=-0.49;95%CI = [-0.89,-0.09]), moderate or high SSB consumption (B=-0.86;95%CI = [-1.30,-0.43] and B=-1.01;95%CI = [-1.47,-0.56], respectively) and households with adolescents (B=-0.57;95%CI = [-1.09,-0.05]) reported lower acceptability of an SSBs tax than their counterparts. Beliefs about effectiveness, appropriateness, socioeconomic and economic benefit, implementation and trust were associated with acceptability (P < 0.001).

Conclusions

Public acceptability of an SSBs tax tends to be higher if revenue is used for health initiatives. Sociodemographic factors, body mass index, SSB consumption and several beliefs about effectiveness, appropriateness, socioeconomic and economic benefit, implementation and trust are associated with acceptability.

Key messages

It should be considered to include a recommendation to use revenue for health initiatives in global guidelines for SSBs taxes. Targeting population subgroups with low levels of support might be an effective strategy for communication campaigns.

Prospective study on dietary intakes of folate, betaine, and choline and cardiovascular disease risk in women

OBJECTIVE

To investigate the association between dietary intakes of folate, betaine and choline and the risk of cardiovascular disease (CVD).

DESIGN

Prospective cohort study.

SUBJECTS

A total of 16 165 women aged 49-70 years without prior CVD. SUBJECTS were breast cancer screening participants in the PROSPECT-EPIC cohort, which is 1 of the 2 Dutch contributions to the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS

Each participant completed a validated food frequency questionnaire. Folate intake was calculated with the Dutch National Food Database. Betaine and choline intakes were calculated with the USDA database containing choline and betaine contents of common US foods. Data on coronary heart disease (CHD) events and cerebrovascular accident (CVA) events morbidity data were obtained from the Dutch Centre for Health Care Information.

RESULTS

During a median follow-up period of 97 months, 717 women were diagnosed with CVD. After adjustment, neither folate, nor betaine, nor choline intakes were associated with CVD (hazard ratios for highest versus lowest quartile were 1.23 (95% confidence interval 0.75; 2.01), 0.90 (0.69; 1.17), 1.04 (0.71; 1.53), respectively). In a subsample of the population, high folate and choline intakes were statistically significantly associated with lower homocysteine levels. High betaine intake was associated with slightly lower high-density lipoprotein (HDL)-cholesterol concentrations.

CONCLUSION

Regular dietary intakes of folate, betaine and choline were not associated with CVD risk in post-menopausal Dutch women. However, the effect of doses of betaine and choline beyond regular dietary intake--for example, via supplementation or fortification--remains unknown.

Effects of Betaine Intake on Plasma Homocysteine Concentrations and Consequences for Health

High plasma concentrations of homocysteine may increase risk of cardiovascular disease. Folic acid lowers plasma homocysteine by 25% maximally, because 5-methyltetrahydrofolate is a methyl donor in the remethylation of homocysteine to methionine. Betaine (trimethylglycine) is also a methyl donor in homocysteine remethylation, but effects on homocysteine have been less thoroughly investigated. Betaine in high doses (6 g/d and higher) is used as homocysteine-lowering therapy for people with hyperhomocysteinemia due to inborn errors in the homocysteine metabolism. Betaine intake from foods is estimated at 0.5-2 g/d. Betaine can also be synthesized endogenously from its precursor choline. Studies in healthy volunteers with plasma homocysteine concentrations in the normal range show that betaine supplementation lowers plasma fasting homocysteine dose-dependently to up to 20% for a dose of 6 g/d of betaine. Moreover, betaine acutely reduces the increase in homocysteine after methionine loading by up to 50%, whereas folic acid has no effect. Betaine doses in the range of dietary intake also lower homocysteine. This implies that betaine can be an important food component that attenuates homocysteine rises after meals. If homocysteine plays a causal role in the development of cardiovascular disease, a diet rich in betaine or choline might benefit cardiovascular health through its homocysteine-lowering effects. However betaine and choline may adversely affect serum lipid concentrations, which can of course increase risk of cardiovascular disease. However, whether the potential beneficial health effects of betaine and choline outweigh the possible adverse effects on serum lipids is as yet unclear.

Consumption of high doses of chlorogenic acid, present in coffee, or of black tea increases plasma total homocysteine concentrations in humans

BACKGROUND

In population studies, high intakes of coffee are associated with raised concentrations of plasma homocysteine, a predictor of risk of cardiovascular disease. Chlorogenic acid is a major polyphenol in coffee; coffee drinkers consume up to 1 g chlorogenic acid/d.

OBJECTIVE

We studied whether chlorogenic acid affects plasma total homocysteine concentrations in humans. For comparison we also studied the effects of black tea rich in polyphenols and of quercetin-3-rutinoside, a major flavonol in tea and apples.

DESIGN

In this crossover study, 20 healthy men and women ingested 2 g (5.5 mmol) chlorogenic acid, 4 g black tea solids containing approximately 4.3 mmol polyphenols and comparable to approximately 2 L strong black tea, 440 mg (0.7 mmol) quercetin-3-rutinoside, or a placebo daily. Each subject received each of the 4 treatments for 7 d, in random order.

RESULTS

Total homocysteine in plasma collected 4-5 h after supplement intake was 12% (1.2 micromol/L; 95% CI: 0.6, 1.7) higher after chlorogenic acid and 11% (1.1 micromol/L; 95% CI: 0.6, 1.5) higher after black tea than after placebo. Total homocysteine in fasting plasma collected 20 h after supplement intake was 4% (0.4 micromol/L; 95% CI: 0.0, 0.8) higher after chlorogenic acid and 5% (0.5 micromol/L; 95% CI: 0.0, 0.9) higher after black tea than after placebo. Quercetin-3-rutinoside did not significantly affect homocysteine concentrations.

CONCLUSIONS

Chlorogenic acid, a compound in coffee, and black tea raise total homocysteine concentrations in plasma. Chlorogenic acid could be partly responsible for the higher homocysteine concentrations observed in coffee drinkers. Whether these effects on homocysteine influence cardiovascular disease risk remains to be established.

Red wine is a poor source of bioavailable flavonols in men

Red wine is a source of polyphenolic antioxidants, of which flavonols such as quercetin are representatives. Red wine might therefore prevent LDL oxidation and atherosclerosis. However, data on the bioavailability of flavonols from wine are lacking. Therefore, we compared the bioavailability of flavonols, especially quercetin, from red wine with that from the major dietary sources, yellow onions and black tea. Twelve healthy men consumed 750 mL red wine, 50 g fried onions or 375 mL of black tea, each for 4 d in random order. These supplements provided similar amounts of quercetin (14-16 mg). There was a washout period of 3 d between each period of supplementation. The plasma quercetin concentration after the consumption of wine was lower than that after onions (P: < 0.05) and not different from that after tea. Urinary excretion of quercetin after wine did not differ from that after onions and was higher than that after tea (P: < 0.05). We conclude that flavonols from red wine are absorbed. However, because one glass of red wine provides fewer available flavonols than one portion of onions or one glass of tea, red wine appears to be a poorer source of flavonols than these other two sources.

Chlorogenic acid and caffeic acid are absorbed in humans

Chlorogenic acid, an ester of caffeic acid and quinic acid, is a major phenolic compound in coffee; daily intake in coffee drinkers is 0.5-1 g. Chlorogenic acid and caffeic acid are antioxidants in vitro and might therefore contribute to the prevention of cardiovascular disease. However, data on the absorption of chlorogenic acid and caffeic acid in humans are lacking. We determined the absorption of chlorogenic acid and caffeic acid in a cross-over study with 4 female and 3 male healthy ileostomy subjects. In such subjects, degradation by the colonic microflora is minimal and absorption can be calculated as the amount ingested minus the amount excreted in ileostomy effluent. The ileostomy subjects ingested 2.8 mmol chlorogenic acid and 2.8 mmol caffeic acid on separate days in random order and subsequently collected ileostomy fluid and urine for 24 h. Absorption of chlorogenic acid was 33 +/- 17% (mean +/- SD) and of caffeic acid 95 +/- 4%. Traces of the ingested chlorogenic acid and 11% of the ingested caffeic acid were excreted in urine. Thus, one third of chlorogenic acid and almost all of the caffeic acid were absorbed in the small intestine of humans. This implies that part of chlorogenic acid from foods will enter into the blood circulation, but most will reach the colon.

Bioavailabilities of quercetin-3-glucoside and quercetin-4'-glucoside do not differ in humans

The flavonoid quercetin is an antioxidant which occurs in foods mainly as glycosides. The sugar moiety in quercetin glycosides affects their bioavailability in humans. Quercetin-3-rutinoside is an important form of quercetin in foods, but its bioavailability in humans is only 20% of that of quercetin-4'-glucoside. Quercetin-3-rutinoside can be transformed into quercetin-3-glucoside by splitting off a rhamnose molecule. We studied whether this 3-glucoside has the same high bioavailability as the quercetin-4'-glucoside. To that end we fed five healthy men and four healthy women (19-57 y) a single dose of 325 micromol of pure quercetin-3-glucoside and a single dose of 331 micromol of pure quercetin-4'-glucoside and followed the plasma quercetin concentrations. The bioavailability was the same for both quercetin glucosides. The mean peak plasma concentration of quercetin was 5.0+/-1.0 micromol/L (+/-SE) after subjects had ingested quercetin-3-glucoside and 4.5+/-0.7 micromol/L after quercetin-4'-glucoside consumption. Peak concentration was reached 37 +/-12 min after ingestion of quercetin-3-glucoside and 27+/-5 min after quercetin-4'-glucoside. Half-life of elimination of quercetin from blood was 18.5+/-0.8 h after ingestion of quercetin-3-glucoside and 17.7+/-0.9 h after quercetin-4'-glucoside. We conclude that quercetin glucosides are rapidly absorbed in humans, irrespective of the position of the glucose moiety. Conversion of quercetin glycosides into glucosides is a promising strategy to enhance bioavailability of quercetin from foods.