Diet and health: what should we eat?

Evaluating adherence to recommended diets in adults: the Alternate Healthy Eating Index

OBJECTIVE

The Healthy Eating Index (HEI), designed to assess adherence to the Dietary Guidelines for Americans and the Food Guide Pyramid, was previously associated with only a small reduction in major chronic disease risk in US adult men and women. We assessed whether an alternate index would better predict risk.

DESIGN

Dietary intake reported by men and women from two prospective cohorts was scored according to an a priori designed Alternate Healthy Eating Index (AHEI). In contrast with the original HEI, the AHEI distinguished quality within food groups and acknowledged health benefits of unsaturated oils. The score was then used to predict development of CVD, cancer or other causes of death in the same population previously tested.

SUBJECTS

67,271 women from the Nurses' Health Study and 38 615 men from the Health Professionals' Follow-up Study.

RESULTS

Men and women with AHEI scores in the top vs. bottom quintile had a significant 20% and 11% reduction in overall major chronic disease, respectively. Reductions were stronger for CVD risk in men (RR = 0.61, 95% CI 0.49-0.75) and women (RR = 0.72, 95% CI 0.60-0.86). The score did not predict cancer risk.

CONCLUSIONS

The AHEI was twice as strong at predicting major chronic disease and CVD risk compared to the original HEI, suggesting that major chronic disease risk can be further reduced with more comprehensive and detailed dietary guidance.

Antioxidant activity of ethanolic and aqueous extracts of Uncaria tomentosa (Willd.) DC

The antioxidant properties of aqueous and ethanolic extracts of the Uncaria tomentosa bark were evaluated. The analysis included trolox equivalent antioxidant capacity (TEAC), peroxyl radical-trapping capacity (PRTC), superoxide radical scavenging activity (SOD) and quantitation of total tannins (TT) and total phenolic compounds (TPC). The obtained results indicate high antioxidant capacity of the studied materials in comparison to the other extracts of fruits, vegetables, cereals and medicinal plants. Higher antioxidant activity and total phenolic compounds of the alcoholic preparations -- TEAC=0.57 mmol of Trolox/g, PRTC=0.52 mmol of Trolox/g and SOD=0.39 U/mg than of the aqueous preparation -- TEAC=0.34 mmol of Trolox/g, PRTC=0.19 mmol of Trolox/g and SOD=0.10 U/mg were observed. These results might suggest higher medical suitability of alcoholic extracts. However, the highly elevated level of tannins in alcoholic extracts may cause undesirable gastric effects.

The effect of nutritional manipulation on ultra-endurance performance: a case study

The Atlantic Rowing Race requires teams of two to cover 3,000 nautical miles over 40-90 days. During this ultra-endurance event, competitors require substantial energy intake to meet metabolic requirements; therefore, sufficient physiological and nutritional support is paramount. Two highly trained males (aged 46) engaged in two 14d dietary interventions, with a 14d recovery period in between, to investigate the effect of such interventions on physiological (cardiovascular, cardiorespiratory, and blood-based measures) and performance-based (distance and split time) parameters during an ultra-endurance (2h on 2h off, for 24h) laboratory-based rowing protocol at 60% VO2max. Diet 1: high fat (HF) [60% fat, 30% carbohydrate and 10% protein] and Diet 2: high carbohydrate (HC) [20%, 70% and 10% respectively]. A greater distance was rowed by both subjects (155, 329 m and 134, 797 m vs 130, 089 m and 122, 112 m) with a concomitant reduced heart rate, volume of oxygen uptake, and respiratory exchange ratio, following the HF as opposed to HC dietary intervention. In summary, ultra-endurance performance was enhanced following a 14d HF diet, without apparent implications on liver function and overall lipid profile.

Molecular targets of dietary agents for prevention and therapy of cancer

While fruits and vegetables are recommended for prevention of cancer and other diseases, their active ingredients (at the molecular level) and their mechanisms of action less well understood. Extensive research during the last half century has identified various molecular targets that can potentially be used not only for the prevention of cancer but also for treatment. However, lack of success with targeted monotherapy resulting from bypass mechanisms has forced researchers to employ either combination therapy or agents that interfere with multiple cell-signaling pathways. In this review, we present evidence that numerous agents identified from fruits and vegetables can interfere with several cell-signaling pathways. The agents include curcumin (turmeric), resveratrol (red grapes, peanuts and berries), genistein (soybean), diallyl sulfide (allium), S-allyl cysteine (allium), allicin (garlic), lycopene (tomato), capsaicin (red chilli), diosgenin (fenugreek), 6-gingerol (ginger), ellagic acid (pomegranate), ursolic acid (apple, pears, prunes), silymarin (milk thistle), anethol (anise, camphor, and fennel), catechins (green tea), eugenol (cloves), indole-3-carbinol (cruciferous vegetables), limonene (citrus fruits), beta carotene (carrots), and dietary fiber. For instance, the cell-signaling pathways inhibited by curcumin alone include NF-kappaB, AP-1, STAT3, Akt, Bcl-2, Bcl-X(L), caspases, PARP, IKK, EGFR, HER2, JNK, MAPK, COX2, and 5-LOX. The active principle identified in fruit and vegetables and the molecular targets modulated may be the basis for how these dietary agents not only prevent but also treat cancer and other diseases. This work reaffirms what Hippocrates said 25 centuries ago, let food be thy medicine and medicine be thy food.

Annurca apple-rich diet restores long-term potentiation and induces behavioral modifications in aged rats

The impairment of brain functions during aging could be prevented by an increase in antioxidative defenses. In fact, dietary manipulation with antioxidants or with antioxidant-rich extracts from vegetables and fruit can ameliorate age-associated behavioral alterations. Moreover, dietary supplements of antioxidants can reverse the age-dependent impairment to sustain long-term potentiation (LTP). There is evidence that fresh fruit could be more effective than antioxidant supplements or fruit and vegetable extracts but the effect of a diet enriched in fresh fruit on brain aging process has not been investigated until now. The aim of the present study was to verify whether dietary manipulation with fresh apples could influence age-induced changes in motor and emotional behavior and in LTP in rats. Groups of aged and young rats were fed with a standard diet or a diet supplemented with fresh apples of annurca variety for 10 weeks and assessed for behavioral performance in the open field and elevated plus maze tests and for the ability to sustain LTP. The brains were then removed, histochemically stained for superoxide dismutase (SOD) and SOD activity was measured by computer-assisted image analysis. The aged rats fed with the enriched diet showed a significant decrease in the anxiety level. Moreover, they improved in the ability to sustain LTP, reaching the level of the young rats. SOD activity was increased in the aged rats fed with the standard diet whereas SOD activity in the hippocampus of the aged rats treated with annurca apple was at the level of the young animals. These results suggest that a diet rich in annurca apple could have an important role in health-care during aging.

The Mediterranean diet: science and practice

OBJECTIVE

To provide an overview of research relevant to the Mediterranean diet.

DESIGN

Personal perspectives.

SETTING

International.

SUBJECT

Populations in Europe, North America, Asia.

RESULTS

Approximately 50 years ago, Keys and colleagues described strikingly low rates of coronary heart disease in the Mediterranean region, where fat intake was relatively high but largely from olive oil. Subsequent controlled feeding studies have shown that compared to carbohydrate, both monounsaturated and polyunsaturated fats reduce LDL and triglycerides and increase HDL cholesterol. Importantly, these beneficial metabolic effects are greater in the presence of underlying insulin resistance. In a detailed analysis within the Nurses' Health Study, trans fat from partially hydrogenated vegetable oils (absent in traditional Mediterranean diets) was most strongly related to risk of heart disease, and both polyunsaturated and monounsaturated fat were inversely associated with risk. Epidemiologic evidence has also supported beneficial effects of higher intakes of fruits and vegetables, whole grains, fish, and daily consumption of moderate amounts of alcohol. Together with regular physical activity and not smoking, our analyses suggest that over 80% of coronary heart disease, 70% of stroke, and 90% of type 2 diabetes can be avoided by healthy food choices that are consistent with the traditional Mediterranean diet.

CONCLUSION

Both epidemiologic and metabolic studies suggest that individuals can benefit greatly by adopting elements of Mediterranean diets.

Water soluble feruloyl arabinoxylans from rice and ragi: changes upon malting and their consequence on antioxidant activity

The objective of this study is to determine the changes brought about by germination on water soluble feruloyl arabinoxylans (feraxans), one of the major components of soluble fibre from rice and ragi and their consequence on antioxidant activity. Soluble feraxans, isolated from native and malted rice and ragi were fractionated on DEAE-cellulose. Ferulic acid content of the major [0.1 molar ammonium carbonate (AC) eluted] fraction was higher in malts (rice: 1045 microg/g; ragi: 1404 microg/g) than in native (rice: 119 microg/g; ragi: 147 microg/g) and this fraction was separated by Sephacryl S-300 chromatography into two peaks each in rice (native: 232 and 24.4 kDa; malt: 75.4 and 39.6 kDa) and ragi (native: 140 and 15.4 kDa; malt: 38.9 and 15.4 kDa). 0.1 molar AC eluted fractions showed very strong antioxidant activity in vitro as determined by beta-carotene-linoleate emulsion (IC50: 0.16-0.24 mg), DPPH* (IC50: 4.1-11.4 mg) and Ferric reducing/antioxidant power, FRAP (EC1: 0.76-3.1mg) assays. Antioxidant activity of feraxans was several (4.9-1400) folds higher than the expected activity due to their bound ferulic acid content. Apart from ferulic acid, presence of sugars with >C=O (uronyl/acetyl) groups and degree/nature of glycan-polymerization were observed to influence antioxidant activity of the polysaccharides. Malting resulted in many dynamic changes in the ferulic acid content in different feraxan types and affected their antioxidant activity.

The role of nutrition in oncology: a need for a change of attitude and curriculum

BACKGROUND

The role of nutrition in cancer is poorly understood by Indian oncologists, who are exposed to minimal education on nutrition in their undergraduate and postgraduate careers.

METHODS

A postal questionnaire survey, without reminder, assessed the knowledge and beliefs about nutrition of 120 oncologists in India (response rate = 58%).

RESULTS

There was a lack of teaching and understanding by surgeons and radiation and medical oncologists about the role of nutrition in prevention, carcinogenesis, treatment, and outcome.

CONCLUSIONS

There needs to be much more emphasis in undergraduate and postgraduate education about the supportive role of nutrition in cancer.

Why do adolescents eat what they eat? Personal and social environmental predictors of fruit, snack and breakfast consumption among 12-14-year-old Dutch students

OBJECTIVE

The aim of the study was to investigate the relative importance of personal and social environmental predictors of the consumption of fruit, high-fat snacks and breakfast.

DESIGN

A school-based cross-sectional survey. Data were collected through written questionnaires.

SETTING

Students from eight schools in the southern part of The Netherlands.

SUBJECTS

Six hundred and one students from preparatory secondary vocational education schools.

RESULTS

About a quarter of the variation in actual behaviours and intentions to change the behaviours could be explained. Stepwise multiple regression analysis revealed that, for all three behaviours, higher intention to change was especially associated with a more positive attitude and subjective norm, and higher intentions to increase fruit intake with more positive self-efficacy expectations. With regard to actual consumption, a more positive attitude towards eating fruit was the only significant correlate of a higher consumption of fruit. A more positive attitude towards eating high-fat snacks, perceived lower intake of the mother, and higher food availability and accessibility were associated with consumption of high-fat snacks, and a more positive attitude to breakfast more frequently was associated with more frequent breakfast consumption.

CONCLUSION

The results indicate that adolescents' attitudes are the most important determinants of different health-related eating behaviours and intentions to change. Interventions promoting a healthy diet for adolescents should include creative strategies to achieve positive associations with healthy dietary changes.

Free radical scavenging properties and phenolic content of Chinese black-grained wheat

Free radical scavenging properties and phenolic content of extracts from a novel Chinese black-grained wheat were evaluated for comparison with selected wheat controls. Extracts of bran and whole meal were compared for their scavenging activities against the 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical. The total phenolic content and phenolic acid levels were determined using colorimetric and high-performance liquid chromatography (HPLC) methods, respectively. There were significant differences in radical scavenging activities and phenolic contents among bran or whole meal samples of Chinese black-grained wheat and selected wheat controls. Chinese black-grained wheat had the strongest scavenging activity and the highest total phenolic content among the wheat samples. The scavenging activity and total phenolic content of wheat bran was generally twice as high as that of whole meal. A positive correlation was found between DPPH radical scavenging activity and total phenolic content of bran (R = 0.86) and whole meal (R = 0.96). In addition, HPLC analysis detected the presence of gallic, p-hydroxybenzoic, caffeic, syringic, p-coumaric, vanillic, gentisic, o-coumaric acid, and ferulic acids in wheat bran. Ferulic acid content was highest among the phenolic acids. Chinese black-grained wheat may be considered as a potential source of natural antioxidants given its high free radical scavenging ability and phenolic content. Additional research is needed to further investigate other phenolic compounds and evaluate their contribution to the antioxidant activity in order to understand the nutraceutical value of the novel black-grained wheat genotype.

Association of consumption of fried food away from home with body mass index and diet quality in older children and adolescents

OBJECTIVES

Rates of overweight have increased dramatically among children in the United States. Although an increase in consumption of food prepared away from home has paralleled overweight trends, few data exist relating food prepared away from home to change in BMI in children. The goals of this study were to (1) examine the cross-sectional and longitudinal associations between consumption of fried foods away from home (FFA) and BMI and (2) examine the cross-sectional associations between intake of FFA and several measures of diet quality.

METHODS

We studied a cohort of 7745 girls and 6610 boys, aged 9 to 14 years, at baseline in 1996. We obtained BMI from self-reported height and weight, measures of diet quality from a food frequency questionnaire, and weekly servings of FFA during the previous year. We performed linear regression analyses to assess the longitudinal associations between change in consumption of FFA on change in BMI, using data from three 1-year periods from 1996 through 1999. We also related consumption of FFA with intake of selected foods and nutrients at baseline.

RESULTS

In cross-sectional analyses, adjusting for potential confounders, mean (SE) BMI was 19.1 (0.13) among children who ate FFA "never or <1/week," 19.2 (0.13) among those who responded "1 to 3 times/week," and 19.3 (0.18) among those who responded "4 to 7 times/week." In longitudinal multivariate models, increasing (over 1 year) consumption of FFA "never or <1/week" to "4 to 7/week" was associated with increasing BMI (beta = 0.21 kg/m2; 95% confidence interval: 0.03-0.39) compared with those with low consumption of FFA at baseline and 1 year later. At baseline, frequency of eating FFA was associated with greater intakes of total energy, sugar-sweetened beverages, and trans fat, as well as lower consumption of low-fat dairy foods and fruits and vegetables.

CONCLUSIONS

These data suggest that older children who consume greater quantities of FFA are heavier, have greater total energy intakes, and have poorer diet quality. Furthermore, increasing consumption of FFA over time may lead to excess weight gain.

Towards a dietary prevention of hereditary breast cancer

Inheritance of a deleterious mutation in BRCA1 or BRCA2 confers a high lifetime risk of developing breast cancer. Variation in penetrance between individuals suggests that factors other than the gene mutation itself may influence the risk of cancer in susceptible women. Several risk factors have been identified which implicate estrogen-induced growth stimulation as a probable contributor to breast cancer pre-disposition. The protein products of both of these genes appear to help preserve genomic integrity via their participation in the DNA damage response and repair pathways. To date, the evidence for a cancer-protective role of dietary nutrients, for the most part those with antioxidant properties, has been based on women without any known genetic pre-disposition and it is important to identify and evaluate dietary factors which may modify the risk of cancer in BRCA carriers. Here we propose that diet modification may modulate the risk of hereditary breast cancer by decreasing DNA damage (possibly linked to estrogen exposure) or by enhancing DNA repair. The prevention of hereditary breast cancer through diet is an attractive complement to current management strategies and deserves exploration.

Dietary cholesterol suppresses the ability of olive oil to delay the development of atherosclerotic lesions in apolipoprotein E knockout mice

To test the hypothesis that cholesterol might suppress the beneficial effect of olive oil in atherosclerosis, we fed apoE KO mice diets containing extra virgin olive oil, either with or without cholesterol, for 10 weeks and assessed the development of atherosclerosis. Within each sex, mice were assigned randomly to one of the following four experimental groups: (1) a standard chow diet, (2) a chow diet supplemented with 0.1% cholesterol (w/w) cholesterol, (3) a chow diet enriched with 20% (w/w) extra virgin olive oil and (4) a chow diet containing 0.1% cholesterol and 20% extra virgin olive oil. On the standard chow diet, average plasma cholesterol levels were higher in males than in females. Olive oil- and cholesterol-enriched diets, separately or in combination, induced hypercholesterolemia in both sexes, and abolished the difference between the sexes in plasma cholesterol levels. The addition of cholesterol to chow or olive oil diets decreased apolipoprotein A-I significantly in females and serum paraoxonase activities in males. The latter activity was higher in females than in males. In both sexes, the size of aortic atherosclerotic lesions was similar in olive oil- and chow-fed animals and smaller than in cholesterol-supplemented groups. Size of aortic lesions were positively correlated with circulating paraoxonase activity, particularly in males, and the relationship remained after adjusting for apolipoprotein A-I and HDL cholesterol levels. Our results demonstrate that the nutritional regulation of paraoxonase is an important determinant of atherosclerotic lesions dependent on sex. They also suggest that the mere inclusion of olive oil in Western diets is insufficient and the adoption of Mediterranean diet would be more effective in retarding the development of atherosclerotic lesions.

The association between tooth loss and the self-reported intake of selected CVD-related nutrients and foods among US women

OBJECTIVES

Many studies have reported associations between oral health and cardiovascular diseases; poor nutritional status due to impaired dentition status has been suggested as a mediator. Our objective is to evaluate the associations between tooth loss and the self-reported consumption of fruits and vegetables and selected CVD-related nutrients.

METHODS

A total of 83,104 US women who completed a food frequency questionnaire (FFQ) in 1990 and 1994 and reported number of natural teeth in 1992, were included in a cross-sectional analysis relating dietary intake to number of natural teeth. A longitudinal analysis was also conducted to evaluate whether tooth loss in 1990-1992 was associated with change in diet between 1990 and 1994.

RESULTS

After adjusting for age, total calorie intake, smoking and physical activity, edentulous women appeared to have dietary intake associated with increased risk for CVD, including significantly higher intake of saturated fat, trans fat, cholesterol and vitamin B12, and lower intake of polyunsaturated fat, fiber, carotene, vitamin C, vitamin E, vitamin B6, folate, potassium, vegetables, fruits, and fruits excluding juices compared with women with 25-32 teeth. In the longitudinal analyses, women who lost more teeth were more likely to change their diet in ways that would potentially increase risk for development of CVD. They also tended to avoid hard foods, such as raw carrot, fresh apple or pear.

CONCLUSIONS

Women with fewer teeth have unhealthier diets such as decreased intake of fruits and vegetables, which could increase CVD risk. Diet may partially explain associations between oral health and cardiovascular disease.

Blueberry extract enhances survival of intraocular hippocampal transplants

Transplantation of neural tissue has been explored as a potential therapy to replace dead or dying cells in the brain, such as after brain injury or neurodegenerative disease. However, survival of transplanted tissue is poor, especially when the transplant recipient is of advanced age. Recent studies have demonstrated improvement of neuronal deficits in aged animals given a diet supplemented with blueberry extract. The present study focuses on the survival of fetal hippocampal transplants to young (4 months) or middle-aged (16 months) animals with or without dietary supplementation with blueberry extract. Results indicate that fetal hippocampus transplanted to middle-aged host animals exhibits poor survival characterized by reduced growth and compromised tissue organization. However, when middle-aged animals were maintained on a diet supplemented with 2% blueberry extract, hippocampal graft growth was significantly improved and cellular organization of grafts was comparable to that seen in tissue grafted to young host animals. Thus, the data suggest that factor(s) in blueberries may have significant effects on development and organization of this important brain region.

Maternal diet and acute lymphoblastic leukemia in young children

Because leukemia clone-specific chromosomal abnormalities are present at birth in children who later develop leukemia, it has been hypothesized that maternal factors, including nutrition during pregnancy, might affect the risk of acute lymphoblastic leukemia (ALL) among young children. We have evaluated this hypothesis in a nationwide case-control study of ALL among children ages 12 to 59 months in Greece. Children (n=131) with ALL were gender and age matched to control children (n=131) hospitalized for minor conditions between 1999 and 2003. The mothers of the children were interviewed in person by trained interviewers who used an extensive food frequency questionnaire addressing diet during the index pregnancy. The analysis was done by modeling the data through conditional logistic regression, also controlling for total energy intake and possible confounding factors. Odds ratios (OR) and 95% confidence intervals (95% CI) were expressed per quintile increase of maternal intake during pregnancy of the specified food group. The risk of ALL in the offspring was lower with increased maternal intake of fruits (OR, 0.72; 95% CI, 0.57-0.91), vegetables (OR, 0.76; 95% CI, 0.60-0.95), and fish and seafood (OR, 0.72; 95% CI, 0.59-0.89) and higher with increased maternal intake of sugars and syrups (OR, 1.32; 95% CI, 1.05-1.67) and meat and meat products (OR, 1.25; 95% CI, 1.00-1.57). Children of women who tend to consume during their pregnancies what is currently considered to be a healthy diet maybe at lower risk of ALL.

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.

Resveratrol causes Cdc2-tyr15 phosphorylation via ATM/ATR-Chk1/2-Cdc25C pathway as a central mechanism for S phase arrest in human ovarian carcinoma Ovcar-3 cells

Resveratrol is one of the most extensively studied cancer chemopreventive agents; however, its mechanisms of action are not completely understood. Here, we observed that resveratrol induces S phase arrest via Tyr15 phosphorylation of Cdc2 in human ovarian carcinoma Ovcar-3 cells. Overexpression of Cdc2AF, a mutant resistant to Thr14 and Tyr15 phosphorylation, ablated resveratrol-induced S phase arrest. Further upstream, we observed that resveratrol causes phosphorylation of cell division cycle 25C (Cdc25C) tyrosine phosphatase via the activation of checkpoint kinases Chk1 and Chk2, which in turn were activated via ATM (ataxia telangiectasia mutated)/ATR (ataxia telangiectasia-Rad3-related) kinase in response to DNA damage, as resveratrol also increased phospho-H2A.X (Ser139), which is known to be phosphorylated by ATM/ATR in response to DNA damage. The involvement of these molecules in resveratrol-induced S phase was also supported by the studies showing that addition of ATM/ATR inhibitor caffeine reverses resveratrol-caused activation of ATM/ATR-Chk1/2 as well as phosphorylation of Cdc25C, Cdc2 and H2A.X, and S phase arrest. In additional studies assessing whether observed effects of resveratrol are specific to Ovcar-3 cells, we observed that it also induces S phase arrest and H2A.X (Ser139) phosphorylation in other ovarian cancer cell lines PA-1 and SKOV-3, albeit at different levels; whereas, resveratrol showed only marginal S phase arrest in normal human foreskin fibroblasts with undetectable level of phospho-H2A.X (Ser139). These findings for the first time identify that resveratrol causes Cdc2-tyr15 phosphorylation via ATM/ATR-Chk1/2-Cdc25C pathway as a central mechanism for DNA damage and S phase arrest selectively in ovarian cancer cells, and provide a rationale for the potential efficacy of ATM/ATR agonists in the prevention and intervention of cancer.

Olive oil and modulation of cell signaling in disease prevention

Epidemiological studies show that populations consuming a predominantly plant-based Mediterranean-style diet exhibit lower incidences of chronic diseases than those eating a northern European or North American diet. This observation has been attributed to the greater consumption of fruits and vegetables and the lower consumption of animal products, particularly fat. Although total fat intake in Mediterranean populations can be higher than in other regions (ca. 40% of calories), the greater proportion is derived from olive oil and not animals. Increased olive oil consumption is implicated in a reduction in cardiovascular disease, rheumatoid arthritis, and, to a lesser extent, a variety of cancers. Olive oil intake also has been shown to modulate immune function, particularly the inflammatory processes associated with the immune system. Olive oil is a nonoxidative dietary component, and the attenuation of the inflammatory process it elicits could explain its beneficial effects on disease risk since oxidative and inflammatory stresses appear to be underlying factors in the etiology of these diseases in man. The antioxidant effects of olive oil are probably due to a combination of its high oleic acid content (low oxidation potential compared with linoleic acid) and its content of a variety of plant antioxidants, particularly oleuropein, hydroxytyrosol, and tyrosol. It is also possible that the high oleic acid content and a proportionate reduction in linoleic acid intake would allow a greater conversion of alpha-linolenic acid (18:3n-3) to longer-chain n-3 PUFA, which have characteristic health benefits. Adoption of a Mediterranean diet could confer health benefits in high-risk populations.

Effect of low and high fat diets on nutrient intakes and selected cardiovascular risk factors in sedentary men and women

OBJECTIVE

The desired level of dietary fat intake is controversial. The effect of decreasing fat intake to 19% and increasing it to 50% from a control diet of 30% on nutritional status and cardiovascular risk factors in healthy individuals was studied.

METHODS

Eleven healthy subjects (5 men and 6 women) were randomized to consume diets with 19% and 50% calories from fat. Each diet lasted 3 weeks, with a one-week washout. The habitual and washout diets were determined to be 30% fat. At the beginning and the end of each diet, fasting blood was collected to determine plasma lipoproteins, and physiological factors were measured.

RESULTS

Total caloric expenditure was similarly balanced to intake on the 30% and 50% fat diets, but intake was significantly lower on the 19% fat diet and led to a loss of 0.6 kg body weight. Consumptions of essential fatty acids, vitamin E and zinc were improved with increased fat intake, but folate intake was compromised on the 30% and 50% fat diets. Compared with the 50% fat diet, subjects consuming the 19% fat diet had significantly lower HDL cholesterol (HDL-C) (54 +/- 3 vs. 63 +/- 3 mg. dL(-1), p < 0.05) and apolipoprotein A1 (ApoA1) (118 +/- 4 vs. 127 +/- 3 mg/dL, p < 0.05). Changing the levels of fat intake did not affect % body fat, heart rate, blood pressure, blood triglycerides, total cholesterol (TC), LDL cholesterol, apolipoprotein B (ApoB), TC/HDL-C and ApoA1/ApoB ratios.

CONCLUSION

A low fat diet (19%) may not provide sufficient calories, essential fatty acids, and some micronutrients (especially vitamin E and zinc) for healthy untrained individuals, and it also lowered ApoA1 and HDL-C. Increasing fat intake to 50% of calories improved nutritional status, and did not negatively affect certain cardiovascular risk factors.

Predictors of drop-out in overweight and obese outpatients

OBJECTIVE

To investigate the impact on drop-out rates of several baseline clinical characteristics of a sample of overweight and obese outpatients.

DESIGN

Retrospective clinical trial.

SUBJECTS

The charts of 383 patients aged 15-82 y attending an outpatient clinic for the treatment of obesity were examined from the first clinical evaluation until 1 y of diet ambulatory treatment.

MEASUREMENTS

We characterised the participants at baseline on the basis of their somatic characteristics, socioeconomic status, obesity-related diseases and dietary habits. The most significant factors resulting in univariate statistical analysis (waist, body mass index (BMI), full-time job, depressive syndrome, number of obesity-related diseases, daily frequency of fruit consumption) were then examined as independent variables in direct multiple logistic regression with the dependent variable drop-out.

RESULTS

The 1-y drop-out rate was 77.3%. A total of 87 patients completed the follow-up study. The noncompleter patients had slightly lower BMI and waist circumference mean values, and they were further regularly employed in full-time jobs, while the completer patients were principally pensioners and housewives. Drop-outs had a lower number of obesity-related diseases and as a result were less depressed. By the logistic regression, full-time job is the best predictor of premature withdrawal (odds ratio=2.40). Age, gender, anthropometric measurements, lifestyle and dietary habits did not result as significant predictors of drop-out.

CONCLUSION

The overweight and obese outpatients at higher risk of ambulatory treatment drop-out are more likely to work full hours, have less obesity-related complications and be less depressed. In our study, the full-time job condition seems to be the strongest predictor of premature withdrawal.

Short-term efficacy of a web-based computer-tailored nutrition intervention: Main Effects and Mediators

BACKGROUND

This study evaluates the short-term efficacy and respondents' evaluations of a Web-based computer-tailored nutrition intervention, aiming to decrease saturated fat intake and increase fruit and vegetable intake. Perceived personal relevance, individualization, and interestingness of the information were tested as mediators of the effects of the tailored intervention.

PURPOSE

The objective was to study the short-term effects of a Web-based computer-tailored nutrition intervention.

METHODS

Respondents (N = 782) were randomly assigned to a tailored intervention group, a generic nutrition information control group, or a no-information control group. Fat, fruit, and vegetable intakes and behavioral determinants were measured at baseline and at 3 weeks postintervention. Posttest group differences were determined by multiple linear regression analyses.

RESULTS

The computer-tailored intervention produced significant effects for the determinants of fat, fruit, and vegetable intake and for vegetable and fruit intake. The tailored information was rated as more personally relevant, individualized, interesting, and new than the generic nutrition information. Perceived personal relevance, individualization, and interestingness were identified as mediators of some of the tailoring effects.

CONCLUSIONS

The findings of this study indicate that Web-based, computer-tailored nutrition information can have a short-term effect on the determinants of fat, fruit, and vegetable intake. The effect of the tailored information may be partly explained by the perceived personal relevance and individualization of the information.

Mediterranean diet and overall mortality differences in the European Union

OBJECTIVE

To assess whether the Mediterranean diet contributes to overall mortality differences and trends between Mediterranean and non-Mediterranean European Union (EU) countries.

DESIGN

Routinely recorded adjusted overall mortality and food availability data in Mediterranean and non-Mediterranean EU countries. A Mediterranean diet score designed a priori was used as instrument.

SETTING

Fifteen EU countries in the 1960s and the 1990s.

SUBJECTS

The general population in the 15 EU countries.

RESULTS

The difference between Mediterranean and non-Mediterranean EU countries in a 7-point Mediterranean diet score was reduced from 2.9 in the 1960s to 1.6 in the 1990s. This reduction may underlie the reduction in the difference in general mortality between these countries, from about 100 deaths per 100,000 person-years in the early 1970s to about 50 deaths per 100,000 person-years in the 1990s.

CONCLUSIONS

The decline in overall mortality in the 15 EU countries over the last 25 years is probably unrelated to diet. However, the gradual loss of the survival advantage of Mediterranean EU citizens, compared with other EU citizens, may be linked to the gradual abandonment by the former of their dietary traditions.

Mediterranean diet and longevity

While several investigations have focused on the association between individual foods and nutrients upon the development of chronic diseases, few have examined the role that entire dietary patterns may play in health and disease. A dietary pattern generally considered to have beneficial health effects is that of the Mediterranean diet. In this paper, five cohort studies exploring the association of Mediterranean diet with overall mortality and hence longevity are reviewed. A number of conclusions can be drawn. First, there appears to exist sufficient evidence that diet does indeed influence longevity. Secondly, an optimal diet for the prevention of both coronary heart disease and cancer is likely to extensively overlap with the traditional Mediterranean diet. It is not yet clear which components in the Mediterranean diet are more important for its apparent health effects, but olive oil, plant foods and moderate wine consumption are likely candidates.

Opuntia ficus indica (L.) Mill. fruit juice protects liver from carbon tetrachloride-induced injury

The protective effects of the juice of Opuntia ficus indica fruit (prickly pear) against carbon tetrachloride (CCl(4))-induced hepatotoxicity were examined in rats. The animals were treated orally with the juice (3 mL/rat) 2 h after administration of the hepatotoxic agent. Preventive effects were studied by giving the juice (3 mL/rat) for 9 consecutive days. On day 9 the rats received the hepatotoxic agent. Morphological and biochemical evaluations were carried out 24, 48 and 72 h after induction of the hepatic damage. Data show that O. ficus indica fruit juice administration exerts protective and curative effects against the CCl(4)-induced degenerative process in rat liver. Histology evaluation revealed a normal hepatic parenchyma at 48 h; the injury was fully restored after 72 h. Moreover, a significant reduction in CCl(4)-induced increase of GOT and GPT plasma levels is evident; these data are in agreement with the functional improvement of hepatocytes. O. ficus indica fruit juice contains many phenol compounds, ascorbic acid, betalains, betacyanins, and a flavonoid fraction, which consists mainly of rutin and isorhamnetin derivatives. Hepatoprotection may be related to the flavonoid fraction of the juice, but other compounds, such as vitamin C and betalains could, synergistically, counteract many degenerative processes by means of their antioxidant activity.

Effects of Chronic Administration of Fruit Extract (Citrus unshiu MARC) on Endothelial Dysfunction in Streptozotocin-Induced Diabetic Rats

We investigated the effects of chronic administration of fruit extract (Citrus unshiu MARC) on the endothelial dysfunction seen in aortae from streptozotocin (STZ)-induced diabetic rats. A ten-week administration of this fruit extract preserved acetylcholine (ACh)-induced endothelium-dependent relaxation, but not sodium nitroprusside (SNP)-induced endothelium-independent relaxation, in the diabetic aorta. In age-matched control rats, chronic administration of the fruit extract had no influence on the ACh- or SNP-induced aortic relaxation. The increased total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels seen in STZ-induced diabetic rats were not normalized by fruit-extract treatment. These results suggest that Citrus unshiu MARC extract preserves endothelial function in the aorta in STZ-induced diabetic rats without lowering plasma cholesterol. This beneficial effect may be due to this extract protecting of nitric oxide against inactivation by oxygen free radicals.

Potential synergy of phytochemicals in cancer prevention: mechanism of action

Epidemiological studies have consistently shown that regular consumption of fruits and vegetables is strongly associated with reduced risk of developing chronic diseases, such as cancer and cardiovascular disease. It is now widely believed that the actions of the antioxidant nutrients alone do not explain the observed health benefits of diets rich in fruits and vegetables, because taken alone, the individual antioxidants studied in clinical trials do not appear to have consistent preventive effects. Work performed by our group and others has shown that fruits and vegetable phytochemical extracts exhibit strong antioxidant and antiproliferative activities and that the major part of total antioxidant activity is from the combination of phytochemicals. We proposed that the additive and synergistic effects of phytochemicals in fruits and vegetables are responsible for these potent antioxidant and anticancer activities and that the benefit of a diet rich in fruits and vegetables is attributed to the complex mixture of phytochemicals present in whole foods. This explains why no single antioxidant can replace the combination of natural phytochemicals in fruits and vegetables to achieve the health benefits. The evidence suggests that antioxidants or bioactive compounds are best acquired through whole-food consumption, not from expensive dietary supplements. We believe that a recommendation that consumers eat 5 to 10 servings of a wide variety of fruits and vegetables daily is an appropriate strategy for significantly reducing the risk of chronic diseases and to meet their nutrient requirements for optimum health.

Various selected vegetables, fruits, mushrooms and red wine residue inhibit bone resorption in rats

To make a broad survey of the effect of components of the human diet on bone resorption, a few items from the following categories were added to rat diets: vegetables, fruits, beans, nuts and seeds, mushrooms, carbohydrate sources and beverages. The effect on bone resorption was measured by the urinary excretion of tritium released from bones of 9-wk-old rats prelabeled with tritiated tetracycline from weeks 1 to 6. The number of rats per experiment was 26--6, 5, 5, 5 and 5 in the untreated control group fed the plain semipurified diet, the positive control group fed onions and three groups fed one of the newly investigated items, respectively. New experiments were added until 10 rats were fed each item in each of two separate experiments. The results for each item were compared to those for the untreated control group (n = 12) investigated simultaneously. We found that feeding rats 1 g/d of dry fennel, celeriac, oranges, prunes, French beans and farmed and wild mushrooms (Agaricus hortensis and Boletus edulis) as well as the freeze-dried residue from red wine significantly (P < 0.05 or lower) inhibited bone resorption. Eighteen items had no significant effect. To date we have found 25/53 items that exhibit inhibitory activity. Activity appears to be restricted to the following categories: vegetables, salads, herbs, mushrooms, fruits and red wine residue (25/36 items effective). Furthermore, as assessed in a similar experimental design with various doses of a mixture of active items, we determined the minimum effective dose of the dry items to be 170 mg/d. These results open the possibility for targeted interventions in humans.

Immunomodulatory activity of curcumin: suppression of lymphocyte proliferation, development of cell-mediated cytotoxicity, and cytokine production in vitro

Curcumin (diferuloylmethane), a major curcumanoid found in the spice turmeric, exhibits anti-inflammatory, anti-oxidant, and chemopreventive activities. However, the effect of curcumin on the development of T cell-mediated immunological responses largely remains unknown. In this study we have investigated the effect of curcumin on mitogen/antigen induced proliferation of splenic lymphocytes, induction of cytotoxic T lymphocytes (CTLs), lymphokine activated killer (LAK) cells, and the production of cytokines by T lymphocytes and macrophages. We found that mitogen, interleukin-2 (IL-2) or alloantigen induced proliferation of splenic lymphocytes, and development of cytotoxic T lymphocytes is significantly suppressed at 12.5-30 micromol/L curcumin. The generation of LAK cells at similar concentrations was less sensitive to the suppressive effect of curcumin compared to the generation of antigen specific CTLs. Curcumin irreversibly impaired the production of these immune functions, since lymphoid cells failed to respond to the activation signals following 8h pretreatment with curcumin. Curcumin also inhibited the expression/production of IL-2 and interferon-gamma (IFN-gamma) by splenic T lymphocytes and IL-12 and tumor necrosis factor-alpha (TNF-alpha) by peritoneal macrophages irreversibly. Curcumin inhibited the activation of the transcription factor nuclear factor kappaB (NF-kappaB) without affecting the levels of constitutively expressed NF-kappaB. The latter result suggests that curcumin most likely inhibits cell proliferation, cell-mediated cytotoxicity (CMC), and cytokine production by inhibiting NF-kappaB target genes involved in induction of these immune responses.

Process evaluation of two environmental nutrition programmes and an educational nutrition programme conducted at supermarkets and worksite cafeterias in the Netherlands

INTRODUCTION

This article describes the process evaluation of two environmental programmes and an educational nutrition programme, implemented at supermarkets and worksite cafeterias. Studies conducted earlier, indicated that the programmes had no effect on consumers' eating behaviour. Consequently, the more specific purpose of the present study was to identify explanations for the ineffectiveness of the programmes and to formulate recommendations for future programmes.

MATERIALS AND METHODS

The environmental programmes included labelling of healthy products and increasing the range of healthy foods on offer. The education programme consisted of several elements, such as brochures and a self-help guide. Semi-structured interviews were conducted with 21 managers of supermarkets and worksite cafeterias where the programmes were implemented.

RESULTS

Although materials were not always entirely compatible with the different supermarkets and worksite cafeterias, the degree of implementation was satisfactory. According to the managers, the programmes were not striking enough, the labelling would have been more effective if it had discriminated between different brands of a product, and the number of new products was too small compared with the total range of foods on offer.

CONCLUSIONS

The findings suggest that programmes should be promoted intensively. Furthermore, the relevant manufacturers and wholesalers supplying worksite cafeterias should be encouraged to increase their range of suitable low-fat products. Finally, the feasibility and possible effects of brand-specific labelling should be investigated further.

Trends in lifestyle 1986-99 in a 25- to 64-year-old population of the Northern Sweden MONICA project

AIMS

The authors explore the time trends in lifestyle factors in the Northern Sweden MONICA population, including physical activity, intake of certain foods, coffee and alcohol consumption, smoking, and the use of smokeless tobacco.

METHODS

Four health surveys during a 14-year time span were compared (1986, 1990, 1994, and 1999). The participation rate in all surveys was high. A questionnaire with similar or comparable questions about lifestyle factors was used across all health surveys.

RESULTS

A large variation was demonstrated in the consumption of saturated fat in dairy products across the surveys. The use of butter on bread and of 3% fat milk clearly declined in favour of using low-fat margarine and 1-1.5% fat milk. A decline in the intake of boiled or baked potatoes together with an increase in the intake of pasta and rice was demonstrated. There were no changes in leisure-time physical activity. The proportion of the population using tobacco was unaltered. In men, smoking declined during the period but simultaneously there was an increase in the use of smokeless tobacco. The use of "boiled" or Scandinavian coffee diminished and more frequent use of alcohol was seen, especially in men.

CONCLUSION

Pronounced changes were seen in food consumption with a decrease in saturated fat intake, boiled coffee, and potatoes and an increase in alcohol, rice, and pasta consumption. No clear time trends were found in physical activity or in the use of tobacco.

Exploring the occurrence and nature of comparison of one's own perceived dietary fat intake to that of self-selected others

Lack of awareness of personal dietary fat intake is associated with a low motivation to change to a diet lower in fat. An optimistic bias in the comparison of one's own fat intake to that of others is associated with this lack of awareness. Insight into the way people make interpersonal comparisons related to fat intake may contribute to a better understanding of dietary intake and its determinants. Such insight may provide suggestions for nutrition education interventions aimed at increasing awareness and intention to change. The present study explores interpersonal comparisons involved in evaluating personal dietary fat intake. One hundred and eighty-nine respondents participated in structured telephone interviews. The respondents reported that they use interpersonal comparison information related to fat intake to some extent and that they mostly compare themselves with close relatives and friends. Respondents who intended to change to a lower fat diet and the younger ones were more likely to compare themselves with others. Comparison targets were perceived to eat small, as well as large or average amounts of fat, which may indicate that people use positive as well as negative role models for making interpersonal comparisons in terms of dietary fat intake.

A life course approach to diet, nutrition and the prevention of chronic diseases

OBJECTIVE

To briefly review the current understanding of the aetiology and prevention of chronic diseases using a life course approach, demonstrating the life-long influences on the development of disease.

DESIGN

A computer search of the relevant literature was done using Medline-'life cycle' and 'nutrition' and reviewing the articles for relevance in addressing the above objective. Articles from references dated before 1990 were followed up separately. A subsequent search using Clio updated the search and extended it by using 'life cycle', 'nutrition' and 'noncommunicable disease' (NCD), and 'life course'. Several published and unpublished WHO reports were key in developing the background and arguments.

SETTING

International and national public health and nutrition policy development in light of the global epidemic in chronic diseases, and the continuing nutrition, demographic and epidemiological transitions happening in an increasingly globalized world. RESULTS OF REVIEW: There is a global epidemic of increasing obesity, diabetes and other chronic NCDs, especially in developing and transitional economies, and in the less affluent within these, and in the developed countries. At the same time, there has been an increase in communities and households that have coincident under- and over-nutrition.

CONCLUSIONS

The epidemic will continue to increase and is due to a lifetime of exposures and influences. Genetic predisposition plays an unspecified role, and with programming during fetal life for adult disease contributing to an unknown degree. A global rise in obesity levels is contributing to a particular epidemic of type 2 diabetes as well as other NCDs. Prevention will be the most cost-effective and feasible approach for many countries and should involve three mutually reinforcing strategies throughout life, starting in the antenatal period.

Dietary change, nutrition education and chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a prevalent and serious condition. Nutrition might play a role in COPD prevention and is definitely important in COPD management. There are some indications from epidemiological studies that dietary factors such as ample consumption of fruit and fish may decrease COPD risk. The available evidence is, however, not substantial enough to warrant dietary recommendations for primary prevention of COPD. Substantial evidence does point to the conclusion that, regardless of disease severity, weight loss is related to decreased exercise capacity, health status and mortality as well as to increased morbidity among patients with moderate to severe COPD. Current nutritional support strategies have primarily focussed on treatment of severely underweight and disabled patients. In an in-patient setting or when incorporated in a pulmonary rehabilitation programme, nutritional support has proved effective in inducing weight gain and related functional improvements. However, such interventions are only feasible for a selected group of patients and are very laborious. Therefore, opportunities for dietary and nutrition interventions in COPD management should be explored, aiming at early detection, prevention and early treatment of involuntary weight loss. This means expanding the target group to include COPD out-patients and primary care patients before they have become underweight, and putting more emphasis on dietary change than on medically prescribed supplementation. Successful intervention assumes (voluntary) adjustment of dietary behaviour, and health professionals may play an essential role in encouraging patients to make and maintain these changes. Achieving dietary change among COPD patients may require a combination of diet counselling and self-management. A model for such a combination is presented.

Swim exercise training and adaptations in the antioxidant defense system of myocardium of old rats: relationship to swim intensity and duration

We examined a suitable swim program of different intensities and durations that could evoke changes in the myocardial antioxidant capacity in 22-month-old rats. Male rats (Rattus norvegicus) were assigned to either a sedentary control (SE-C) group or one of six trainee groups. Animals were swim-exercised for 4 weeks with either 20 min or 40 min/day, and three intensities, low, moderate and high. Low-intensity at 20 min/day elicited maximum swim velocity (Sv) and endurance capacity (P<0.05). While serum total cholesterol, triglyceride and low-density lipoprotein (LDL-C) levels were significantly reduced, high-density lipoprotein (HDL-C) showed an increase (P<0.05) in low-intensity trained rats (20 min/day) over SE-C. Notable reduction in blood lactate was also evident. Exercise training significantly increased superoxide dismutase (Mn-SOD), decreased lipid peroxidation products, malondialdehyde and lipofuscin in the left and right ventricles. Increased Mn-SOD with concomitant decrease in lipofuscin in left ventricle was significantly greater than in right ventricle. Moderate- to high-intensity exercise was not effective in either reducing lipid peroxidation products or elevating Mn-SOD activity. These data suggest that swim training at low-intensity of 20 min/day is beneficial as a major protective adaptation against oxidative stress in old myocardium.

[Trends in diabetes mellitus in Brazil: the role of the nutritional transition]

Prevalence of type 2 diabetes mellitus has increased rapidly and is expected to increase even further. In Latin America countries there is an upward trend among the younger age groups, with a major negative impact on the quality of life and burden of the disease for the health care system. Increasing rates of overweight and obesity associated with lifestyle changes and aging of the population are the main contributing factors to the increasing prevalence of type 2 diabetes. Dietary shifts in the Brazilian population (low frequency of fiber-rich foods and heavy consumption of saturated fatty acids and sugars) and sedentary lifestyle are the main risk factors for obesity, type 2 diabetes, and other chronic diseases. Diabetes prevention programs are being promoted in several countries with results showing improvement in quality of life.

Immunomodulatory activity of resveratrol: discrepant in vitro and in vivo immunological effects

trans-Resveratrol is a dietary polyphenolic compound present in grapes, which has been shown to exhibit strong anti-inflammatory, antioxidant, and chemopreventive activities. In this study we have compared the in vitro and in vivo effects of resveratrol on the development of various cell-mediated immune responses, including mitogen/antigen-induced T cell proliferation, induction of cytotoxic T lymphocytes (CTLs), interleukin-2 (IL-2) induced lymphokine activated killer cells, and cytokine production. We found significant suppression (>90%) of the mitogen/antigen-induced T cell proliferation and development of allo-antigen specific CTLs in vitro with resveratrol at a concentration of 25 microM. Intragastric administration of resveratrol (2 mg daily) to mice for 4 weeks showed no effect on age-related gain in body weight, peripheral blood cell counts (WBC, RBC, or platelets), or the cellularity of bone marrow or spleen. The CD4(+) and CD8(+) T cells in spleen or colony-forming units-total in the marrow also remained unaffected by treatment with resveratrol. Spleen cells, which were stimulated in vitro after being removed from mice which had been administered resveratrol for 2 or 4 weeks, showed no significant change in IL-2 or concanavalin A induced proliferation of T cells or production of IL-2 induced lymphokine activated killer cells. Further, the production of in interferon-gamma and IL-12 was not affected by administration of resveratrol, but production of tumor necrosis factor-alpha was reduced. Even when conducted entirely in vivo, treatment with resveratrol was found to only marginally reduce allo-antigen induced T cell proliferation and the generation of CTLs in the draining lymph nodes. Thus, even though resveratrol strongly inhibits T cell proliferation and production of cytolytic cells in vitro, oral administration of resveratrol for 4 weeks does not induce hematologic or hematopoietic toxicity, and only marginally reduces the T cell-mediated immune responses.

An ad libitum, very low-fat diet results in weight loss and changes in nutrient intakes in postmenopausal women

OBJECTIVES

To determine whether a very low-fat diet (<15% of energy intake) consumed ad libitum during an 8-month period can achieve weight loss of 5% to 10% of initial body weight while still providing adequate intakes of other essential nutrients.

DESIGN

Longitudinal, 8-month, ad libitum, free living, very low-fat diet trial.

SUBJECTS

Fifty-four of the sixty-four healthy postmenopausal women recruited completed the entire study (age 59+/-8 years, BMI=29.6+/-6.3). Twenty-four of these women used hormone replacement therapy, thirty women did not.

INTERVENTION

Weekly sessions aimed at teaching and reinforcing a very low-fat intake diet for eight months. MAIN: outcome measures Body weight, percent body fat, waist-to-hip ratio, resting energy expenditure, respiratory quotient, and nutrient intakes derived from 7-day food records at the beginning and at 2, 4, 6, and 8 months of the study. Statistical analysis performed Repeated measures analysis of variance and Tukey post hoc analysis were used to analyze significant differences in mean data (P<.05).

RESULTS

Fat intake decreased from 33.2+/-7.5% to 11+/-4% over the 8-month intervention period (P<.00001). Weight loss was 6.0 kg+/- 4.2 kg (P<.000038), an 8% weight change, and decrease in percent body fat of 2.7%+/-0.2% (P< or =.000046). Weight correlated better with the self-reported fat intake (r=0.321, P<.01) than the energy intake (r=0.263, P<.05) at baseline. Fiber intake increased from 16 g+/-0.6 g to 23 g+/-0.2 g (P<.0005). All micronutrient intakes remained at or above preintervention ranges, except for a decrease in vitamin E intake from 8.1 mg+/-4.0 mg to 3.7 mg+/-1.1 mg (P<.0005) on the very low-fat diet and linoleic acid from 6.3%+/-1.5% to 2.5%+/-0.7% (P<.000001) with no significant reduction in linolenic acid. Hormone replacement was not associated with the amount of weight loss.

APPLICATIONS

This study demonstrates that adherence to a very low-fat diet consumed ad libitum causes weight loss in the 5% to 10% range and a reduction of body fat. These reductions, along with the observed decreases in fat intake, are associated with improved health outcomes. Because of the decreased vitamin E and n-3 fatty acid intake, emphasis on foods high in these nutrients may need to be encouraged for those consuming a very low-fat diet.

Dietary fiber and progression of atherosclerosis: the Los Angeles Atherosclerosis Study

BACKGROUND

Several epidemiologic studies found weak protective relations between dietary fiber intake and the risk of cardiovascular disease events. However, few of the studies addressed possible mechanisms of the effect.

OBJECTIVE

In the present study, we estimated relations between the progression of atherosclerosis and the intake of selective dietary fiber fractions. Mediation of the relations by serum lipids was also investigated.

DESIGN

Participants who were free of heart disease and aged 40-60 y were recruited into the cohort (n = 573; 47% women). The intima-media thickness (IMT) of the common carotid arteries was measured ultrasonographically at the baseline examination and at 2 follow-up examinations (n = 500), dietary intakes were assessed with six 24-h recalls (3 at baseline and 3 at the first follow-up examination), and blood samples were analyzed at baseline and at both follow-up examinations.

RESULTS

A significant inverse association was observed between IMT progression and the intakes of viscous fiber (P = 0.05) and pectin (P = 0.01). Correction for measurement error increased the magnitude of these estimated effects. The ratio of total to HDL cholesterol was inversely related to the intakes of total fiber (P = 0.01), viscous fiber (P = 0.05), and pectin (P = 0.01). The magnitude of the association between IMT progression and the intakes of viscous fiber and pectin was attenuated by adjustment for serum lipids.

CONCLUSIONS

The intake of viscous fiber, especially pectin, appears to protect against IMT progression. Serum lipids may act as a mediator between dietary fiber intake and IMT progression.

Dietary Pattern Is Associated with Homocysteine and B Vitamin Status in an Urban Chinese Population

To identify existing dietary patterns and examine associations between these patterns and plasma homocysteine and B vitamin concentrations in an urban Chinese population living in Beijing (n = 119), dietary information was collected with a food frequency questionnaire designed for this population. Plasma homocysteine and B vitamin concentrations were examined. Food group variables, expressed as percentages of total energy intake, were entered into cluster analysis to define three distinct dietary pattern groups. The prevalence of high homocysteine (>11 micromol/L for women and 12 micromol/L for men), was 31.9%; of low folate (<6.8 nmol/L), 36.2%; of low vitamin B-12 (<221 pmol/L), 36.9%; and of low vitamin B-6 (<30 nmol/L), 16.0%. The three dietary patterns derived were defined by relatively greater intake of 1) fruit and milk, 2) red meat and 3) refined cereals. More than 40% of subjects in the refined cereals group had high plasma homocysteine and low plasma folate concentrations, and 67% had low plasma vitamin B-12 concentrations. Those following the refined cereals pattern were 4 and 5.2 times more likely to have high homocysteine and low vitamin B-12 concentrations, respectively, relative to the fruit and milk dietary pattern group (P < 0.01), after adjustment for potential confounders. High intake of refined cereals was associated with low B vitamin and high homocysteine concentrations, whereas the pattern high in fruit and milk was associated with the lowest homocysteine. Dietary patterns appear to play an important role in the micronutrient and homocysteine status of these Chinese adults.

Tracing the Mediterranean diet through principal components and cluster analyses in the Greek population

OBJECTIVE

To identify dietary patterns, and their socio-demographic and lifestyle correlates in a large sample of Greek adults, and assess their adherence to the traditional Mediterranean diet.

DESIGN

Principal component (PC) analysis was used to identify dietary patterns among 28 034 participants of the Greek branch of the European Prospective Investigation into Cancer and Nutrition. Dietary information was collected through a validated, semiquantitative, food-frequency questionnaire. The extracted PCs were subsequently regressed on sociodemographic and lifestyle variables. Analyses were also performed to classify individuals with similar dietary behavior into clusters.

RESULTS

Four PCs were identified: PC1 resembled the Mediterranean diet, PC2 approximated a vegetarian diet with emphasis on seed oils, PC3 reflected a preference for sweets, and PC4 reflected a Western diet. PC1 and PC2 were positively associated with age, education, physical activity, and nonsmoking status. Females, in comparison to males, scored higher on PC1 but lower on PC2. Males, younger, more educated individuals, nonsmokers and residents of Greater Athens (Attica) scored higher on PC3. PC4 was associated with younger age, less education, and current smoking. In cluster analyses, cluster A contrasted clusters B and C in having much higher mean PC1- and PC2-scores and substantially lower PC3- and PC4-scores. PC1 and PC4 were, respectively, positively and inversely correlated with an a priori Mediterranean-diet score; PC2 and PC3 were unrelated to it.

CONCLUSION

The Mediterranean-like PC1-score as well as the vegetarian-like PC2 were higher among older, more educated people, and were associated with a healthier lifestyle than PC4, which reflected a Western-type diet. PC1 was strongly positively associated with an a priori Mediterranean-diet score.

Model for incorporating social context in health behavior interventions: applications for cancer prevention for working-class, multiethnic populations

BACKGROUND

This article proposes a conceptual framework for addressing social contextual factors in cancer prevention interventions, and describes work that operationalizes this model in interventions for working class, multiethnic populations.

METHODS

The Harvard Cancer Prevention Program Project Includes Three Studies: (1) an intervention study in 25 small businesses; (2) an intervention study in 10 health centers; and (3) a computer simulation modeling project that translates risk factor modifications into gains in life expectancy and number of cancers averted. The conceptual framework guiding this work articulates pathways by which social context may influence health behaviors, and is used to frame the interventions and guide evaluation design.

RESULTS

Social contextual factors cut across multiple levels of influence, and include individual factors (e.g., material circumstances, psychosocial factors), interpersonal factors (e.g., social ties, roles/responsibilities, social norms), organizational factors (e.g., work organization, access to health care), and neighborhood/community factors (e.g., safety, access to grocery stores). Social context is shaped by sociodemographic characteristics (e.g., social class, race/ethnicity, gender, age, language) that impact day-to-day realities.

CONCLUSIONS

By illuminating the pathways by which social contextual factors influence health behaviors, it will be possible to enhance the effectiveness of interventions aimed at reducing social inequalities in risk behaviors.

Tooth loss and dietary intake

BACKGROUND

Several studies have reported that impaired dentition status is associated with poor nutritional intake. However, most of these studies are cross-sectional and thus are unable to clarify the temporal sequence.

METHODS

We assessed the longitudinal relation between tooth loss and changes in consumption of fruits and vegetables and of nutrients important for general health among 31,813 eligible male health professionals.

RESULTS

Subjects who lost five or more teeth had a significantly smaller reduction in consumption of dietary cholesterol and vitamin B12, greater reduction in consumption of polyunsaturated fat and smaller increase in consumption of dietary fiber and whole fruit than did subjects who had lost no teeth. Men who had lost teeth also were more likely to stop eating apples, pears and raw carrots.

CONCLUSIONS

The results support the temporal association between tooth loss and detrimental changes in dietary intakes, which could contribute to increased risk of developing chronic diseases.

PRACTICE IMPLICATIONS

Dietary evaluation and recommendations can be incorporated into dental visits to provide a greater benefit to patients.