Ten-year incidence of coronary heart disease in the Honolulu Heart Program. Relationship to nutrient intake

n-6 Fatty acids and cardiovascular health: a review of the evidence for dietary intake recommendations

n-6 PUFA are well known for their critical role in many physiological functions and seem to reduce risks of CHD. However, some argue that excessive consumption of n-6 PUFA may lead to adverse effects on health and therefore recommend reducing dietary n-6 PUFA intake or fixing an upper limit. In this context, the present work aimed to review evidence on the link between n-6 PUFA and risks of CVD. Epidemiological studies show that n-6 PUFA dietary intake significantly lowers blood LDL-cholesterol levels. In addition, n-6 PUFA intake does not increase several CVD risk factors such as blood pressure, inflammatory markers, haemostatic parameters and obesity. Data from prospective cohort and interventional studies converge towards a specific protective role of dietary n-6 PUFA intake, in particular linoleic acid, against CVD. n-6 PUFA benefits are even increased when SFA intake is also reduced. In regards to studies examined in this narrative review, recommendation for n-6 PUFA intake above 5 %, and ideally about 10 %, of total energy appears justified.

Cardiac mortality is associated with low levels of omega-3 and omega-6 fatty acids in the heart of cadavers with a history of coronary heart disease

The benefits of omega-3 (ie, eicosapentaenoic acid and docosahexaenoic acid [DHA]) and omega-6 (ie, linoleic acid and arachidonic acid [AA]) fatty acids on reducing cardiac mortality are still debated. In this study, we tested the hypothesis that high levels of omega-3 and omega-6 fatty acids in heart tissues are associated with low cardiac mortality in Thai cadavers. One hundred fresh cadavers were examined in this study. The cause of death, history of coronary heart disease (CHD), and fish consumption habits were obtained from death certificates, cadaver medical record profiles, and a questionnaire to a person who lived with the subject before death. In each cadaver, biopsies of cardiac tissues were taken from the interventricular septum for measurement of fatty acid. Of the 100 cadavers (average age, 69 +/- 13 years), 60 were men. The frequency of fish consumption was directly associated with omega-3 and omega-6 fatty acids in heart tissues (P < .01). History of CHD and cause of death (cardiac vs noncardiac) were not significantly associated with levels of omega-3 or omega-6 fatty acids. However, in cadavers with a history of CHD, high levels of omega-3 and omega-6, particularly DHA and AA, were associated with low cardiac mortality (P < .05). Fish consumption is associated with levels of omega-3 and omega-6 fatty acids in heart tissues. Although omega-3 and omega-6 fatty acids are not associated with cardiac mortality in the overall studied population, their low levels (especially DHA and AA) in heart tissues are associated with high cardiac mortality in cadavers with a history of CHD.

Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease

BACKGROUND

A reduction in dietary saturated fat has generally been thought to improve cardiovascular health.

OBJECTIVE

The objective of this meta-analysis was to summarize the evidence related to the association of dietary saturated fat with risk of coronary heart disease (CHD), stroke, and cardiovascular disease (CVD; CHD inclusive of stroke) in prospective epidemiologic studies.

DESIGN

Twenty-one studies identified by searching MEDLINE and EMBASE databases and secondary referencing qualified for inclusion in this study. A random-effects model was used to derive composite relative risk estimates for CHD, stroke, and CVD.

RESULTS

During 5-23 y of follow-up of 347,747 subjects, 11,006 developed CHD or stroke. Intake of saturated fat was not associated with an increased risk of CHD, stroke, or CVD. The pooled relative risk estimates that compared extreme quantiles of saturated fat intake were 1.07 (95% CI: 0.96, 1.19; P = 0.22) for CHD, 0.81 (95% CI: 0.62, 1.05; P = 0.11) for stroke, and 1.00 (95% CI: 0.89, 1.11; P = 0.95) for CVD. Consideration of age, sex, and study quality did not change the results.

CONCLUSIONS

A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat.

Saturated fat, carbohydrate, and cardiovascular disease

A focus of dietary recommendations for cardiovascular disease (CVD) prevention and treatment has been a reduction in saturated fat intake, primarily as a means of lowering LDL-cholesterol concentrations. However, the evidence that supports a reduction in saturated fat intake must be evaluated in the context of replacement by other macronutrients. Clinical trials that replaced saturated fat with polyunsaturated fat have generally shown a reduction in CVD events, although several studies showed no effects. An independent association of saturated fat intake with CVD risk has not been consistently shown in prospective epidemiologic studies, although some have provided evidence of an increased risk in young individuals and in women. Replacement of saturated fat by polyunsaturated or monounsaturated fat lowers both LDL and HDL cholesterol. However, replacement with a higher carbohydrate intake, particularly refined carbohydrate, can exacerbate the atherogenic dyslipidemia associated with insulin resistance and obesity that includes increased triglycerides, small LDL particles, and reduced HDL cholesterol. In summary, although substitution of dietary polyunsaturated fat for saturated fat has been shown to lower CVD risk, there are few epidemiologic or clinical trial data to support a benefit of replacing saturated fat with carbohydrate. Furthermore, particularly given the differential effects of dietary saturated fats and carbohydrates on concentrations of larger and smaller LDL particles, respectively, dietary efforts to improve the increasing burden of CVD risk associated with atherogenic dyslipidemia should primarily emphasize the limitation of refined carbohydrate intakes and a reduction in excess adiposity.

Dietary cholesterol and coronary artery disease: a systematic review

Coronary heart disease (CHD) remains one of the leading causes of death in the United States and other industrialized nations. A better understanding of modifiable risk factors for CHD is critical in order to effectively prevent this disease. Dietary factors known to influence the risk of CHD include saturated fats, trans-fats, and polyunsaturated fatty acids. Although higher plasma levels of low-density lipoprotein cholesterol are associated with an increased risk of coronary disease and lipid-lowering therapy has been shown to reduce the risk of cardiovascular disease, the relation between dietary cholesterol and the risk of CHD is not clearly understood. This article reviews the current evidence on the association between dietary cholesterol and the risk of CHD.

Cardiovascular disease risk of dietary stearic acid compared with trans, other saturated, and unsaturated fatty acids: a systematic review

BACKGROUND

High stearic acid (STA) soybean oil is a trans-free, oxidatively stable, non-LDL-cholesterol-raising oil that can be used to replace trans fatty acids (TFAs) in solid fat applications.

OBJECTIVE

The objective was to assess the cardiovascular health effects of dietary STA compared with those of trans, other saturated, and unsaturated fatty acids.

DESIGN

We reviewed epidemiologic and clinical studies that evaluated the relation between STA and cardiovascular disease (CVD) risk factors, including plasma lipids and lipoproteins, hemostatic variables, and inflammatory markers.

RESULTS

In comparison with other saturated fatty acids, STA lowered LDL cholesterol, was neutral with respect to HDL cholesterol, and directionally lowered the ratio of total to HDL cholesterol. STA tended to raise LDL cholesterol, lower HDL cholesterol, and increase the ratio of total to HDL cholesterol in comparison with unsaturated fatty acids. In 2 of 4 studies, high-STA diets increased lipoprotein(a) in comparison with diets high in saturated fatty acids. Three studies showed increased plasma fibrinogen when dietary STA exceeded 9% of energy (the current 90th percentile of intake is 3.5%). Replacing industrial TFAs with STA might increase STA intake from 3.0% (current) to approximately 4% of energy and from 4% to 5% of energy at the 90th percentile. One-to-one substitution of STA for TFAs showed a decrease or no effect on LDL cholesterol, an increase or no effect on HDL cholesterol, and a decrease in the ratio of total to HDL cholesterol.

CONCLUSIONS

TFA intake should be reduced as much as possible because of its adverse effects on lipids and lipoproteins. The replacement of TFA with STA compared with other saturated fatty acids in foods that require solid fats beneficially affects LDL cholesterol, the primary target for CVD risk reduction; unsaturated fats are preferred for liquid fat applications. Research is needed to evaluate the effects of STA on emerging CVD risk markers such as fibrinogen and to understand the responses in different populations.

The effect of dairy foods on CHD: a systematic review of prospective cohort studies

There is interest in the degree to which fats in dairy foods contribute to CHD. We undertook a systematic review to investigate the effect of dairy consumption on CHD using prospective cohort studies. A systematic search of electronic databases identified studies relating dairy food intake in adulthood to episodes or death from CHD, IHD and myocardial infarction. Included studies were assessed for quality based on study methodology, validity of dietary assessment, success of follow-up, standardised assessment of CHD, IHD or myocardial infarction end points and appropriateness of statistical adjustment. Data from twelve cohorts involving >280,000 subjects were included. Most studies had follow-up of >80 %, adjusted statistically for three or more confounders and used standard criteria to determine end points. About half the studies used a validated FFQ, administered the FFQ more than once or had follow-up of >20 years. Fewer than half the studies involved subjects representative of the general population. Four of the twelve cohorts found no association between dairy intake and CHD. Eight studies reported varying relationships between different dairy foods and CHD or differential associations based on race, sex or over time. Although dairy foods contribute to the SFA composition of the diet, this systematic review could find no consistent evidence that dairy food consumption is associated with a higher risk of CHD. This could be due to the limited sensitivity of the dietary assessment methods to detect an effect of a single food in a mixed diet on complex clinical outcomes.

Coronary heart disease, serum lipids, platelets and dietary fish in two communities in northern Norway

Coronary heart disease (CHD) mortality was registered in an inland and a coastal community in Northern Norway. Subgroups of healthy males from the communities were investigated further. The daily consumption of fish in the coastal and inland areas was 132.4 g and 55.1 g respectively, and the intake of eicosapentaenoic acid was 0.9 g and 0.25 g. The content of n-3 polyunsaturated fatty acids in platelet phospholipids and primary bleeding time were similar in the two groups. Linoleic acid was lower and saturated fatty acids were higher in phospholipids in men from the coastal area. Collagen-induced platelet aggregation was increased and serum triglyceride concentration was higher in men from the coastal area. CHD mortality during a 10-year period was higher in the coastal area for both sexes. This may be associated with differences in serum triglyceride levels and platelet fatty acid composition. This study indicates that a high consumption of lean fish is not sufficient to induce changes in blood lipids and platelet function associated with low CHD mortality and it does not seem to prevent high CHD mortality.

A reappraisal of the impact of dairy foods and milk fat on cardiovascular disease risk

Background

This review provides a reappraisal of the potential effects of dairy foods, including dairy fats, on cardiovascular disease (CVD)/coronary heart disease (CHD) risk. Commodities and foods containing saturated fats are of particular focus as current public dietary recommendations are directed toward reducing the intake of saturated fats as a means to improve the overall health of the population. A conference of scientists from different perspectives of dietary fat and health was convened in order to consider the scientific basis for these recommendations.

Aims

This review and summary of the conference focus on four key areas related to the biology of dairy foods and fats and their potential impact on human health: (a) the effect of dairy foods on CVD in prospective cohort studies; (b) the impact of dairy fat on plasma lipid risk factors for CVD; (c) the effects of dairy fat on non-lipid risk factors for CVD; and (d) the role of dairy products as essential contributors of micronutrients in reference food patterns for the elderly.

Conclusions

Despite the contribution of dairy products to the saturated fatty acid composition of the diet, and given the diversity of dairy foods of widely differing composition, there is no clear evidence that dairy food consumption is consistently associated with a higher risk of CVD. Thus, recommendations to reduce dairy food consumption irrespective of the nature of the dairy product should be made with caution.

Lifestyle approaches and dietary strategies to lower LDL-cholesterol and triglycerides and raise HDL-cholesterol

This article discusses specific dietary factors as well as dietary patterns that affect the major coronary heart disease (CHD) lipid risk factors (ie, LDL-C, HDL-C, and TG). Based on a very large evidence base, it is clear that diet and lifestyle practices can markedly affect these major CHD lipid risk factors, and consequently decrease CHD risk substantively.

Omega-6 and trans fatty acids in blood cell membranes: a risk factor for acute coronary syndromes?

BACKGROUND

Although fatty acid intake has been associated with risk of coronary disease events, the association between blood omega-6 and trans fatty acids (FAs) at the time of an acute coronary syndrome (ACS) is unknown.

METHODS

The relationship of blood FA composition to ACS was analyzed in 768 incident cases and 768 controls (matched on age, sex, and race).

RESULTS

Compared to controls, ACS cases' blood cell membrane content of linoleic acid was 13% lower (P < .0001); arachidonic acid was 3.6% higher (P < .001); the trans isomer of oleic acid was 13.3% higher (P < .0001); and the trans-trans isomer of linoleic acid was 13.3% higher (P = .003). In multivariable analyses, a 1-SD decrease in linoleic acid was associated with >3 times the odds for being a case (odds ratio [OR] 3.23, 95% confidence interval [CI] 2.63-4.17). The relationship of arachidonic acid to ACS was U shaped; compared to the first quartile of arachidonic acid, the ORs for case status in the second, third, and fourth quartiles were 0.73 (95% CI 0.47-1.13), 0.65 (95% CI 0.41-1.04), and 2.32 (95% CI 1.39-3.90), respectively. The OR for a 1-SD increase in trans oleic acid was 1.24 (95% CI 1.06-1.45), and for trans-trans linoleic acid, 1.1 (95% CI 0.93-1.30). All associations were independent of membrane omega-3 FA content.

CONCLUSIONS

High blood levels of linoleic acid but low levels of trans oleic acid are inversely associated with ACS. The relationship of arachidonic acid to ACS appears more complex.

Linoleic acid and coronary heart disease

The extent to which higher intakes of linoleic acid (LA) affect risk for coronary heart disease (CHD) is examined by reviewing a wide variety of study types, mostly in humans. In experimental studies, LA has been shown to lower serum levels of low-density lipoprotein cholesterol (LDL-C), especially when substituted for saturated fatty acids. Such an effect would be expected to reduce risk for CHD. In observational studies in which the dietary intake or serum content of LA were either cross-sectionally or prospectively related risk for CHD, higher LA intakes or serum levels have usually been associated with reduced risk. The pooled results from 5 randomized trials where LA was substituted for saturated fatty acids revealed a significant decrease in risk for CHD events with an LA intake 2-3 times current levels. Thus, current recommendations to consume 5-10% of energy from LA are evidence-based, and should not be reduced.

Markers of dietary fat quality and fatty acid desaturation as predictors of total and cardiovascular mortality: a population-based prospective study

BACKGROUND

Desaturase indexes, as markers of endogenous fatty acid desaturation, and a characteristic serum fatty acid (FA) composition are related to cardiovascular and metabolic diseases, but the relation to mortality is poorly investigated.

OBJECTIVE

The objective was to evaluate the relation between dietary fat biomarkers, desaturase indexes, and mortality.

DESIGN

In this community-based prospective sample, 50-y-old men were followed for a maximum of 33.7 y. Cox proportional hazard analysis was conducted to investigate desaturase indexes (stearoyl-CoA-desaturase and Delta(6)- and Delta(5)-desaturase) and the relation of individual serum esterified fatty acids (FAs) in relation to total and cardiovascular mortality in the total study sample (n = 2009) and in a healthy subsample (n = 1885). Desaturase indexes were estimated as product-to-precursor FA ratios.

RESULTS

During follow-up, 1012 men in the total sample died and 931 men in the healthy subsample died. Desaturase indexes predicted both total and cardiovascular mortality. The relations were independent of smoking status, physical activity, BMI, total cholesterol, and hypertension. The adjusted and standardized (per SD) hazard ratios (HRs) and 95% CIs for cardiovascular mortality were 1.15 (1.04, 1.27) for stearoyl-CoA-desaturase, 1.12 (1.0, 1.24) for Delta(6)-desaturase, and 0.88 (0.80, 0.98) for Delta(5)-desaturase, respectively. The proportion of serum linoleic acid was inversely related, whereas serum FAs associated with saturated fat intake (palmitic, palmitoleic, and dihomo-gamma-linolenic acids) were directly related to total and cardiovascular mortality.

CONCLUSIONS

Altered endogenous FA desaturation might contribute to mortality risk because we observed independent associations between desaturase activity indexes and mortality. The proportion of linoleic acid was inversely related, and FAs reflecting saturated fat intake were directly related to mortality.

Cardiovascular event risk in relation to dietary fat intake in middle-aged individuals: data from The Malmö Diet and Cancer Study

BACKGROUND AND DESIGN

The hypothesis that diets rich in total and saturated fat and poor in unsaturated fats increase the risk for cardiovascular disease is still vividly debated. The aim of this study was to examine whether total fat, saturated fat, or unsaturated fat intakes are independent risk factors for cardiovascular events in a large population-based cohort.

METHODS

28 098 middle-aged individuals (61% women) participated in the Malmö Diet and Cancer Study between 1991 and 1996. In this analysis, individuals with an earlier history of cardiovascular disease were excluded. With adjustments made for confounding by age and various anthropometric, social, dietary, and life-style factors, hazard ratios (HR) were estimated for individuals categorized by quartiles of fat intake [HR (95% confidence interval, CI), Cox's regression model].

RESULTS

No trend towards higher cardiovascular event risk for women or men with higher total or saturated fat intakes, was observed. Total fat: HR (95% CI) for fourth quartile was 0.98 (0.77-1.25) for women, 1.02 (0.84-1.23) for men; saturated fat: 0.98 (0.71-1.33) for women and 1.05 (0.83-1.34) for men. Inverse associations between unsaturated fat intake and cardiovascular event risk were not observed.

CONCLUSIONS

In relation to risks of cardiovascular events, our results do not suggest any benefit from a limited total or saturated fat intake, nor from relatively high intake of unsaturated fat.

The role of dietary n-6 fatty acids in the prevention of cardiovascular disease

n-6 Fatty acids, like n-3 fatty acids, play essential roles in many biological functions. Because n-6 fatty acids are the precursors of proinflammatory eicosanoids, higher intakes have been suggested to be detrimental, and the ratio of n-6 to n-3 fatty acids has been suggested by some to be particularly important. However, this hypothesis is based on minimal evidence, and in humans higher intakes of n-6 fatty acids have not been associated with elevated levels of inflammatory markers. n-6 Fatty acids have long been known to reduce serum total and low-density lipoprotein cholesterol, and increases in polyunsaturated fat intake, mostly as n-6 fatty acids, were a cornerstone of dietary advice during the 1960s and 1970s. In the United States, for example, intake of n-6 fatty acids doubled and coronary heart disease (CHD) mortality fell by 50% over a period of several decades. In a series of relatively small, older randomized trials, in which intakes of polyunsaturated fat were increased (even up to 20% of calories), rates of CHD were generally reduced. In a more recent detailed examination of fatty acid intake within the Nurses' Health Study, greater intake of linoleic acid, up to about 8% of energy, has been strongly related to lower incidence of myocardial infarction or CHD death. Because n-3 fatty acids were also related inversely to risk of CHD, the ratio was unrelated to risk. n-6 Fatty acids reduce insulin resistance, probably by acting as a ligand for peroxisome proliferator-activated receptors-gamma, and intakes have been inversely related to risk of type 2 diabetes. Adequate intakes of both n-6 and n-3 fatty acids are essential for good health and low rates of cardiovascular disease and type 2 diabetes, but the ratio of these fatty acids is not useful. Reductions of linoleic acid to "improve" this ratio would likely increase rates of cardiovascular disease and diabetes.

1-Tetradecanol complex reduces progression of Porphyromonas gingivalis-induced experimental periodontitis in rabbits

BACKGROUND

It has been recently shown that monounsaturated fatty acids inhibit endothelial activation and reduce tissue responsiveness to cytokines. The present study has been planned to investigate topical application of a novel monounsaturated fatty acid complex (1-tetradecanol complex) for prevention of Porphyromonas gingivalis-induced periodontitis in rabbits.

METHODS

Experimental periodontitis was induced in New Zealand white rabbits with silk sutures tied around the mandibular second premolars bilaterally, followed by the topical application of 10(9) colony forming units (CFU) of P. gingivalis. 1-Tetradecanol complex (1-TDC) was topically applied at 1- and 10-mg/ml concentrations in five animals in each group, whereas control animals received olive oil vehicle (five animals) three times per week for 6 weeks. Negative controls included ligature alone (14 animals) or ligature + P. gingivalis (non-treatment; 15 animals). Rabbits were sacrificed after 6 weeks, and mandibular block sections were obtained; tissues were decalcified and embedded in paraffin. Thin sections (5 microm) were stained with hematoxylin and eosin or tartrate-resistant acid phosphatase. Macroscopic and histologic evaluation of samples was followed by the characterization of cellular inflammatory infiltrate and quantitative histomorphometric measurements.

RESULTS

Treatment with both concentrations of 1-TDC and vehicle resulted in significant prevention of macroscopic periodontal inflammation and bone loss (75%; P <0.05) compared to the non-treatment (ligature + P. gingivalis) group, where significant periodontal tissue destruction characterized by attachment and bone loss was detected. However, there was no statistically significant difference between the vehicle and both 1-TDC groups. Histologically, 1-TDC inhibited inflammatory cell infiltration and prevented osteoclastogenesis, whereas treatment with vehicle did not show the same effect as in the 1-TDC groups; the difference between vehicle and the higher concentration of 1-TDC (10 mg/ml) was statistically significant.

CONCLUSION

Topical application of an esterified monounsaturated fatty acid complex (1-TDC) was found promising in preventing bone loss, inflammatory cell infiltration, and connective tissue destruction in the rabbit periodontitis model.

Pistachio Nut Consumption and Serum Lipid Levels

OBJECTIVE

Clinical and epidemiological studies have reported the beneficial effects of tree nuts and peanuts on serum lipid levels. We studied the effects of consuming 15% of the daily caloric intake in the form of pistachio nuts on the lipid profiles of free-living human subjects with primary, moderate hypercholesterolemia (serum cholesterol greater than 210 mg/dL).

METHODS

design: Randomized crossover trial. setting: Outpatient dietary counseling and blood analysis. subjects: 15 subjects with moderate hypercholesterolemia. intervention: Fours weeks of dietary modification with 15% caloric intake from pistachio nuts.

MEASURES OF OUTCOME

Endpoints were serum lipid levels of total cholesterol, HDL-C, LDL-C, VLDL-C, triglycerides and apolipoproteins A-1 and B-100. BMI, blood pressure, and nutrient intake (total energy, fat, protein, and fiber) were also measured at baseline, during, and after dietary intervention.

RESULTS

No statistically significant differences were observed for total energy or percent of energy from protein, carbohydrate or fat. On the pistachio nut diet, a statistically significant decrease was seen for percent energy from saturated fat (mean difference, -2.7%; 95% CI, -5.4% to -0.08%; p = 0.04). On the pistachio nut diet, statistically significant increases were seen for percent energy from polyunsaturated fat (mean difference, 6.5%; 95% CI, 4.2% to 8.9%; p<.0001) and fiber intake (mean difference, 15 g; 95% CI, 8.4 g to 22 g; p = 0.0003). On the pistachio diet, statistically significant reductions were seen in TC/HDL-C (mean difference, -0.38; 95% CI, -0.57 to -0.19; p = 0.001), LDL-C/HDL-C (mean difference, -0.40; 95% CI, -0.66 to -0.15; p = 0.004), B-100/A-1 (mean difference, -0.11; 95% CI, -0.19 to -0.03; p = 0.009) and a statistically significant increase was seen in HDL-C (mean difference, 2.3; 95% CI, 0.48 to 4.0; p = 0.02). No statistically significant differences were seen for total cholesterol, triglycerides, LDL-C, VLDL-C, apolipoprotein A-1 or apolipoprotein B-100. No changes were observed in BMI or blood pressure.

CONCLUSION

A diet consisting of 15% of calories as pistachio nuts (about 2-3 ounces per day) over a four week period can favorably improve some lipid profiles in subjects with moderate hypercholesterolemia and may reduce risk of coronary disease.

Fatty acids and CHD

During the last century much evidence has accumulated to suggest that from a public health perspective the type of fat is more important than the amount of fat. Saturated andtrans-fatty acids increase and bothn-6 andn-3 PUFA decrease the risk of CHD. Most of the knowledge about the effects of dietary fatty acids on CHD risk is based on observational studies and controlled dietary experiments with intermediate end points (e.g. blood lipoprotein fractions). Information from high-quality randomised controlled trials on fatty acids and CHD is lacking. The Netherlands Institute for Public Health has calculated the potential health gain that can be achieved if the fatty acid composition of the current Dutch diet is replaced by the recommended fatty acid composition. The recommendations of The Netherlands Health Council are: saturated fatty acids <10% energy intake;trans-fatty acids <1% energy intake; fish consumption (an indicator ofn-3 PUFA) once or twice weekly. Implementation of this recommendation could reduce the incidence of CHD in The Netherlands by about 25 000/year and the number of CHD-related deaths by about 6000/year and increase life expectancy from age 40 years onwards by 0.5 year. These projections indicate the public health potential of interventions that modify the fatty acid composition of the diet.

Intake and adipose tissue composition of fatty acids and risk of myocardial infarction in a male Portuguese community sample

OBJECTIVE

To evaluate the relation between intake and adipose tissue composition of fatty acids and acute myocardial infarction in Portuguese men.

DESIGN

Case-control study. Diet was assessed using a semiquantitative food frequency questionnaire. In 49 case and 49 control subjects, adipose tissue composition was assessed by gas-liquid chromatography.

SUBJECTS/SETTING

Population-based; subjects were 297 consecutively admitted cases of first acute myocardial infarction in a tertiary care hospital who were aged>or=40 years. Three hundred ten community controls were selected by random-digit dialing.

MAIN OUTCOME MEASURE

Odds ratio (OR).

STATISTICAL ANALYSIS PERFORMED

Logistic regression, adjusting for age, education, family history of acute myocardial infarction, smoking, physical activity, body mass index, and energy intake.

RESULTS

Total fat intake (OR 0.45, fourth quartile, P=0.02), lauric acid (OR 0.44, fourth quartile, P=0.02), palmitic acid (OR 0.58, fourth quartile, P=0.03), and oleic acid (OR 0.42, fourth quartile, P=0.03) were inversely associated with acute myocardial infarction. No significant effects were found for the remaining fatty acids. In the adipose tissue composition data, the adjusted risk estimates of acute myocardial infarction for the highest vs the lowest tertile were 0.16, 0.14, and 0.04 for lauric, oleic, and trans-fatty acids, respectively. A significant direct association was found for palmitic and linoleic acids (adjusted ORs for the highest tertile were 9.02 and 3.63, respectively).

CONCLUSIONS

Low intake of total fat and lauric acid from dairy products was associated with acute myocardial infarction. The association of polyunsaturated fatty acids with risk of acute myocardial infarction was nonsignificant after adjustment for energy intake and confounders. Recommendations on fatty acid intake should aim for both an upper and lower limit.

Effect of dietary hempseed intake on cardiac ischemia-reperfusion injury

Polyunsaturated fatty acids (PUFAs) have significant, cardioprotective effects against ischemia. Hempseed contains a high proportion of the PUFAs linoleic acid (LA) and alpha-linolenic acid (ALA), which may have opposing effects on postischemic heart performance. There are no reported data concerning the cardiovascular effects of dietary hempseed intake. A group of 40 male Sprague-Dawley rats were distributed evenly into four groups that were fed for 12 wk a normal rat chow supplemented with hempseed (5% and 10%), palm oil (1%), or a 10% partially delipidated hempseed that served as a control. Plasma ALA and gamma-linolenic acid levels were significantly elevated in the rats that were fed a 5% or 10% hempseed-supplemented diet, but in heart tissue only ALA levels were significantly elevated in the rats fed these diets compared with control. After the dietary interventions were completed, postischemic heart performance was evaluated by measuring developed tension, resting tension, the rates of tension development and relaxation, and the number of extrasystoles. Hearts from rats fed a hempseed-supplemented diet exhibited significantly better postischemic recovery of maximal contractile function and enhanced rates of tension development and relaxation during reperfusion than hearts from the other groups. These hearts, however, were not protected from the occurrence of extrasystoles, nor were the increases in resting tension altered during ischemia or reperfusion as a function of any dietary intervention. Our data demonstrate that dietary hempseed can provide significant cardioprotective effects during postischemic reperfusion. This appears to be due to its highly enriched PUFA content.

Low-carbohydrate-diet score and the risk of coronary heart disease in women

BACKGROUND

Low-carbohydrate diets have been advocated for weight loss and to prevent obesity, but the long-term safety of these diets has not been determined.

METHODS

We evaluated data on 82,802 women in the Nurses' Health Study who had completed a validated food-frequency questionnaire. Data from the questionnaire were used to calculate a low-carbohydrate-diet score, which was based on the percentage of energy as carbohydrate, fat, and protein (a higher score reflects a higher intake of fat and protein and a lower intake of carbohydrate). The association between the low-carbohydrate-diet score and the risk of coronary heart disease was examined.

RESULTS

During 20 years of follow-up, we documented 1994 new cases of coronary heart disease. After multivariate adjustment, the relative risk of coronary heart disease comparing highest and lowest deciles of the low-carbohydrate-diet score was 0.94 (95% confidence interval [CI], 0.76 to 1.18; P for trend=0.19). The relative risk comparing highest and lowest deciles of a low-carbohydrate-diet score on the basis of the percentage of energy from carbohydrate, animal protein, and animal fat was 0.94 (95% CI, 0.74 to 1.19; P for trend=0.52), whereas the relative risk on the basis of the percentage of energy from intake of carbohydrates, vegetable protein, and vegetable fat was 0.70 (95% CI, 0.56 to 0.88; P for trend=0.002). A higher glycemic load was strongly associated with an increased risk of coronary heart disease (relative risk comparing highest and lowest deciles, 1.90; 95% CI, 1.15 to 3.15; P for trend=0.003).

CONCLUSIONS

Our findings suggest that diets lower in carbohydrate and higher in protein and fat are not associated with increased risk of coronary heart disease in women. When vegetable sources of fat and protein are chosen, these diets may moderately reduce the risk of coronary heart disease.

Dietary fat intake and risk of coronary heart disease: the Strong Heart Study

BACKGROUND

The results of previous studies on the association between dietary fat intake and coronary heart disease (CHD) incidence are inconsistent.

OBJECTIVE

The aim of this study was to examine the association between dietary fat intake and CHD incidence in American Indians in the Strong Heart Study.

DESIGN

A total of 2938 participants aged 47-79 y and free of CHD at the second examination (1993-1995) were examined and followed for CHD, nonfatal CHD, and fatal CHD events to 31 December 2002. Dietary intake was assessed by using a 24-h diet recall and was calculated as percentages of energy.

RESULTS

Participants were followed for a mean (+/-SD) of 7.2 +/- 2.3 y. During follow-up, 436 incident CHD cases (298 nonfatal CHD and 138 fatal CHD events) were ascertained. Participants aged 47-59 y in the highest quartile of intake of total fat, saturated fatty acids, or monounsaturated fatty acids had higher CHD mortality than did those in the lowest quartile [hazard ratio (95% CI): 3.57 (1.21, 10.49), 5.17 (1.64, 16.36), and 3.43 (1.17, 10.04), respectively] after confounders were controlled for. These associations were not observed for those aged 60-79 y.

CONCLUSIONS

Total fat, saturated fatty acid, and monounsaturated fatty acid intake were strong predictors of CHD mortality in American Indians aged 47-59 y, independent of other established CHD risk factors. It may be prudent for American Indians to reduce their fat intake early in life to reduce the risk of dying from CHD.

The skinny on low-carbohydrate diets: should they be recommended to patients with the metabolic syndrome?

One in four adults living in the United States has metabolic syndrome, a constellation of risk factors associated with increased risk for developing type 2 diabetes and cardiovascular disease. A common characteristic in patients with metabolic syndrome is abdominal obesity along with an increased body mass index. Traditional dietary recommendations for treating the metabolic syndrome and associated obesity include high-carbohydrate, low-fat regimens. Despite the widespread use of these dietary guidelines, the rates of metabolic syndrome and obesity continue to rise in the United States. As a result, public interest in alternative dietary approaches to weight loss has escalated, sparking renewed interest in low-carbohydrate diet regimens, most notably Dr. Atkins' New Diet Revolution, a New York Times bestseller. Despite this renewed interest, there is little scientific evidence to determine the safety and efficacy of low-carbohydrate diets on cardiovascular health. Because most energy in a low-carbohydrate diet are derived from protein and fat, there is considerable concern that such diets will raise lipid levels and overall risk for coronary disease. In this article, we review the sparse literature on the impact of low-carbohydrate diets on weight loss and lipid parameters.

Synergistic effects of depressed mood and obesity on long-term cardiovascular risks in 1510 obese men and women: results from the MONICA-KORA Augsburg Cohort Study 1984-1998

OBJECTIVE

To examine the contribution of depressed mood in obese subjects on the prediction of a future coronary heart disease event (CHD).

DESIGN

A prospective population-based cohort study of three independent cross-sectional surveys with 6239 subjects, 45-74 years of age and free of diagnosed CHD, stroke and cancer. During a mean follow-up of 7 years, 179 CHD events occurred among men and 50 events among women.

SUBJECTS

A total of 737 (23%) male and 773 (26%) female subjects suffering from obesity (BMI >or=30 kg/m2).

MEASUREMENTS

Body weight determined by trained medical staff following a standardized protocol; standardized questionnaires to assess subsyndromal depressive mood and other psychosocial features.

RESULTS

The main effect of obesity to predict a future CHD (hazard ratio, HR=1.38, 95% CI 1.03-1.84; P=0.031) and the interaction term of obesity by depression (HR=1.73, 95% CI 0.98-3.05; P=0.060) were borderline significant, both covariate adjusted for multiple risk factors. Relative to the male subgroup with normal body weight and no depression, the male obese group with no depression was not at significantly increased risk for CHD events (HR=1.17, 95% CI 0.76-1.80; P=0.473) whereas CHD risk in males with both obesity and depressed mood was substantially increased (HR=2.32, 95% CI 1.45-3.72, P>0.0001). The findings for women were similar, however, not significant probably owing to lack of power associated with low event rates. Combining obesity and depressed mood resulted in a relative risk to suffer from a future CHD event of HR 1.84 (95% CI 0.79-4.26; P=0.158).

CONCLUSIONS

Depressed mood substantially amplifies the CHD risk of middle-aged obese, but otherwise apparently healthy men. The impact of depression on the obesity risk in women is less pronounced.

Incidence of recognized and unrecognized myocardial infarction in men and women aged 55 and older: the Rotterdam Study

AIMS

Contemporary data on the incidence of unrecognized myocardial infarction (MI) among subjects aged 55 and older are limited.

METHODS AND RESULTS

We studied the incidence of recognized and unrecognized MI in the Rotterdam Study, a population-based cohort of men and women aged 55 and older. The baseline examination was performed during 1990-93, with follow-up examinations during 1994-95, and 1997-2000. Baseline and follow-up 12-lead ECGs were analysed by the Modular ECG Analysis System. The 5148 participants who had no evidence of prevalent infarction were the subjects for analysis. Incident recognized infarction was defined as the occurrence of a fatal or non-fatal event coded as I21 according to the International Classification of Diseases, 10th edition. A repeat ECG was available in 4187 subjects. An unrecognized infarction was considered to have occurred if there was electrocardiographic evidence in the absence of a clinically recognized event. During a median follow-up of 6.4 years, 141 incident recognized infarctions occurred and the incidence rate of this event was 5.0 per 1000 person years. The incidence was higher in men (8.4) than in women (3.1). The incidence rate of unrecognized infarction was 3.8 per 1000 person years. Men (4.2) and women (3.6) had approximately similar incidence. Hence, the proportion of unrecognized infarction was lower in men (33%) than in women (54%). This difference in proportion of unrecognized infarctions was independent of age.

CONCLUSION

A high proportion of incident MIs remains clinically unrecognized. As a history of MI is associated with an increased risk of repeat cardiovascular complications, our data suggest a need for periodical electrocardiographic screening to recognize (prevalent) infarctions and to install effective preventive treatment in those aged 55 and older.

Prevalence, incidence, primary care burden and medical treatment of angina in Scotland: age, sex and socioeconomic disparities: a population-based study

OBJECTIVE

To examine the epidemiology, primary care burden and treatment of angina in Scotland.

DESIGN

Cross-sectional data from primary care practices participating in the Scottish continuous morbidity recording scheme between 1 April 2001 and 31 March 2002.

SETTING

55 primary care practices (362 155 patients).

PARTICIPANTS

9508 patients with angina.

RESULTS

The prevalence of angina in Scotland was 28/1000 in men and 25/1000 in women (p < 0.05) and increased with age. The prevalence of angina also increased with increasing socioeconomic deprivation from 18/1000 in the least deprived category to 31/1000 in the most deprived group (p < 0.001 for trend). The incidence of angina was higher in men (1.8/1000) than in women (1.4/1000) (p = 0.004) and increased with increasing age and socioeconomic deprivation. Socioeconomically deprived patients (0.48 contacts/patient among the most deprived) were less likely than affluent patients (0.58 contacts/patient among the least deprived) to see their general practitioner on an ongoing basis p = 0.006 for trend). Among men, 52% were prescribed beta blockers, 44% calcium channel blockers, 72% aspirin, 54% statins and 36% angiotensin converting enzyme inhibitors or angiotensin receptor blockers. The corresponding prescription rates for women were 46% (p < 0.001), 41% (p = 0.02), 69% (p < 0.001), 45% (p < 0.001) and 30% (p < 0.001). Among patients < 75 years old 52% were prescribed a beta blocker and 58% a statin. The corresponding figures for patients >or= 75 years were 42% (p < 0.001) and 31% (p < 0.001).

CONCLUSIONS

Angina is a common condition, more so in men than in women. Socioeconomically deprived patients are more likely to have angina but are less likely to consult their general practitioner. Guideline-recommended treatments for angina are underused in women and older patients. These suboptimal practice patterns, which are worst in older women, are of particular concern, as in Scotland more women (and particularly older women) than men have angina.

Nutrition is a powerful independent risk factor for coronary heart disease in women--The CORA study: a population-based case-control study

BACKGROUND

It is still common practice to rely mostly on drug treatment for preventing cardiovascular disease, although a healthy nutrition has been defined that may prevent most premature cardiovascular events.

OBJECTIVES

This research raises the question of the magnitude of the effect of nutrition on cardiovascular disease independent of that of clinical risk factors, which are the targets of drug therapy.

DESIGN

The study of coronary risk factors for atherosclerosis in women compares clinical, biochemical, and lifestyle factors in 200 consecutive pre- and postmenopausal women with incident coronary heart disease (CHD) to those in 255 age-matched population-based controls.

RESULTS

Cases reported a higher intake of energy, predominantly through animal fat and protein reflected by a higher consumption of meat and sausage, while controls ate more fruit and vegetables. Multivariate analysis adjusted for clinical risk factors depicted a high intake of meat and sausage and a low consumption of fruit and vegetables as independent risk factors with an odds ratio of 2.5 (95% confidence interval 1.1-5.7) and 0.7 (95% confidence interval 0.5-1.0) for each 100 g per day, respectively. These dietary factors were found to be significantly more pronounced in cases with any clinical risk factor identified in this population as compared to controls with the same risk factors.

CONCLUSIONS

The CORA-study clearly indicates a major impact of dietary habits on CHD in women independent of, and additive to, that of conventional risk factors. Thus, in clinical practice, the potential of nutrition as part of a healthy lifestyle is commonly greatly underestimated in favour of drug treatment.

Saturated and cis- and trans-unsaturated fatty acids intake in rural and urban Costa Rican adolescents

OBJECTIVE

The purpose of this study is to determine whether intake of saturated fatty acids and cis- and trans-unsaturated fatty acids is associated with an urban compared to a rural lifestyle, and whether these associations are responsible for differences in plasma lipid concentrations.

METHODS

Two hundred seventy-five adolescents, aged 12 to 19 years, living in rural and urban areas of San José, Costa Rica, were included in the study. All participants completed three-day food records, provided a fasting blood sample, and carried out a modified Harvard Step Test.

RESULTS

Compared to rural, urban adolescents reported higher intakes of energy-adjusted individual and total saturated fatty acids, total n-3, total n-6 (p < 0.05). Compared to rural, urban adolescents had higher intake of 18:1 (3.65 vs. 3.25, p = 0.0001) and 18:2 (0.62 vs. 0.80, p = 0.001) trans fatty acids, as well as lower intake of carbohydrate (p < 0.05). Palm shortening was the main source of saturated fat (32%), and partially hydrogenated soybean oil used for cooking was the main source of n-3 fatty acids (33%), n-6 fatty acids (33%) and trans fatty acids (34%). Compared to rural, urban adolescents had lower systolic and diastolic blood pressure and higher plasma HDL cholesterol concentration (44 vs. 40 mg/dL, p < 0.0001), but were more likely to be sedentary (68% vs. 57%, p < 0.0001). Among environmental factors, higher carbohydrate intake was a significant determinant of a lower HDL cholesterol (beta coeff = -1.45, p = 0.04), while lauric and myristic fatty acids correlated with increased LDL cholesterol (beta coeff = 3.6, 1.7, p < 0.05).

CONCLUSIONS

A diet containing less carbohydrate and less saturated fatty acids contributes to a more beneficial lipid profile in Costa Rican adolescents, but a trend towards high trans fatty acids intake, particularly in the urban area, is worrisome given the well-known adverse effects of trans fatty acids.

Intake of milk fat, reflected in adipose tissue fatty acids and risk of myocardial infarction: a case–control study

OBJECTIVE

To study the association between content of fatty acids from milk fat (14:0, 15:0 and 17:0) in adipose tissue and risk of a first myocardial infarction (MI).

DESIGN AND SUBJECTS

A case-control study with 99 patients and 98 population controls both men and postmenopausal women, age 45-75 year. Adipose tissue fatty acids were determined by gas-liquid chromatography.

RESULTS

The content of 14:0, 14:1, 15:0, 17:0 and 17:1 were all significantly higher in adipose tissue of controls than of the patients. Age and sex adjusted odds ratios (OR) for MI were significantly reduced with increasing quartiles of 14:0, 14:1, 15:0 and 17:1 in adipose tissue, but except for 15:0 (OR = 0.36, 95% CI 0.13-0.99), the trend was no longer significant after further adjustment for waist-to-hip ratio, smoking and family history for coronary heart disease. Correlations between 14:0 and 15:0 in adipose tissue, and waist-to-hip ratio were significantly negative (r = -0.22 for both, P < 0.01).

CONCLUSION

Our study suggests that intake of dairy fat or some other component of dairy products, as reflected by C15:0 as marker in adipose tissue, may protect persons at increased risk from having a first MI, and that the causal effects may rely on other factors than serum cholesterol.

SPONSORSHIP

Throne Holst's foundation for Nutrition Research, Research Council of Norway, The Norwegian Association of Margarine Producers, DeNoFa Fabriker A/S, TINE BA.

Effects of dietary fats versus carbohydrates on coronary heart disease: A review of the evidence

Recommendations arising from the traditional diet-coronary heart disease (CHD) paradigm, which focuses on effects of total and saturated fat on serum total and low-density lipoprotein cholesterol, may have failed to reduce CHD risk and inadvertently exacerbated dyslipidemia, insulin resistance, and weight gain, particularly among individuals who are older, female, sedentary, or obese. A suitable dietary paradigm must consider types and qualities of fats and carbohydrates consumed, their effects on a range of intermediary risk factors, and characteristics that may modify individual susceptibility. Based on current evidence, replacement of total, unsaturated, and even possibly saturated fats with refined, high-glycemic index carbohydrates is unlikely to reduce CHD risk and may increase risk in persons predisposed to insulin resistance. In contrast, a diet that is 1) rich in whole grains and other minimally processed carbohydrates; 2) includes moderate amounts of fats (approximately 30%-40% of total energy), particularly unsaturated fats and omega-3 polyunsaturated fats from seafood and plant sources; 3) is lower in refined grains and carbohydrates; and 4) eliminates packaged foods, baked goods, and fast foods containing trans fatty acids, will likely reduce the risk of CHD.

Protein, body weight, and cardiovascular health

Widespread popularity of high-protein diets has drawn controversy as well as scientific interest. By reducing intake of carbohydrates and increasing consumption of fats and proteins, such diets are thought to increase satiety, facilitate weight loss, and improve cardiovascular risk factors. In recent years, many randomized controlled studies have compared the effects of higher-protein diets on weight loss and cardiovascular risk factors with those of lower-protein diets. The aim of this review was to provide an overview of experimental and epidemiologic evidence regarding the role of protein in weight loss and cardiovascular risk. Emerging evidence from clinical trials indicates that higher-protein diets increase short-term weight loss and improve blood lipids, but long-term data are lacking. Findings from epidemiologic studies show a significant relationship between increased protein intake and lower risk of hypertension and coronary heart disease. However, different sources of protein appear to have different effects on cardiovascular disease. Although optimal amounts and sources of protein cannot be determined at this time, evidence suggests a potential benefit of partially replace refined carbohydrates with protein sources low in saturated fats.

Dietary cholesterol, atherosclerosis and coronary heart disease

As early as at the beginning of the last century, animal studies have pointed to a causal role of dietary cholesterol in atherogenesis. In humans, however, most observational studies have not provided convincing evidence for an impact of cholesterol intake on coronary heart disease (CHD). Rather, these studies have consistently established a close association between a certain eating pattern and the risk of CHD. This eating pattern has usually been characterized by a high intake of total fat, saturated fatty acids (SFA) and cholesterol, and a low intake of fiber and polyunsaturated fatty acids (PUFA). In typical western diets the amounts of total fat, SFA, and cholesterol are strongly correlated with each other, while they are negatively related to the intake of fiber and PUFA. Thus, it has not been possible to determine whether the association between the above mentioned eating pattern and CHD is due to the high consumption of SFA, cholesterol, both, or an insufficient supply of one or more protective factors such as fiber or PUFA. As the consumption of eggs leads to a high intake of cholesterol without necessarily resulting in high uptake levels of SFA and total fat, several groups have tried to elucidate the effect of cholesterol by investigating the relationship between the consumption of eggs and the development of CHD. Based on these studies, the association between dietary cholesterol and CHD risk is, if anything, minor in nature. This is consistent with the finding that an increase in dietary cholesterol intake results in only a minimal increase in the total/high-density lipoprotein cholesterol ratio. Taken together these studies suggest that the association between dietary cholesterol and CHD is small, as most subjects can effectively adapt to higher levels of cholesterol intake. Nevertheless, lowering dietary cholesterol content might reduce the risk of CHD considerably in a subgroup of individuals who are highly responsive to changes in cholesterol intake.

The association between total energy intake and early mortality: data from the Malmö Diet and Cancer Study

OBJECTIVES

In animal studies, low energy intake (EI) has been associated with a longer lifespan. We examine whether EI is an independent risk factor for prospective all-cause mortality, cardiovascular and cancer mortality in humans.

DESIGN

Population-based, prospective cohort study.

SETTING AND SUBJECTS

The Malmö Diet and Cancer Study is a population-based prospective cohort study. A total of 28 098 individuals, mean age 58.2 years, completed questionnaires on diet and life-style and attended a physical examination during 1991-96.

MAIN OUTCOME MEASURES

Information on mortality was acquired from national registries during a mean follow-up time of 6.6 years. Subjects were categorized by quartiles of total EI. The first quartile was used as a reference point in estimating multivariate relative risks (RR; 95% CI, Cox's regression model). Adjustments were made for confounding by age and various life-style factors.

RESULTS

The lowest total mortality was observed for women in the third quartile (RR: 0.74; CI: 0.57-0.96) and for men in the second and third quartiles (RR: 0.85; CI: 0.69-1.04 and RR: 0.85; CI: 0.69-1.04 respectively). Similar U-shaped patterns were observed for cardiovascular mortality amongst women and cancer mortality amongst men. A statistically significant trend (P = 0.029) towards lower cardiovascular mortality from the first to the fourth quartile was observed for men.

CONCLUSIONS

Low caloric consumers did, on average, not have lower mortality than average or high caloric consumers. Generally, individuals approximately meeting national recommendations for total EI had the lowest mortality. For men, high caloric intake was associated with lower cardiovascular mortality.

Polyunsaturated Fatty Acids and Cardiovascular Health

Epidemiologic studies have shown a beneficial association between polyunsaturated fatty acid (PUFA), specifically linoleic acid (C18:2, n-6), intake and cardiovascular disease morbidity and mortality. Clinical studies have shown that n-6 PUFAs have the most potent cholesterol-lowering effects of the individual fatty acid classes, and emerging evidence suggests that PUFAs have favorable effects on postprandial lipemia. However, some studies suggest that high intakes of linoleic acid may have adverse effects on proinflammatory cytokines and adhesion molecules. Research is needed to establish the optimal level of dietary PUFAs that maximally affects the greatest number of health risk factors.

Dietary fat and risk of coronary heart disease: possible effect modification by gender and age

In a 16-year follow-up study (ending in 1998) of 3,686 Danish men and women aged 30-71 years at recruitment, the association between energy intake from dietary fat and the risk of coronary heart disease was evaluated while assessing the possible modifying role of gender and age. In the models used, total energy and protein intake were fixed. Differences in intake of energy from fat thus reflected complementary differences in intake of energy from carbohydrates. A 5% higher level of energy from saturated fat intake was associated with a 36% greater risk of coronary heart disease among women (hazard ratio (HR) = 1.36, 95% confidence interval (CI): 0.98, 1.88). No overall association between saturated fat and coronary heart disease was found among men. However, age-dependent analyses showed that saturated fat was positively associated with coronary heart disease among the younger men (HR = 1.29, 95% CI: 0.87, 1.91) and the younger women (HR = 2.68, 95% CI: 1.40, 5.12) but not among the older men (HR = 0.94, 95% CI: 0.70, 1.28) and the older women (HR = 1.22, 95% CI: 0.86, 1.71). Polyunsaturated fat was inversely associated with coronary heart disease among women and men, although not significantly. In conclusion, the present study suggests that coronary heart disease risk relates to both the quantity and the quality of dietary fats.

A comparison of dietary habits among women in Japan and Hawaii

OBJECTIVE

To compare the dietary habits of Japanese women in Japan with those of Japanese and Caucasian women living in Hawaii.

DESIGN

Data from two previous cross-sectional studies conducted within two years in Hawaii and Gifu, Japan were pooled and analysed. Dietary intakes were assessed with validated food-frequency questionnaires and urine samples were collected for isoflavone measurement.

SETTING

Participants were recruited through mammography clinics in both locations.

SUBJECTS

In Hawaii, 164 Caucasian and 146 Japanese women; in Japan, 206 women.

RESULTS

Dietary habits differed considerably by ethnicity and location. In comparison to the Caucasian diet, the diet in Japan was relatively low in fat and high in carbohydrates and protein, whereas the Japanese women in Hawaii reported intermediate intakes. Japanese women in Gifu consumed a diet that was relatively high in fish, soy, eggs and vegetables, and low in fruits, dairy products and meat. In contrast, the Caucasian women consumed the most dairy products and fruits and the Japanese women in Hawaii reported the highest grain and meat intakes.

CONCLUSIONS

The diet of Japanese women in Hawaii appeared to be a combination of foods eaten in Japan and the dietary habits of Caucasian women in Hawaii, but eating habits in Japan are also different from traditional nutritional patterns. This study illustrates several problems related to dietary comparisons across populations and provides information for future investigations on chronic disease risk.

Exercise, body mass index, caloric intake, and cardiovascular mortality

BACKGROUND

The association of physical inactivity and elevated body mass index (BMI) with cardiovascular disease (CVD) risk is well established. The relationship of dietary caloric intake and CVD risk is less certain.

METHODS

The epidemiologic follow-up of the First National Health and Nutrition Examination Survey (1971-1992) was examined to determine the relationship of caloric intake, BMI, and physical activity to CVD mortality. Of 14,407 participants, 9790 subjects aged 25 to 74 years met inclusion criteria. The CVD mortality rate was the outcome.

RESULTS

During the 17 years of follow-up, there were 3183 deaths, 1531 of which were due to CVD (9.11/1000 person-years). People with relatively less physical activity, lower caloric intake, and who were overweight (BMI 25 to 29.9 kg/m(2)) and obese (BMI > or =30 kg/m(2)) had a less favorable baseline CVD risk profile than did those who were more active and of normal weight and had greater caloric intake. Age- and race/ethnicity-adjusted CVD mortality rates were highest among those with the least physical activity and lowest caloric intake, and who were overweight or obese. Moreover, subjects of normal weight who exercised most were more likely to have high caloric intake and lower CVD mortality (5.9 vs 14.7 per 1000 person-years, p =0.01) than subjects who were obese and exercised least. In Cox regression analysis, controlling for relevant CVD risk factors, least physical activity was independently associated with increased CVD mortality (hazard ratio=1.32, 95% confidence interval [CI]=1.13-1.53); and obesity was associated with increased CVD mortality (hazard ratio=1.24, 95% CI=1.06-1.44). Although highest dietary caloric intake was associated with reduced CVD mortality (hazard ratio=0.83, 95% CI=0.74-0.93), after adjusting for physical activity and BMI, there was no significant association of highest caloric intake with CVD mortality (hazard ratio=0.91, 95% CI=0.81-1.01).

CONCLUSIONS

In this large general population sample, lower levels of physical activity and obesity were independently associated with decreased CVD survival. Moreover, when BMI, physical activity, and other relevant characteristics were taken into account, caloric intake was not related to CVD mortality.

Individual saturated fatty acids and nonfatal acute myocardial infarction in Costa Rica

BACKGROUND

Epidemiological studies on the effect of individual saturated fatty acids (SFAs) on cardiovascular disease, especially in developing countries with different dietary patterns, are scarce.

OBJECTIVE

To determine the risk of nonfatal acute myocardial infarction (MI) associated with consumption of individual SFAs and their food sources in Costa Rica.

DESIGN

The cases (n=485) were survivors of a first acute MI and were matched by age, sex and area of residence to population controls (n=508). Data on anthropometrical measurements, lifestyle and diet were collected using interviewer-administered questionnaires.

RESULTS

In analyses adjusted for confounders, consumption of total and individual SFAs was associated with an increased risk of MI. The odds ratio (OR) (95% confidence intervals) for 1% increase in energy from total saturated fat was 1.12 (1.03-1.21) while it was 1.51 (1.03-2.22) for lauric acid+myristic acid, 1.14 (1.01-1.30) for palmitic acid and 2.00 (1.34-3.00) for stearic acid. Although lauric and myristic acids were associated with increased risk of MI, they were consumed in small amounts and most of the saturated fat (87%) came from palmitic and stearic acids, which derived mainly from red meat and fried foods. Consumption of cheese (1-2 vs 0 servings/day) was associated with increased risk of MI (OR=3.07; 95% confidence interval: 1.74-5.39; P for trend <0.0001), while consumption of low-fat milk was not.

CONCLUSION

Increased consumption of total and individual SFAs is associated with increased risk of MI. Lauric, myristic and stearic acids were more potent than palmitic acid.

Plasma fatty acid composition and incidence of coronary heart disease in middle aged adults: the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND AND AIM

To prospectively investigate the relation of plasma cholesterol ester (CE) and phospholipid (PL) fatty acid (FA) composition with incidence of coronary heart disease (CHD).

METHODS AND RESULTS

3,591 white participants in the Minneapolis field center of the Atherosclerosis Risk in Communities Study, aged 45-64 years, were studied. Plasma FA composition of CEs and PLs was quantified using gas-liquid chromatography and expressed as percentage of total FAs. Incident CHD was identified during 10.7 years of follow-up. In both CE and PL fractions, the proportions of stearic (18:0) acid, dihomo-gamma-linolenic (20:3n6) acid and total saturated fatty acids (SFAs) were significantly higher while arachidonic (20:4n6) acid and total polyunsaturated fatty acids (PUFAs) were significantly lower among participants who developed incident CHD (n = 282). After adjusting for age, gender, smoking, alcohol drinking, sports activity, and non-FA dietary factors, the incidence of CHD was significantly and positively associated with the proportion of dihomo-gamma-linolenic acid but inversely associated with arachiadonic acid. The multiply-adjusted rate ratios (RRs) of CHD incidence for the highest versus the lowest quintile were 1.31 in CE and 1.44 in PL for dihomo-gamma-linolenic acid (p for trend: 0.05 and 0.017, respectively), 0.59 in CE and 0.65 in PL for arachidonic acid (p: 0.016 and 0.024, respectively). Also significantly and positively associated with incident CHD were PL stearic acid and CE linolenic (18:3n3) acid. Only a borderline significant positive association was observed for total SFAs in CE (multivariate RRs across quintiles: 1.00, 1.15, 1.40, 1.62, 1.32; p = 0.07). Total PUFAs or monounsaturated FA were not independently associated with CHD.

CONCLUSIONS

Our study found a weak positive association of SFAs with incident CHD. Our findings also confirm that FA metabolism in the body, such as the activity of delta-5 desaturase, which converts dihomo-gamma-linolenic acid to arachidonic acid, may affect the development of CHD.

Fortification, supplementation, and nutrient balance

Efforts to combat nutrient deficiencies have centered on supplemental nutrient administration and addition of selected nutrients to the food chain in the form of food fortification. Over the past several decades, and as the association between diet and chronic diseases became apparent, supplementation and fortification were also targeted at healthy individuals, with the aim of reducing their risk of future diseases such as cardiovascular diseases, diabetes, and cancer. While supplementation strategies are playing a major role in reducing micronutrient deficiencies around the world, there is less compelling evidence for their role in reducing risk of chronic diseases in healthy individuals, perhaps with the exception of folic acid and reduction of neural tube defects. Nevertheless, with our increasing understanding of the genetic heterogeneity of human nutrient requirements, it is likely that certain groups or populations may clearly benefit from higher intakes of certain nutrients. In addition to supplementation or fortification with specific nutrients, the consumption of certain dietary patterns (such as the Mediterranean diet) is associated with a reduced risk of chronic diseases, particularly cardiovascular diseases.

Carbohydrates, dietary glycaemic load and glycaemic index, and risk of acute myocardial infarction

OBJECTIVES

To assess the relation between selected carbohydrate foods, dietary glycaemic load and glycaemic index, and the risk of non-fatal acute myocardial infarction in a population with a high intake of refined carbohydrates.

DESIGN AND SETTING

Hospital based case-control study conducted in Milan, Italy, between 1995 and 1999.

PATIENTS

433 non-diabetic subjects with a first episode of non-fatal acute myocardial infarction, and 448 controls admitted to hospital for a wide spectrum of acute conditions unrelated to known or potential risk factors for acute myocardial infarction.

METHODS

Information was collected by interviewer administered questionnaires. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were obtained by multiple logistic regression models.

RESULTS

Compared with patients in the lowest tertile of intake, the multivariate OR for those in the highest tertile was 1.00 for bread, 1.27 for pasta and rice, 1.38 for soups, 0.78 for potatoes, 0.97 for desserts, and 1.00 for sugar. The OR for the highest tertile of score was 1.08 for glycaemic load and 1.38 for glycaemic index. None of the estimates was significant. A significant association with acute myocardial infarction risk was found for glycaemic index in patients aged > or = 60 years (OR 1.81, 95% CI 1.07 to 3.07 for the highest tertile of score compared with the lowest) and in those with a body mass index > or = 25 kg/m2 (OR 2.02, 95% CI 1.21 to 3.34).

CONCLUSIONS

In this Italian population high glycaemic load and glycaemic index were not strongly associated with acute myocardial infarction risk, but slightly increased odds ratios were observed for glycaemic index in elderly people and in association with overweight.