Exposure and effectiveness of phytosterol/-stanol-enriched margarines

Knowledge as to cholesterol reduction and use of phytosterol-enriched dietary foods in the general population: Insights from the Hamburg City Health Study

BACKGROUND AND AIMS

Dietary approaches to lowering cholesterol appear to be common knowledge. However, the marketing of phytosterol-enriched products and their recommendation by guidelines for individuals at increased risk of cardiovascular disease have given rise to concern, since phytosterols may be atherogenic and inappropriately used by healthy individuals of higher social status at low cardiovascular risk. Hence, we have investigated awareness of cholesterol lowering lifestyle measures and attitudes towards consumption of phytosterol-enriched foods.

METHODS

Data from validated questionnaires supplemented by queries on cholesterol lowering and phytosterol-enriched products were analyzed using data of 7223 participants of the Hamburg City Health Study, an ongoing cohort study of the general population aged 45-74 years.

RESULTS

95.9% of the participants agreed that lifestyle may lower cholesterol and 76.6% claimed knowledge of measures that lower plasma cholesterol. As to effective approaches, 80.2% suggested physical activity, 67.8% reducing dietary fat, followed by sugar-sweetened beverages or stress, increasing water consumption, or dietary fiber and only 16.2% stated statins and 9.3% phytosterol-enriched products. Compared to nonusers, the 2.0% female and 2.8% male individuals regularly using phytosterol-enriched products had a lower educational status, higher cardiovascular risk, but no difference in income and were characterized by adverse dietary habits. The study has been registered in ClinicalTrial.gov (NCT03934957).

CONCLUSIONS

In the general population awareness of hypercholesterolemia is high but knowledge on how to lower plasma cholesterol does not necessarily follow scientific evidence. There is a trend towards the use of phytosterol-enriched products by individuals at increased cardiovascular risk independent of income.

The effectiveness and cost-effectiveness of plant sterol or stanol-enriched functional foods as a primary prevention strategy for people with cardiovascular disease risk in England: a modeling study

This study appraises the effectiveness and cost-effectiveness of consumption of plant sterol-enriched margarine-type spreads for the prevention of cardiovascular disease (CVD) in people with hypercholesterolemia in England, compared to a normal diet. A nested Markov model was employed using the perspective of the British National Health Service (NHS). Effectiveness outcomes were the 10-year CVD risk of individuals with mild (4-6 mmol/l) and high (above 6 mmol/l) cholesterol by gender and age groups (45-54, 55-64, 65-74, 75-85 years); CVD events avoided and QALY gains over 20 years. This study found that daily consumption of enriched spread reduces CVD risks more for men and older age groups. Assuming 50% compliance, 69 CVD events per 10,000 men and 40 CVD events per 10,000 women would be saved over 20 years. If the NHS pays the excess cost of enriched spreads, for the high-cholesterol group, the probability of enriched spreads being cost-effective is 100% for men aged over 64 years and women over 74, at £20,000/QALY threshold. Probabilities of cost-effectiveness are lower at younger ages, with mildly elevated cholesterol and over a 10-year time horizon. If consumers bear the full cost of enriched spreads, NHS savings arise from reduced CVD events.

The development of phytosterol-lecithin mixed micelles and organogels

We demonstrate that by mixing the phytosterol-ester oryzanol with lecithin in an organic solvent, both components may be dispersed at much higher concentrations than they may be individually. Dynamic light scattering and molecular dynamics simulations show that the mechanism for this is the formation of r ∼ 4 nm mixed micelles. Infrared spectroscopy and simulations suggest that these micelles are formed due in part to hydrogen bonding of the phosphate of the lecithin head-group, and the phenol group of the oryzanol. Rheology shows that by mixing these materials at an equimolar ratio, highly viscous suspensions are created. Furthermore, by adding water to these samples, a solid-like gel may be formed which offers mechanical properties close to those desired for a margarine type spread, whilst still solubilizing the oryzanol.

Materiality matters: Blurred boundaries and the domestication of functional foods

Previous scholarship on novel foods, including functional foods, has suggested that they are difficult to categorise for both regulators and users. It is argued that they blur the boundary between ‘food' and ‘drug' and that uncertainties about the products create ‘experimental' or ‘restless' approaches to consumption. We investigate these uncertainties drawing on data about the use of functional foods containing phytosterols, which are licensed for sale in the EU for people wishing to reduce their cholesterol. We start from an interest in the products as material objects and their incorporation into everyday practices. We consider the scripts encoded in the physical form of the products through their regulation, production and packaging and find that these scripts shape but do not determine their use. The domestication of phytosterols involves bundling the products together with other objects (pills, supplements, foodstuffs). Considering their incorporation into different systems of objects offers new understandings of the products as foods or drugs. In their accounts of their practices, consumers appear to be relatively untroubled by uncertainties about the character of the products. We conclude that attending to materials and practices offers a productive way to open up and interrogate the idea of categorical uncertainties surrounding new food products.

LDL-cholesterol-lowering effect of plant sterols and stanols across different dose ranges: a meta-analysis of randomised controlled studies

Phytosterols (PS, comprising plant sterols and plant stanols) have been proven to lower LDL-cholesterol concentrations. The dose-response relationship for this effect has been evaluated in several meta-analyses by calculating averages for different dose ranges or by applying continuous dose-response functions. Both approaches have advantages and disadvantages. So far, the calculation of averages for different dose ranges has not been done for plant sterols and stanols separately. The objective of the present meta-analysis was to investigate the combined and separate effects of plant sterols and stanols when classified into different dose ranges. Studies were searched and selected based on predefined criteria. Relevant data were extracted. Average LDL-cholesterol effects were calculated when studies were categorised by dose, according to random-effects models while using the variance as weighing factor. This was done for plant sterols and stanols combined and separately. In total, 124 studies (201 strata) were included. Plant sterols and stanols were administered in 129 and fifty-nine strata, respectively; the remaining used a mix of both. The average PS dose was 2.1 (range 0.2-9.0) g/d. PS intakes of 0.6-3.3 g/d were found to gradually reduce LDL-cholesterol concentrations by, on average, 6-12%. When plant sterols and stanols were analysed separately, clear and comparable dose-response relationships were observed. Studies carried out with PS doses exceeding 4 g/d were not pooled, as these were scarce and scattered across a wide range of doses. In conclusion, the LDL-cholesterol-lowering effect of both plant sterols and stanols continues to increase up to intakes of approximately 3 g/d to an average effect of 12%.

Cardiovascular risk and lifestyle habits of consumers of a phytosterol-enriched yogurt in a real-life setting

BACKGROUND

Data on the characteristics of consumers of phytosterol-enriched products and modalities of consumption are rare. An observational study evaluating the lifestyle characteristics and cardiovascular risk (CVR) profile of phytosterol-enriched yogurt consumers was performed in France.

METHODS

Subjects were recruited from general practitioners via electronic medical records. Data were obtained from 358 consumers and 422 nonconsumers with 519 subject questionnaires (243 consumers, 276 nonconsumers; 67% response).

RESULTS

Consumers had more cardiovascular risk factors than nonconsumers (2.0 ± 1.5 versus 1.6 ± 1.4; P < 0.001) and a higher 10-year SCORE cardiovascular risk (1.8 ± 2.0% versus 1.6 ± 2.2%; P = 0.008); they were older (P = 0.030) and had a higher incidence of hypercholesterolaemia (P < 0.001) and family or personal history of heart disease (P = 0.023/P = 0.026, respectively). Among consumers not on cholesterol-lowering medication, 99% were eligible for lifestyle interventions and 56% were eligible for lipid-lowering drug according to European guidelines. Consumers had a healthier lifestyle, with a higher (fruit/vegetable - saturated fatty acid) score than nonconsumers (P = 0.035), focused more on low-intensity leisure activity (P = 0.023), spent more time travelling by foot or bicycle (P = 0.012) and were more likely to act to reduce CVR. Phytosterol-enriched yogurt intake conformed to recommendations in two-thirds of consumers and was mainly consumed because of concerns over cholesterol levels and CVR.

CONCLUSIONS

The higher cardiovascular disease risk profile of phytosterol-enriched yogurt consumers corresponds to a population for whom European guidelines recommend lifestyle changes to manage cholesterol. The coherence of the data in terms of risk factors, adherence to lifestyle recommendations and the consumption of phytosterol-enriched yogurt conforming to recommendations reflects a health-conscious consumer population.

A spread containing bioactive milk peptides Ile-Pro-Pro and Val-Pro-Pro, and plant sterols has antihypertensive and cholesterol-lowering effects

Lifestyle intervention is recommended as the primary treatment for mild hypertension and hypercholesterolemia. We studied the effects of a spread containing bioactive milk peptides IPP and VPP, as well as plant sterols, on cardiovascular risk factors in 104 hypertensive, hypercholesterolemic subjects in a randomised, placebo-controlled double-blind intervention. Middle-aged subjects consumed 20 g day⁻¹ of a spread containing 4.2 mg of IPP and VPP as well as 2 g of plant sterols for 10 weeks after a 2 week run-in period. Blood pressure was measured at home 3 times a week. Office blood pressure and 24 h ambulatory blood pressure measurements were performed at the end of the run-in and intervention periods. Blood samples were analysed for serum lipids, plasma glucose and inflammation markers. A significant decrease (-4.1 mmHg vs. -0.5 mmHg, p = 0.007) in systolic blood pressure was seen in the active group, compared to placebo at home measurements. Office blood pressure and 24 h nighttime or daytime ambulatory systolic or diastolic pressure did not differ between the groups. Total (-0.16 vs. 0.25 mmol l⁻¹, p = 0.005) and LDL cholesterol (-0.16 vs. 0.18 mmol l⁻¹, p = 0.006) decreased significantly in the active group compared to the placebo. No significant differences between groups were seen for plasma glucose or inflammation markers. The results thus suggest that milk peptides IPP and VPP and plant sterols, in a low-fat spread matrix, produce a clinically significant reduction in systolic blood pressure as well as serum total and LDL cholesterol without adverse effects. Functional foods that affect 2 major risk factors offer a safe and convenient way to reduce the risk of cardiovascular disease by supporting lifestyle intervention.

Worldwide consumption of functional foods: a systematic review

The present systematic review was performed to assess differences in the worldwide consumption of functional foods. The Medline and Scopus databases were used to search the existing literature. A total of 23 studies that examined functional food consumption and included information on the country, gender, and age of participants were identified for inclusion. The studies investigated a variety of functional foods, and analysis of the findings indicates it is not possible to reach generalized conclusions about consumer choices regarding functional food consumption. Gender, age, level of education, and personal health status may each predict consumption of one or more functional foods. Further studies aimed at gaining a better understanding of the factors that influence consumption of functional foods are needed.

Modelling approach to simulate reductions in LDL cholesterol levels after combined intake of statins and phytosterols/-stanols in humans

BACKGROUND

To examine the effects on LDL cholesterol of the combined use of statins and phytosterols/-stanols, in vivo studies and clinical trials are necessary. However, for a better interpretation of the experimental data as well as to possibly predict cholesterol levels given a certain dosing regimen of statins and phytosterols/-stanols a more theoretically based approach is helpful. This study aims to construct a mathematical model to simulate reductions in low-density lipoprotein (LDL) cholesterol in persons who combine the use of statins with a high intake of phytosterols/-stanols, e.g. by the use of functional foods.

METHODS AND RESULTS

The proposed model includes the cholesterol pool size in the liver and serum levels of very low-density lipoprotein (VLDL) cholesterol. Both an additional and a multiplicative effect of phytosterol/-stanol intake on LDL cholesterol reduction were predicted from the model. The additional effect relates to the decrease of dietary cholesterol uptake reduction, the multiplicative effect relates to the decrease in enterohepatic recycling efficiency, causing increased cholesterol elimination through bile. From the model, it was demonstrated that a daily intake of 2 g phytosterols/-stanols reduces LDL cholesterol level by about 8% to 9% on top of the reduction resulting from statin use. The additional decrease in LDL cholesterol caused by phytosterol/-stanol use at the recommended level of 2 g/d appeared to be similar or even greater than the decrease achieved by doubling the statin dose.

CONCLUSION

We proposed a simplified mathematical model to simulate the reduction in LDL cholesterol after separate and combined intake of statins and functional foods acting on intestinal (re)absorption of cholesterol or bile acids in humans. In future work, this model can be extended to include more complex (regulatory) mechanisms.

Dose-dependent cholesterol-lowering effects of phytosterol/phytostanol-enriched margarine in statin users and statin non-users under free-living conditions

OBJECTIVE

To assess the effectiveness (extent to which an intervention works in daily medical practice) of the use of phytosterol/phytostanol-enriched margarines to lower total and non-HDL cholesterol levels in users and non-users of statins.

DESIGN

Retrospective cohort study.

SETTING

Data were obtained from questionnaires on health and food intake from a population-based longitudinal cohort linked to pharmacy-dispensing records.

SUBJECTS

The analysis included 3829 men and women (aged 31-71 years) who were examined during 1998-2002 and re-examined at 5-year follow-up during 2003-2007.

RESULTS

Recommended doses of margarines were consumed by only 9 % of the subjects. Serum total cholesterol decreased by respectively -0·16 (95 % CI -0·26, -0·05) mmol/l, -1·40 (95 % CI -1·51, -1·30) mmol/l and -1·64 (95 % CI -1·91, -1·37) mmol/l in subjects who started to use phytosterols/phytostanols only, statins only or a combination of both compounds at some point in time between examination and re-examination, compared with subjects who did not start using phytosterols/phytostanols or statins. Cholesterol-lowering effects of the phytosterols/phytostanols were similar in statin users and statin non-users and increased with increasing intake of enriched margarine (no intake, 0; low intake, -0·017 (95 % CI -0·16, 0·13) mmol/l; medium intake, -0·089 (95 % CI -0·22, 0·038) mmol/l; high intake, -0·32 (95 % CI -0·50, -0·14) mmol/l).

CONCLUSIONS

Although recommended intake levels of the enriched margarines were not reached by all persons, these data show that under customary conditions of use phytosterols/phytostanols are effective in lowering cholesterol levels in both statin users and non-users.

Consumption of a plant sterol-based spread derived from rice bran oil is effective at reducing plasma lipid levels in mildly hypercholesterolaemic individuals

To establish the effectiveness of a new phytosterol-containing spread derived from rice bran oil (RBO), a randomised, double-blind, cross-over human clinical trial was conducted over 12 weeks. A total of eighty mildly hypercholesterolaemic (total blood cholesterol level ≥ 5 and ≤ 7·5 mmol/l with a serum TAG level of ≤ 4·5 mmol/l) individuals were randomised into two groups (n 40). Group 1 consumed spread only daily for 4 weeks. They were randomised to consume 20 g RBO spread (RBOS), 20 g standard spread (SS) or 20 g phytosterol-enriched spread (PS). After a 4-week period, individuals changed to the next randomised treatment until all three treatments had been consumed. Group 2 consumed spread plus oil daily for 4 weeks. They consumed 20 g RBOS plus 30 ml RBO, 20 g SS plus 30 ml sunflower oil or 20 g RBOS. Blood samples were collected for the analysis of lipid parameters, and 3 d diet records were collected. Compared with SS, RBOS significantly reduced total cholesterol by 2·2 % (P = 0·045), total cholesterol:HDL by 4·1 % (P = 0·005) and LDL-cholesterol by 3·5 % (P = 0·016), but was not as effective overall as PS, which reduced total cholesterol by 4·4 % (P = 0·001), total cholesterol:HDL by 3·4 % (P = 0·014) and LDL-cholesterol by 5·6 % (P = 0·001). In group 2, the addition of RBO to the RBOS produced no differences in cholesterol levels. These results confirm that RBOS is effective in lowering serum cholesterol when consumed as part of a normal diet.

Lowering LDL cholesterol with margarine containing plant stanol/sterol esters: is it still relevant in 2011?

Recommendations about the use of plant stanol/sterol esters have not been updated since 2001. There have been many developments in medicines for lipid-lowering since 2001. In this review, the use of margarines containing stanol or sterol esters, to lower LDL cholesterol is considered in the 2011 setting. Firstly, there is a brief overview of the effects of the stanols/sterols on LDL cholesterol, which shows that these agents have a modest ability to lower LDL cholesterol, and are not effective in all conditions. Secondly, the relevance of the stanols/sterols in 2010/1 is questioned, given they have not been shown to reduce clinical endpoints, and have no effects on HDL cholesterol or triglyceride levels. Finally, there is a section comparing the stanols/sterols with the present day prescription lipid lowering medicines. Prescription drugs (statins, ezetimibe, and niacin) have a much greater ability to lower LDL cholesterol than the stanol/sterol esters, and also increase levels of HDL cholesterol and decrease levels of triglycerides. The statins and niacin have been shown to reduce cardiovascular clinical endpoints. Except in borderline normo/hypercholesterolemia, prescription drugs should be preferred to stanol/sterol esters for lowering LDL cholesterol in 2011.

Support of drug therapy using functional foods and dietary supplements: focus on statin therapy

Functional foods and dietary supplements might have a role in supporting drug therapy. These products may (1) have an additive effect to the effect that a drug has in reducing risk factors associated with certain conditions, (2) contribute to improve risk factors associated with the condition, other than the risk factor that the drug is dealing with, or (3) reduce drug-associated side effects, for example, by restoring depleted compounds or by reducing the necessary dose of the drug. Possible advantages compared with a multidrug therapy are lower drug costs, fewer side effects and increased adherence. In the present review we have focused on the support of statin therapy using functional foods or dietary supplements containing plant sterols and/or stanols, soluble dietary fibre, n-3 PUFA or coenzyme Q10. We conclude that there is substantial evidence that adding plant sterols and/or stanols to statin therapy further reduces total and LDL-cholesterol by roughly 6 and 10 %, respectively. Adding n-3 PUFA to statin therapy leads to a significant reduction in plasma TAG of at least 15 %. Data are insufficient and not conclusive to recommend the use of soluble fibre or coenzyme Q10 in patients on statin therapy and more randomised controlled trials towards these combinations are warranted. Aside from the possible beneficial effects from functional foods or dietary supplements on drug therapy, it is important to examine possible (negative) effects from the combination in the long term, for example, in post-marketing surveillance studies. Moreover, it is important to monitor whether the functional foods and dietary supplements are taken in the recommended amounts to induce significant effects.

Functional foods: the case for closer evaluation

Current regulations focus on the mandatory safety evaluation of functional foods before they come to market, but Nynke de Jongand colleagues argue that the effects of such foods should also be evaluated after they have been launched