Trans-unsaturated Fat Research Articles

Putting saturated fat in context-replacement and total intake matter.

The manuscript ‘Saturated Fat: Villain and Bogeyman in the Development of Cardiovascular Disease?’ was recently published in European Journal of Preventive Cardiology.1 Given the extraordinary importance of nutrition on health, we would like to contextualize this review and help avoid unnecessary public confusion. We agree with the authors that complexities exist in nutritional research. With regard to this specific review, it is important to consider what macronutrient may have replaced saturated fatty acids (SFA) in cited studies. Specifically, was SFA replaced with polyunsaturated fatty acids (PUFAs), monounsaturated fatty acids (MUFAs), or healthful carbohydrates such as whole grains? Or was SFA replaced with refined grains, sugar, or harmful trans unsaturated fats? Many of the SFA studies and reviews cited by the authors did not account for replacement or were in the context of replacement with refined carbohydrates or trans fat. When replacement is accounted for, the adverse effects of SFA on cardiovascular outcomes are much more consistent. The authors actually report several meta-analyses of observational studies and clinical trials showing that replacing SFA with PUFA is associated with reduced risk of cardiovascular disease, even though they conclude these beneficial effects ‘remain elusive’. This was also demonstrated in a 2015 study of over 120 000 individuals showing that replacement of SFA with PUFA as well as MUFA or whole-grain carbohydrates was associated with improved cardiovascular outcomes, while replacement with refined carbohydrates or smaller amounts of trans fat was associated with no difference.2 Though this particular study accounted for replacement macronutrients and met all inclusion criteria for the authors’ review, it was not cited. The authors also failed to mention that several older studies supposedly vindicating SFA, such as the Sydney Diet Heart Study from decades ago, included PUFA from vegetable oil products high in harmful trans fat. Fortunately, vegetable oils with artificial trans fat are now banned in most industrialized countries.

Impact of polymorphism in oleogels of N-palmitoyl-L-phenylalanine.

Gels of edible oils, also called oleogels, are developed as alternative products of solid fats to limit the uptake of saturated and trans-unsaturated fats and lower the associated risk of coronary disease. The gelation of oils can be achieved with a low molecular weight organogelator (LMWO), a compound that self-assembles at low concentrations in a solid 3D network and provides the mixture its solid-like behavior. We have studied N-palmitoyl-L-phenylalanine (Palm-Phe), an endogenous compound (i.e. naturally present in the human body) as a model LMWO of rapeseed oil. Palm-Phe forms gels at a concentration of 1 wt% in rapeseed oil. We have studied the thermodynamic and mechanical behavior of the corresponding gels. As evidenced by DSC and rheology, this system exhibits two transitions upon heating, in addition to the sol-gel transition, a gel-gel transition between two polymorphic gels. The structural differences between both polymorphs were revealed using cryo-SEM, X-rays scattering, and FTIR experiments. The metastability of one of the polymorphs was proven by ageing and annealing experiments.

Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies

Objective To systematically review associations between intake of saturated fat and trans unsaturated fat and all cause mortality, cardiovascular disease (CVD) and associated mortality, coronary heart disease (CHD) and associated...

A prospective study of adolescent dietary fat consumption and endometriosis risk

Modifiable risk factors such as diet may be important in halting the progression of endometriosis, the prevalence of pain symptoms, and the development of infertility. In adults, saturated and trans-unsaturated fat consumption have been associated with an increased risk, while omega-3 fatty acids have been associated with a decreased risk of endometriosis. There is currently no literature on the effect of diet across the life course. The objective of this study was to analyze the relation between dietary fat consumption during adolescence and subsequent surgical diagnosis of endometriosis.

Long-term intake of dietary fat and risk of ulcerative colitis and Crohn's disease

IntroductionDietary fats influence intestinal inflammation and regulate mucosal immunity. Data on the association between dietary fat and risk of Crohn's disease (CD) and ulcerative colitis (UC) are limited and conflicting.MethodsWe...

A prospective study of dietary fat consumption and endometriosis risk

Endometriosis is a prevalent but enigmatic gynecologic disorder for which few modifiable risk factors have been identified. Fish oil consumption has been associated with symptom improvement in studies of women with primary dysmenorrhea and with decreased endometriosis risk in autotransplantation animal studies. To investigate the relation between dietary fat intake and the risk of endometriosis, we analyzed 12 years of prospective data from the Nurses' Health Study II that began in 1989. Dietary fat was assessed via food frequency questionnaire in 1991, 1995 and 1999. We used Cox proportional hazards models adjusted for total energy intake, parity, race and body mass index at age 18, and assessed cumulatively averaged fat intake across the three diet questionnaires. During the 586 153 person-years of follow-up, 1199 cases of laparoscopically confirmed endometriosis were reported. Although total fat consumption was not associated with endometriosis risk, those women in the highest fifth of long-chain omega-3 fatty acid consumption were 22% less likely to be diagnosed with endometriosis compared with those with the lowest fifth of intake [95% confidence interval (CI) = 0.62-0.99; P-value, test for linear trend (Pt) = 0.03]. In addition, those in the highest quintile of trans-unsaturated fat intake were 48% more likely to be diagnosed with endometriosis (95% CI = 1.17-1.88; Pt = 0.001). These data suggest that specific types of dietary fat are associated with the incidence of laparoscopically confirmed endometriosis, and that these relations may indicate modifiable risk. This evidence additionally provides another disease association that supports efforts to remove trans fat from hydrogenated oils from the food supply.

Fat Consumption and Its Association With Age-Related Macular Degeneration

To evaluate associations between past dietary fat intake and the prevalence of age-related macular degeneration (AMD). Six thousand seven hundred thirty-four participants aged 58 to 69 years in 1990-1994 took part in this cohort study. Participants' nutrient intakes were estimated from a food frequency questionnaire at baseline. At follow-up from 2003 to 2006, digital macula photographs of both eyes were evaluated for early and late AMD signs. Logistic regression was used to estimate odds ratios, with adjustment for age, smoking, and other potential confounders. Higher trans-unsaturated fat intake was associated with an increased prevalence of late AMD; the odds ratio comparing the highest with the lowest quartile of trans fat was 1.76 (95% confidence interval, 0.92-3.37; P = .02). Higher omega-3 fatty acid intake (highest quartile vs lowest quartile) was inversely associated with early AMD (odds ratio, 0.85; 95% confidence interval, 0.71-1.02; P = .03). Olive oil intake (> or =100 mL/week vs <1 mL/week) was associated with decreased prevalence of late AMD (odds ratio, 0.48; 95% confidence interval, 0.22-1.04; P = .03). No significant associations with AMD were observed for intakes of fish, total fat, butter, or margarine. A diet low in trans-unsaturated fat and rich in omega-3 fatty acids and olive oil may reduce the risk of AMD.

Dietary fatty acid intakes and the risk of ovulatory infertility

Background: Pharmacologic activation of the peroxisome proliferator–activated receptor γ (PPAR-γ) improves ovulatory function in women with polycystic ovary syndrome, and specific dietary fatty acids can affect PPAR-γ activity.Objective: The objective of the study was to assess whether the intakes of total fat, cholesterol, and major types of fatty acids affect the risk of ovulatory infertility.Design: We conducted a prospective cohort study of 18 555 married, premenopausal women without a history of infertility who attempted a pregnancy or became pregnant between 1991 and 1999. Diet was assessed twice during follow-up by using a food-frequency questionnaire.Results: During follow-up, 438 incidents of ovulatory infertility were reported. In logistic regression analyses, intakes of total fat, cholesterol, and most types of fatty acids were not related to ovulatory infertility. Each 2% increase in the intake of energy from trans unsaturated fats, as opposed to that from carbohydrates, was associated with a 73% greater risk of ovulatory infertility after adjustment for known and suspected risk factors for this condition [relative risk (RR) = 1.73; 95% CI: 1.09, 2.73]. Obtaining 2% of energy intake from trans fats rather than from n−6 polyunsaturated fats was associated with a similar increase in the risk of ovulatory infertility (RR = 1.79; 95% CI: 1.11, 2.89). In addition, obtaining 2% of energy from trans fats rather than from monounsaturated fats was associated with a more than doubled risk of ovulatory infertility (RR = 2.31; 95% CI: 1.09, 4.87).Conclusion:trans Unsaturated fats may increase the risk of ovulatory infertility when consumed instead of carbohydrates or unsaturated fats commonly found in nonhydrogenated vegetable oils.

Facts on fats

Cardiovascular disease and age-related macular degeneration (AMD) may share common risk factors in their causal pathways. Decades of research from the cardiovascular sciences on fats have led investigators to focus on specific types of fats rather than total fat as a whole. They have established that saturated and trans-unsaturated fats (trans fats) are damaging to cardiovascular health while polyunsaturated fats, particularly the marine omega 3 fatty acids appear protective. This has led to a number of studies investigating the associations of fat and AMD. Though the causal relationship between fats and AMD remain unproven, some studies suggest that an association may be present. To be able to understand and interpret the study results and their implications, an understanding of the fats in the diet is important. This review aims to give an overview of fatty acids, particularly the trans-unsaturated fatty acids, and the relevant food groups.

Progression of Age-Related Macular Degeneration: Association With DietaryFat, Transunsaturated Fat, Nuts, and Fish Intake—Correction

Progression of Age-Related Macular Degeneration: Association With DietaryFat, Transunsaturated Fat, Nuts, and Fish Intake—Correction

Dietary fats and the risk of incident Alzheimer disease.

Few studies have investigated the effects of dietary fats on the development of Alzheimer disease. We examined the associations between intake of specific types of fat and incident Alzheimer disease in a biracial community study. We performed clinical evaluations on a stratified random sample of 815 community residents aged 65 years and older who were unaffected by Alzheimer disease at baseline and who completed a food-frequency questionnaire a mean of 2.3 years before clinical evaluation. After a mean follow-up of 3.9 years, 131 persons developed Alzheimer disease. Intakes of saturated fat and trans-unsaturated fat were positively associated with risk of Alzheimer disease, whereas intakes of omega-6 polyunsaturated fat and monounsaturated fat were inversely associated. Persons in the upper fifth of saturated-fat intake had 2.2 times the risk of incident Alzheimer disease compared with persons in the lowest fifth in a multivariable model adjusted for age, sex, race, education, and apolipoprotein E epsilon4 allele status (95% confidence interval, 1.1-4.7). Risk also increased with consumption of trans-unsaturated fats, beginning with the second fifth of intake (relative risk, 2.4 compared with the lowest fifth; 95% confidence interval, 1.1-5.3). We observed linear inverse associations between Alzheimer disease and vegetable fat (P =.002), and, after further adjustment for other types of fat, marginally significant associations with intake of omega-6 polyunsaturated fat (P =.10 for trend) and monounsaturated fat (P =.10 for trend). Intakes of total fat, animal fat, and dietary cholesterol were not associated with Alzheimer disease. High intake of unsaturated, unhydrogenated fats may be protective against Alzheimer disease, whereas intake of saturated or trans-unsaturated (hydrogenated) fats may increase risk.

Randomized clinical trials on the effects of dietary fat and carbohydrate on plasma lipoproteins and cardiovascular disease

Several dietary approaches have reduced cardiovascular events in randomized clinical trials. Replacing saturated fat with polyunsaturated fat prevented coronary events in men, and a Mediterranean diet and fatty fish improved survival. None of these trials had much impact on total fat intake but rather increased vegetable oils, n-3 fatty acids, or many other plant foods or nutrients that are linked to coronary prevention. The reductions in cardiovascular disease (CVD) caused by these dietary therapies compare favorably with drug treatments for hyperlipidemia and hypertension. Improvement in blood lipid risk factors is an important mechanism to explain the results of trials of unsaturated fats. When saturated or trans unsaturated fats are replaced with monounsaturated or n-6 polyunsaturated fats from vegetable oils, primarily low-density lipoprotein (LDL) cholesterol decreases. The LDL to high-density lipoprotein (HDL) cholesterol ratio decreases. When carbohydrates are used to replace saturated fats, in a low-fat diet, LDL and HDL decrease similarly, and the ratio is not improved; triglycerides increase as well when carbohydrate increases, except when low glycemic index foods are used. The n-3 polyunsaturated fats in fish oils suppress cardiac arrhythmias and reduce triglycerides, but they have little effect on LDL or HDL cholesterol levels. The theme should be that diet has benefits that come directly from foods, as well as from the reduction in saturated fats, cholesterol, meats, and fatty dairy foods. It is likely that many diets could be designed that could prevent CVD. This potential diversity is crucial for engaging the diverse cultures and tastes of people worldwide in cardiovascular disease prevention.

The effect of dietary intervention on serum lipid levels in type 2 diabetes mellitus.

Dietary therapy is the cornerstone of lipid management in patients with type 2 diabetes mellitus. The key strategies are the reduction of intake of saturated fat, trans unsaturated fat and cholesterol, and the reduction of energy intake to promote weight loss. This approach will produce significant improvements in the serum levels of low-density lipoprotein (LDL) cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol. According to both the American Diabetes Association and the National Cholesterol Education Program (NCEP), the primary target of therapy is the serum LDL cholesterol level, with the secondary targets being non-HDL cholesterol, triglycerides, and HDL cholesterol. The recently updated guidelines of the NCEP place new emphasis on increasing soluble fiber intake to 10 to 25 g/d and adding foods fortified with plant stanols/sterols (2 g/d) as options to enhance the LDL cholesterol-lowering effect of diet.

Prospective study of fat and protein intake and risk of intraparenchymal hemorrhage in women.

-Dietary animal fat and protein have been inversely associated with a risk of intraparenchymal hemorrhage in ecological studies. In 1980, 85 764 women in the Nurses' Health Study cohort, who were 34 to 59 years old and free of diagnosed cardiovascular disease and cancer, completed dietary questionnaires. From these questionnaires, we calculated fat and protein intake. By 1994, after 1.16 million person-years of follow-up, 690 incident strokes, including 74 intraparenchymal hemorrhages, had been documented. Multivariate-adjusted risk of intraparenchymal hemorrhage was higher among women in the lowest quintile of energy-adjusted saturated fat intake than at all higher levels of intake (relative risk [RR], 2.36; 95% CI, 1.10 to 5.09; P:=0.03). For trans unsaturated fat, the corresponding RR was 2.50 (95% CI, 1.35 to 4.65; P:=0.004). Animal protein intake was inversely associated with risk (RR in the highest versus lowest quintiles, 0.32; 95% CI, 0.10 to 1.00; P:=0.04). The excess risk associated with low saturated fat intake was observed primarily among women with a history of hypertension (RR, 3.66; 95% CI, 1.09 to 12.3; P=0.04), but such an interaction was not seen for trans unsaturated fat or animal protein. These nutrients were not related to risk of other stroke subtypes. Dietary cholesterol and monounsaturated and polyunsaturated fat were not related to risk of any stroke subtype. Low intake of saturated fat and animal protein was associated with an increased risk of intraparenchymal hemorrhage, which may help to explain the high rate of this stroke subtype in Asian countries. The increased risk with low intake of saturated fat and trans unsaturated fat is compatible with the reported association between low serum total cholesterol and risk.

Dietary fat and protein in relation to risk of non-Hodgkin's lymphoma among women.

Non-Hodgkin's lymphoma occurs more frequently in individuals with suppressed immune status, and some types of dietary fat and protein have been associated with decreased immune responses. In this study, we examined the intake of specific types of dietary fat and protein in relation to the risk of non-Hodgkin's lymphoma. We documented 199 incident cases of non-Hodgkin's lymphoma in a cohort of 88 410 women, who were enrolled in the Nurses' Health Study and were aged 34-60 years in 1980, during 14 years of follow-up. Relative risks of the disease and 95% confidence intervals (95% CIs) were calculated. All P values are two-sided and were considered to be statistically significant for P<.05. Intake of saturated fat was associated with an increase in risk that was not statistically significant; the multivariate relative risk for the highest versus the lowest quintiles of intake was 1.4 (95% CI = 0.7-3.0; P for trend =.42). Intake of beef, pork, or lamb as a main dish was associated with a statistically significantly increased risk of non-Hodgkin's lymphoma; the multivariate relative risk for consumption of these meats at least once per day as compared with less than once per week was 2.2 (95% CI = 1.1-4.4; P for trend =.002). Higher intake of trans unsaturated fat was also statistically significantly associated with an increased risk of the disease; the multivariate relative risk for the highest versus the lowest quintiles was 2.4 (95% CI = 1.3-4.6; P for trend =.01). Higher intake of red meat cooked by broiling or barbecuing-but not by roasting, pan-frying, or boiling or stewing-was associated with an increase in risk that was not statistically significant. Greater dietary intake of certain meats and fats was associated with a higher risk of non-Hodgkin's lymphoma. These relationships and their potential mechanisms deserve further examination.

AHA Science Advisory. Monounsaturated fatty acids and risk of cardiovascular disease. American Heart Association. Nutrition Committee.

This report summarizes our current understanding of how monounsaturated fatty acids (MUFAs) affect risk for cardiovascular disease (CVD). This is a topic that has attracted considerable scientific interest,1 2 3 in large part because of uncertainty regarding whether MUFA or carbohydrate should be substituted for saturated fatty acids (SFAs) and the desirable quantity of MUFA to include in the diet. MUFAs are distinguished from the other fatty acid classes on the basis of having only 1 double bond. In contrast, polyunsaturated fatty acids (PUFAs) have 2 or more double bonds, and SFAs have none. The position of the hydrogen atoms around the double bond determines the geometric configuration of the MUFA and hence whether it is a cis or trans isomer. In a cis MUFA, the hydrogen atoms are present on the same side of the double bond, whereas in the trans configuration, they are on opposite sides. The American Heart Association Nutrition Committee recently published a scientific statement regarding the relationship of trans MUFA to CVD risk,4 and the present statement, therefore, will be limited to a discussion of dietary cis MUFAs, of which oleic acid ( cis C18:1) comprises ≈92% of cis MUFAs. In the United States, average total MUFA intake is 13% to 14% of total energy intake, an amount that is comparable to (or slightly greater than) SFA intake. In contrast, PUFAs contribute less (ie, 7% of energy). The major emphasis of current dietary guidelines involves replacing SFAs with complex carbohydrates to achieve a total fat intake of ≤30% of calories. There is evidence suggesting that the substitution of MUFA instead of carbohydrate for SFA calories may favorably affect CVD risk.5 6 7 The American Heart Association dietary guidelines for healthy American adults recommend a diet that provides <10% of calories from SFA, up …

Association of dietary intake of fat and fatty acids with risk of breast cancer.

High intakes of fat and specific fatty acids, including total, animal, saturated, polyunsaturated, and trans-unsaturated fats, have been postulated to increase breast cancer risk. To determine whether intakes of fat and fatty acids are associated with breast cancer. Cohort study (Nurses' Health Study) conducted in the United States beginning in 1976. A total of 88795 women free of cancer in 1980 and followed up for 14 years. Relative risk (RR) of invasive breast cancer for an incremental increase of fat intake, ascertained by food frequency questionnaire in 1980, 1984, 1986, and 1990. A total of 2956 women were diagnosed as having breast cancer. Compared with women obtaining 30.1% to 35% of energy from fat, women consuming 20% or less had a multivariate RR of breast cancer of 1.15 (95% confidence interval [CI], 0.73-1.80). In multivariate models, the RR (95% CI) for a 5%-of-energy increase was 0.97 (0.94-1.00) for total fat, 0.98 (0.96-1.01) for animal fat, 0.97 (0.93-1.02) for vegetable fat, 0.94 (0.88-1.01) for saturated fat, 0.91 (0.79-1.04) for polyunsaturated fat, and 0.94 (0.88-1.00) for monounsaturated fat. For a 1% increase in energy from trans-unsaturated fat, the values were 0.92 (0.86-0.98), and for a 0.1% increase in energy from omega-3 fat from fish, the values were 1.09 (1.03-1.16). In a model including fat, protein, and energy, the RR for a 5% increase in total fat, which can be interpreted as the risk of substituting this amount of fat for an equal amount of energy from carbohydrate, was 0.96 (95% CI, 0.93-0.99). In similar models, no significant association of risk was evident with any major types of fat. We found no evidence that lower intake of total fat or specific major types of fat was associated with a decreased risk of breast cancer.

Trans-unsaturated fats and heart disease

Trans-unsaturated fats and heart disease

Dietary fat intake and the risk of coronary heart disease in women.

The relation between dietary intake of specific types of fat, particularly trans unsaturated fat and the risk of coronary disease remains unclear. We therefore studied this relation in women enrolled in the Nurses' Health Study. We prospectively studied 80,082 women who were 34 to 59 years of age and had no known coronary disease, stroke, cancer, hypercholesterolemia, or diabetes in 1980. Information on diet was obtained at base line and updated during follow-up by means of validated questionnaires. During 14 years of follow-up, we documented 939 cases of nonfatal myocardial infarction or death from coronary heart disease. Mutivariate analyses included age, smoking status, total energy intake, dietary cholesterol intake, percentages of energy obtained from protein and specific types of fat, and other risk factors. Each increase of 5 percent of energy intake from saturated fat, as compared with equivalent energy intake from carbohydrates, was associated with a 17 percent increase in the risk of coronary disease (relative risk, 1.17; 95 percent confidence interval, 0.97 to 1.41; P=0.10). As compared with equivalent energy from carbohydrates, the relative risk for a 2 percent increment in energy intake from trans unsaturated fat was 1.93 (95 percent confidence interval, 1.43 to 2.61; P<0.001); that for a 5 percent increment in energy from monounsaturated fat was 0.81 (95 percent confidence interval, 0.65 to 1.00; P=0.05); and that for a 5 percent increment in energy from polyunsaturated fat was 0.62 (95 percent confidence interval, 0.46 to 0.85; P= 0.003). Total fat intake was not signficantly related to the risk of coronary disease (for a 5 percent increase in energy from fat, the relative risk was 1.02; 95 percent confidence interval, 0.97 to 1.07; P=0.55). We estimated that the replacement of 5 percent of energy from saturated fat with energy from unsaturated fats would reduce risk by 42 percent (95 percent confidence interval, 23 to 56; P<0.001) and that the replacement of 2 percent of energy from trans fat with energy from unhydrogenated, unsaturated fats would reduce risk by 53 percent (95 percent confidence interval, 34 to 67; P<.001). Our findings suggest that replacing saturated and trans unsaturated fats with unhydrogenated monounsaturated and polyunsaturated fats is more effective in preventing coronary heart disease in women than reducing overall fat intake.

Effect of trans-unsaturated fats on experimental atherosclerosis in vervet monkeys

Vervet monkeys ( Ceropithecus aethiops pygerethrus) were placed on semipurified diets containing 14% fat of which 3.2 or 6.0% was present as trans-unsaturated fatty acid (t-FA). Two groups were fed the high and low levels of t-FA for a year and two others were fed t-FA for 6 months and then returned to the control diet for 6 months more. One other group was fed the control diet for a year. The control diet contained 14% fat which was a mixture of 72% olive oil and 28% corn oil. There were no significant differences in weight gain. Monkeys fed 6% t-FA or control diets for one year had lowest liver weights. Serum cholesterol and triglycerides in monkeys fed 3.2% t-FA for one year were 134 and 55 mg/dl, respectively; in monkeys returned to control diet after 6 months on 6% t-FA the values were 146 and 50 g/dl. Serum and triglyceride levels for the,other 3 groups were 166 ± 2 and 70 ± 2 mg/dl. Liver cholesterol levels ranged from 4.0 mg/g (3.2% t-FA) to 4.7 mg/g (control) and 4.8 mg/g (6% t-FA). Lecithin: cholesterol acyltransferase (LCAT) activity was 59.0 μM/h for controls and ranged from 52.4 μM/h (3.2% t-FA) to 73.4 μM/h (6% t-FA). Cholesterol synthesis by liver slices was not affected by diet when the substrate was acetate. When mevalonate was used, the monkeys fed either level of t-FA for 12 months exhibited greatly reduced (about 80%) cholesterogenesis. The levels of t-FA in serum and liver reflected the amount in the diet. After being returned to control diet levels of t-FA in serum and liver of monkeys (fed 3.2% t-FA) fell by 97 and 94%, respectively, and those in serum and liver of monkeys fed 6% t-FA fell by 65 and 91%. There were no significant differences in aortic atherosclerosis or arteriosclerosis. The level of atherosclerosis (% of arterial surface) in monkeys fed 3.2% t-FA was 2.47 ± 1.25; in those fed 3.2% t-FA for 6 months then returned to control diet it was 5.09 ± 2.61; in monkeys fed 6% t-FA it was 5.29 ± 3.98 and in those fed 6% t-FA for 6 months then returned to control diet it was 2.95 ± 1.04. The level of atherosclerosis in the control monkeys was 6.55 ± 2.44. The percentage of aortic surface bearing arteriosclerosis in the 5 group was: 1.30 ± 0.78; 1.35 ± 0.68; 0.41 ± 0.22; 6.43 ± 4.34; and 0.50 ± 0.23. Female monkeys exhibited more severe atherosclerosis and less severe arteriosclerosis. The data are consistent with findings by ourselves and others which suggest that trans-unsaturated fat does not carry a special risk for atherosclerosis.