Major Scientific Advances with Dairy Foods in Nutrition and Health

Web-based nutrition education intervention improves self-efficacy and self-regulation related to increased dairy intake in college students

Dairy consumption declines substantially during young adulthood. Interventions that incorporate theory-based nutrition education can provide insight into factors associated with dietary choices. The aim of this experimental study was to improve outcome expectations, self-efficacy, self-regulation, and behavior related to dairy intake in college students using social cognitive theory. Students (n=294) enrolled in a personal health class were randomized to intervention (n=148) or comparison group (n=146). The 5-week intervention (March 2006 to April 2006) was conducted using an online course system; components included e-mail messages, posted information, and behavior checklists with tailored feedback. Multivariate analysis of covariance with age and sex as covariates (P<0.05) was conducted to measure change related to dairy intake and social cognitive theory variables. Ninety-two percent of participants (n=135 intervention, n=136 control) completed the study. Dairy intake from food records did not differ between groups at baseline; baseline intake for all participants (mean ± standard error) was 0.45 ± 0.05 servings/day for low-fat dairy products and 1.44 ± 0.06 servings/day for total dairy products. Participants in the intervention group made greater increases in use of self-regulatory strategies (P=0.038) and self-efficacy for consuming three servings/day of dairy products (P=0.049), but not in outcome expectations or consumption of dairy products. A Web-based intervention designed to change dairy intake in college students was effective in modifying some social cognitive theory constructs; strategies that positively impact outcome expectations and social support through online interventions require further development.

Survey of the fatty acid composition of retail milk differing in label claims based on production management practices

Consumers are becoming increasingly health conscious, and food product choices have expanded. Choices in the dairy case include fluid milk labeled according to production management practices. Such labeling practices may be misunderstood and perceived by consumers to reflect differences in the quality or nutritional content of milk. Our objective was to investigate nutritional differences in specialty labeled milk, specifically to compare the fatty acid (FA) composition of conventional milk with milk labeled as recombinant bST (rbST)-free or organic. The retail milk samples (n=292) obtained from the 48 contiguous states of the United States represented the consumer supply of pasteurized, homogenized milk of 3 milk types: conventionally produced milk with no specialty labeling, milk labeled rbST-free, and milk labeled organic. We found no statistical differences in the FA composition of conventional and rbST-free milk; however, these 2 groups were statistically different from organic milk for several FA. When measuring FA as a percentage of total FA, organic milk was higher in saturated FA (65.9 vs. 62.8%) and lower in monounsaturated FA (26.8 vs. 29.7%) and polyunsaturated FA (4.3 vs. 4.8%) compared with the average of conventional and rbST-free retail milk samples. Likewise, among bioactive FA compared as a percentage of total FA, organic milk was slightly lower in trans 18:1 FA (2.8 vs. 3.1%) and higher in n-3 FA (0.82 vs. 0.50%) and conjugated linoleic acid (0.70 vs. 0.57%). From a public health perspective, the direction for some of these differences would be considered desirable and for others would be considered undesirable; however, without exception, the magnitudes of the differences in milk FA composition among milk label types were minor and of no physiological importance when considering public health or dietary recommendations. Overall, when data from our analysis of FA composition of conventional milk and milk labeled rbST-free or organic were combined with previous analytical comparisons of the quality and composition of these retail milk samples, results established that there were no meaningful differences that would affect public health and that all milks were similar in nutritional quality and wholesomeness.

Milk intake and its association with metabolic syndrome in Korean: analysis of the third Korea National Health and Nutrition Examination Survey (KNHANES III)

Although previous studies have shown that milk intake has some protective effects on metabolic syndrome (MS), there are few data on the relation between MS and milk consumption in Korean. To evaluate the association between milk intake frequency and MS, 4,890 subjects (2,052 men and 2,838 women) were included in the analysis, based on the national data from representative random sample of the third Korea National Health and Nutrition Examination Survey (KNHANES III) in 2005. We conducted both univariate and multivariate logistic regression analysis with adjustment for confounding factors associated with MS. Mean (±SD) age of subjects was 47.1±15.5 yr. In univariate analysis, the risk of MS was inversely associated with the frequency of milk intake, but this relation was attenuated in multivariate regression. In the individuals with BMI ≥23 kg/m(2), those with highest quartile of milk consumption (once daily or more) had significantly lower risk of MS (OR [95% CI] 0.72 [0.57-0.92] compared with lowest quartile [those rarely consumed]) after adjustment, but not among leaner individuals (BMI <23 kg/m(2)). Korean overweight adults who drink milk more frequently may be protected against MS. But it seems that this relation is somewhat different among MS components.

A high calcium, skim milk powder diet results in a lower fat mass in male, energy-restricted, obese rats more than a low calcium, casein, or soy protein diet

The combination of dairy protein and dietary calcium (Ca) may enhance weight loss more effectively than either compound alone. Our purpose in this study was to determine the effect of various protein sources [skim milk powder (SMP), whey, casein, and soy protein isolate (SPI)] and 2 levels of Ca [low, 0.67% Ca (LC) or high, 2.4% Ca (HC)] on weight loss. Sixty-four 12-wk-old Sprague-Dawley, diet-induced obese rats were assigned to 1 of 8 energy-restricted (ER) diets for 4 wk with 1 of the 4 protein sources and either LC or HC concentrations. Rats were ER to 70% of the ad libitum food and energy intake of a reference group (n = 8) fed the AIN-93M diet. The interaction between dietary protein and Ca affected final body weight and fat mass (FM) (P < 0.05). FM was less in rats fed SMP-HC than in those fed casein-LC or SPI-LC. Lean body mass was greater in rats fed SMP than in those fed whey. Rats fed HC diets had a lower plasma glucagon area under the curve (AUC) than those fed LC diets. The blood glucose AUC, homeostatic model of insulin resistance, and the expression of certain hepatic genes involved in energy metabolism were affected by protein and Ca. These data suggest that consuming a diet containing SMP and HC is associated with a lower FM in obese, male, ER rats than in diets containing casein or SPI and LC; however, the role of SMP and Ca in glucose homeostasis remains to be determined.

Biomarkers of milk fat and the risk of myocardial infarction in men and women: a prospective, matched case-control study

BACKGROUND

High intakes of saturated fat have been associated with cardiovascular disease, and milk fat is rich in saturated fat.

OBJECTIVE

The objective of this study was to investigate the association between the serum milk fat biomarkers pentadecanoic acid (15:0), heptadecanoic acid (17:0), and their sum (15:0+17:0) and a first myocardial infarction (MI).

DESIGN

The study design was a prospective case-control study nested within a large population-based cohort in Sweden. Included in the study were 444 cases (307 men) and 556 controls (308 men) matched on sex, age, date of examination, and geographic region. Clinical, anthropometric, biomarker fatty acid, physical activity, and dietary data were collected. The odds of a first MI were investigated by using conditional logistic regression.

RESULTS

In women, proportions of milk fat biomarkers in plasma phospholipids were significantly higher (P < 0.05) in controls than in cases and were, in general, negatively, albeit weakly, correlated with risk factors for metabolic syndrome. The crude standardized odds ratios of becoming an MI case were 0.74 (95% CI: 0.58, 0.94) in women and 0.91 (95% CI: 0.77, 1.1) in men. After multivariable adjustment for confounders, the inverse association remained in both sexes and was significant in women. In agreement with biomarker data, quartiles of reported intake of cheese (men and women) and fermented milk products (men) were inversely related to a first MI (P for trend < 0.05 for all).

CONCLUSIONS

Milk fat biomarkers were associated with a lower risk of developing a first MI, especially in women. This was partly confirmed in analysis of fermented milk and cheese intake. Components of metabolic syndrome were observed as potential intermediates for the risk relations.

Dairy food consumption and obesity-related chronic disease

Dairy food comprises a range of different products with varying nutritional components. In the context of a healthy diet, dairy food may provide protection against and amelioration of chronic diseases related to obesity. These include overweight, insulin resistance/metabolic syndrome/type 2 diabetes, hypertension/stroke, and cardiovascular disease. Eliciting how dairy food may have this impact represents a challenge for modern nutritional science and requires an integration of knowledge from observational studies of population dietary patterns and disease prevalence, and experimental studies testing the effect of dairy food consumption. It also benefits from the recent identification of biomarkers of dairy fat intake and from mechanistic studies that support the plausibility of the observed effects. Future research might discriminate between types of dairy foods and focus on the synergy provided by the food matrix, rather than simply the component parts of the food.

Effects of whey protein isolate on body composition, lipids, insulin and glucose in overweight and obese individuals

The health benefits currently associated with increased dairy intake may be attributable to the whey component of dairy proteins. The present study evaluated the effects of whey protein supplementation on body composition, lipids, insulin and glucose in comparison to casein and glucose (control) supplementation in overweight/obese individuals for 12 weeks. The subjects were randomised to whey protein, casein or glucose supplementation for 12 weeks according to a parallel design. Fasting blood samples and dual-energy X-ray absorptiometry measurements were taken. Seventy men and women with a mean age of 48.4 (SEM 0.86) years and a mean BMI of 31.3 (SEM 0.8) kg/m2 completed the study. Subjects supplemented with whey protein had no significant change in body composition or serum glucose at 12 weeks compared with the control or casein group. Fasting TAG levels were significantly lowered in the whey group compared with the control group at 6 weeks (P = 0.025) and 12 weeks (P = 0.035). There was a significant decrease in total cholesterol and LDL cholesterol at week 12 in the whey group compared with the casein (P = 0.026 and 0.045, respectively) and control groups (P < 0.001 and 0.003, respectively). Fasting insulin levels and homeostasis model assessment of insulin resistance scores were also significantly decreased in the whey group compared with the control group (P = 0.049 and P = 0.034, respectively). The present study demonstrated that supplementation with whey proteins improves fasting lipids and insulin levels in overweight and obese individuals.

Dairy consumption and patterns of mortality of Australian adults

BACKGROUND/OBJECTIVES

Dairy foods contain various nutrients that may affect health. We investigated whether intake of dairy products or related nutrients is associated with mortality due to cardiovascular disease (CVD), cancer and all causes.

SUBJECTS/METHODS

We carried out a 16-year prospective study among a community-based sample of 1529 adult Australians aged 25-78 years at baseline. Habitual intakes of dairy products (total, high/low-fat dairy, milk, yoghurt and full-fat cheese), calcium and vitamin D were estimated as mean reported intake using validated food frequency questionnaires (FFQs) self-administered in 1992, 1994 and 1996. National Death Index data were used to ascertain mortality and cause of death between 1992 and 2007. Hazard ratios (HRs) were calculated using Cox regression analysis.

RESULTS

During an average follow-up time of 14.4 years, 177 participants died, including 61 deaths due to CVD and 58 deaths due to cancer. There was no consistent and significant association between total dairy intake and total or cause-specific mortality. However, compared with those with the lowest intake of full-fat dairy, participants with the highest intake (median intake 339 g/day) had reduced death due to CVD (HR: 0.31; 95% confidence interval (CI): 0.12-0.79; P for trend=0.04) after adjustment for calcium intake and other confounders. Intakes of low-fat dairy, specific dairy foods, calcium and vitamin D showed no consistent associations.

CONCLUSIONS

Overall intake of dairy products was not associated with mortality. A possible beneficial association between intake of full-fat dairy and cardiovascular mortality needs further assessment and confirmation.

Overview of the physiological changes and optimal diet in the golden age generation over 50

Basically, our lifespan is determined genetically. However, several other parameters such as the environment, lifestyle and diet have a high impact on living in the best of health. Many older persons suffer from various diseases, which often cannot be avoided; however, their development can be postponed and symptoms can be mitigated by a balanced diet, moderate physical activity as well as a healthy lifestyle. These diseases are, for example, sarcopenia (degenerative loss of muscle mass), osteoporosis (decomposition of bone structure), digestive restrictions, sensory impairment, water imbalance or a compromised immune system. Psychological modifications, obesity and loss of weight also commonly occur in older adults. To define an adequate diet for elderly between the ages 50 and 80 is difficult, even impossible, because the nutritional requirements differ between the dynamic quinquagenarian and the frailer eighty-year-old. However, several studies have shown that sufficient consumption of high-quality proteins, calcium, vitamin D, anti-oxidative food compounds, water as well as adapted energy values and nourishment with high-nutrient density in combination with physical activity especially help one to remain healthy to a great age. The cornerstone of healthy ageing is the maintenance of normal bodyweight in order to prevent the development of diseases such as osteoporosis, coronary heart disease or diabetes type 2. This publication will review the physiological changes that occur with advanced age and consequential nutritional recommendations for elderly persons.

Effects of a fibre-enriched milk drink on insulin and glucose levels in healthy subjects

Background

The glycaemic response to foods is dependent on the quality and content of carbohydrates. Carbohydrates in the form of dietary fibre have favourable effects on insulin and glucose metabolism and may help to control energy intake. Dairy products have a relatively low carbohydrate content, and most of the carbohydrate is in the form of lactose which causes gastrointestinal symptoms in part of the population. In order to avoid these symptoms, dairy products can be replaced with lactose-free dairy products which are on the market in many parts of the world. However, the effects of lactose-free products on insulin and glucose metabolism have not been studied.

Methods

In the present study, we investigated the effects of 1) a lactose-free milk drink, 2) a novel fibre-enriched, fat- and lactose-free milk drink and 3) normal fat-free milk on serum glucose and insulin levels and satiety using a randomized block design. Following an overnight fast, 26 healthy volunteers ingested 200 ml of one of these drinks on three non-consecutive days. Insulin and glucose levels and subjective satiety ratings were measured before the ingestion of the milk product and 20, 40, 60, 120 and 180 minutes after ingestion. The responses were calculated as the area under the curve subtracted by the baseline value (AUC minus baseline).

Results

The insulin response was significantly lower for the fibre-enriched milk drink than it was for the other milk products (AUC, P = 0.007). There were no differences in the response for glucose or in the AUC for the subjective satiety ratings between the studied milk products.

Conclusion

The present results suggest that this novel milk drink could have positive effects on insulin response.

Potential estimation of major mineral contents in cow milk using mid-infrared spectrometry

Milk and dairy products are a major source of minerals, particularly calcium, involved in several metabolic functions in humans. Currently, several dairy products are enriched with calcium to prevent osteoporosis. The development of an inexpensive and fast quantitative analysis for minerals is required to offer dairy farmers an opportunity to improve the added value of the produced milk. The aim of this study was to develop 5 equations to measure Ca, K, Mg, Na, and P contents directly in bovine milk using mid-infrared (MIR) spectrometry. A total of 1,543 milk samples were collected between March 2005 and May 2006 from 478 cows during the Walloon milk recording and analyzed by MIR spectrometry. Using a principal component approach, 62 milk samples were selected by their spectral variability and separated in 2 calibration sets. Five outliers were detected and deleted. The mineral contents of the selected samples were measured by inductively coupled plasma atomic emission spectrometry. Using partial least squares combined with a repeatability file, 5 calibration equations were built to estimate the contents of Ca, K, Mg, Na, and P in milk. To assess the accuracy of the developed equations, a full cross-validation and an external validation were performed. The cross-validation coefficients of determination (R(2)cv) were 0.80, 0.70, and 0.79 for Ca, Na, and P, respectively (n = 57), and 0.23 and 0.50 for K and Mg, respectively (n = 31). Only Ca, Na, and P equations showed sufficient R(2)cv for a potential application. These equations were validated using 30 new milk samples. The validation coefficients of determination were 0.97, 0.14, and 0.88 for Ca, Na, and P, respectively, suggesting the potential to use the Ca and P calibration equations. The last 30 samples were added to the initial milk samples and the calibration equations were rebuilt. The R(2)cv for Ca, K, Mg, Na, and P were 0.87, 0.36, 0.65, 0.65, and 0.85, respectively, confirming the potential utilization of the Ca and P equations. Even if new samples should be added in the calibration set, the first results of this study showed the feasibility to quantify the calcium and phosphorus directly in bovine milk using MIR spectrometry.

Impact of dairy and sweetened beverage consumption on diet and weight of a multiethnic population of head start mothers

Mothers with children in Head Start play a critical role in providing healthful diets and modeling good dietary behaviors to their children, but there is little information available on their diet, especially on beverage consumption. The objective of this study was to assess the association of milk and sweetened beverage consumption with nutrient intake, dietary adequacy, and weight of a multiethnic population of Head Start mothers. Using a cross-sectional, secondary analysis, African-American (43%), Hispanic (33%), and white (24%) women (n=609) were divided into four beverage consumption groups: high milk/low sweetened beverage, high milk/high sweetened beverage, low milk/low sweetened beverage, and low milk/high sweetened beverage. Nutrient intake was determined by averaging 24-hour dietary recalls from 3 nonconsecutive days. Dietary adequacy was determined with the Mean Adequacy Ratio. Mean body mass index for the four beverage consumption groups was compared; there were no differences among the groups (overall mean+/-standard error=30.8+/-0.3). Women in the high milk/low sweetened beverage group had higher mean intakes of vitamins A, D, and B-6; riboflavin; thiamin; folate; phosphorus; calcium; iron; magnesium; and potassium (P<0.0125 for all) when compared with the other beverage consumption groups. Mean Adequacy Ratio was highest in the high milk/low sweetened beverage (71.8+/-0.8) and lowest in the low milk/high sweetened beverage (58.4+/-0.8) consumption groups (P<0.0125). Women in the high milk/low sweetened beverage group consumed more nutrient-dense foods. Overall consumption of milk was low. Consumption of high milk/low sweetened beverage was associated with improved nutrient intake, including the shortfall nutrients, ie, calcium, potassium, magnesium, and vitamin A.

Global trends in milk quality: implications for the Irish dairy industry

The quality of Irish agricultural product will become increasingly important with the ongoing liberalisation of international trade. This paper presents a review of the global and Irish dairy industries; considers the impact of milk quality on farm profitability, food processing and human health, examines global trends in quality; and explores several models that are successfully being used to tackle milk quality concerns. There is a growing global demand for dairy products, fuelled in part by growing consumer wealth in developing countries. Global dairy trade represents only 6.2% of global production and demand currently outstrips supply. Although the Irish dairy industry is small by global standards, approximately 85% of annual production is exported annually. It is also the world's largest producer of powdered infant formula. Milk quality has an impact on human health, milk processing and on-farm profitability. Somatic cell count (SCC) is a key measure of milk quality, with a SCC not exceeding 400,000 cells/ml (the EU milk quality standard) generally accepted as the international export standard. There have been ongoing improvements in milk quality among both established and emerging international suppliers. A number of countries have developed successful industry-led models to tackle milk quality concerns. Based on international experiences, it is likely that problems with effective translation of knowledge to practice, rather than incomplete knowledge per se, are the more important constraints to national progress towards improved milk quality.

A bovine whey protein extract can enhance innate immunity by priming normal human blood neutrophils

Bovine milk-derived products, in particular whey proteins, exhibit beneficial properties for human health, including the acquired immune response. However, their effects on innate immunity have received little attention. Neutrophils are key cells of innate defenses through their primary functions of chemotaxis, phagocytosis, oxidative burst, and degranulation. A whey protein extract (WPE) purified from bovine lactoserum was evaluated for its direct and indirect effects on these primary functions of normal human blood neutrophils in vitro. Although WPE had no direct effects on primary functions, a 24-h pretreatment of neutrophils with WPE was associated with a significant and dose-dependent increase of their chemotaxis, superoxide production, and degranulation in response to N-formyl-methionine-leucine-phenylalanine, as well as of their phagocytosis of bioparticles. The pretreatment increased the surface expression of CD11b, CD16B, and CD32A receptors. The major WPE protein components beta-lactoglobulin (beta-LG) and alpha-lactalbumin (alpha-LA) were the main active fractions having an additive effect on human neutrophils that became more responsive to a subsequent stimulation. This effect on NADPH oxidase activity was associated with translocation of p47(phox) to plasma membrane. Glycomacropeptide, a peptide present in measurable amounts in WPE products, was able to enhance the individual effect of beta-LG or alpha-LA on neutrophils. The present data suggest that WPE, through beta-LG and alpha-LA, has the capacity to enhance or "prime" human neutrophil responses to a subsequent stimulation, an effect that could be associated with increased innate defenses in vivo.

Food safety: unpasteurized milk: a continued public health threat

Although milk and dairy products are important components of a healthy diet, if consumed unpasteurized, they also can present a health hazard due to possible contamination with pathogenic bacteria. These bacteria can originate even from clinically healthy animals from which milk is derived or from environmental contamination occurring during collection and storage of milk. The decreased frequency of bovine carriage of certain zoonotic pathogens and improved milking hygiene have contributed considerably to decreased contamination of milk but have not, and cannot, fully eliminate the risk of milkborne disease. Pasteurization is the most effective method of enhancing the microbiological safety of milk. The consumption of milk that is not pasteurized increases the risk of contracting disease from a foodstuff that is otherwise very nutritious and healthy. Despite concerns to the contrary, pasteurization does not change the nutritional value of milk. Understanding the science behind this controversial and highly debated topic will provide public health care workers the information needed to discern fact from fiction and will provide a tool to enhance communication with clients in an effort to reduce the incidence of infections associated with the consumption of unpasteurized milk and dairy products.

Beneficial health effects of milk and fermented dairy products--review

Milk is a complex physiological liquid that simultaneously provides nutrients and bioactive components that facilitate the successful postnatal adaptation of the newborn infant by stimulating cellular growth and digestive maturation, the establishment of symbiotic microflora, and the development of gut-associated lymphoid tissues. The number, the potency, and the importance of bioactive compounds in milk and especially in fermented milk products are probably greater than previously thought. They include certain vitamins, specific proteins, bioactive peptides, oligosaccharides, organic (including fatty) acids. Some of them are normal milk components, others emerge during digestive or fermentation processes. Fermented dairy products and probiotic bacteria decrease the absorption of cholesterol. Whey proteins, medium-chain fatty acids and in particular calcium and other minerals may contribute to the beneficial effect of dairy food on body fat and body mass. There has been growing evidence of the role that dairy proteins play in the regulation of satiety, food intake and obesity-related metabolic disorders. Milk proteins, peptides, probiotic lactic acid bacteria, calcium and other minerals can significantly reduce blood pressure. Milk fat contains a number of components having functional properties. Sphingolipids and their active metabolites may exert antimicrobial effects either directly or upon digestion.

The impact of dairy product consumption on nutrient adequacy and weight of Head Start mothers

OBJECTIVE

To assess the relationship of dairy product consumption on diet quality and weight of low-income women.

SETTING

Head Start centres in Texas and Alabama, USA.

DESIGN

Cross-sectional study. Women were divided into dairy consumption groups: < or =1, >1 to < or =2 and >2 servings/d. Nutrient intake/diet quality was determined by calculating the percentage meeting the Estimated Average Requirement, guidelines for fat and added sugar, and Mean Adequacy Ratio (MAR). Mean BMI was compared for the dairy consumption groups.

SUBJECTS

Mothers with children in Head Start; 609 African-Americans (43 %), Hispanic-Americans (32 %) and European-Americans (24 %).

RESULTS

Fifteen per cent of participants consumed >2 servings of dairy products and 57 % consumed < or =1 serving of dairy daily. Intakes of protein, vitamin D, riboflavin, P, Ca, K, Mg and Zn were significantly higher in those consuming >2 servings/d. Total SFA were higher and added sugars were lower in those consuming >2 servings of dairy products daily compared with those consuming < or =2 servings/d. Forty-one per cent of women consuming >2 servings of dairy daily had MAR scores under 85 compared with 94 % consuming < or =1 serving/d. Mean BMI was 30.36 kg/m2; there was no association between BMI and dairy product consumption.

CONCLUSIONS

Consumption of dairy products was low and was not associated with BMI in this low-income population. Higher levels of dairy product consumption were associated with higher MAR scores and improved intakes of Ca, K and Mg, which have been identified as shortfall nutrients in the diets of adults.

Purification and identification of bovine cheese whey fatty acids exhibiting in vitro antifungal activity

Milk lipids contain several bioactive factors exhibiting antimicrobial activity against bacteria, viruses, and fungi. In the present study, we demonstrate that free fatty acids (FFA) derived from the saponification of bovine whey cream lipids are active in vitro at inhibiting the germination of Candida albicans, a morphological transition associated with pathogenicity. This activity was found to be significantly increased when bovine FFA were enriched in non-straight-chain FFA. At low cell density, this non-straight-chain FFA-enriched fraction was also found to inhibit in a dose-dependant manner the growth of both developmental forms of C. albicans as well as the growth of Aspergillus fumigatus. Using an assay-guided fractionation, the main components responsible for these activities were isolated. On the basis of mass spectroscopic and gas chromatographic analysis, antifungal compounds were identified as capric acid (C10:0), lauroleic acid (C12:1), 11-methyldodecanoic acid (iso-C13:0), myristoleic acid (C14:1n-5), and gamma-linolenic acid (C18:3n-6). The most potent compound was gamma-linolenic acid, with minimal inhibitory concentration values of 5.4 mg/L for C. albicans and 1.3 mg/L for A. fumigatus, in standardized conditions. The results of this study indicate that bovine whey contains bioactive fatty acids exhibiting antifungal activity in vitro against 2 important human fungal pathogens.

Emerging health properties of whey proteins and their clinical implications

The nursery rhyme "Little Miss Muffet sat on a tuffet (small stool) eating her curds and whey. ..." is recognition of the fact that over the centuries "curds and whey", the two major components of cow's milk, have been widely accepted as part of a healthy diet. Milk provides complete nourishment for the neonate for six months from birth, containing factors that help develop various organ systems including the brain, immune system, and the intestine. Importantly it provides immune protection at a time when the neonates own immune system, though fully developed, is albeit immature. Many adult consumers include cow's milk as part of a healthy diet as it provides protein and essential nutrients, vitamins, and minerals, in particular calcium for strong bones. There is a growing appreciation that milk, and in particular whey, contains components that not only provide nutrition, but can also prevent and attenuate disease, or augment conventional therapies, when delivered in amounts that exceed normal dietary intakes. This paper reviews the emerging health properties of whey proteins and their clinical implications.

Whey proteins in the regulation of food intake and satiety

Whey protein has potential as a functional food component to contribute to the regulation of body weight by providing satiety signals that affect both short-term and long-term food intake regulation. Because whey is an inexpensive source of high nutritional quality protein, the utilization of whey as a physiologically functional food ingredient for weight management is of current interest. At present, the role of individual whey proteins and peptides in contributing to food intake regulation has not been fully defined. However, Whey protein reduces short-term food intake relative to placebo, carbohydrate and other proteins. Whey protein affects satiation and satiety by the actions of: (1) whey protein fractions per se; (2) bioactive peptides; (3) amino-acids released after digestion; (4) combined action of whey protein and/or peptides and/or amino acids with other milk constituents. Whey ingestion activates many components of the food intake regulatory system. Whey protein is insulinotropic, and whey-born peptides affect the renin-angiotensin system. Therefore whey protein has potential as physiologically functional food component for persons with obesity and its co-morbidities (hypertension, type II diabetes, hyper- and dislipidemia). It remains unclear, however, if the favourable effects of whey on food intake, subjective satiety and intake regulatory mechanisms in humans are obtained from usual serving sizes of dairy products. The effects described have been observed in short-term experiments and when whey is consumed in much higher amounts.

Anti-ageing effect of a lactococcal strain: analysis using senescence-accelerated mice

The effects of oral administration of a lactococcal strain on physiological changes associated with ageing were investigated using senescence-accelerated mice (SAM). SAM develop normally, but then show an early onset and irreversible advancement of senescence. SAMP6 is a SAM strain that develops osteoporosis with ageing. Oral administration of heat-killedLactococcus lactissubsp.cremorisH61 (strain H61) to aged SAMP6 mice was associated with reduced bone density loss, a suppression of incidence of skin ulcers and reduced hair loss, compared with controls. Spleen cells from mice fed strain H61 produced more interferon-γ and IL-12 than those from control mice, suggesting that administration of strain H61 altered immune responses. The numbers of viable cells ofBifidobacteriumsp.,Bacteroidessp. andEnterococcussp. in faeces were similar for mice fed the strain H61 and control diets, but counts forStaphylococcussp. were significantly lower (P < 0·05) in mice fed strain H61. Mice fed strain H61 had similar serum concentrations of thiobarbituric acid-reactive substances as in controls, indicating a lack of effect on lipid peroxidation status. Administration of living cells of strain H61 or fermented milk containing strain H61 was also associated with a suppression of incidence of skin ulcers and reduced hair loss. These results indicate that oral administration of strain H61 has the potential to suppress some of the manifestations associated with ageing.

Calcium consumption and insulin resistance syndrome parameters. Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR)

BACKGROUND AND AIM

A number of studies have investigated the role of dietary calcium in lipid metabolism and weight regulation, and the influence of dairy products on the incidence of insulin resistance syndrome. In this study we have examined the relationship between dietary calcium and the established parameters of the insulin resistance syndrome.

METHODS AND RESULTS

The study population (n=4372) was taken from the DESIR (Data from the Epidemiological Study on the Insulin Resistance Syndrome) cohort. Data for parameters relating to the syndrome were recorded, including glucose, serum insulin, triglycerides, HDL-cholesterol, waist circumference and blood pressure. Total energy, calcium and alcohol intake were estimated using a food-frequency questionnaire. Relationships between dietary calcium density and the above parameters were analyzed by multiple linear regression models, adjusted for age, smoking, alcohol consumption and physical activity. From one quartile of calcium density to the next, mean systolic and diastolic blood pressures and insulin concentrations decreased in women by 0.9 mm Hg, 0.5 mm Hg and 2.4%, respectively, and HDL-cholesterol increased by 0.007 mmol/l (all p<0.05) after adjustment for age, smoking, alcohol intake and physical activity. In men, there was an increase of 0.2 kg/m(2) in the body mass index(BMI) and a decrease of 0.4 mm Hg in diastolic blood pressure (both p<0.05).

CONCLUSIONS

These results confirm a beneficial association between dietary calcium and arterial blood pressure, insulin and HDL-cholesterol levels in women, whereas in men there was only a beneficial association with diastolic blood pressure.

Antioxidant nature of bovine milk beta-lactoglobulin

Heating is necessary for processing milk in the dairy industry, which evidently produces a conformational change in beta-lactoglobulin (beta-LG). beta-Lactoglobulin, a major protein that accounts for approximately 10 to 15% of total milk proteins, is a globular protein consisting of 162 AA with a relative molecular mass of 18.4 kDa. The purpose of the present study was to determine the antioxidant role of beta-LG in milk and the possible mechanism involved. We showed that beta-LG is a mild antioxidant whose potency is less than that of vitamin E and probucol (the latter being an antioxidant used for clinical therapy). The conversion of the beta-LG monomer to dimer was responsible, in part, for the mode of action in protecting low-density lipoproteins against copper-induced oxidation. Cross-linking the free thiol groups of beta-LG by heating (100 degrees C for 2 min), or chemically modifying the beta-LG by carboxymethylation to block the thiol groups resulted in a substantial loss of antioxidant activity. The data suggest that Cys-121 plays an essential role in the antioxidant nature of beta-LG. By using an anti-LG antibody affinity column to deplete the beta-LG from milk, we observed from the lost antioxidant activity that beta-LG contributes approximately 50% of the total activity. Because beta-LG is extremely sensitive to thermal denaturation, to maintain its antioxidant nature, dairy products consumed daily should not be overheated in order to maintain its antioxidant nature.