Erythrocyte fatty acids, plasma lipids, and cardiovascular disease in rural China

Fatty Acid Profile and Genetic Variants of Proteins Involved in Fatty Acid Metabolism Could Be Considered as Disease Predictor

Circulating fatty acids (FA) have an endogenous or exogenous origin and are metabolized under the effect of many enzymes. They play crucial roles in many mechanisms: cell signaling, modulation of gene expression, etc., which leads to the hypothesis that their perturbation could be the cause of disease development. FA in erythrocytes and plasma rather than dietary FA could be used as a biomarker for many diseases. Cardiovascular disease was associated with elevated trans FA and decreased DHA and EPA. Increased arachidonic acid and decreased Docosahexaenoic Acids (DHA) were associated with Alzheimer's disease. Low Arachidonic acid and DHA are associated with neonatal morbidities and mortality. Decreased saturated fatty acids (SFA), increased monounsaturated FA (MUFA) and polyunsaturated FA (PUFA) (C18:2 n-6 and C20:3 n-6) are associated with cancer. Additionally, genetic polymorphisms in genes coding for enzymes implicated in FA metabolism are associated with disease development. FA desaturase (FADS1 and FADS2) polymorphisms are associated with Alzheimer's disease, Acute Coronary Syndrome, Autism spectrum disorder and obesity. Polymorphisms in FA elongase (ELOVL2) are associated with Alzheimer's disease, Autism spectrum disorder and obesity. FA-binding protein polymorphism is associated with dyslipidemia, type 2 diabetes, metabolic syndrome, obesity, hypertension, non-alcoholic fatty liver disease, peripheral atherosclerosis combined with type 2 diabetes and polycystic ovary syndrome. Acetyl-coenzyme A carboxylase polymorphisms are associated with diabetes, obesity and diabetic nephropathy. FA profile and genetic variants of proteins implicated in FA metabolism could be considered as disease biomarkers and may help with the prevention and management of diseases.

Serum level of endogenous secretory receptor for advanced glycation end products and other factors in type 2 diabetic patients with mild cognitive impairment

OBJECTIVE

Determine the serum levels of endogenous secretory receptor for advanced glycation end products (esRAGEs) in patients with type 2 diabetes and mild cognitive impairment (MCI) and in control patients with type 2 diabetes but no MCI, and examine the relationship of esRAGE and MCI with other clinical factors.

RESEARCH DESIGN AND METHODS

A total of 101 patients with type 2 diabetes who were hospitalized in the Department of Endocrinology at Fujian Provincial Hospital between January 2010 and January 2011 were enrolled. There were 58 patients with MCI and 43 patients without MCI (control). Serum levels of esRAGE were measured using an enzyme-linked immunosorbent assay (ELISA). Other clinical parameters were also measured.

RESULTS

Type 2 diabetic patients with MCI had a longer duration of diabetes; elevated HbA(1c), total cholesterol (CHOL), LDL cholesterol (LDL-C), triglyceride (TG), intima-media thickness, C-reactive protein (CRP), and brachial-ankle pulse wave velocity (ba-PWV); and lower ankle brachial index (ABI) and esRAGE relative to the control group. Among patients with MCI, the Montreal Cognitive Assessment (MoCA) score was positively correlated with serum esRAGE but negatively correlated with CHOL. Spearman rank correlation analysis indicated that esRAGE was positively correlated with MoCA score and ABI but negatively correlated with ba-PWV, CHOL, TG, and CRP in all subjects.

CONCLUSIONS

Our results suggest that esRAGE may be a potential protective factor for dyslipidemia, atherosclerosis, and MCI in patients with type 2 diabetes.

Dietary fat quality and coronary heart disease prevention: A unified theory based on evolutionary, historical, global, and modern perspectives

A large and growing body of evidence indicates that dietary fatty acids regulate crucial metabolic processes involved in the pathogenesis of coronary heart disease (CHD). Despite this evidence, optimal dietary fatty acid intakes for CHD prevention remain unclear. Significant gaps in the modern nutrition literature and contradictions in its interpretation have precluded broad consensus. These shortcomings can be addressed through the incorporation of evolutionary, historical, and global perspectives. The objective of this review is to propose a unified theory of optimal dietary fatty acid intake for CHD prevention that integrates critical insights from evolutionary, historical, global, and modern perspectives. This broad approach may be more likely than previous methods to characterize optimal fatty acid intakes.

Risk of colorectal cancer is linked to erythrocyte compositions of fatty acids as biomarkers for dietary intakes of fish, fat, and fatty acids

Consumption of fish rich in n-3 polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid, is suggested to reduce colorectal cancer risk through inhibition of the arachidonic acid (AA) cascade related to tumorigenesis and cell proliferation. High intake of saturated fatty acids (SFAs) may increase the risk. To examine associations between colorectal cancer risk and fatty acid compositions in erythrocyte membranes, as biomarkers for dietary intakes of fish, fat, and fatty acids, we conducted a case-control study with 74 incident cases and 221 noncancer controls (matched by age, sex, and season of sample collection). Erythrocyte fatty acids were measured using an accelerated solvent extraction and a gas-liquid chromatography. Colorectal cancer had no association with dietary intakes of meat, fish, fat, and fatty acids. However, the risk was inversely associated with erythrocyte compositions of docosahexaenoic acid, AA, and PUFAs [the highest to the lowest tertile, odds ratios, 0.36, 0.42, and 0.15; 95% confidence intervals, 0.14-0.93, 0.18-0.95, and 0.05-0.46; P(trend) < 0.05, respectively] and positively with those of palmitic acid, SFAs, and the ratio of SFAs/PUFAs (odds ratios, 6.46, 8.20, and 9.45; 95% confidence intervals, 2.41-17.26, 2.86-23.52, and 2.84-31.43; P(trend) < 0.005, respectively). In conclusion, we could clearly show decreased and increased risks for colorectal cancer related to PUFAs and SFAs compositions in erythrocyte membranes, respectively, but further research is needed to investigate the discrepancy between our findings and the generally accepted role of the AA cascade.

Fish consumption, blood docosahexaenoic acid and chronic diseases in Chinese rural populations

The Chinese traditional diet is low in fat. However, there is regional variability in the amount, type of fat consumed and the pattern of chronic diseases. An epidemiological survey of 65 rural counties in China (6500 subjects) was conducted in the 1980s. We have re-examined the red blood cell fatty acid and antioxidant composition, with fish consumption. Fish consumption correlated significantly with the levels of docosahexaenoic acid (DHA) in red blood cells (RBC) (r=0.640, P<0.001), selenium (r=0.467, P<0.001) and glutathione peroxidase (r=0.333, P<0.01) in plasma. The proportion of DHA in RBC was inversely associated with total plasma triglyceride concentrations. A strong inverse correlation between DHA in RBC and cardiovascular disease (CVD) was found. The strongest correlation was the combination of DHA and oleic acid. RBC docosahexaenoic acid itself also correlated negatively and significantly with most chronic diseases and appeared to be more protective than either eicosapentaenoic or the omega3 docosapenataenoic acids. These results demonstrate the protective nature of fish consumption and DHA, found in high fat Western diets, operates at a low level of fat. This finding suggests the protective effect of fish consumption as validated by red cell DHA is universal. The protective effect is, therefore, most likely to be due to the fundamental properties of docosahexaenoic acid in cell function.

Moderate dietary fat consumption as a risk factor for ischemic heart disease in a population with a low fat intake: a case-control study in Korean men

BACKGROUND

Dietary fat intake is associated with the incidence of ischemic heart disease (IHD) in Western countries. In populations in which both the average dietary fat consumption and the incidence of IHD are lower than in Western countries, the association of dietary fat intake with IHD incidence remains unknown.

OBJECTIVE

We conducted a case-control study to examine the association of dietary fat with IHD incidence in Korean men.

DESIGN

The case group consisted of 108 patients with electrocardiogram-confirmed myocardial infarction or angiographically confirmed (> or =50% stenosis) IHD who were admitted to a university teaching hospital in Seoul, Republic of Korea. The controls were 142 age-matched patients admitted to the departments of ophthalmology and orthopedic surgery at the same hospital. Dietary fat intake was assessed by a nutritionist using a semiquantitative food-frequency questionnaire. Body mass index (BMI), cigarette use, alcohol intake, exercise, and history of disease were determined during an interview and examination.

RESULTS

In a univariate analysis, the mean percentages of energy from total fat, saturated fatty acids, and monounsaturated fatty acids were significantly higher in the cases than in the controls. BMI, smoking, and a history of hypertension were associated with the occurrence of IHD. In multiple logistic analyses, total fat intake was a significant risk factor (odds ratio: 1.08 for 1% of energy intake; 95% CI: 1.02, 1.14) after adjustment for BMI and smoking.

CONCLUSION

In a population with a relatively low fat intake (19% of energy intake), a moderate increase in total fat intake may be a risk factor for IHD.

Ad libitum intake of low-fat diets rich in either starchy foods or sucrose: effects on blood lipids, factor VII coagulant activity, and fibrinogen

People are advised to reduce their intake of saturated fat and replace it by carbohydrate to avoid coronary heart disease. It is unknown whether sucrose and starchy foods, two major sources of carbohydrates, have similar effects on cardiovascular risk markers if incorporated as a replacement for saturated fat into diets eaten ad libitum. We served 20 healthy, normal-weight women aged 21 to 52 years three strictly controlled diets ad libitum: FAT, high in total fat (46% of total energy [E%]) and saturated fat (21 E%); STARCH, high in total carbohydrates (59 E%) and low in sucrose (2.5 E%); and SUCROSE, high in total carbohydrates (59 E%) and sucrose (23.2 E%). The diets were eaten in randomized order for a period of 2 weeks. Blood lipids, factor VII coagulant activity (FVIIc), and fibrinogen concentrations were measured with subjects in the fasted state (9:45 AM) and the postabsorptive state (6:00 PM). STARCH was associated with lower total cholesterol (mean difference, 0.34 mmol/L; 95% confidence interval [CI], 0.18 to 0.50), low-density lipoprotein (LDL) cholesterol (0.25 mmol/L; 95% CI, 0.13 to 0.37), fasting triglycerides (0.15 mmol/L; 95% CI, 0.07 to 0.23), nonfasting triglycerides (0.44 mmol/L; 95% CI, 0.30 to 0.58), and nonfasting FVIIc (9.8%; 95% CI, 3.8 to 15.8) than SUCROSE. Compared with FAT, STARCH resulted in a desirable decrease of LDL cholesterol and nonfasting FVIIc. STARCH was also associated with a minor weight loss (0.7 kg) that was not found on the other 2 diets. We conclude that starchy foods with a natural content of dietary fiber can be recommended as substitutes for saturated fat in the dietary prevention of coronary heart disease. According to the present short-term findings in healthy females, substitution with sucrose is not advisable.

Thinness and weight loss: beneficial or detrimental to longevity?

This review examined the hypotheses that 1) low body mass index (BMI) is optimal for longevity and 2) weight loss reduces mortality rates. The preponderance of epidemiological evidence fails to support either of these hypotheses. Indeed, a number of studies show that thinness and weight loss (regardless of initial BMI) are associated with increased mortality rates. These findings cannot be attributed to smoking status or to weight loss resulting from subclinical disease. The effect of intentional weight loss on mortality rates depends upon health status. For overweight individuals in good health, there is no compelling evidence to show that mortality rates are reduced with weight loss. Even among overweight persons with one or more obesity-related health conditions, specific weight loss recommendations may be unnecessary: 1) the reduction in mortality rate associated with intentional weight loss is independent of the amount of weight loss, 2) the reductions in all-cause mortality rate associated with increased physical activity and fitness (23-44%), independent of changes in body weight, are greater than that reported for intentional weight loss (approximately 20%), and 3) many obesity-related health conditions (e.g., hypertension, dyslipidemias, insulin resistance, glucose intolerance) can be ameliorated independently of weight loss. In view of the potential risks associated with weight loss and weight cycling, it is suggested that public health may be better served by placing greater emphasis on lifestyle changes and less attention to weight loss per se.

Nonhypercholesterolemic effects of a palm oil diet in Chinese adults

The effects on serum lipids of palm oil (PA) used in Chinese diets were compared with those of soybean oil (SO), peanut oil (PE) and lard (LA) in normocholesterolemic subjects and with that of PE in hypercholesterolemic subjects. Normocholesterolemic subjects [120 men, 18-25 y, total cholesterol (TC) 2.8-5.0 mmol/L] were assigned to four groups to consume test diets for six consecutive weeks after a run-in period of 3 wk. About 30% of dietary energy was derived from fat, 75-80% of which came from test oils. In comparison with the entry level, the average serum TC and LDL cholesterol (LDL-C) were 6.7 and 13.1% lower, respectively, in the PA group and 22.8 and 30.7% higher, respectively, (P < 0.05) in the LA group. At the end of the test, serum TC, LDL-C and the ratio of TC/HDL cholesterol (HDL-C) in the PA group were significantly lower than those of the LA group. Hypercholesterolemic subjects (31 men, 20 women, 32-68 y, TC 5.5-7.0 mmol/L) were divided into two groups. For 6 wk, one group (15 men, 10 women) consumed the PA diet; another group (16 men, 9 women) consumed the PE diet. After a 3-wk interval, the two groups interchanged diets for another 6 wk. The test diets again contained about 30% energy from fat, 60-65% of which came from test oils. Compared with entry values, the PA diet caused significant reductions in serum TC, LDL-C and TC/HDL-C during the first 6 wk and also a significant reduction in TC/HDL-C during the second 6 wk. The PE diet had no significant influence on serum lipids in either experimental period.

Plasma fatty acid levels in South African interethnic male high school pupils at different ultimate risks of coronary heart disease

While coronary heart disease (CHD) is responsible for about a quarter of deaths in South African white, coloured and Indian populations, the rate is very low in the black population. Dietary risk factors for CHD include high intakes of saturated fatty acids and cholesterol, with low intakes of mono and polyunsaturated fatty acids. In a characterization study, plasma fatty acid profiles have been determined in seven groups of high school pupils aged 16-18 years, namely, white, rural black, urban black and middle-class and lower socio-economic class coloureds and Indians. Plasma fatty acids were measured by gas liquid chromatography in 20 subjects from each group. Contrary to expectation, urban and rural black pupils had the highest mean molar composition of saturated fatty acids, largely myristic (14:0) and palmitic (16:0) acids. Rural blacks and middle-class coloureds had the highest molar percentage composition of monounsaturated fatty acids, primarily oleic acid (18:1). Again unexpectedly, white, coloured and Indian groups had the highest level of polyunsaturated fatty acids, due entirely to linoleic acid (18:2). As the findings are unrelated to proneness to CHD mortality in the particular communities studied, plasma fatty acid levels are not predictive of the disease. Epidemiologically, there are many examples of lack of correlation in serum lipid levels and proneness to CHD.

A low-fat diet supplemented with monounsaturated fat results in less HDL-C lowering than a very-low-fat diet

OBJECTIVE

The purpose of this study was to compare the effects of a very-low-fat diet with a low-fat diet supplemented with monounsaturated oil on plasma lipid levels in subjects with hypercholesterolemia.

DESIGN

The 8-week study was divided into one 2-week baseline diet and two 3-week intervention periods in a randomized crossover design.

SETTING

The study was conducted in an outpatient setting at the Deakin Institute of Human Nutrition, Deakin University, Geelong, Australia.

SUBJECTS

Twenty-four free-living subjects with hypercholesterolemia participated in and completed the study.

INTERVENTION

After a 2-week baseline period of a self-selected diet, subjects were assigned to one of two dietary interventions: a very-low-fat (10% of energy from fat), high-carbohydrate diet or a low-fat (26% of energy from fat) diet supplemented with olive oil and an olive oil-based margarine.

MAIN OUTCOME MEASURES

Lipid measurements included total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride concentrations. Plasma cholesteryl esters were measured to monitor compliance.

STATISTICAL ANALYSES

A paired t test was used to assess differences between treatment periods for each subject. The dependence of the difference between treatment periods on the covariates of age, sex, initial cholesterol concentration, and energy intake was analyzed using repeated measures and analysis of covariance.

RESULTS

The low-fat diet supplemented with monounsaturated fat resulted in significantly less high-density lipoprotein cholesterol lowering than the very-low-fat diet (P=.005). Both interventions resulted in significant reductions in both low-density lipoprotein cholesterol and total cholesterol compared with the baseline diet.

APPLICATIONS

This study suggests that a low-fat diet enriched with olive oil provides advantages over a very-low-fat diet in the control of serum lipoproteins among persons with hypercholesterolemia.

A preliminary study of potential dietary risk factors for coronary heart disease among Chinese American adolescents

This study investigated dietary knowledge, attitudes toward diet, behavioral factors affecting diet, and dietary patterns between American Chinese middle school students and Chinese middle school students living in China. Significant differences occurred in these variables between the two groups of students. Chinese students living in China had less knowledge and a less favorable attitude. However, they exhibited more positive behavioral factors affecting diet which include culture, religion, customs, economic factors, beliefs, and values. As for the dietary pattern, Chinese student living in China consumed less meat, dairy products, fat, sweets and snacks, and fast foods, and consumed more fruits, vegetables, and starch.

Estimating the risks and prevalence of hypertension in a suburban area of Beijing

Community-oriented primary care (COPC) provides a framework for identifying and addressing a defined community's health and health care needs. The research reported upon here is based on a community health survey in a new suburban neighborhood (Tayuan region) in the Haidian district of Beijing, conducted by the Beijing Medical University Department of Preventive Medicine and Health Care, to serve as a basis for planning health care services for the residents in that community. The analyses focus on the prevalence and predictors of hypertension among older adult residents (those 45 years of age and older). Based on logistic regression analyses, the odds ratios (in parentheses) confirm that individuals with a family history of cardiovascular disease were more likely to have been diagnosed as hypertensive (1.57). Hypertensives were also more likely to have uncontrolled systolic (3.85) or diastolic (4.75) blood pressure and associated behavioral and biologic risks, such as obesity (1.87) and renal damage (2.60). These risks were even greater among current or former smokers. These analyses will inform the design of community-oriented primary care interventions in that particular community in the People's Republic of China. They also signal important implications and highlight practical methods for assessing and targeting interventions in U.S. communities facing comparable, but unexamined, risks.

Diet and blood nutrient correlations with ischemic heart, hypertensive heart, and stroke mortality in China

Though major differences exist in subcategory mortality levels, cardiovascular disease remains a leading cause of death among both Asian Chinese and Westerners. This paper examines the possible relationship between cardiovascular mortality and biochemical, diet and lifestyle factors based on two surveys in China. Statistically significant associations indicate five variables negatively correlated: molybdenum, oleic acid, liquor consumption (males), legumes, and age at first pregnancy with ischemic heart disease; molybdenum, oleic acid (females) and age at first pregnancy with hypertensive heart disease; and legumes and age at first pregnancy with stroke. Five variables were positively correlated: triglycerides and herpes antibodies with ischemic heart disease; salt and phosphorus (females) with hypertensive heart disease; and only albumin (males) with stroke. Some findings confirm those observed in the West (salt, triglycerides, herpes, legumes, oleic acid, and liquor), but molybdenum and age at first pregnancy have not been emphasized previously. Still others significant in the West have not been observed here, such as cholesterol and smoking.

Nutrition and the global risk for chronic diseases: the INTERHEALTH nutrition initiative. The INTERHEALTH Steering Committee

As chronic, noncommunicable diseases (NCDs) have emerged as leading causes of morbidity and mortality worldwide, the World Health Organization's INTERHEALTH Programme, an international collaboration currently involving 15 countries, has focused its attention on population-based NCD prevention. Participating nations include Australia, Chile, China, Cuba, Cyprus, Finland, Japan, Lithuania, Malta, Mauritius, Russia, Sri Lanka, Tanzania, Thailand, and the United States. This paper will review and assess global trends in food and nutrient intake among INTERHEALTH countries between 1954 and 1986.

Abnormal polyunsaturated lipid metabolism in the obese Zucker rat, with partial metabolic correction by gamma-linolenic acid administration

Below-normal proportions of phospholipid (PL) arachidonic acid (20:4 omega 6) have been reported in serum from obese humans and in liver from obese Zucker rats. This implies an abnormality of 20:4 omega 6 formation from linoleic acid (18:2 omega 6), possibly in the delta 6 desaturase step, or alternatively an abnormality in the catabolism or distribution of arachidonate. We previously speculated that a reduced proportion of 20:4 omega 6 in hepatic PL could contribute to the etiology of genetic obesity. Providing 18:3 omega 6 would bypass delta 6 desaturase and possibly normalize hepatic PL 20:4 omega 6. Therefore weanling Zucker rats were given free access to a defined diet (11% of energy as soy oil) and gavaged daily with 100 microL of either black currant oil concentrate ([BCO] 8% 18:2 omega 6 and 70% 18:3 omega 6) or soy oil ([Soy] 55% 18:2 omega 6 and < 0.1% 18:3 omega 6). Groups of eight lean and eight obese animals were randomized to receive Soy or BCO in a 2 x 2 design; 10 obese and 10 lean rats were fed a stock diet (nongavaged reference). All groups of lean rats had identical weight gain; food intake for Soy lean and BCO lean did not differ. The obese reference animals and Soy obese animals did not differ in weight gain. However, BCO obese animals ate less food (P < .06), gained less weight (P < .0001), and had lower percent body fat (P < .05) compared with the Soy obese animals. The fatty acid constituents from serum, liver, and adipose tissue showed marked differences between lean and obese animals. Hepatic PL 20:4 omega 6 was lower in Soy obese than in lean (P < .002), but was normalized by BCO gavage (diet effect, P < .007). The paucity of hepatic PL 20:4 omega 6 was not due to reduced desaturase activity, as the proportions of other desaturase products (20:3 omega 6, 20:3 omega 9, 20:5 omega 3) were significantly elevated in Soy obese rat liver and serum. Serum and hepatic cholesteryl ester 20:4 omega 6 levels were elevated in obese versus lean rats (P < .02 and P < .0001), indicating abnormal arachidonate distribution in the obese Zucker rat. Because BCO selectively reduced weight gain and percent body fat in obese Zucker rats, our results imply a role for abnormal omega 6 fatty acid metabolism in the etiology of Zucker obesity.(ABSTRACT TRUNCATED AT 400 WORDS)

Humans, lipids and evolution

The genetically ordered physiology of contemporary humans was selected over eons of evolutionary experience for a nutritional pattern affording much less fat, particularly less saturated fat. Current dietary recommendations do not accord exactly with those generated by an understanding of prior hominoid/hominid evolution. Similarly, widely advocated standards for serum cholesterol values fail to match those observed in recently studied hunter-gatherers, whose experience represents the closest living approximation of "natural" human lipid metabolism. The evolutionary paradigm suggests that fats should comprise 20-25% of total energy intake, that the ratio of polyunsaturated to saturated fat should exceed 1.0, and that total serum cholesterol levels should be below 150 mg/dL (approximately 4 mM/L).