Emerging Nutrition Science on Fatty Acids and Cardiovascular Disease: Nutritionists’ Perspectives

Recent dietary guidance for heart health recommends a reduction (by ∼50%) in saturated fatty acid (SFA) intake to reduce LDL cholesterol and to decrease risk of cardiovascular disease (CVD). The 2010 Dietary Guidelines for Americans recommends substituting unsaturated fat [both polyunsaturated and monounsaturated fatty acids (PUFAs and MUFAs, respectively)] for SFAs. There are many dietary options that can be implemented to replace SFAs, given the different sources of unsaturated fats in the food supply. Compelling evidence exists for the cardioprotective benefits of n–3 (ω-3) PUFAs, both marine- and plant-derived. In addition, the evidence of cardioprotective benefits of n–6 (ω-6) PUFAs is strong, whereas that for MUFAs is mixed, although there is emerging evidence of benefits. Quantitatively, lowering SFAs by 50% will require, in part, substituting food sources of n–6 and n–3 PUFAs and MUFAs for food sources of SFAs. The use of n–3 PUFAs as a replacement for SFAs will result in a shortfall in reaching the SFA goal because of the relatively low amounts that can be incorporated in the diet, even with very high n–3 PUFA substitution. SFAs also can be replaced with dietary carbohydrate and/or protein. Replacing SFAs with carbohydrate, specifically refined sources, however, has little impact on reducing CVD risk. There is evidence about the health benefits of dietary protein on CVD risk, which merits study. Dietary guidelines have advanced considerably with the “replacement of SFA with unsaturated fat message” instead of recommending decreasing SFAs alone. A key question that remains is what is the optimal mix of macronutrients to maximally reduce CVD risk.     

Saturated fatty acids intake in relation to C-reactive protein,adiponectin, and leptin: A population-based study

ObjectiveEvidence on the relation of saturated fatty acids (SFA) with inflammatory markers and adipokines is scarce and inconsistent. This study aimed to evaluate the association of the intake of total SFA, their subtypes (lauric, myristic, palmitic, and stearic acids), and SFA to polyunsaturated fatty acids (PUFA) ratio (SFA/PUFA ratio) with serum concentrations of high-sensitivity C-reactive protein (hs-CRP), adiponectin, and leptin among Portuguese adults.MethodsWe studied 395 non-institutionalized inhabitants of Porto (52.2% women; age range: 26–64 y) who were evaluated in 2010–2011, as part of EPIPorto study. Fatty acids intake was assessed with a validated semi-quantitative food frequency questionnaire. Blood was sampled after an overnight fast and serum concentrations of hs-CRP (through particle-enhanced immunonephelometry), adiponectin, and leptin (through radioimmunoassay) were determined. Regression coefficients (β) and 95% confidence intervals (CI) were obtained from linear regression models, stratified by sex.ResultsAfter adjusting for age, education, regular physical exercise, smoking, and central body fat percentage, hs-CRP was significantly and positively associated with lauric (β = 0.218; 95% CI, 0.071–0.365) and myristic acids (β = 0.220; 95% CI, 0.073–0.368) and with SFA/PUFA ratio (β = 0.171; 95% CI, 0.022–0.320) in men, but not in women. For adiponectin and leptin, no significant associations with SFA intake were observed in either sex.ConclusionsA detrimental role of lauric and myristic acids and of high SFA/PUFA ratio is suggested by their association with elevated hs-CRP concentrations in men. Our findings may be helpful in the planning of dietary modifications aimed at the modulation of inflammatory activity that could be an intermediate step to coronary events.     

Total fat intake is associated with decreased mortality in Japanese men but not in women

Dietary guidelines generally recommend avoiding a high-fat diet. However, the relationship between fat subtypes and mortality remains unclear especially in a population with a relatively low intake of fat. We aimed to prospectively examine the relationship between dietary fat intake and all-cause and cause-specific mortality in a Japanese community. In 1992, a total of 28,356 residents of Takayama, Japan, without cancer, stroke, or coronary heart disease, responded to a validated 169-item FFQ. We identified 4616 deaths during a 16-y follow-up. The HR of mortality according to the percentage of energy from the total and subtypes of fat when substituted for an isoenergic quantity of carbohydrate was calculated after controlling for potential confounders. A high intake of total fat and PUFA was associated with a decrease in all-cause mortality in men; the HR for the highest compared with the lowest quintile were 0.83 (95% CI: 0.70, 0.99; P-trend = 0.048) for total fat and 0.77 (95% CI: 0.62, 0.95; P-trend = 0.05) for PUFA. Both fats were associated with a decrease in mortality from cancer and diseases other than cardiovascular disease. In women, a higher SFA intake was associated with higher all-cause mortality [HR = 1.22 (95% CI: 0.99, 1.49; P-trend = 0.03)]. A favorable effect was suggested for total fat and PUFA intakes on mortality in men except for that from cardiovascular disease, whereas increased SFA intake may be associated with adverse health consequences in women.     

The role of reducing intakes of saturated fat in the prevention of cardiovascular disease: where does the evidence stand in 2010?

Current dietary recommendations advise reducing the intake of saturated fatty acids (SFAs) to reduce coronary heart disease (CHD) risk, but recent findings question the role of SFAs. This expert panel reviewed the evidence and reached the following conclusions: the evidence from epidemiologic, clinical, and mechanistic studies is consistent in finding that the risk of CHD is reduced when SFAs are replaced with polyunsaturated fatty acids (PUFAs). In populations who consume a Western diet, the replacement of 1% of energy from SFAs with PUFAs lowers LDL cholesterol and is likely to produce a reduction in CHD incidence of ≥2-3%. No clear benefit of substituting carbohydrates for SFAs has been shown, although there might be a benefit if the carbohydrate is unrefined and has a low glycemic index. Insufficient evidence exists to judge the effect on CHD risk of replacing SFAs with MUFAs. No clear association between SFA intake relative to refined carbohydrates and the risk of insulin resistance and diabetes has been shown. The effect of diet on a single biomarker is insufficient evidence to assess CHD risk. The combination of multiple biomarkers and the use of clinical endpoints could help substantiate the effects on CHD. Furthermore, the effect of particular foods on CHD cannot be predicted solely by their content of total SFAs because individual SFAs may have different cardiovascular effects and major SFA food sources contain other constituents that could influence CHD risk. Research is needed to clarify the role of SFAs compared with specific forms of carbohydrates in CHD risk and to compare specific foods with appropriate alternatives.     

Dietary Intake of Specific Fatty Acids and Breast Cancer Risk Among Postmenopausal Women in the VITAL Cohort

Studies of dietary fat intake and breast cancer have been inconsistent and few have examined specific fatty acids. We examined the association between specific monounsaturated (MUFA), polyunsaturated (PUFA), saturated (SFA), and trans-fatty acids (TFA) and breast cancer risk. Participants, 50–76 yr, were female members of the VITamins And Lifestyle (VITAL) Cohort, who were postmenopausal at baseline. In 2000–2002, participants completed a food frequency questionnaire. Seven hundred seventy-two incident, primary breast cancer cases were identified using a population-based cancer registry. Cox proportional hazard models estimated hazard ratios (HR) and 95% confidence intervals (95% CI) for the association between fatty acid intake and breast cancer risk. Intake of total MUFAs (highest vs. lowest quintile: HR = 1.61, 95% CI: 1.08–2.38, P trend = 0.02), particularly myristoleic and erucic acids, was associated with increased breast cancer risk. Whereas total SFA was suggestive of an increased risk (HR = 1.47, 95% CI: 1.00–2.15, P trend = 0.09), strong associations were observed for palmitic, margaric, and stearic acids. Total TFA and PUFA intake were not associated with breast cancer. However, among TFAs, linolelaidic acid was positively associated with risk; among PUFAs, intake of eicosapentaenoic and docosahexaenoic acids were inversely associated with risk. Our findings show that fatty acids are heterogeneous in their association with postmenopausal breast cancer risk.     

The Mediterranean-type diet: is there a need for further modification?

The effects on plasma lipoproteins of four fat-modified diets were assessed in 11 nuns in a contemplative order in the Mediterranean region of Spain. Diet 1 [high polyunsaturated fatty acid (PUFA), low monounsaturated fatty acid (MUFA), low ratio of PUFAs to saturated fatty acids (P:S)] and diet 3 (low PUFA, high MUFA, low P:S) induced significant, directly comparable reductions in total plasma (12% and 13%, respectively) and low-density-lipoprotein (LDL) cholesterol (24% and 19%, respectively). Diet 2 [high PUFA, high MUFA, low saturated fatty acid (SFA), high P:S] induced greater decrements (23% and 30% in total plasma and LDL cholesterol, respectively). Diet 4 (low PUFA, low MUFA, high SFA, low P:S) induced a significant increase in LDL cholesterol of 11%. No significant changes in high-density-lipoprotein cholesterol were observed with these diets. Because the effects of PUFAs and MUFAs are comparable, no recommendations on modifying the habitual, high-MUFA-containing Mediterranean diet need be made other than, perhaps, a reduction in the overall intake of SFAs.     

Food uses and health effects of corn oil

This review of corn oil provides a scientific assessment of the current knowledge of its contribution to the American diet. Refined corn oil is composed of 99% triacylglycerols with polyunsaturated fatty acid (PUFA) 59%, monounsaturated fatty acid 24%, and saturated fatty acid (SFA) 13%. The PUFA is linoleic acid (C18:2n-6) primarily, with a small amount of linolenic acid (C18:3n-3) giving a n-6/n-3 ratio of 83. Corn oil contains a significant amount of ubiquinone and high amounts of alpha- and gamma-tocopherols (vitamin E) that protect it from oxidative rancidity. It has good sensory qualities for use as a salad and cooking oil. Corn oil is highly digestible and provides energy and essential fatty acids (EFA). Linoleic acid is a dietary essential that is necessary for integrity of the skin, cell membranes, the immune system, and for synthesis of icosanoids. Icosanoids are necessary for reproductive, cardiovascular, renal, and gastrointestinal functions and resistance to disease. Corn oil is a highly effective food oil for lowering serum cholesterol. Because of its low content of SFAs which raises cholesterol and its high content of PUFAs which lowers cholesterol, consumption of corn oil can replace SFAs with PUFAs, and the combination is more effective in lowering cholesterol than simple reduction of SFA. PUFA primarily lowers low-density-lipoprotein cholesterol (LDL-C) which is atherogenic. Research shows that PUFA has little effect on high-density-lipoprotein cholesterol (HDL-C) which is protective against atherosclerosis. PUFA generally improves the ratio of LDL-C to HDL-C. Studies in animals show that PUFA is required for the growth of cancers; the amount required is considered to be greater than that which satisfies the EFA requirement of the host. At this time there is no indication from epidemiological studies that PUFA intake is associated with increased risk of breast or colon cancer, which have been suggested to be promoted by high-fat diets in humans. Recommendations for minimum PUFA intake to prevent gross EFA deficiency are about 3% of energy (en%). Recommendations for prevention of heart disease are 8-10 en%. Consumption of PUFA in the United States is 5-7 en%. The use of corn oil to contribute to a PUFA intake of 10 en% in the diet would be beneficial to heart health. No single source of salad or cooking oil provides an optimum fatty acid (FA) composition. Many questions remain to be answered about the relation of FA composition of the diet to various physiological functions and disease processes.     

Association between interaction and ratio of ω-3 and ω-6 polyunsaturated fatty acid and the metabolic syndrome in adults

ObjectiveTo investigate the association of the intakes of ω-3 (including α-linolenic acid [ALA], eicosapentaenoic acid [EPA] plus docosahexaenoic acid [DHA]) and ω-6 polyunsaturated fatty acids (PUFAs), the interaction, and the ratio of these PUFAs with the metabolic syndrome (MetS) in adults.MethodsThis cross-sectional study was conducted in a random sample of participants (n = 2451, 19–84 y old) in the Tehran Lipid Glucose Study. Dietary intake was assessed using a validated semiquantitative food-frequency questionnaire. Anthropometric characteristics, blood pressure, and fasting plasma concentrations of glucose and lipids were measured. The MetS was defined according to the Adult Treatment Panel III guidelines.ResultsAmong the PUFAs, the ALA and ω-6 PUFA intakes were inversely associated with the MetS. Subjects in the highest quartile of ALA and ω-6 fatty acid intakes had a 38% (odds ratio 0.62, 95% confidence interval 0.41–0.95) and a 0.47% (odds ratio 0.53, 95% confidence interval 0.31–0.89) lower prevalence of MetS, respectively, compared with those in the lowest quartile. The dietary ratio of ω-6 to ω-3 fatty acids was not associated with the MetS. When the interaction between ALA and ω-6 fatty acid was assessed, the ALA intake was associated with a lower prevalence of the MetS, without modification by the ω-6 PUFA intake. Subjects with at least the median ALA intake (1084 mg/d) had a lower prevalence of the MetS, irrespective of an ω-6 PUFA intake lower or higher than the median compared with subjects with intakes below the median for both.ConclusionThe ALA intake was inversely associated with the MetS, irrespective of the background intake of ω-6 PUFAs, in adults.     

Food uses and health effects of corn oil.

This review of corn oil provides a scientific assessment of the current knowledge of its contribution to the American diet. Refined corn oil is composed of 99% triacylglycerols with polyunsaturated fatty acid (PUFA) 59%, monounsaturated fatty acid 24%, and saturated fatty acid (SFA) 13%. The PUFA is linoleic acid (C18:2n-6) primarily, with a small amount of linolenic acid (C18:3n-3) giving a n-6/n-3 ratio of 83. Corn oil contains a significant amount of ubiquinone and high amounts of alpha- and gamma-tocopherols (vitamin E) that protect it from oxidative rancidity. It has good sensory qualities for use as a salad and cooking oil. Corn oil is highly digestible and provides energy and essential fatty acids (EFA). Linoleic acid is a dietary essential that is necessary for integrity of the skin, cell membranes, the immune system, and for synthesis of icosanoids. Icosanoids are necessary for reproductive, cardiovascular, renal, and gastrointestinal functions and resistance to disease. Corn oil is a highly effective food oil for lowering serum cholesterol. Because of its low content of SFAs which raises cholesterol and its high content of PUFAs which lowers cholesterol, consumption of corn oil can replace SFAs with PUFAs, and the combination is more effective in lowering cholesterol than simple reduction of SFA. PUFA primarily lowers low-density-lipoprotein cholesterol (LDL-C) which is atherogenic. Research shows that PUFA has little effect on high-density-lipoprotein cholesterol (HDL-C) which is protective against atherosclerosis. PUFA generally improves the ratio of LDL-C to HDL-C. Studies in animals show that PUFA is required for the growth of cancers; the amount required is considered to be greater than that which satisfies the EFA requirement of the host. At this time there is no indication from epidemiological studies that PUFA intake is associated with increased risk of breast or colon cancer, which have been suggested to be promoted by high-fat diets in humans. Recommendations for minimum PUFA intake to prevent gross EFA deficiency are about 3% of energy (en%). Recommendations for prevention of heart disease are 8-10 en%. Consumption of PUFA in the United States is 5-7 en%. The use of corn oil to contribute to a PUFA intake of 10 en% in the diet would be beneficial to heart health. No single source of salad or cooking oil provides an optimum fatty acid (FA) composition. Many questions remain to be answered about the relation of FA composition of the diet to various physiological functions and disease processes.     

Plasma fatty acid composition is associated with the metabolic syndrome and low-grade inflammation in overweight adolescents

BACKGROUND: Together with adiposity, plasma fatty acid (FA) composition can modulate the development of the metabolic syndrome (MS). OBJECTIVE: Our aim was to investigate the relations of FA composition in plasma phospholipids and cholesterol esters (CEs) with weight status, MS, and inflammation in adolescents. DESIGN: Plasma FA composition was measured by gas-liquid chromatography in 120 (60 normal-weight and 60 overweight) 12-y-old adolescents. We also measured the presence of MS, insulin resistance with the homeostasis model assessment, and interleukin 6 and C-reactive protein concentrations in the adolescents. RESULTS: MS was present in 25% of the overweight adolescents but in none of the normal-weight adolescents. Compared with overweight adolescents, normal-weight adolescents had lower saturated FAs (SFAs) in both phospholipids (P < 0.001) and CEs (P < 0.01) and higher docosahexaenoic acid in phospholipids (P < 0.001). In overweight subjects, FA composition was associated with MS features independent of body fat. The odds ratios of MS for a 0.1 increase in the ratio of polyunsaturated FAs (PUFA) to SFAs (PUFA:SFA) were 0.91 in phospholipids (P = 0.03) and 0.90 in CEs (P = 0.06). In phospholipids, PUFA:SFA and linoleic acid were associated positively with HDL cholesterol (P < 0.01 for both). PUFA:SFA in phospholipids and CEs were associated inversely with interleukin 6 (P < 0.05 for both). Eicosapentaenoic acid in phospholipids (P = 0.06) and CEs (P < 0.05) and linolenic acid in CEs (P < 0.05) were inversely related to C-reactive protein. These relations remained significant after adjustment for the waist-to-hip ratio. No significant relation between FA composition and the homeostasis model assessment was observed. CONCLUSIONS: Plasma FA composition is associated with weight status in healthy adolescents. High intake of long-chain PUFAs, especially n-3 PUFAs, may protect obese subjects against MS and low-grade inflammation as early as adolescence.     

Fat intake in children with autism spectrum disorder in the Mediterranean region (Valencia,Spain)

Objective: Children with autism spectrum disorder (ASD) have been found to have alterations in dietary fat intake and fat quality. The fat intakes of the foods consumed by children with and without ASD were compared, and the deficiency and excess of these nutrients were examined.

Methods: In a matched case–control study, 3-day food diaries were completed by 105 children with ASD and 495 typically developing (TD) 6- to 9-year-old children in Valencia (Spain). We used the probabilistic approach and estimated average requirement cut-point to evaluate the risk of inadequate nutrients intakes. These were compared between groups and with Spanish recommendations using linear and logistic regression, respectively.

Results: Groups did not differ significantly in age, total dietary intake, Healthy Eating Index, or food variety score. Children with ASD had lower saturated fatty acids (SFAs) and ω-3 polyunsaturated fatty acids (PUFAs) intakes, but their total PUFAs and (PUFAs?+?monounsaturated fatty acids (MUFAs)/SFAs, PUFAs/SFAs intakes and ω-6/ω-3 ratios were higher than TD children. The total fat and cholesterol intakes of both groups were slightly above Spanish recommendations. Both groups had low ω-6 intakes, very low ω-3 intakes, and high ω-6/ω-3 ratios.

Conclusion: Further research is required to clarify associations between ASD symptomatology, fat-eating patterns and health status.     

Cholesterol, phytosterol and polyunsaturated fatty acid levels in 1982 and 1957 Japanese diets

The dietary intake of cholesterol, phytosterol and PUFA in Japanese was investigated to obtain information on dietary parameters related to coronary artery disease. Three daily menus for both 1957 and 1982 were prepared based on the daily per capita consumption of foods and nutrient intakes from national surveys. From 1957 to 1982, the average daily intake of cholesterol rose 2.1-fold from 183 to 376 mg while that of phytosterol remained at about 373 mg. Daily intakes of total fatty acid (19.2 g), PUFA (7.3 g), MUFA (5.8 g) and SFA (6.1 g) in 1957 increased in 1982 to 48.7 g, 11.9 g, 19.5 g and 17.3 g, respectively. The ratio of PUFA/SFA decreased to 56% from 1.23 in 1957 to 0.69 in 1982 and the PUFA/MUFA ratio also decreased to 48%. The PUFA/cholesterol ratio was lower in 1982 (31.8) than in 1957 (42.6), and the decrease in the phytosterol/cholesterol ratio to 46% was greater than that in the PUFA/cholesterol ratio (which only fell to 75% of the 1957 value). Thus, comparison of the 1982 and 1957 intakes indicated the increase in risk factors, cholesterol and SFA intake, and the decrease in the ratio of PUFA/SFA in the Japanese population during the past few decades.     

High dietary saturated fat intake accentuates obesity risk associated with the fat mass and obesity-associated gene in adults

Fat mass and obesity-associated (FTO) is the strongest genetic determinant of obesity identified to date. Dietary fat is a key environmental factor that may interact with genotype to affect risk of obesity and metabolic syndrome (MetS). This study investigated associations among FTO rs9939609, obesity measures, and MetS phenotypes in adults and determined potential modulation by dietary fat intake at baseline and after a 7.5-y follow-up when MetS cases and controls were selected. FTO rs9939609 genotype, biochemical, dietary, and lifestyle measurements were determined in the LIPGENE-SU.VI.MAX study (n = 1754). FTO rs9939609 A allele carriers had a higher risk of being overweight or obese [OR = 1.66 (95% CI: 1.07, 2.57); P = 0.02] and of having a larger abdominal circumference [OR = 1.42 (95% CI: 1.01, 1.99); P = 0.04] compared with the TT homozygotes. These associations were independent of physical activity and energy intake and were maintained over the follow-up period, particularly in the MetS individuals. High dietary SFA intake (≥ 15.5% energy) and a low dietary PUFA:SFA intake ratio (<0.38) further accentuated the risk of having a BMI ≥ 25 kg/m(2) and being abdominally obese. Non-risk allele carriers appeared to be unresponsive to dietary SFA intake or to the dietary PUFA:SFA intake ratio with respect to obesity measures. In conclusion, FTO rs9939609 was associated with obesity measures, especially in those with the MetS, which was further exacerbated by high dietary SFA intake at baseline and 7.5 y later. These data indicate important novel modulation of genetic risk by dietary fat exposure in individuals with increased cardiometabolic risk.     

Australian children are not consuming enough long-chain omega-3 polyunsaturated fatty acids for optimal health

ObjectivesTo determine children’s polyunsaturated fatty acid (PUFA) intakes, compare these with adequate intake and adjusted suggested dietary targets, and determine if intakes between children of different body weight and physical activity levels differed.MethodsThe necessary data files were obtained from the Australian Social Science Data Archive and were merged for 4486 children 2 to 16 y old, with physical activity data collected only for children 5 to 16 y old.ResultsThe median (interquartile range) PUFA intakes at 2 to 3, 4 to 8, 9 to 13, and 14 to 16 y were 4.7 g (3.1–6.2), 6.0 g (4.4–8.1), 7.1 g (5.3–9.7), and 8.5 g (6.0–11.3), respectively, for linoleic acid; 0.75 g (0.57–1.0), 0.91 g (0.67–1.2), 1.02 g (0.73–1.42), and 1.15 g (0.81–1.62), respectively, for α-linolenic acid; and 56 mg (29–104), 68 mg (37–128), 88 mg (46–159), and 98 mg (49–190), respectively, for long-chain (LC) ω-3 PUFAs. Most children met the adequate intakes for linoleic acid and α-linolenic acid, but only 50% to 60% of children met the adequate intake for LC ω-3 PUFAs. Furthermore, only 6% of children met the adjusted suggested dietary target for LC ω-3 PUFA per day. Comparison of LC ω-3 PUFA tertile intakes showed no differences in intakes in different weight categories and physical activity levels.ConclusionMost Australian children are not consuming enough LC ω-3 PUFAs for optimal health.     

Serum lipid profile and fatty acid composition of erythrocyte phospholipids in children and adolescents with primary hyperlipidemia

This study aimed at characterizing the fatty acid (FA) composition of red blood cell (RBC) phospholipids in children and adolescents with primary hyperlipidemia, and to ascertain potential association with serum lipid profile and dietary factors. At this purpose, 54 probands aged 6–17 years were recruited. Subjects showed a low omega-3 index (eicosapentaenoic acid, EPA?+?docosahexaenoic acid, DHA <4%). Compared to males, females had a trend toward lower levels of total monounsaturated fatty acids (MUFA) and MUFA/saturated fatty acids (SFAs) ratio in RBCs. An inverse relationship between MUFA concentration in RBCs and serum cholesterol or HDL-C/triglycerides ratio was found. Omega-6 polyunsaturated fatty acids (n-6 PUFA) were positively associated to serum HDL-C levels, and inversely to dietary cholesterol. Fiber intake was positively associated with MUFA/SFA ratio. In conclusion, we provide the first experimental data on phospholipid FA composition of RBCs in hyperlipidemic children, showing sex differences and an overall low omega 3-index.     

Threshold Effects of Total Copper Intake on Cognitive Function in US Older Adults and the Moderating Effect of Fat and Saturated Fatty Acid Intake

BackgroundEvidence for a relationship between total copper intake and cognition is lacking, and few studies have assessed the moderating effect of dietary fat and saturated fatty acid (SFA) intake on this relationship.ObjectiveOur aim was to explore the curvilinear association between total copper intake and cognitive function in older adults, and to clarify the moderating effect of dietary fat and SFA intake on the association.DesignThis was a cross-sectional analysis of data from National Health and Nutrition Examination Surveys 2011-2014.ParticipantsThe analysis included 2,483 participants aged 60 years and older.Main outcome measuresCognitive function was evaluated by the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Word Learning subtest, the Animal Fluency Test, and the Digit Symbol Substitution Test (DSST).Statistical analyses performedSmooth curve fitting and two-piecewise linear regression models were performed to address the nonlinear association between total copper intake and cognitive function. Multivariable quadratic regression models and analyses stratified by total fat or SFA intake were used to assess the effects of the interaction between copper and fat intake and between copper and SFA intake on cognitive function.ResultsThere was a nonlinear association between total copper intake and cognitive test scores. The inflection point of copper was 0.8 mg/d for the Consortium to Establish a Registry for Alzheimer’s Disease Word Learning subtest and 1.4 mg/d for both the Animal Fluency test and the DSST. When copper intake was below the inflection point, positive associations were apparent for copper intake and Consortium to Establish a Registry for Alzheimer’s Disease Word Learning subtest scores (β = 3.9; 95% CI 1.2 to 6.5), Animal Fluency test scores (β = 1.7, 95% CI .9 to 2.6), and DSST scores (β = 6.0, 95% CI 3.8 to 8.3). When copper intake was above the inflection point, a nonsignificant downward trend was found. Interactive effects between total copper and total fat intake (P interaction = .000) and between total copper and SFA intake (P interaction = .011) on the DSST scores were observed. In the low fat intake and low SFA intake groups, DSST scores first increased and then decreased with increasing copper. However, in the high fat intake and high SFA intake groups, DSST scores first increased and then flattened with increasing copper.ConclusionsThe present study suggests a nonlinear association between copper intake and cognitive function and identifies threshold effects of copper intake on cognitive function. Copper intake below the inflection point was positively and independently associated with cognitive function. High fat and high SFA intake may protect older adults against a decline in DSST scores related to high copper intake.     

Changes in dietary intake and food sources of saturated and cis and trans unsaturated fatty acids in Costa Rican adolescents: 1996 versus 2006

ObjectiveTo identify how dietary intake and food sources of saturated (SFA) and cis (PUFA) and trans (TFA) unsaturated fatty acids in the diet of Costa Rican adolescents changed from 1996 to 2006—a period with several public health nutrition changes.MethodsCross-sectional comparisons used data from measured food records of 133 adolescents (ages 12–17 y) surveyed in 1996 and a similar group of adolescents surveyed in 2006. Values obtained in 1996 and 2006 were compared with the current World Health Organization guidelines for chronic disease prevention.ResultsAdolescents surveyed in 2006 reported a significantly higher mean daily energy intake from linoleic acid (LA) and alpha-linolenic acid (ALA) (0.9% and 7.8%, respectively) compared with the 1996 cohort, whereas SFA and TFA were significantly lower (9.5% and 1.3%, respectively). Food sources of fat also changed. In 2006, 2% of SFA in the diet came from palm shortening (compared with 34% in 1996); 39% of TFA came from ruminant-derived foods (in 1996, soybean oil was the main contributor of TFA, 34%), and bakery products (mainly pre-packaged cookies) provided 25% of the source of TFA, compared with only 11% in 1996. Dietary fatty intake of Costa Rican adolescents in 2006 is closer to WHO guidelines compared with 1996.ConclusionsAfter public health initiatives that changed fatty acid profile of most foods, intakes of TFA, SFA, and food sources of fatty acids in adolescents’ diets improved. Public health nutrition efforts should continue to strengthen diets that are low in SFA and TFA and higher in ALA content among Costa Rican adolescents.     

Polyunsaturated fatty acid intake is adversely related to liver function in HIV-infected subjects: the THUSA study

BACKGROUND: Dietary fat intake in the South African population is increasing. This population also has a high prevalence of HIV infection. However, information about metabolic effects of dietary fatty acids on HIV-infected subjects is lacking. OBJECTIVE: Our objective was to investigate the relation between dietary fatty acid intake and liver function in HIV-infected compared with HIV-uninfected subjects. DESIGN: This cross-sectional epidemiologic survey included a representative sample of 1854 apparently healthy black volunteers aged > or =15 y, who were recruited from 37 randomly selected sites throughout the North West province of South Africa. Data from 216 asymptomatic HIV-infected and 1604 HIV-uninfected subjects were used. RESULTS: Intakes of polyunsaturated fatty acids (PUFAs), linoleic acid (n-6), and the ratio of PUFAs to saturated fatty acids (SFAs) were positively associated with all the liver enzymes measured in HIV-infected subjects (R = 0.16-0.65). Most of these R values differed significantly from the R values for HIV-uninfected subjects. No associations were seen between liver enzymes and intakes of SFAs and monounsaturated fatty acids. Vitamin E intake was positively associated with serum gamma-glutamyl transpeptidase (R = 0.23), alanine aminotransferase (R = 0.37), and aspartate aminotransferase (R = 0.58) in HIV-infected subjects; these correlations differed significantly from those of the HIV-uninfected subjects because PUFA sources are the main carriers of vitamin E. CONCLUSIONS: The results suggest that n-6 PUFA intakes may be related to liver damage in these HIV-infected asymptomatic subjects. The reasons or mechanisms responsible are not clear, and further research is necessary to determine the optimal safe amounts for intake of n-6 PUFAs by HIV-infected subjects, especially in countries with traditionally high intakes of n-6 PUFA-rich vegetable oils.     

Moderate Freshwater Fish Intake,but Not n-3 Polyunsaturated Fatty Acids,Is Associated with a Reduced Risk of Small for Gestational Age in a Prospective Cohort of Chinese Pregnant Women

BackgroundAlthough previous studies have found that maternal fish intake is associated with fetal growth, the role of freshwater fish intake remains unknown.ObjectiveOur aim was to examine the relationships of freshwater fish and n-3 polyunsaturated fatty acids (PUFAs) intake with the risk of small for gestational age (SGA) in Chinese pregnant women.DesignThis was a prospective analysis of data from the Tongji Birth cohort in Wuhan, China, from 2018 to 2021.Participants/settingsThis study included 1,701 pregnant women who had completed a food frequency questionnaire dietary assessment during mid-pregnancy.Main outcome measuresIntake of fish was assessed by a semi-quantitative food frequency questionnaire. Total intake of n-3 PUFAs was the sum of data collected from both dietary and supplemental sources of n-3 PUFAs. Birth information was extracted from medical records.Statistical analysesMultivariate logistic regression models were applied to estimate odds ratios and 95% CIs.ResultsThe median (interquartile range) intake of freshwater fish and total n-3 PUFAs was 12.1 (4.3 to 26.4) g/d and 68.2 (24.5 to 370.0) mg/d, respectively. Moderate intake of freshwater fish was associated with reduced risk of SGA. Compared with the lowest quintile (0–3.2 g/d), the multivariable-adjusted odds ratio for women in the fourth quintile of freshwater fish intake (17.9 to 30.0 g/d) was 0.50 (95% CI 0.25 to 0.96). We found a nonlinear association between freshwater fish intake and SGA risk (P_nonlinearity = .027). However, maternal n-3 PUFAs intake was not significantly associated with SGA risk, either from total intake or from dietary sources alone.ConclusionsModerate freshwater fish intake during pregnancy is associated with lower risk of SGA in a Chinese population. This finding provides supportive evidence for freshwater fish intake during pregnancy, particularly for the inland areas of developing countries.