Food group and nutrient intakes at baseline in the Multiple Risk Factor Intervention Trial

Relationship between bread and obesity

Some studies have indicated that promoting the Mediterranean diet pattern as a model of healthy eating may help to prevent weight gain and the development of overweight/obesity. Bread consumption, which has been part of the traditional Mediterranean diet, has continued to decline in Spain and in the rest of the world, because the opinion of the general public is that bread fattens. The present study was conducted to assess whether or not eating patterns that include bread are associated with obesity and excess abdominal adiposity, both in the population at large or in subjects undergoing obesity management. The results of the present review indicate that reducing white bread, but not whole-grain bread, consumption within a Mediterranean-style food pattern setting is associated with lower gains in weight and abdominal fat. It appears that the different composition between whole-grain bread and white bread varies in its effect on body weight and abdominal fat. However, the term ‘whole-grain bread’ needs to be defined for use in epidemiological studies. Finally, additional studies employing traditional ways of bread production should analyse this effect on body-weight and metabolic regulation.

Dietary cholesterol, heart disease risk and cognitive dissonance

In the 1960s, the thesis that dietary cholesterol contributes to blood cholesterol and heart disease risk was a rational conclusion based on the available science at that time. Fifty years later the research evidence no longer supports this hypothesis yet changing the dietary recommendation to limit dietary cholesterol has been a slow and at times contentious process. The preponderance of the clinical and epidemiological data accumulated since the original dietary cholesterol restrictions were formulated indicate that: (1) dietary cholesterol has a small effect on the plasma cholesterol levels with an increase in the cholesterol content of the LDL particle and an increase in HDL cholesterol, with little effect on the LDL:HDL ratio, a significant indicator of heart disease risk, and (2) the lack of a significant relationship between cholesterol intake and heart disease incidence reported from numerous epidemiological surveys. Over the last decade, many countries and health promotion groups have modified their dietary recommendations to reflect the current evidence and to address a now recognised negative consequence of ineffective dietary cholesterol restrictions (such as inadequate choline intake). In contrast, health promotion groups in some countries appear to suffer from cognitive dissonance and continue to promote an outdated and potentially hazardous dietary recommendation based on an invalidated hypothesis. This review evaluates the evidence for and against dietary cholesterol restrictions and the potential consequences of such restrictions.

Beta glucan: health benefits in obesity and metabolic syndrome

Despite the lack of international agreement regarding the definition and classification of fiber, there is established evidence on the role of dietary fibers in obesity and metabolic syndrome. Beta glucan (β-glucan) is a soluble fiber readily available from oat and barley grains that has been gaining interest due to its multiple functional and bioactive properties. Its beneficial role in insulin resistance, dyslipidemia, hypertension, and obesity is being continuously documented. The fermentability of β-glucans and their ability to form highly viscous solutions in the human gut may constitute the basis of their health benefits. Consequently, the applicability of β-glucan as a food ingredient is being widely considered with the dual purposes of increasing the fiber content of food products and enhancing their health properties. Therefore, this paper explores the role of β-glucans in the prevention and treatment of characteristics of the metabolic syndrome, their underlying mechanisms of action, and their potential in food applications.

Dietary cholesterol: from physiology to cardiovascular risk

Dietary cholesterol comes exclusively from animal sources, thus it is naturally present in our diet and tissues. It is an important component of cell membranes and a precursor of bile acids, steroid hormones and vitamin D. Contrary to phytosterols (originated from plants), cholesterol is synthesised in the human body in order to maintain a stable pool when dietary intake is low. Given the necessity for cholesterol, very effective intestinal uptake mechanisms and enterohepatic bile acid and cholesterol reabsorption cycles exist; conversely, phytosterols are poorly absorbed and, indeed, rapidly excreted. Dietary cholesterol content does not significantly influence plasma cholesterol values, which are regulated by different genetic and nutritional factors that influence cholesterol absorption or synthesis. Some subjects are hyper-absorbers and others are hyper-responders, which implies new therapeutic issues. Epidemiological data do not support a link between dietary cholesterol and CVD. Recent biological data concerning the effect of dietary cholesterol on LDL receptor-related protein may explain the complexity of the effect of cholesterol on CVD risk.

Dietary intervention promoting high intakes of fruits and vegetables: short-term effects on eating behaviors in overweight-obese postmenopausal women

OBJECTIVE

To compare changes in eating behaviors in response to two dietary interventions: one focusing on restrictive messages to limit consumption of high-fat foods (LOFAT) and the other one based on non-restrictive messages to increase consumption of fruits and vegetables (HIFV).

METHODS

Sixty-eight overweight-obese postmenopausal women were randomly assigned to one of the two 6-month dietary interventions that included three group sessions and ten individual sessions with a dietitian. Anthropometric variables and eating behaviors were measured at baseline, 3months and 6months.

RESULTS

Body weight decreased significantly in both groups at 6months compared to baseline (LOFAT: -3.5±2.9kg; HIFV: -1.6±2.9kg). At 6months, dietary restraint score was higher in the LOFAT group compared to the HIFV group (12.7±4.2 vs 10.5±4.9; p<0.05). Disinhibition and hunger decreased significantly in the HIFV group after 6months while only hunger decreased in the LOFAT group.

CONCLUSION

A weight loss approach based on increasing fruit and vegetable consumption leads to a significant weight loss and is associated with a decrease in disinhibition and hunger without any increase in dietary restraint.

Where Do Eggs Fit in a Heart-Healthy Diet?

Eggs make up a relatively small contribution to the energy consumption of the average American, in part because of the perception that the cholesterol content makes them a forbidden food for a heart-healthy diet. The relationship between egg cholesterol, blood cholesterol, and cardiovascular disease risk is complex and not clearly understood. In addition, eggs provide many valuable and bioavailable nutrients. Thus, the place of eggs in meal planning should be reconsidered while keeping in mind the diet and lifestyle recommendations of the American Heart Association.

Egg consumption, serum total cholesterol concentrations and coronary heart disease incidence: Japan Public Health Center-based prospective study

Limited egg consumption is often recommended to reduce serum cholesterol concentration for the prevention of CHD. We examined the association of egg consumption and total cholesterol concentration with the risk of CHD. A total of 90 735 subjects (19 856 men and 21 408 women, aged 40-59 years in cohort I; 23 463 men and 26 008 women, aged 40-69 years in cohort II) were followed from 1990-4 to the end of 2001 under the Japan Public Health Center-based prospective study. Total cholesterol was obtained in 36 % of the subjects. Men and women were combined for the analyses. The subjects were categorised into four groups according to egg consumption. Subjects with total cholesterol >or=2200 mg/l were less frequent in frequent egg consumption groups in both cohorts (trend P<0.0001). Subjects with <1 d/week of egg consumption were more likely to avoid a cholesterol-rich diet. Egg consumption was not associated with the risk of CHD, although total cholesterol was significantly related to the risk of CHD. The multivariate hazard ratio of CHD in subjects with total cholesterol >or=2400 v. <1800 mg/l was 2.17 (95 % CI 1.22, 3.85; trend P=0.0018). In conclusion, eating eggs more frequently, up to almost daily, was not associated with an increase in CHD incidence for middle-aged Japanese men and women. Subjects with hypercholesterolaemia were less frequently in frequent egg consumption groups, probably because they avoided eating eggs.

A Review of Scientific Research and Recommendations Regarding Eggs

For much of the past 40 years, the public has been warned away from eggs because of a concern over coronary heart disease risk. This concern is based on three observations: 1. eggs are a rich source of dietary cholesterol; 2. when fed experimentally, dietary cholesterol increases serum cholesterol and; 3. high serum cholesterol predicts the onset of coronary heart disease. However, data from free-living populations show that egg consumption is not associated with higher cholesterol levels. Furthermore, as a whole, the epidemiologic literature does not support the idea that egg consumption is a risk factor for coronary disease. Within the nutritional community there is a growing appreciation that health derives from an overall pattern of diet rather than from the avoidance of particular foods, and there has been a shift in the tone in recent dietary recommendations away from "avoidance" messages to ones that promote healthy eating patterns. The most recent American Heart Association guidelines no longer include a recommendation to limit egg consumption, but recommend the adoption of eating practices associated with good health. Based on the epidemiologic evidence, there is no reason to think that such a healthy eating pattern could not include eggs.

Dietary intake in male and female smokers, ex-smokers, and never smokers: the INTERMAP study

This report examines dietary intakes in smokers, ex-smokers, and never smokers in INTERMAP. The 4680 participants aged 40-59 years-from 17 population samples in four countries (China, Japan, UK, USA)-provided four 24-h recalls to assess nutrient intakes and two 24-h urine collections to assess excretion of urea, sodium (Na), potassium (K), etc. Compared to never smokers, current smokers generally consumed more energy from alcohol and saturated fats (SFA), less energy from vegetable protein and carbohydrates, less dietary fibre, vitamin E, beta carotene, vitamin C, thiamine, riboflavin, folate, vitamin B6, calcium, iron, phosphorus, magnesium (Mg), and K per 1000 kcal, excreted less K and urea (marker of dietary protein), had a lower ratio of polyunsaturated fat (PFA) to SFA intake, higher Keys dietary lipid score, and higher dietary and urinary Na/K. There were few differences between smokers and never smokers for total energy intake, energy from total and animal protein, monounsaturated fats, PFA, omega 3 and omega 6 PFA, dietary cholesterol, total vitamin A, retinol, vitamin D, vitamin B12, and urinary and dietary Na. Compared to ex-smokers, smokers generally consumed less energy from vegetable protein, omega 3 PFA, carbohydrates, less dietary fibre, beta carotene, vitamin E, vitamin C, thiamine, riboflavin, folate, vitamin B6, iron, phosphorus, Mg, had lower PFA/SFA, and excreted less urea and K. In conclusion, INTERMAP results are consistent with other reports indicating that smokers have less healthful diets than nonsmokers. Public health interventions in smokers should focus not only on helping them to quit smoking but also on improving their diets to further reduce cancer and cardiovascular disease risks.

What Can Intervention Studies Tell Us about the Relationship between Fruit and Vegetable Consumption and Weight Management?

Given the recent surge in obesity, effective dietary strategies for weight management are required. Because fruits and vegetables are high in water and fiber, incorporating them in the diet can reduce energy density, promote satiety, and decrease energy intake. Although few interventions have specifically addressed fruit and vegetable consumption, evidence suggests that coupling advice to increase intake of these foods with advice to decrease energy intake is a particularly effective strategy for weight management. This approach may facilitate weight loss because it emphasizes positive messages rather than negative, restrictive messages.

Socioeconomic differences among Australian adults in consumption of fruit and vegetables and intakes of vitamins A, C and folate

OBJECTIVE

To determine whether socioeconomic groups differ in their food intakes for fruit and vegetables, their consumption of fruit and vegetables dense in vitamin A, folate and vitamin C, and their nutrient intakes of vitamin C, folate and vitamin A.

METHODS

The 1995 Australian National Nutrition Survey collected food intake data from 8883 adults aged 18-64 years using a 24-h dietary recall. Fruit and vegetables were measured as amount (g) consumed. Intakes of nutrients were estimated from the 24-h dietary recall data. Participants were categorized by whether or not they consumed fruit or vegetables high in vitamin A, folate and vitamin C. Gross annual household income was used to measure socioeconomic position.

RESULTS

Participants from low-income households consumed a smaller quantity of fruit and vegetables. They were also less likely to consume fruit and vegetables high in vitamin C, folate and vitamin A. Consistent with these findings, men and women from disadvantaged socioeconomic groups had lower intakes of vitamin C and folate compared with their more affluent counterparts. These differences were small to moderate in magnitude. Vitamin A intakes were not significantly related to income.

CONCLUSION

As well as promoting healthy dietary practices, nutrition-promotion strategies should target the nutrient intakes of lower socioeconomic groups. These programmes should focus on improving the quantity and choice of fruit and vegetables consumed by people from low-income households.

Nutritional contribution of eggs to American diets

OBJECTIVES

The main purposes of this study were (1) to assess the nutritional significance of eggs in the American diet and (2) to estimate the degree of association between egg consumption and serum cholesterol concentration.

METHODS

Data from the most recent National Health and Nutritional Examination Survey (NHANES III, 1988-94) were utilized to compare the nutritional quality indicators of diets that contained eggs (USDA food grouping system) with those that did not. Nutrient intake (from 24-hour dietary recall), egg intake (from food frequency questionnaire), sociodemographic data and blood cholesterol levels of subjects who met inclusion criteria (n = 27,378) were grouped according to the occurrence and frequency of egg consumption and were analyzed using SUDAAN.

RESULTS

Daily nutrient intake of egg consumers (EC) was significantly greater than that of nonconsumers (NC) for all nutrients studied (except dietary fiber and vitamin B6). Eggs contributed < 10% of daily intake of energy and vitamin B6, 10% to 20% of folate and total, saturated and polyunsaturated fat, and 20% to 30% of vitamins A, E and B12 in EC. Compared to EC, NC had higher rates of inadequate intake (defined by Estimated Average Requirements (EAR) or < 70% Recommended Dietary Allowance (RDA)) for vitamin B12 (10% vs. 21%), vitamin A (16% vs. 21%), vitamin E (14% vs. 22%) and vitamin C (15% vs. 20%). After adjusting for demographic (age, gender and ethnicity) and lifestyle variables (smoking and physical activity), dietary cholesterol was not related to serum cholesterol concentration. People who reported eating > or = 4 eggs/wk had a significantly lower mean serum cholesterol concentration than those who reported eating < or = 1 egg/wk (193 mg/dL vs. 197 mg/dL, p < 0.01). More frequent egg consumption was negatively associated with serum cholesterol concentration (beta = -6.45, p < 0.01).

CONCLUSIONS

In this cross-sectional and population-based study, egg consumption made important nutritional contributions to the American diet and was not associated with high serum cholesterol concentrations.

Blood pressure responses to high-calcium skim milk and potassium-enriched high-calcium skim milk

OBJECTIVE

This study was designed to evaluate the effect of high-calcium skim milk or potassium-enriched high-calcium skim milk on blood pressure compared with nonenriched skim milk.

DESIGN

This was a randomized double-blind controlled trial. Each milk intervention lasted for 4 weeks, with a minimum of 4 weeks of wash-out between interventions.

METHODS

We recruited 38 healthy people, aged over 40 years, to take part in a double-blind, randomized, controlled cross-over study. We asked them to replace their usual liquid milk with two servings per day of skim milk (control), high-calcium skim milk or potassium-enriched high-calcium skim milk. We measured office blood pressures (seated and standing) at the start and after 2 and 4 weeks of milk intervention and we measured daytime ambulatory blood pressures at the start and after 4 weeks of milk intervention. Each milk intervention was interspaced by a 4-week interval.

RESULTS

Office systolic blood pressure (standing) decreased from 127 +/- 16 to 124 +/- 16 mmHg (P<0.05) after 4 weeks of skim milk and from 130 +/- 18 to 126 +/- 17 mmHg (P<0.05) after 4 weeks of high calcium skim milk. After 4 weeks of consuming the potassium-enriched high-calcium milk, systolic blood pressure decreased from 125 +/- 18 to 117 +/- 16 mmHg (P<0.001) seated, and from 130 +/- 16 to 122 +/- 15 mmHg (P<0.001) standing. There were no significant changes in office diastolic blood pressure after any milk. There was no change in ambulatory blood pressure after either skim milk or high-calcium skim milk. After 4 weeks of potassium-enriched high-calcium milk, ambulatory daytime systolic blood pressure decreased from 138 +/- 13 to 135 +/- 11 mm Hg (P<0.05) and daytime diastolic blood pressure decreased from 80 +/- 8 to 78 +/- 9 mmHg (P<0.05).

CONCLUSIONS

High-calcium milk enriched with potassium has a small hypotensive effect in healthy people aged over 40 years.