Health effects of trans-fatty acids: experimental and observational evidence

Food choice, eating behavior, and food liking differs between lean/normal and overweight/obese, low-income women

The higher rate of obesity among low-income women has widely been attributed to environmental barriers; however, many low-income women are still able to maintain a healthy weight despite obesogenic environments. To better understand personal and behavioral attributes related to food choice and weight, overweight/obese women and lean/normal weight women living in similar low-income environments, participated in focus groups, and taste testing sessions to investigate food liking (n=83). During focus groups, lean/normal weight participants reported that health was influential in food choice, while overweight/obese participants expressed cost as being more of a factor. Both BMI (kg/m(2)) groups reported that taste was of greatest importance. Personal factors, like emotional eating, and overeating were also discussed with differences noted between BMI (kg/m(2)) groups. Quantitative data also showed cost to be more important for overweight/obese women. Taste testing results revealed that overweight/obese participants had a higher overall liking for both healthy and less healthy foods, as well as other food categories. Additionally, these women had a higher liking of fat in the context of spreadable fats. Our results show that a variety of complex factors interact to influence eating behavior and present weight status of women living in similarly impoverished environments. However, findings from this exploratory study should be confirmed through further research.

Reporting of trans-fat on labels of Brazilian food products

Objective

The present study investigated how trans-fat is reported on the packaging of foods sold in a Brazilian supermarket.

Design

The present descriptive, cross-sectional study analysed the ingredient list, nutrition facts label and claims of no trans-fat on the packaging.

Setting

A large supermarket in Florianópolis, Brazil.

Subjects

All food products available at the supermarket.

Results

Of the 2327 study products, more than half had components containing trans-fat in the ingredient list, especially hydrogenated vegetable fat and its alternative names. A small percentage of food products reported some trans-fat content on the nutrition facts label and roughly a quarter of the food products claimed to contain no trans-fat on the front of the packaging. There was very low agreement among the trans-fat content reported in the nutrition facts label, claims of no trans-fat made on the packaging and the ingredient list.

Conclusions

There was low agreement among the different ways of reporting trans-fat, suggesting that it is not possible to rely on the nutrition facts label or no trans-fat claims printed on the packaging of Brazilian food products. Hence, the Brazilian legislation on food labels needs to change to improve the reliability of food labels and to help control the trans-fat intake of the population.

Dietary fats and other nutrients on stroke

PURPOSE OF REVIEW

This review summarizes current epidemiologic evidence regarding the associations of dietary fat and other nutrients with risk of stroke.

RECENT FINDINGS

Recent epidemiologic studies show no association of total fat intake or absolute intakes of saturated, monounsaturated, or polyunsaturated fat with risk of stroke. Data on long-chain omega-3 polyunsaturated fatty acids in relation to stroke risk are inconclusive but may favor fewer strokes in women. Insufficient evidence exists for trans fatty acids, other fatty acids, and dietary cholesterol intake. Present evidence indicates that high dietary magnesium and potassium intakes may lower the risk of stroke, whereas a high sodium (salt) intake and a low dietary vitamin D intake likely increase stroke risk. Calcium does not prevent stroke in populations with moderate-to-high calcium intakes but might play a role in populations with low calcium intakes. Supplementation with single vitamins likely has no protective effect on stroke in well nourished populations.

SUMMARY

Available epidemiologic evidence indicates that diets high in magnesium and potassium may play a role in the prevention of stroke, whereas a high sodium intake is a risk factor. It remains unclear whether specific fatty acids, dietary cholesterol, and combinations of vitamins affect the risk of stroke.

Trans-fatty acids, dangerous bonds for health? A background review paper of their use, consumption, health implications and regulation in France

INTRODUCTION

Trans-fatty acids (TFAs) can be produced either from bio-hydrogenation in the rumen of ruminants or by industrial hydrogenation. While most of TFAs' effects from ruminants are poorly established, there is increasing evidence that high content of industrial TFAs may cause deleterious effects on human health and life span.

MATERIAL AND METHODS

Indeed, several epidemiological and experimental studies strongly suggest that high content of most TFA isomers could represent a higher risk of developing cardiovascular diseases by a mechanism that lowers the "good HDL cholesterol" and raises the "bad LDL cholesterol."

RESULTS

With respect to the general precautionary principle and considering the existence of an international policy consensus regarding the need for public health action, some industrialized countries, such as France, are still not sufficiently involved in preventive strategies that aim to efficiently reduce TFAs content and TFAs consumption and produce alternative healthier fat sources.

CONCLUSION

In this manuscript, we provide an overview about TFAs origins, their use and consumption among French population. We also discuss their potential human health implications as well as the preventive and regulatory measures undertaken in France.

Erythrocyte trans-fatty acids, type 2 diabetes and cardiovascular risk factors in middle-aged and older Chinese individuals

AIMS/HYPOTHESIS

Few data are available about intakes and food sources of trans-fatty acids (TFAs) or their associations with cardiometabolic outcomes in Asian people who consume a prudent diet but are experiencing rapid nutritional transitions. We aimed to investigate the relationships between TFA biomarkers and type 2 diabetes and cardiovascular risk factors in Chinese individuals.

METHODS

Erythrocyte fatty acids were measured by gas chromatography among 3,107 men and women (50-70 years) recruited from urban and rural areas in Beijing and Shanghai, China.

RESULTS

Total trans-18:1 and two trans-18:2 isomers were detected and accounted for 0.37% of the total fatty acids in the erythrocytes. Concentrations of TFAs were higher in women than men, and in urban than rural residents. Of the TFAs, trans-18:1, but not trans-18:2, showed a modest association with dairy consumption (β = 0.27), but not with other foods. After adjustment for BMI, social-demographic, lifestyle and dietary factors and other TFAs, erythrocyte trans-18:1 was shown to be associated with a lower risk of type 2 diabetes (OR comparing extreme [first and fourth] quartiles 0.68, 95% CI 0.48, 0.97, p(trend) = 0.02), as well as 20-50% lower odds of central obesity, dyslipidaemia, hyperglycaemia, insulin resistance and chronic inflammation. In contrast, trans-18:2 fatty acids were positively associated with high triacylglycerol (p(trend) < 0.001) and LDL-cholesterol (p(trend) = 0.03) levels, but not with diabetes and other cardiometabolic risk factors.

CONCLUSIONS/INTERPRETATION

Among middle-aged and older Chinese individuals with overall low erythrocyte TFAs levels, trans-18:1 might serve as a marker of dairy intake. Higher trans-18:1 levels were associated with a lower risk of type 2 diabetes, whereas higher trans-18:2 levels were associated with dyslipidaemia.

Trans fatty acid intake and serum cholesterol levels in young Japanese women

There are very limited data concerning the influence of low-level trans fatty acid (TFA) intake on blood lipid levels. In this study, correlation of total and diene TFA intake with serum cholesterol levels was studied in young Japanese women. The mean intakes of total and diene TFAs were 0.36% and 0.05% of energy, respectively. There was a significant correlation between total fat intake and TFA intake. TFA intake was significantly correlated with erythrocyte TFA content. Total TFA intake was not correlated with total, LDL- or HDL-cholesterol levels. No correlatuon was found between diene TFA intake and cholesterol level. Total and diene TFA intake were not correlated with hemoglobin A1c or C-reactive protein levels. These results suggest that the average TFA intake of young Japanese women does not adversely affect serum cholesterol levels.

Ruminant-produced trans-fatty acids raise plasma HDL particle concentrations in intact and ovariectomized female Hartley guinea pigs

Cardiovascular disease (CVD) is the leading cause of death among women worldwide, and risk for developing CVD increases postmenopause. Consumption of trans-fatty acids (tFA) has been positively associated with CVD incidence and mortality. The current study was designed to assess the effects of diets high in industrially produced (IP)-tFA, from partially hydrogenated vegetable oils (PHVO), and ruminant-produced (RP)-tFA, from butter oil (BO), on risk factors for CVD. Thirty-two female Hartley guinea pigs, one-half of which were ovariectomized (OVX) to mimic the postmenopausal condition, were fed hypercholesterolemic diets containing 9% by weight PHVO or BO (n = 8/diet and ovariectomy) for 8 wk. The plasma and hepatic lipids did not differ between IP- and RP-tFA groups or between intact and OVX guinea pigs. The BO diet resulted in higher concentrations of plasma total and small HDL particle subclass concentrations than the PHVO diet regardless of ovariectomy status. The intact BO group had higher concentrations of large HDL particles than the intact PHVO group. HDL mean particle size tended to be larger (P = 0.07) in the PHVO groups compared with the BO groups regardless of ovariectomy status. There was a trend toward an interaction between diet and ovariectomy status for LDL mean particle size, which tended to be larger in OVX guinea pigs fed PHVO (P = 0.07). In summary, consumption of IP- and RP-tFA resulted in differential effects on HDL particle subclass profiles in female guinea pigs. The effect of tFA consumption and hormonal status on HDL particle subclass metabolism and the subsequent impact on CVD in females warrants further investigation.

Nutrition and the healthy heart with an exercise boost

In this era of potent medications and major cardiovascular (CV) procedures, the value of nutrition can be forgotten. A healthy diet is essential, regardless of CV risk. Caloric balance is inherent to a good diet. Despite patients who say they eat little, ideal weight can be maintained if calories are burned. Composition is another component of a healthy diet. The Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets provide proof of CV benefit from their specific content. Metabolic syndrome (MS) is associated with poor diet and obesity. A healthy diet with good nutrition benefits the MS patient and associated conditions such as obesity and diabetes. Exercise, in conjunction with a healthy diet and good nutrition, helps maintain optimal weight and provides CV benefit such as decreased inflammation and increased vasodilatation. Whether vitamins or other nutritional supplements are important in a healthy diet is unproven. Nevertheless, the most promising data of added benefit to a healthy diet is with vitamin D. Some dietary supplements also have promise. Alcohol, in moderation, especially red wine, has nutritional and heart protective benefits. Antioxidants, endogenous or exogenous, have received increased interest and appear to play a favorable nutritional role. CV health starts with good nutrition.

Ácidos graxos trans em produtos alimentícios brasileiros: uma revisão sobre aspectos relacionados à saúde e à rotulagem nutricional

Nos últimos anos, vários estudos apontam a relação positiva entre ácidos graxos trans e desenvolvimento de doenças cardiovasculares, materno-infantis, inflamatórias e de câncer. A Organização Mundial de Saúde alertou para a necessidade da diminuição do consumo desses ácidos graxos, o que culminou com a recomendação de sua eliminação em 2004. A rotulagem é uma medida que auxilia a população na escolha alimentar. Este artigo apresenta uma revisão sobre ácidos graxos trans, desde sua formação, efeitos para a saúde e as medidas atuais de controle da sua ingestão, enfatizando a rotulagem de alimentos. A busca de informações, relativa ao período de 1990 a 2012, foi realizada nos bancos de dados Scopus, PubMed, SciELO, Science Direct, Lilacs, bem como em sites oficiais nacionais e internacionais. Os unitermos utilizados em português e inglês foram: “ácidos graxos trans” e/ou “gordura hidrogenada”, conjugados à “rotulagem” e/ou “regulação” e/ou “legislação”. O controle dos ácidos graxos trans pode ser realizado pela diminuição de seu consumo por meio de medidas industriais, medidas individuais e coletivas, resultantes de um trabalho educativo, além de forças políticas. Em relação à rotulagem, mesmo existindo legislação brasileira que obrigue as indústrias a informarem a quantidade de ácidos graxos trans por porção em alimentos industrializados, observaram-se alguns questionamentos sobre como são disponibilizadas tais informações. Salienta-se que a efetiva diminuição dos ácidos graxos trans pode levar um tempo considerável, dada a adaptação cultural e tecnológica necessárias. Contudo, é uma medida importante, pois o resultado desse controle será a melhoria da saúde da população.

Trans-fatty acid consumption and heart rate variability in 2 separate cohorts of older and younger adults

BACKGROUND

Trans-fatty acid (TFA) consumption is associated with risk of coronary heart disease, and trans-18:2, but not trans-18:1, in red blood cell membranes has been associated with sudden cardiac arrest. Abnormal heart rate variability (HRV) reflects autonomic dysfunction and predicts cardiac death. Relationships between TFA consumption and HRV remain understudied. We determined whether total TFA consumption, as well as trans-18:1 and trans-18:2 TFA consumption, was independently associated with HRV in 2 independent cohorts in the United States and Portugal.

METHODS AND RESULTS

In 2 independent cohorts of older US adults (Cardiovascular Health Study [CHS], age 72±5 years, 1989/1995) and young Portuguese adults (Porto, age 19±2 years, 2008/2010), we assessed habitual TFA intake by food frequency questionnaires in CHS (separately estimating trans-18:1 and trans-18:2) and multiple 24-hour recalls in Porto (estimating total TFA only, which in a subset correlated with circulating trans-18:2 but not trans-18:1, suggesting that we captured the former). HRV was assessed using 24-hour Holters in CHS (n=1076) and repeated short-term (5-minute) ECGs in Porto (n=160). We used multivariate-adjusted linear regression to relate TFA consumption to HRV cross-sectionally (CHS, Porto) and longitudinally (CHS). In CHS, higher trans-18:2 consumption was associated with lower 24-hour SD of all normal-to-normal intervals both cross-sectionally (-12%; 95% CI, -19% to -6%; P=0.001) and longitudinally (-15%; 95% CI, -25% to -4%; P= 0.009) and lower 24-hour SD of 5-minute average N-N intervals and mean of the 5-minute SD of N-N intervals calculated over 24 hours (P<0.05 each). Higher trans-18:1 consumption in CHS was associated with more favorable 24-hour HRV in particular time-domain indices (24-hour SD of all normal-to-normal intervals, SD of 5-minute average N-N intervals, mean of the 5-minute SD of N-N intervals calculated over 24 hours; P<0.05 each). In Porto, each higher SD TFA consumption was associated with 4% lower 5-minute 24-hour SD of all normal-to-normal intervals (95% CI, -8% to -1%; P=0.04) and 7% lower 5-minute square root of the mean of the squares of successive N-N differences (95% CI, -13% to -1%; P=0.04).

CONCLUSIONS

Trans-18:2 consumption is associated with specific, less favorable indices of HRV in both older and young adults. Trans-18:1 consumption is associated with more favorable HRV indices in older adults. Our results support the need to investigate potential HRV-related mechanisms, whereby trans-18:2 may increase arrhythmic risk.

Plasma phospholipid fatty acid concentration and incident coronary heart disease in men and women: the EPIC-Norfolk prospective study

BACKGROUND

The lack of association found in several cohort studies between dietary saturated fat and coronary heart disease (CHD) risk has renewed debate over the link between dietary fats and CHD.

METHODS AND FINDINGS

We assessed the relationship between plasma phospholipid fatty acid (PFA) concentration and incident CHD using a nested case control design within a prospective study (EPIC-Norfolk) of 25,639 individuals aged 40-79 years examined in 1993-1997 and followed up to 2009. Plasma PFA concentrations were measured by gas chromatography in baseline samples retrieved from frozen storage. In 2,424 men and women with incident CHD compared with 4,930 controls alive and free of cardiovascular disease, mean follow-up 13 years, saturated PFA (14:0, 16:0,18:0) plasma concentrations were significantly associated with increased CHD risk (odds ratio [OR] 1.75, 95% CI 1.27-2.41, p<0.0001), in top compared to bottom quartiles (Q), and omega-6 polyunsaturated PFA concentrations were inversely related (OR 0.77, 0.60-0.99, p<0.05) after adjusting for age, sex, body mass index, blood pressure, smoking, alcohol intake, plasma vitamin C, social class, education, and other PFAs. Monounsaturated PFA, omega-3 PFA, and trans PFA concentrations were not significantly associated with CHD. Odd chain PFA (15:0, 17:0) concentrations were significantly inversely associated with CHD (OR 0.73, 0.59-0.91, p<0.001, Q4 versus Q1). Within families of saturated PFA or polyunsaturated PFA, significantly heterogeneous relationships with CHD were observed for individual fatty acids.

CONCLUSIONS

In this study, plasma concentrations of even chain saturated PFA were found to be positively and omega-6 polyunsaturated PFA inversely related to subsequent coronary heart disease risk. These findings are consistent with accumulating evidence suggesting a protective role of omega-6 fats substituting for saturated fats for CHD prevention.

Separation of cis-trans phospholipid isomers using reversed phase LC with high resolution MS detection

The increased presence of synthetic trans fatty acids into western diets has been shown to have deleterious effects on physiology and raising an individual's risk of developing metabolic disease, cardiovascular disease, and stroke. The importance of these fatty acids for health and the diversity of their (patho) physiological effects suggest that not only should the free trans fatty acids be studied but also monitoring the presence of these fats into the side chains of biological lipids, such as glycerophospholipids, is also essential. We developed a high resolution LC-MS method that quantitatively monitors the major lipid classes found in biospecimens in an efficient, sensitive, and robust manner while also characterizing individual lipid side chains through the use of high energy collisional dissociation (HCD) fragmentation and chromatographic alignment. We herein show how this previously described reversed phase method can baseline separate the cis-trans isomers of phosphatidylglycerol and phosphatidylcholine (PC) with two 18:1 side chains, in both positive and negative mode, as neat solutions and when spiked into a biological matrix. Endogenous PC (18:1/18:1)-cis and PC (18:1/18:1)-trans isomers were examined in mitochondrial and serum profiling studies, where rats were fed diets enriched in either trans 18:1 fatty acids or cis 18:1 fatty acids. In this study, we determined the cis:trans isomer ratios of PC (18:1/18:1) and related this ratio to dietary composition. This generalized LC-MS method enables the monitoring of trans fats in biological lipids in the context of a nontargeted method, allowing for relative quantitation and enhanced identification of unknown lipids in complex matrixes.

Trans fatty acids: induction of a pro-inflammatory phenotype in endothelial cells

Epidemiological data have shown an association of the intake of industrial produced trans fatty acids (TFA) and sudden cardiac death. The present study examines the impact of elaidic acid (t18:1n-9) and linoelaidic acid (t18:2n-6) on the human aortic endothelial cell functional response. Trans fatty acids predominately incorporated into the phospholipid component while only a minute fraction of the total fatty acids (FA) incorporated into triacylglycerol. Trans fatty acids incorporated into the plasma membranes at the expense of the saturated-FA, stearic, palmitic, and to a lesser extent, myristic acid. Both t18:1n-9 and t18:2n-6 induced a pro-inflammatory response by elevating surface expression of intercellular adhesion molecule-1 (ICAM-1). Neither oleic nor linoleic evoked a pro-inflammatory phenotype under the maximal 50 µM treatments. Both TFA and stearic acid increased phosphorylation of the ICAM-1 transcriptional regulator, nuclear factor-κβ (NF-κβ), while oleic and linoleic acids did not appear to alter the phosphorylation status. Elaidic acid minimally affected endothelial cell growth, whereas linoelaidic acid completely inhibited growth at 100 µM and imparted limited cytotoxicity up to 300 µM. Stearic acid induced cytotoxicity at concentrations above 75 µM, while oleic and linoleic acids evoked gradual dose-dependent growth inhibition with cytotoxicity occurring only at linoleic acid concentrations greater than 200 µM. In conclusion, t18:1n-9 and t18:2n-6 fatty acids effectively incorporated into the phospholipid component of endothelial cells and subsequently induce a pro-inflammatory phenotype.

Fatty acids as biocompounds: their role in human metabolism, health and disease: a review. part 2: fatty acid physiological roles and applications in human health and disease

BACKGROUND

This is the second of two review parts aiming at describing the major physiological roles of fatty acids, as well as their applications in specific conditions related to human health.

RESULTS

The review included the current literature published in Pubmed up to March 2011. In humans, fatty acids are a principle energy substrate and structural components of cell membranes (phospholipids) and second messengers. Fatty acids are also ligands of nuclear receptors affecting gene expression. Longer-chain (LC) polyunsaturated fatty acids (PUFA), including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid are precursors of lipid mediators such as eicosanoids (prostaglandins, leukotrienes, thromboxanes), resolvins and neuroprotectins. Lipid mediators produced by EPA and DHA (LC n-3 PUFA; mainly found in oily fish) are considered as inflammation-resolving, and thus, fish oil has been characterised as antiinflammatory. Recommendations for EPA plus DHA intake from oily fish vary between 250-450 mg/day. Dietary reference values for fat vary between nutrition bodies, but mainly agree on a low total and saturated fat intake. The existing literature supports the protective effects of LC n-3 PUFA (as opposed to n-6 PUFA and saturated fat) in maternal and offspring health, cardiovascular health, insulin sensitivity, the metabolic syndrome, cancer, critically ill patients, and immune system disorders.

CONCLUSION

Fatty acids are involved in multiple pathways and play a major role in health. Further investigation and a nutrigenomics approach to the effects of these biocompounds on health and disease development are imperative and highlight the importance of environmental modifications on disease outcome.

Profile of trans fatty acids (FAs) including trans polyunsaturated FAs in representative fast food samples

The content of trans fat in foods is most commonly determined by summing the levels of individual trans fatty acids (FAs), analyzed as FA methyl esters (FAME) by gas chromatography. Current Official Methods of the American Oil Chemists' Society (AOCS) enable quantitation of total trans fat in foods but were not designed for the determination of transFA isomeric compositions. In the present study, the content of trans fat in 32 representative fast food samples ranged from 0.1 to 3.1 g per serving, as determined according to AOCS Official Method Ce 1j-07. Further analysis of FAME using the 200 m SLB-IL111 ionic liquid column yielded quantitative results of total, trans, saturated, and cis unsaturated fat that were comparable to those of Method Ce 1j-07 and also allowed for the complementary determination of individual trans 18:1, trans 18:2, and trans 18:3 FA isomeric compositions under conditions suitable for routine sample analysis.

Potential cardiovascular mortality reductions with stricter food policies in the United Kingdom of Great Britain and Northern Ireland

OBJECTIVE

To estimate how much more cardiovascular disease (CVD) mortality could be reduced in the United Kingdom through more progressive nutritional targets.

METHODS

Potential reductions in CVD mortality in the United Kingdom between 2006 (baseline) and 2015 were estimated by synthesizing data on population, diet and mortality among adults aged 25 to 84 years. The effect of specific dietary changes on CVD mortality was obtained from recent meta-analyses. The potential reduction in CVD deaths was then estimated for two dietary policy scenarios: (i) modest improvements (simply assuming recent trends will continue until 2015) and (ii) more substantial but feasible reductions (already seen in several countries) in saturated fats, industrial trans fats and salt consumption, plus increased fruit and vegetable intake. A probabilistic sensitivity analysis was conducted. Results were stratified by age and sex.

FINDINGS

The first scenario would result in approximately 12 500 fewer CVD deaths per year (range: 5500-30 300). Approximately 4800 fewer deaths from coronary heart disease and 1800 fewer deaths from stroke would occur among men, and 3500 and 2400 fewer, respectively, would occur among women. More substantial dietary improvements (no industrial trans fats, reduction in saturated fats and salt and substantial increases in fruit and vegetable intake) could result in approximately 30 000 fewer (range: 13 300-74 900) CVD deaths.

CONCLUSION

Excess dietary trans fats, saturated fats and salt, along with insufficient fruits and vegetables, generate a substantial burden of CVD in the United Kingdom. Further improvements resembling those attained by other countries are achievable through stricter dietary policies.

Trans fat, aspirin, and ischemic stroke in postmenopausal women

OBJECTIVE

To examine the associations between dietary fat intake and ischemic stroke among postmenopausal women.

METHODS

We conducted a prospective cohort study of 87,025 generally healthy postmenopausal women (age, 50-79 years) enrolled in the Women's Health Initiative Observational Study. Repeated and validated dietary assessments were done using a self-administered food frequency questionnaire. We used Cox proportional hazards models to estimate hazard ratios (HRs) of ischemic stroke based on quintiles of the cumulative average of fat intake.

RESULTS

We documented 1,049 incident cases of ischemic stroke over 663,041 person-years of follow-up. Women in the highest quintile of trans fat intake had a significantly higher incidence of ischemic stroke (HR, 1.39; 95% confidence interval [CI], 1.08-1.79; p-trend = 0.048) compared with women in the lowest quintile, while controlling for multiple covariates. The observed association was modified by aspirin use (p-interaction = 0.02). The HR was 1.66 (95% CI, 1.21-2.36; p-trend < 0.01) among baseline non-aspirin users (n = 67,288) and 0.95 (95% CI, 0.60-1.48; p-trend = 0.43) among aspirin users (n = 19,736). No significant associations were found between intakes of saturated, monounsaturated, or polyunsaturated fat and ischemic stroke or any ischemic stroke subtypes.

INTERPRETATION

In this large cohort of postmenopausal women, higher intake of trans fat was associated with incident ischemic stroke independent of major lifestyle/dietary factors. Aspirin use may attenuate the potential adverse effect of trans fat intake on ischemic stroke.

Foods for the prevention of diabetes: how do they work?

With the diabetes epidemic reaching menacing proportions worldwide, there is an urgent need for the development of cost-efficient prevention strategies to be effective at the population level. Great potential in this direction lies in properly designed, large-scale dietary interventions. The macronutrient composition and the caloric content of our diet are major determinants of glucose homeostasis and there is a continuously growing list of foods, nutrients or individual compounds that have been associated with an increased or reduced incidence of diabetes mellitus. These include fat, carbohydrates, fibre, alcohol, polyphenols and other micronutrients or individual dietary compounds, which have been shown to either promote or prevent a progression towards a (pre-)diabetic state. This review aims to briefly summarize relevant epidemiological data linking foods to diabetes and to provide insights into the mechanisms through which these effects are mediated. These include improvement of insulin sensitivity or promotion of insulin resistance, regulation of inflammatory pathways, regulation of glucose transport and tissue glucose uptake, aggravation or attenuation of postprandial glycaemia/insulinaemia, interactions with hormonal responses and β-cell-dependent mechanisms.

Nutritional modulation of insulin resistance

Insulin resistance has been proposed as the strongest single predictor for the development of Type 2 Diabetes (T2DM). Chronic oversupply of energy from food, together with inadequate physical activity, have been recognized as the most relevant factors leading to overweight, abdominal adiposity, insulin resistance, and finally T2DM. Conversely, energy reduced diets almost invariably to facilitate weight loss and reduce abdominal fat mass and insulin resistance. However, sustained weight loss is generally difficult to achieve, and distinct metabolic characteristics in patients with T2DM further compromise success. Therefore, investigating the effects of modulating the macronutrient composition of isoenergetic diets is an interesting concept that may lead to additional important insights. Metabolic effects of various different dietary concepts and strategies have been claimed, but results from randomized controlled studies and particularly from longer-term-controlled interventions in humans are often lacking. However, some of these concepts are supported by recent research, at least in animal models and short-term studies in humans. This paper provides an update of the current literature regarding the role of nutrition in the modulation of insulin resistance, which includes the discussion of weight-loss-independent metabolic effects of commonly used dietary concepts.

Fatty acid distribution of cord and maternal blood in human pregnancy: special focus on individual trans fatty acids and conjugated linoleic acids

Background

Maternal nutrition in pregnancy has a crucial impact on the development of the fetus. Dietary trans fatty acids (tFA) are known to have adverse health effects, especially during pregnancy. However, the distribution of tFA produced via partial hydrogenation of vegetable oils (mainly elaidic acid; t9) differs compared to ruminant-derived tFA (mainly vaccenic acid; t11). Recent findings indicate that they may have different impact on human health.

Therefore, in this study, plasma and erythrocytes of mother-child pairs (n = 55) were sampled to investigate the distribution of tFA, including individual trans C18:1 fatty acids and conjugated linoleic acids (CLA) in fetal related to maternal lipids; with additional consideration of maternal dairy fat intake.

Results

Portion of t9 and t11, but also of c9,t11 CLA was higher in maternal than in fetal blood lipids. The portion of t9 in maternal and fetal lipids differed only slightly. In contrast, the portion of fetal t11 was only half of that in maternal blood. This led to a fetal t9/t11-index in plasma and erythrocytes being twice as high compared to the maternal values. A high dairy fat intake resulted in elevated portions of t11 and its Δ9-desaturation product c9,t11 CLA in maternal blood. In contrast, in the respective fetal blood lipids only c9,t11 CLA, but not t11 was increased. Nevertheless, a positive association between maternal and fetal plasma exists for both t11 and c9,t11 CLA. Furthermore, in contrast to t9, t11 was not negatively associated with n-3 LC-PUFA in fetal blood lipids.

Conclusions

Fetal blood fatty acid composition essentially depends on and is altered by the maternal fatty acid supply. However, in addition to dietary factors, other aspects also contribute to the individual fatty acid distribution (oxidation, conversion, incorporation). The lower portion of fetal t11 compared to maternal t11, possibly results from Δ9-desaturation to c9,t11 CLA and/or oxidation. Based on the fatty acid distribution, it can be concluded that t11 differs from t9 regarding its metabolism and their impact on fetal LC-PUFA.

Inverse association between trans isomeric and long-chain polyunsaturated fatty acids in pregnant women and their newborns: data from three European countries

BACKGROUND

trans unsaturated fatty acids are thought to interfere with essential fatty acid metabolism. To extend our knowledge of this phenomenon, we investigated the relationship between trans isomeric and long-chain polyunsaturated fatty acids (LCPUFA) in mothers during pregnancy and in their infants at birth.

METHODS

Fatty acid composition of erythrocyte phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was determined in Spanish (n = 120), German (n = 78) and Hungarian (n = 43) women at the 20th and 30th week of gestation, at delivery and in their newborns.

RESULTS

At the 20th week of gestation, the sum of trans fatty acids in PE was significantly (p < 0.01) lower in Hungarian [0.73 (0.51), % wt/wt, median (IQR)] than in Spanish [1.42 (1.36)] and German [1.30 (1.21)] women. Docosahexaenoic acid (DHA) values in PE were significantly (p < 0.01) higher in Hungarian [5.65 (2.09)] than in Spanish [4.37 (2.60)] or German [4.39 (3.3.2)] women. The sum of trans fatty acids significantly inversely correlated to DHA in PCs in Spanish (r = -0.37, p < 0.001), German (n = -0.77, p < 0.001) and Hungarian (r = -0.35, p < 0.05) women, and in PEs in Spanish (r = -0.67, p < 0.001) and German (r = -0.71, p < 0.001), but not in Hungarian (r = -0.02) women. Significant inverse correlations were seen between trans fatty acids and DHA in PEs at the 30th week of gestation (n = 241, r = -0.52, p < 0.001), at delivery (n = 241, r = -0.40, p < 0.001) and in cord lipids (n = 218, r = -0.28, p < 0.001).

CONCLUSION

Because humans cannot synthesize trans isomeric fatty acids, the data obtained in the present study support the concept that high maternal trans isomeric fatty acid intake may interfere with the availability of LCPUFA both for the mother and the fetus.

Dietary fat intake and quality of life: the SUN project

Background

Few studies have related nutritional factors with quality of life in healthy populations. The purpose of the study was to assess whether dietary fat intake is associated to mental and physical quality of life.

Methods

This analysis included 8,430 participants from the SUN (Seguimiento Universidad de Navarra) Project. The intake of saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), trans unsaturated fatty acids (TFA), and monounsaturated fatty acids (MUFA) was assessed through a 136-item food frequency questionnaire at baseline. Quality of life was measured with the SF-36 Health Survey after 4 years of follow-up. Generalized Linear Models were fitted to assess the regression coefficients (b) and their 95% confidence intervals (95% CI) for the 8 domains of the SF-36 according to successive quintiles of each kind of fatty acids intake.

Results

The multivariate-adjusted models revealed a significant inverse association for SFA intake (in quintiles) and two of the physical domains (physical functioning and general health). E.g. for general health domain: (highest quintile of intake (Q5) vs. lowest quintile (Q1), b = -1.6; 95% CI = -3.1, -0.1. General health also showed a dose-response relationship (p for trend < 0.05). For TFA intake (in quintiles), a significant inverse association was found for most of the mental domains (vitality, social functioning and role emotional). E.g. for vitality domain (Q5) vs. (Q1), b = -2.0, 95% CI = -3.4 to -0.6. We also found an inverse association between TFA intake and the bodily pain domain: (Q5 vs. Q1), b = -2.6; 95% CI = -4.4 to -0.8, with a statistically significant dose-response relationship (p for trend < 0.05). Except for TFA intake and the mental domains, the rest of the associations were attenuated when we repeated the analysis adjusting for adherence to the Mediterranean diet.

Conclusions

A detrimental relationship between TFA intake at baseline and most of the SF-36 mental domains measured 4 years later were found, whereas weak inverse associations were found for SFA intake and some physical domains.

Ecological-level associations between highly processed food intakes and plasma phospholipid elaidic acid concentrations: results from a cross-sectional study within the European prospective investigation into cancer and nutrition (EPIC)

Elaidic acid is the main unnatural trans fatty acid isomer occurring during partial hydrogenation of vegetable oils used as ingredients for the formulation of processed foods. The main objective is to assess associations between processed food intakes and plasma phospholipid elaidic acid concentrations within the European Prospective Investigation into Cancer and Nutrition study. A cross-sectional study was used to determine fatty acid profiles in 3,003 subjects from 16 centers. Single 24-h dietary recalls (24-HDR) were collected using a standardized computerized interview program. Food intakes were computed according to their degree of processing (moderately/nonprocessed foods, processed staple foods, highly processed foods). Adjusted ecological and individual correlations were calculated between processed food intakes and plasma elaidic acid levels. At the population level, mean intakes of highly processed foods were strongly correlated with mean levels of plasma elaidic acid in men (P = 0.0016) and in women (P = 0.0012). At the individual level, these associations remained but at a much lower level in men (r = 0.08, P = 0.006) and in women (r = 0.09, P = 0.0001). The use of an averaged 24-HDR measure of highly processed food intakes is adequate for predicting mean levels of plasma elaidic acid among European populations.

High disaccharide intake associates with atherogenic lipoprotein profile

Increased plasma concentrations of small LDL particles denote an atherogenic lipoprotein phenotype (ALP) that is correlated with increased circulating TAG and reduced HDL-cholesterol. Principal component analyses of subfraction concentrations have previously been used in the Swedish population-based Malmö Diet and Cancer (MDC) cohort to identify three independent components, one pattern representing the ALP. The aim of the present study was to examine the associations between macronutrient intakes and the principal component representing the ALP. We examined 4301 healthy subjects (46-68 years old, 60 % women) at baseline in the MDC cohort. Dietary data were collected using a modified diet history method. Plasma lipoprotein subfractions were measured using a high-resolution ion mobility method. The principal component corresponding to the ALP was significantly associated with a higher intake of disaccharides, and inversely related to protein and alcohol consumption (P < 0·001 for all). The present findings indicate that the ALP may be improved by a low intake of disaccharides, and moderate intakes of protein and alcohol.

Comparison of diet consumption, body composition and lipoprotein lipid values of Kuwaiti fencing players with international norms

BACKGROUND

No published data is currently available that describes the dietary patterns or physiological profiles of athletes participating on the Kuwaiti national fencing team and its potential impact on health and physical performance. The purpose of this investigation was to: 1) collect baseline data on nutrient intake 2) collect, analyze and report baseline for body composition, plasma lipid and lipoprotein concentrations during the competitive season, 3) compare the results with the international norms, 4) and provide necessary health and nutritional information in order to enhance the athletes' performance and skills.

METHODS

Fifteen national-class fencers 21.5 ± 2.6 years of age participated in this study. Food intake was measured using a 3-day food record. Body composition was estimated using both the BOD POD and Body Mass Index (BMI). Total blood lipid profiles and maximum oxygen consumption was measured for each of the subjects during the competitive season.

RESULTS

The results of the present study showed significant differences in dietary consumption in comparison with the recommended dietary allowances (RDA). The blood lipids profile and body composition (BMI and % body fat) were in normal range in comparison with international norms However, the average VO2 max value was less than the value of the other fencers.

CONCLUSION

Due to the results of the research study, a dietary regimen can be designed that would better enhance athletic performance and minimize any health risks associated with nutrition. Percent body fat and BMI will also be categorized for all players. In addition, the plasma blood tests will help to determine if any of the players have an excessive level of lipids or any blood abnormalities. The outcomes of present study will have a direct impact on the players health and therefore their skills and athletic performance.

Deleterious impact of elaidic fatty acid on ABCA1-mediated cholesterol efflux from mouse and human macrophages

Consumption of trans fatty acids (TFA) increase cardiovascular risk more than do saturated FA, but the mechanisms explaining their atherogenicity are still unclear. We investigated the impact of membrane incorporation of TFA on cholesterol efflux by exposing J774 mouse macrophages or human monocyte-derived macrophages (HMDM) to media enriched or not (standard medium) with industrially produced elaidic (trans-9 18:1) acid, naturally produced vaccenic (trans-11 18:1) acid (34 h, 70 μM) or palmitic acid. In J774 macrophages, elaidic and palmitic acid, but not vaccenic acid, reduced ABCA1-mediated efflux by ~23% without affecting aqueous diffusion, SR-BI or ABCG1-mediated pathways, and this effect was maintained in cholesterol-loaded cells. The impact of elaidic acid on the ABCA1 pathway was weaker in cholesterol-normal HMDM, but elaidic acid induced a strong reduction of ABCA1-mediated efflux in cholesterol-loaded cells (-36%). In J774 cells, the FA supplies had no impact on cellular free cholesterol or cholesteryl ester masses, the abundance of ABCA1 mRNA or the total and plasma membrane ABCA1 protein content. Conversely, TFA or palmitic acid incorporation induced strong modifications of the membrane FA composition with a decrease in the ratio of (cis-monounsaturated FA+polyunsaturated FA):(saturated FA+TFA), with elaidic and vaccenic acids representing each 20% and 13% of the total FA composition, respectively. Moreover, we demonstrated that cellular ATP was required for the effect of elaidic acid, suggesting that it contributes to atherogenesis by impairing ABCA1-mediated cholesterol efflux in macrophages, likely by decreasing the membrane fluidity, which could thereby reduce ATPase activity and the function of the transporter.

Differential effects of the trans-18:1 isomer profile of partially hydrogenated vegetable oils on cholesterol and lipoprotein metabolism in male F1B hamsters

Trans-fatty acid consumption from partially hydrogenated vegetable oil (PHVO) has been positively associated with multiple cardiovascular disease risk factors and events. This study was designed to examine the effects of trans-fatty acid isomer profile of PHVO on plasma lipids and lipoproteins and hepatic expression of key genes involved in cholesterol and fatty acid metabolism. Thirty-three male F(1)B strain Syrian Golden Hamsters were allocated to 1 of 3 hypercholesterolemic diets containing (5% by weight): 1) tristearin [control fat (CON)]; 2) partially hydrogenated high-oleic acid sunflower oil (PH-SUN); or 3) partially hydrogenated high-linoleic acid safflower oil (PH-SAF). PH-SUN contained more trans-4 to trans-10 18:1 compared with PH-SAF, which contained more trans-11 to trans-16 18:1. The addition of both PHVO to the diet increased plasma total cholesterol concentrations relative to CON, but only PH-SUN increased the plasma ratio of non-HDL:HDL cholesterol compared with CON. PH-SUN increased VLDL (total, large, and medium) and IDL particle concentrations while decreasing total, medium, and small HDL particle concentrations relative to CON. Both PHVO diets increased the hepatic cholesterol ester concentration, whereas the hepatic TG concentration was lower in PH-SUN compared with PH-SAF and CON. Levels of hepatic LDL receptor, HMG-CoA reductase, and sterol response element binding protein 1 mRNA were specifically reduced in the PH-SUN group compared to the CON group. Expression of SREBP1c was upregulated in both PHVO groups compared to CON, whereas only the PH-SAF group had higher levels of the lipogenic enzymes acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase-1 compared to CON. These results indicate that differences in the trans-fatty acid profile of PHVO can differentially affect lipid and lipoprotein metabolism.

Trans fats-sources, health risks and alternative approach - A review

Trans fatty acids have the presence of one or more double bonds in the trans configuration instead of the usual cis configuration. They are desired by Vanaspati industry as they impart firmness to margarines and plasticity as well as emulsion stability to shortenings. Research has proved the direct connection of trans fatty acids with cardiovascular diseases, breast cancer, shortening of pregnancy period, risks of preeclampsia, disorders of nervous system and vision in infants, colon cancer, diabetes, obesity and allergy. In light of these new findings trans fatty intake should be zero and new technology of hydrogenation of oils is to be developed which produce zero trans fatty acids at the same time preserve the desirable properties contributed by trans fatty acids to the hydrogenated oils. Presently in India there is no system to monitor and regulate the amount of trans fats in processed foods and hence a stringent food law is immediately required.

A high intake of trans fatty acids has little effect on markers of inflammation and oxidative stress in humans

Consumption of industrial trans fatty acids (iTFA) increases LDL cholesterol, decreases HDL cholesterol, and is strongly associated with a higher risk of cardiovascular disease (CVD). However, changes in circulating cholesterol cannot explain the entire effect. Therefore, we studied whether iTFA and conjugated linoleic acid (CLA) affect markers of inflammation and oxidative stress. Sixty-one healthy adults consumed each of 3 diets for 3 wk, in random order. Diets were identical except for 7% of energy provided by oleic acid (control diet), iTFA, or CLA. At the end of the 3 wk, we measured plasma inflammatory markers IL-6, C-reactive protein, tumor necrosis factor receptors I and II (TNF-RI and -RII), monocyte chemotactic protein-1 and E-selectin, and urinary 8-iso-PGF(2α), a marker of lipid peroxidation. Consumption of iTFA caused 4% lower TNF-RI concentrations and 6% higher E-selectin concentrations compared with oleic acid (control) and had no significant effect on other inflammatory markers. CLA did not significantly affect inflammatory markers. The urine concentration of 8-iso-PGF(2α) [geometric mean (95% CI)] was greater after the iTFA [0.54 (0.48, 0.60) nmol/mmol creatinine] and the CLA [1.2 (1.1, 1.3) nmol/mmol creatinine] diet periods than after the control period [0.45 (0.41, 0.50) nmol/mmol creatinine; P < 0.05]. In conclusion, high intakes of iTFA and CLA did not substantially affect plasma concentrations of inflammatory markers, but they increased the urine 8-iso-PGF(2α) concentration. However, it is unlikely this plays a major role in the mechanism by which iTFA increase the risk of CVD. However, more research is needed to fully understand the implications of these findings.

The role of diet in the prevention of type 2 diabetes

Type 2 diabetes mellitus is an important preventable disease and a growing public health problem. Epidemiologic and interventional studies suggest that weight loss is the main driving force to reduce diabetes risk. Landmark clinical trials of lifestyle changes in subjects with prediabetes have shown that diet and exercise leading to weight loss consistently reduce the incidence of diabetes. However, from these studies it cannot be established whether dietary changes alone play a significant role in preventing diabetes. Here we review epidemiologic and clinical trial evidence relating nutrients, foods and dietary patterns to diabetes risk and the possible mechanisms involved. The differential effects of carbohydrate and fat quantity and quality, and those of specific foods and whole diets are discussed. Importantly, most dietary components influencing diabetes risk have similar effects on biomarkers of cardiovascular risk and inflammation. The conclusion is that there is no universal dietary strategy to prevent diabetes or delay its onset. Together with the maintenance of ideal body weight, the promotion of the so-called prudent diet (characterized by a higher intake of food groups that are generally recommended for health promotion, particularly plant-based foods, and a lower intake of red meat, meat products, sweets, high-fat dairy and refined grains) or a Mediterranean dietary pattern rich in olive oil, fruits and vegetables, including whole grains, pulses and nuts, low-fat dairy, and moderate alcohol consumption (mainly red wine) appears as the best strategy to decrease diabetes risk, especially if dietary recommendations take into account individual preferences, thus enabling long-time adherence.

Consumer perceptions of trans fats in 2009 show awareness of negative effects but limited concern regarding use in snack foods

The purpose of this study was to determine consumers' perceptions of industrially produced trans fats. A cross-sectional study was conducted in Regina at 3 different grocery store chains located in 3 different regions. A 21-item survey was administered in English by 3 research assistants at the grocery stores over a 5-day period. Of 498 potential respondents who were approached, 211 completed the survey, for a 42% response rate. The majority of respondents were female and over 61 years of age. When respondents were asked if they looked for information on food packages while grocery shopping, none of the respondents indicated that they looked for trans fat on the food label. Ninety-six percent of respondents identified that trans fat is found in processed foods, whereas 42% of respondents incorrectly identified trans fat as being found in nonhydrogenated margarines. More female respondents self-reported that they had made dietary changes to decrease trans fat intake as compared with male respondents (p < 0.05). Those participants who made dietary changes to decrease trans fat intake had higher mean knowledge scores than did those who did not make changes (p < 0.043). Sixty-three percent of respondents indicated that they would not make dietary changes to their snack food selections even if their selections contained trans fat. Consumers know a little about trans fats and consider them to be a concern. However, consumers are reluctant to make dietary changes to limit these fats in their snack food selections.

Fast-food and commercial baked goods consumption and the risk of depression

OBJECTIVE

Whereas the relationship between some components of diet, such as n-3 fatty acids and B-vitamins, and depression risk has been extensively studied, the role of fast-food or processed pastries consumption has received little attention.

DESIGN

Consumption of fast food (hamburgers, sausages, pizza) and processed pastries (muffins, doughnuts, croissants) was assessed at baseline through a validated semi-quantitative FFQ. Participants were classified as incident cases of depression if they reported a physician diagnosis of depression or the use of antidepressant medication in at least one of the follow-up questionnaires. Cox regression models were fit to assess the relationship between consumption of fast food and commercial baked goods and the incidence of depression.

SETTING

The SUN (Seguimiento Universidad de Navarra - University of Navarra Follow-up) Project, Spain.

SUBJECTS

Participants (n 8964) from a Spanish cohort.

RESULTS

After a median follow-up of 6·2 years, 493 cases of depression were reported. A higher risk of depression was associated with consumption of fast food (fifth (Q5) v. first quintile (Q1): hazard ratio (HR) = 1·36; 95 % CI 1·02, 1·81; P trend = 0·003). The results did not change after adjustment for the consumption of other food items. No linear relationship was found between the consumption of commercial baked goods and depression. Participants belonging to consumption quintiles Q2-Q5 showed an increased risk of depression compared with those belonging to the lowest level of consumption (Q1; HR = 1·38; 95 % CI 1·06, 1·80).

CONCLUSIONS

Fast-food and commercial baked goods consumption may have a detrimental effect on depression risk.

A prospective study of trans fat intake and risk of preeclampsia in Denmark

BACKGROUND/OBJECTIVES

An association between biomarkers of trans fat intake and greater risk of preeclampsia has been reported, but research in this area is scant. Thus, we examined the association of second trimester intake of trans fats with risk of preeclampsia and severe preeclampsia.

SUBJECTS/METHODS

We followed 67,186 pregnancies of women participating in the Danish National Birth Cohort between 1998 and 2003. Diet was assessed with a food frequency questionnaire at gestation week 25, and preeclampsia diagnosis was obtained by linkage with the Danish National Patient Registry.

RESULTS

There were 1804 cases of preeclampsia and 402 cases of severe preeclampsia identified in the cohort. Intake of trans fats decreased during the study period as a consequence of a reduction in industrial trans fat intake. Second trimester intake of trans fats was unrelated to risk of preeclampsia or severe preeclampsia. The relative risk (95% confidence interval; P, trend) of preeclampsia and severe preeclampsia comparing top to bottom quintiles of trans fat intake were 0.95(0.81; 1.11, 0.33) and 1.07 (0.78; 1.48, 0.92), respectively.

CONCLUSION

Second trimester intake of trans fats is unrelated to risk of preeclampsia within the intake range observed in a period of gradual reduction of industrial trans fats from the Danish food supply.

Effectiveness and cost effectiveness of cardiovascular disease prevention in whole populations: modelling study

OBJECTIVE

To estimate the potential cost effectiveness of a population-wide risk factor reduction programme aimed at preventing cardiovascular disease.

DESIGN

Economic modelling analysis.

SETTING

England and Wales. Population Entire population. Model Spreadsheet model to quantify the reduction in cardiovascular disease over a decade, assuming the benefits apply consistently for men and women across age and risk groups.

MAIN OUTCOME MEASURES

Cardiovascular events avoided, quality adjusted life years gained, and savings in healthcare costs for a given effectiveness; estimates of how much it would be worth spending to achieve a specific outcome.

RESULTS

A programme across the entire population of England and Wales (about 50 million people) that reduced cardiovascular events by just 1% would result in savings to the health service worth at least £30m (€34m; $48m) a year compared with no additional intervention. Reducing mean cholesterol concentrations or blood pressure levels in the population by 5% (as already achieved by similar interventions in some other countries) would result in annual savings worth at least £80m to £100m. Legislation or other measures to reduce dietary salt intake by 3 g/day (current mean intake approximately 8.5 g/day) would prevent approximately 30,000 cardiovascular events, with savings worth at least £40m a year. Legislation to reduce intake of industrial trans fatty acid by approximately 0.5% of total energy content might gain around 570,000 life years and generate NHS savings worth at least £230m a year.

CONCLUSIONS

Any intervention that achieved even a modest population-wide reduction in any major cardiovascular risk factor would produce a net cost saving to the NHS, as well as improving health. Given the conservative assumptions used in this model, the true benefits would probably be greater.