Amelioration of nutritional properties of bakery fat using omega-3 fatty acid-rich edible oils: a review.

Bakery products have gained prominence in modern diets due to their convenience and accessibility, often serving as staple meals across diverse regions. However, the fats used in these products are rich in saturated fatty acids and often comprise trans fatty acids, which are considered as a major biomarker for non-communicable diseases like cardiovascular disorders, obesity and diabetes. Additionally, these fats lack the essential omega-3 fatty acids, which are widely known for their therapeutic benefits. They play a major role in lowering the risk of cardiovascular diseases, cancer and diabetes. Thus, there is need for incorporating these essential fatty acids into bakery fats. Nevertheless, fortifying food products with polyunsaturated fatty acids (PUFAs) poses several challenges due to their high susceptibility to oxidation. This oxidative deterioration leads to not only the formation of undesirable flavors, but also a loss of nutritional value in the final products. This review focuses on the development of healthier trans-fat-free bakery fat enriched with omega-3 fatty acids and its effect on the physicochemical, functional, sensory and nutritional properties of bakery fats and products. Further, the role of various technologies like physical blending, enzymatic interesterification and encapsulation to improve the stability of PUFA-rich bakery fat is discussed, where microencapsulation emerged as a novel and effective technology to enhance the stability and shelf life. By preventing deteriorative changes, microencapsulation ensures that the nutritional, physicochemical and sensory properties of food products remain intact. Novel modification methods like interesterification and microencapsulation used for developing PUFA-rich bakery fats have a potential to address the health risks occurring due to consumption of bakery fat having higher amount of saturated and trans fatty acids. © 2023 Society of Chemical Industry.

Food security and diet quality in a racially diverse cohort of postpartum women in the USA.

Food insecurity has been associated with poor diet, but few studies focused on the postpartum period - an important time for women's health. We examined associations between food security and diet quality in postpartum women and assessed whether participation in federal food assistance programmes modified this potential relation. Using longitudinal data, we analysed the association between food security at 3 months postpartum and a modified Alternate Healthy Eating Index-2010 (AHEI) at 6 months postpartum (excluding alcohol). We conducted multivariable linear regressions examining associations between food security and AHEI. We assessed two food assistance programmes as potential effect modifiers. The sample included 363 postpartum women from the Nurture study, located in the Southeastern USA (2013-2017). Among women, 64·4 % were Black and 45·7 % had a high school diploma or less. We found no evidence of an interaction between food security and two federal food assistance programmes. In adjusted models, marginal, low and very low food security were not associated with AHEI. However, low (ß: -0·64; 95 % CI -1·15, -0·13; P = 0·01) and very low (ß: -0·57; 95 % CI -1·02, -0·13; P = 0·01) food security were associated with greater trans fat intake. Food security status was not associated with overall diet quality but was associated with higher trans fat (low and very low) and more moderate alcohol (marginal) intake. Future studies should assess the consistency and generalisability of these findings.

A Heat Transfer Model and Supporting Experiments to Guide the Uniform Gelation of Molecular Oleogels During Scale-up.

The quest for novel vegetable oil structuring strategies has been progressing since the discovery of the deleterious impacts of trans fats. Although oleogelation using bioderived molecular gelators has been proven to be successful as an alternative to traditional hydrogenation methods, efforts are needed to meet the industrial requirements. A major constraint during the fabrication of oleogels is to achieve consistency in physical properties during scale-up. Experiments showed that gelation fails to occur when larger volumes were prepared based on the minimum gelation concentration (MGC) of gelators, determined using the smallest oil volume (1 mL), a general laboratory practice. This observation was consistent with all the molecular gelators used in this study; sorbitol dioctanoate, mannitol dioctanoate, and 12-hydroxystearic acid. To understand this behavior, a mathematical model was developed since gelator network propagation is governed by the cooling rate. The model indicates that maintenance of a minimal thermal gradient via uniform heat dissipation and gelation time is necessary to achieve homogeneous gel propagation across the vial. With these predictions, we hypothesized and confirmed that oleogels with constant surface area-to-volume ratio could result in identical gelation times and consistent physical properties (MGC, melting temperature, melting enthalpy, yield stress, solid phase content, and oil binding capacity) during scale-up.

Trans-fat labelling information on prepackaged foods and beverages sold in Hong Kong in 2019.

OBJECTIVE: To examine the labelling status of trans-fat of pre-packaged foods sold in Hong Kong. DESIGN: Data from 19 027 items in the 2019 FoodSwitch Hong Kong database were used. Ingredient lists were screened to identify specific (e.g. partially hydrogenated vegetable oil, PHVO) and non-specific trans-fat ingredient indicators (e.g. hydrogenated oil). Trans-fat content was obtained from the on-pack nutrition labels, which was converted into proportion of total fat (%total fat). Descriptive statistics were calculated for trans-fat content and the number of specific, non-specific and total trans-fat ingredients indicators found on the ingredients lists. Comparisons were made between regions using one-way ANOVA and χ2 for continuous and categorical variables, respectively. SETTING: Cross-sectional audit. PARTICIPANTS: Not applicable. RESULTS: A total of 729 items (3·8 % of all products) reported to contain industrially produced trans-fat, with a median of 0·4 g/100 g or 100 ml (interquartile range (IQR): 0·1-0·6) and 1·2 %totalfat (IQR: 0·6-2·9). 'Bread and bakery products' had the highest proportion of items with industrially produced trans-fat (18·9 %). 'Non-alcoholic beverages' had the highest proportion of products of 'false negatives' labelling (e.g. labelled as 0 trans-fat but contains PHVO; 59·3 %). The majority of products with trans-fat indicator originated from Asia (70 %). CONCLUSIONS: According to the labelling ∼4 % of pre-packaged food and beverages sold in Hong Kong in 2019 contained industrially produced trans-fat, and a third of these had trans-fat >2 %total fat. The ambiguous trans-fat labelling in Hong Kong may not effectively assist consumers in identifying products free from industrially produced trans-fat.

Nutrient comparisons of margarine/margarine-like products, butter blend products and butter in the US marketplace in 2020 post-FDA ban on partially hydrogenated oils.

OBJECTIVE: To evaluate the fatty acid profiles and relevant vitamin and mineral compositions of margarine/margarine-like products and butter blend products available in the US marketplace and to compare with butter. DESIGN: Analysis of the food and nutrient composition information available for margarine/margarine-like products, butter blend products and butter in the 2021 version of the University of Minnesota Nutrition Coordinating Center (NCC) Food and Nutrient Database. SETTING: The US retail food marketplace in 2020. PARTICIPANTS: A selection of eighty-three margarine/margarine-like or butter blend products available in the USA in 2020 and regular and whipped butter (both salted and unsalted). RESULTS: All products contained no or negligible amounts of trans fat. Mean daily values (DV) for SFA per 1 tablespoon ranged from 11 % for margarine/margarine-like tub and squeeze products to 18 % for margarine/margarine-like stick products and butter blend products. In contrast, one tablespoon butter provides 36 % of the DV for SFA. Results from ANOVA comparing the percent of total fat from SFA, PUFA and MUFA by product type indicated significant differences for SFA (P < 0·01) and PUFA (P < 0·01), but not MUFA (P = 0·07). CONCLUSIONS: Leading brands of margarine/margarine-like and butter blend products examined in this study were found to be in greater alignment with current dietary recommendations for fatty acids and cholesterol than butter. Margarine/margarine-like tub and squeeze products were found to be optimal over margarine/margarine-like stick products and butter blend products. Future research should include an examination of private label products.

Industrially produced trans fat: Usage, health implications, global and indian regulations.

Global momentum is growing for the total elimination of industrially produced trans fats from the food systems as they are known to have deleterious health effects on various body functions particularly the cardiovascular health. Many developed nations such as Denmark have completely eliminated the use of industrially produced trans fats from the food supply. India is undergoing a significant nutrition transition that has substantially increased the intake of processed and ready-to-eat foods, abundant in trans fats. The Indian regulator-Food Safety and Standards Authority of India is all set to reduce the industrially produced trans fats to <2% by the end of year 2021 in a phased manner. Multiple strategies such as reducing trans fat limit in oils and fats, mandatory labeling on food products, introduction of "Trans-fat free" claim and logo have been adopted by the Indian regulatory body, to achieve the goal of trans fat free India. This review comprehensively summarizes from a public health perspective the usage of industrially-produced trans fats in Indian food industry, its effects on health, the global strategies to limit its content, and the current Indian regulations.

Food democracy, health disparities and the New York City trans fat policy.

OBJECTIVE: To investigate food democracy and health disparities in the New York City (NYC) trans fat policy process. DESIGN: Texts from semi-structured interviews, public testimony and comments on the policy were analysed using categorization and thematic coding. A priori content analysis for themes of food democracy was followed by open, axial and selective coding for sub-themes on health disparities. Data and method triangulation and respondent validation were used to establish data dependability, trustworthiness and representativeness. SETTING: NYC. PARTICIPANTS: Interviews from a purposive, snowballed sample of thirty-three participants included restaurateurs, scientists, health and consumer advocates, consumers and policy makers. Additionally, 261 pages of transcript from public testimony of fifty-three participants and a purposive sample of public comments on the policy from a pool of 2157 were analysed. RESULTS: Principles of food democracy involving inclusive citizenship, access to information, collaborative participation and focus on collective good were well represented in the data. Additionally, sub-themes linked to health disparities included: government responsibility for fairer access to healthier foods; recognition that people made choices based on circumstances; concern for vulnerable groups; and outrage with a food industry viewed as unconcerned for public health. CONCLUSIONS: Principles of food democracy present in the successful process of adoption of the 2006 NYC trans fat policy addressed nutrition-related health. Food democracy is a contemporary food system and policy approach with potential for public health benefits in reducing nutrition-related health disparities.

The global fight against trans-fat: the potential role of international trade and law.

Non-communicable diseases in general and cardiovascular diseases in particular are a leading cause of death globally. Trans-fat consumption is a significant risk factor for cardiovascular diseases. The World Health Organization's 'REPLACE' action package of 2018 aims to eliminate it completely in the global food supply by 2023. Legislative and other regulatory actions (i.e., banning trans-fat) are considered as effective means to achieve such a goal. Both wealthier and poorer countries are taking or considering action, as shown by the United States food regulations and Cambodian draft food legislation discussed in this paper. This paper reviews these actions and examines public and private stakeholders' incentives to increase health-protecting or health-promoting standards and regulations at home and abroad, setting the ground for further research on the topic. It focuses on the potential of trade incentives as a potential driver of a 'race to the top'. While it has been documented that powerful countries use international trade instruments to weaken other countries' national regulations, at times these powerful countries may also be interested in more stringent regulations abroad to protect their exports from competition from third countries with less stringent regulations. This article explores practical and principled considerations on how such a dynamic may spread trans-fat restrictions globally. It argues that trade dynamics and public health considerations within powerful countries may help to promote anti-trans-fat regulation globally but will not be sufficient and is ethically questionable. True international regulatory cooperation is needed and could be facilitated by the World Health Organization. Nevertheless, the paper highlights that international trade and investment law offers opportunities for anti-trans-fat policy diffusion globally.

Maternal intake of trans-unsaturated or interesterified fatty acids during pregnancy and lactation modifies mitochondrial bioenergetics in the liver of adult offspring in mice.

The quality of dietary lipids in the maternal diet can programme the offspring to diseases in later life. We investigated whether the maternal intake of palm oil or interesterified fat, substitutes for trans-unsaturated fatty acids (FA), induces metabolic changes in the adult offspring. During pregnancy and lactation, C57BL/6 female mice received normolipidic diets containing partially hydrogenated vegetable fat rich in trans-unsaturated fatty acids (TG), palm oil (PG), interesterified fat (IG) or soyabean oil (CG). After weaning, male offspring from all groups received the control diet until day 110. Plasma glucose and TAG and liver FA profiles were ascertained. Liver mitochondrial function was accessed with high-resolution respirometry by measuring VO2, fluorimetry for detection of hydrogen peroxide (H2O2) production and mitochondrial Ca2+ uptake. The results showed that the IG offspring presented a 20 % increase in plasma glucose and both the IG and TG offspring presented a 2- and 1·9-fold increase in TAG, respectively, when compared with CG offspring. Liver MUFA and PUFA contents decreased in the TG and IG offspring when compared with CG offspring. Liver MUFA content also decreased in the PG offspring. These modifications in FA composition possibly affected liver mitochondrial function, as respiration was impaired in the TG offspring and H2O2 production was higher in the IG offspring. In addition, mitochondrial Ca2+ retention capacity was reduced by approximately 40 and 55 % in the TG and IG offspring, respectively. In conclusion, maternal consumption of trans-unsaturated and interesterified fat affected offspring health by compromising mitochondrial bioenergetics and lipid metabolism in the liver.

The association between fatty acid index and in vitro fertilization outcomes.

PURPOSE: Fatty acids have been shown to play an important role in oocyte competence and early implantation of the embryo. Our hypothesis-generating study sought to determine if individual fatty acids expressed as a percentage of total erythrocyte fatty acids are associated with embryo quality and other in vitro fertilization (IVF) outcomes. METHODS: This was a prospective cohort study at an academic fertility center. Sixty women undergoing their first IVF cycle were recruited. Serum measurements of 22 fatty acids were obtained. We calculated each fatty acid as a percentage of total fatty acids, defined as the index for that individual fatty acid. RESULTS: Omega-3 index had no correlation with IVF outcomes. A negative correlation was found between the trans fatty acid index, elaidic acid (EA), and IVF outcomes, including fertilization rate (r = - 0.261, p = 0.04), blastocyst conversion rate (r = - 0.41, p = 0.001), and number of usable blastocysts and embryos (r = - 0.411, p = 0.001). There was no correlation between EA index and number of oocytes retrieved, embryo grade, or clinical pregnancy. No consistent correlations were observed with the additional fatty acids analyzed. CONCLUSIONS: No correlation was observed between omega-3 index and IVF outcomes. Elevated erythrocyte EA index, the major trans fatty acid commonly consumed in hydrogenated oils, margarine, and fried foods, was negatively correlated with number of usable blastocysts and embryos, blastocyst conversion, and fertilization rate. Our findings suggest preliminary evidence that trans fat may be negatively associated with IVF outcomes.

Modulation of the voltage-dependent anion channel of mitochondria by elaidic acid.

Dietary trans fatty acids (TFAs) are known to increase the risk of cardiovascular diseases by altering plasma lipid profile and activating various inflammatory signaling pathways. Here we show that elaidic acid (EA), the most abundant TFA in diet, alters the electrophysiological properties of voltage-dependent anion channel (VDAC) of mitochondria. Purified bovine brain VDAC, when incorporated in the planar lipid bilayer (PLB) composed of 1,2-diphytanoyl-sn-glycero-3 phosphatidyl choline (DPhPC) and EA in a 9 to 1 ratio (wt/wt), exhibited complete closing events at different voltages. The closing events were observed at even -10 mV, a voltage at which VDAC usually remains fully open all the time. Additionally, the voltage sensitivity of VDAC was lost in presence of EA; the channel conductance did not decrease with increasing voltages. In identical experimental conditions, membrane containing oleic acid (OA), the cis isomer of EA did not produce any such effect. We propose that EA possibly exerts its adverse effect by modulating VDAC.

Dietary fat intakes in Irish adults in 2011: how much has changed in 10 years?

Imbalances in dietary fat intakes are linked to several chronic diseases. This study describes dietary intakes and food sources of fat and fatty acids in 1051 Irish adults (aged 18-90 years), using data from the 2011 national food consumption survey, the National Adult Nutrition Survey. It also compares current intakes for 18-64-year-olds with those reported in the last such survey in 2001, the North/South Ireland Food Consumption Survey. Dietary fat intakes were estimated using data from 4-d semi-weighed (2011) and 7-d estimated (2001) food diaries. In 2011, intakes for 18-64-year-olds were as follows: total fat, 34·1 (sd 6·1) % total energy (%TE); SFA, 13·3 (sd 3·3) %TE; MUFA, 12·5 (sd 2·6) %TE; PUFA, 6·1 (sd 2·2) %TE; and trans-fat, 0·511 (sd 0·282) %TE. Apart from MUFA, intakes decreased (P65 years had the highest intakes of SFA; however, intakes were typically higher than UK-recommended values for all groups. In contrast, intakes of long-chain n-3 fatty acids were lowest in younger age groups. Intakes of trans-fat were well within UK-recommended levels. Although there have been some improvements in the profile of intakes since 2001, imbalances persist in the quantity and quality of dietary fat consumed by Irish adults, most notably for total and SFA and for younger age groups for long-chain n-3 fatty acids.

Tick front-of-pack label has a positive nutritional impact on foods sold in New Zealand.

OBJECTIVE: Nutritional impact of the Tick front-of-pack labelling programme was evaluated by investigating nutrient changes to the purchased food supply and the nutritional quality of Tick v. non-Tick products. Factors influencing manufacturers' decisions to develop and license Tick products were also explored. DESIGN: Observational, cross-sectional and change over time data. SETTING: New Zealand food supply, 2011-2013. SUBJECTS: Forty-five newly licensed Tick products from five food categories were analysed: Edible Oil Spreads, Yoghurt & Dairy Desserts, Frozen Desserts, Ready Meals and Processed Poultry. Four manufacturers of these products were interviewed. RESULTS: Eligible products (31 % of all Tick products in these categories) removed 4·1 million megajoules of energy, 156·0 tonnes of saturated fat, 15·4 tonnes of trans-fat and 4·0 tonnes of sodium from food products sold in New Zealand over three years. In each food category, these Tick products were, on average, 14-76 % lower in energy, saturated fat, trans-fat and sodium than non-Tick products, indicating healthier options. Participating manufacturers reported that international market trends and consumer demand for tasty, healthy foods primarily influenced Tick product development and sales. Tick was used as part of their marketing strategy as it was perceived as a credible, well-recognised logo for New Zealand consumers. Tick was cited as the primary initiative encouraging saturated fat reduction. CONCLUSIONS: The Tick Programme is continuing to encourage manufacturers to make meaningful improvements to the nutritional quality of the New Zealand food supply. Over time, these changes are likely to influence population nutrient intakes and reduce CVD risk factors.

Fat composition of vegetable oil spreads and margarines in the USA in 2013: a national marketplace analysis.

Worldwide, the fat composition of spreads and margarines ("spreads") has significantly changed over the past decades. Data on fat composition of US spreads are limited and outdated. This paper compares the fat composition of spreads sold in 2013 to that sold in 2002 in the USA. The fat composition of 37 spreads representing >80% of the US market sales volume was determined by standard analytical methods. Sales volume weighted averages were calculated. In 2013, a 14 g serving of spread contained on average 7.1 g fat and 0.2 g trans-fatty acids and provided 22% and 15% of the daily amounts recommended for male adults in North America of omega-3 α-linolenic acid and omega-6 linoleic acid, respectively. Our analysis of the ingredient list on the food label showed that 86% of spreads did not contain partially hydrogenated vegetable oils (PHVO) in 2013. From 2002 to 2013, based on a 14 g serving, total fat and trans-fatty acid content of spreads decreased on average by 2.2 g and 1.5 g, respectively. In the same period, the overall fat composition improved as reflected by a decrease of solid fat (from 39% to 30% of total-fatty acids), and an increase of unsaturated fat (from 61% to 70% of total-fatty acids). The majority of US spreads no longer contains PHVO and can contribute to meeting dietary recommendations by providing unsaturated fat.

Elaidate, an 18-carbon trans-monoenoic fatty acid, but not physiological fatty acids increases intracellular Zn(2+) in human macrophages.

Artificial trans fatty acids promote atherosclerosis by blocking macrophage clearance of cell debris. Classical fatty-acid response mechanisms include TLR4-NF-κB activation, and Erk1/2 phosphorylation, but these may not indicate long-term mechanisms. Indeed, nuclear NF-κB was increased by 60 min treatment by 30 µM of the 18 carbon trans unsaturated fatty acid elaidic acid (elaidate), the physiological cis-unsaturated fatty acid oleic acid (oleate), and the 18 or 16 carbon saturated fatty acids stearic and palmitic acid (stearate or palmitate). However, except for stearate, effects on related pathways were minimal at 44 h. To determine longer term effects of trans fatty acids, we compared mRNA expression profiles of (trans) elaidate to (cis) oleate, 30 µM, at 44 h in human macrophages. We found that elaidate changed Zn(2+) -homeostasis gene mRNAs markedly. This might be important because Zn(2+) is a major regulator of macrophage activity. Messenger RNAs of seven Zn(2+) -binding metallothioneins decreased 2-4-fold; the zinc importer SLC39A10 increased twofold, in elaidate relative to oleate-treated cells. Results were followed by quantitative PCR comparing cis, trans, and saturated fatty acid effects on Zn(2+) -homeostasis gene mRNAs. This confirmed that elaidate uniquely decreased metallothionein expression and increased SLC39A10 at 44 h. Further, intracellular Zn(2+) was measured using N-(carboxymethyl)-N-[2-[2-[2(carboxymethyl) amino]-5-(2,7,-difluoro-6-hydroxy-3-oxo-3H-xanthen-9-yl)-phenoxy]-ethoxy]-4-methoxyphenyl]glycine, acetoxymethyl ester (FluoZin-3-AM). This showed that, at 44 h, only cells treated with elaidate had increased Zn(2+) . The durable effect of elaidate on Zn(2+) activation is a novel and specific effect of trans fatty acids on peripheral macrophage metabolism.

Aligning food-processing policies to promote healthier fat consumption in India.

India is undergoing a shift in consumption from traditional foods to processed foods high in sugar, salt and fat. Partially hydrogenated vegetable oils (PHVOs) high in trans-fat are often used in processed foods in India given their low cost and extended shelf life. The World Health Organization has called for the elimination of PHVOs from the global food supply and recommends their replacement with polyunsaturated fat to maximize health benefits. This study examined barriers to replacing industrially produced trans-fat in the Indian food supply and systematically identified potential policy solutions to assist the government in encouraging its removal and replacement with healthier polyunsaturated fat. A combination of food supply chain analysis and semi-structured interviews with key stakeholders was conducted. The main barriers faced by the food-processing sector in terms of reducing use of trans-fat and replacing it with healthier oils in India were the low availability and high cost of oils high in polyunsaturated fats leading to a reliance on palm oil (high in saturated fat) and the low use of those healthier oils in product reformulation. Improved integration between farmers and processors, investment in technology and pricing strategies to incentivize use of healthier oils for product reformulation were identified as policy options. Food processors have trouble accessing sufficient affordable healthy oils for product reformulation, but existing incentives aimed at supporting food processing could be tweaked to ensure a greater supply of healthy oils with the potential to improve population health.

Identifying the Barriers and Opportunities for Enhanced Coherence between Agriculture and Public Health Policies: Improving the Fat Supply in India.

The national Government of India has published draft regulation proposing a 5% upper limit of trans fat in partially hydrogenated vegetable oils (PHVOs). Global recommendations are to replace PHVOs with unsaturated fat but it is not known whether this will be feasible in India. We systematically identified policy options to address the three major underlying agricultural sector issues that influence reformulation with healthier oils: the low productivity of domestically produced oilseeds leading to a reliance on palm oil imports, supply chain wastage, and the low availability of oils high in unsaturated fats. Strengthening domestic supply chains in India will be necessary to maximize health gains associated with product reformulation.

Enhanced cold plasma hydrogenation with glycerol as hydrogen source for production of trans-fat-free margarine.

The quest for better nutritious foods has encouraged novel scientific investigations to find trans-fat reduction methods. This research proposes an innovative approach for the production of healthier trans-fat-free margarine from palm oil by the use of dielectric barrier discharge (DBD) plasma technology with glycerol serving as the principal source of hydrogen. The effectiveness of DBD plasma in hydrogenating palm olein was investigated. By employing a methodical series of experiments and thorough analytical approaches, examination of the saturated fatty acid conversion experienced its iodine value (IV) reduction from 67.16 ± 0.70 to 31.61 ± 1.10 under the optimal process parameters of 1 L min-1 He flow rate, 35 W plasma discharge power, 10 mm gap size, ambient initial temperature, and 12 h reaction time with solid texture. According to the method for producing trans-fat-free margarine in the absence of a catalyst and H2 gas, the hydrogenation rate of the prepared mixture of palm olein-glycerol was remarkably improved; the trans-fat content in the produced product was zero; the efficacy of incorporating cis- and trans-isomerization was lowered, and the method has a promising industrial application prospect.

The Lipid-Heart Hypothesis and the Keys Equation Defined the Dietary Guidelines but Ignored the Impact of Trans-Fat and High Linoleic Acid Consumption.

In response to a perceived epidemic of coronary heart disease, Ancel Keys introduced the lipid-heart hypothesis in 1953 which asserted that high intakes of total fat, saturated fat, and cholesterol lead to atherosclerosis and that consuming less fat and cholesterol, and replacing saturated fat with polyunsaturated fat, would reduce serum cholesterol and consequently the risk of heart disease. Keys proposed an equation that would predict the concentration of serum cholesterol (ΔChol.) from the consumption of saturated fat (ΔS), polyunsaturated fat (ΔP), and cholesterol (ΔZ): ΔChol. = 1.2(2ΔS - ΔP) + 1.5ΔZ. However, the Keys equation conflated natural saturated fat and industrial trans-fat into a single parameter and considered only linoleic acid as the polyunsaturated fat. This ignored the widespread consumption of trans-fat and its effects on serum cholesterol and promoted an imbalance of omega-6 to omega-3 fatty acids in the diet. Numerous observational, epidemiological, interventional, and autopsy studies have failed to validate the Keys equation and the lipid-heart hypothesis. Nevertheless, these have been the cornerstone of national and international dietary guidelines which have focused disproportionately on heart disease and much less so on cancer and metabolic disorders, which have steadily increased since the adoption of this hypothesis.

Short-term effects of dietary trans fatty acids compared with saturated fatty acids on selected measures of inflammation, fatty acid profiles, and production in early lactating Holstein dairy cows.

Feeding rations supplemented with fats may provide an opportunity to manipulate the health and performance of dairy cows; however, the relative effects of specific fats, such as trans fatty acids (TFA), are poorly understood. The objective of this study was to investigate the effects of a ration supplemented with TFA on the fatty acid (FA) profile of peripheral blood mononuclear cells (PBMC), plasma lipids, and milk; the gene expression of inflammatory markers; production of acute phase proteins; and production performance in early lactating dairy cows. Trans fat was fed at 0, 1.5, and 3% of dry matter, replacing (1:1 wt:wt) saturated fatty acids (SFA). Multiparous lactating Holstein cows at 7 d in milk (n=12) were randomly assigned to a treatment sequence in a 3 × 3 balanced Latin square design; each period lasted 14 d. Milk and heparinized blood were collected on d 0 (pretreatment) and on d 10 and 14 of each period. Plasma was collected and solid-phase extraction was used to isolate plasma phospholipids and nonesterified fatty acids. Additionally, PBMC were isolated for FA analysis and gene expression analysis by reverse transcription-PCR using bovine RPS9 as the endogenous control. The FA composition of PBMC, plasma lipid fractions, and milk were analyzed by gas chromatography. Data were analyzed using the MIXED procedure (SAS Institute Inc., Cary, NC). As dietary TFA increased, the percentage of some 18:1 trans isomers increased in PBMC, plasma lipids, and milk. Dietary TFA had no detectable effect on mRNA expression of proinflammatory TNFα or IL6. Expression of IL1ß and ICAM1 decreased with increasing TFA. In addition, supplementation of TFA did not affect percentages of milk fat, protein, lactose, or solids-not-fat, or somatic cell count. Overall, dietary TFA increased the trans FA present in PBMC, plasma lipids, and milk; however, dietary TFA decreased PBMC expression of some of the proinflammatory markers tested at the mRNA level compared with SFA in early lactating dairy cows. Together, these findings provide evidence that over short period of times, dietary TFA might be slightly less immune-stimulatory than dietary SFA.