Dietary calcium intake in lactose maldigesting intolerant and tolerant African-American women

Metal exposure in the Greenlandic ACCEPT cohort: follow-up and comparison with other Arctic populations

Humans are exposed to metals through diet and lifestyle e.g. smoking. Some metals are essential for physiologically body functions, while others are non-essential and can be toxic to humans. This study follows up on metal concentrations in the Greenlandic ACCEPT birth-cohort (mothers and fathers) and compares with other Arctic populations. The data from 2019 to 2020 include blood metal concentrations, lifestyle and food frequency questionnaires from 101 mothers and 76 fathers, 24-55 years, living in Nuuk, Sisimiut, and Ilulissat. A high percentage (25-45%) exceeded international guidance values for Hg. For the mothers, the metal concentrations changed significantly from inclusion at pregnancy to this follow-up 3-5 years after birth; some increased and others decreased. Most metals differed significantly between mothers and fathers, while few also differed between residential towns. Several metals correlated significantly with marine food intake and socio-economic factors, but the direction of the correlations varied. Traditional marine food intake was associated positively with Se, As and Hg. To the best of our knowledge, this study provides the most recent data on metal exposure of both men and women in Greenland, elucidating metal exposure sources among Arctic populations, and documents the need for continuing biomonitoring to follow the exceeding of guidance values for Hg. [Figure: see text].

Calcium restriction for 28 days markedly and negatively influences bone mineral density of the femur and lumbar vertebrae regardless of the high-fat diet ingestion in young adult male rats

Calcium (Ca) is necessary for bone calcification, and Ca deficiency leads to decreased bone mineral density (BMD). Epidemiological studies have reported a correlation between Ca intake and BMD. Although the influences of Ca deficiency on BMD have been reported, the effects of Ca restriction on bone during high-fat diet ingestion remain unclear. Therefore, we hypothesized that high-fat diet ingestion would potentiate the negative effects of Ca restriction on bone. Sprague-Dawley strain male rats (aged 11 weeks) were divided into 4 groups: basic control diet (Cont.) (11% lipid energy rate, 0.5% calcium), basic control diet with Ca restriction (CaR) (11% lipid energy rate, 0.02% calcium), high-fat diet (HF) (40% lipid energy rate, 0.5% calcium), and high-fat diet with Ca restriction (HFCaR) (40% lipid energy rate, 0.02% calcium). At 28 days after starting the experimental diets, body weights were higher in the high-fat diet groups (HF and HFCaR) than in the standard-fat diet groups (Cont. and CaR) on 2-way analysis of variance. The apparent Ca absorption rate in the Ca-restricted groups (CaR and HFCaR) was higher than in the Ca-sufficient groups (Cont. and HF). BMD and bone strength parameters of the femur and lumbar vertebrae in the Ca-restricted groups were markedly lower than in the Ca-sufficient groups, whereas there were no significant differences between the standard-fat diet and HF diet groups. These results suggest that 28 days of Ca restriction increases the risk of bone fracture and osteoporosis.

Use of a Novel Probiotic Formulation to Alleviate Lactose Intolerance Symptoms-a Pilot Study

Lactose intolerance is a common condition caused by lactase deficiency and may result in symptoms of lactose malabsorption (bloating, flatulence, abdominal discomfort, and change in bowel habits). As current data is limited, the aim of our study was to assess the efficacy of probiotics with a β-galactosidase activity on symptoms of lactose malabsorption and on the lactose hydrogen breath test (LHBT). The study group comprised eight symptomatic female patients with a positive LHBT. Patients were treated for 6 months with a probiotic formula with β-galactosidase activity (Bio-25, Ambrosia-SupHerb, Israel). All patients completed a demographic questionnaire as well as a diary for the assessment of symptom severity and frequency at entry, every 8 weeks, and at the end of the treatment period. Measurements of hydrogen (H₂) levels (parts per million, ppm) at each of these time points were also performed. End points were a decrease of 50% in symptom severity or frequency, and the normalization (decrease below cutoff point of 20 ppm) of the breath test. Mean age and mean body mass index (BMI) were 36.4 ± 18.6 years and 23.2 kg/m², respectively. Compared to baseline scores, the frequency of most symptoms, and the severity of bloating and flatulence, improved after treatment. Normalization of LHBT was obtained in only two patients (25%). In this pilot study, Bio-25, a unique formulation of probiotics with β-galactosidase activity, demonstrated symptom resolution in most patients with lactose malabsorption. A larger randomized trial is warranted to confirm these preliminary findings.

Calcium Deficiency in Diet Decreases the Magnesium Content in Bone and Affects Femur Physicochemical Properties in Growing Rats

This study evaluates the effect of three calcium levels in the diet (normal, moderate, and severe calcium depletion) on bone metabolism of male Wistar rats during their growth period. Bone mineral density (BMD) and femur length were determined in vivo during the growth stage using a single X-ray transmission system. The apparent calcium absorption was calculated in the rat adolescent and adulthood stages. At the end of the experiment, calcium concentrations in serum and urine were analyzed. The bones were evaluated postmortem to corroborate in vivo analyses. Microstructural properties of cortical and trabecular tissues of femurs bones were assessed using scanning electron microscopy. Bone mineral contents (Mg, Ca, P, and K) were quantified by inductively coupled plasma. Severe calcium depletion in the diets in the development stage affects the bone quality parameters such as bone mineral density and mineral content. Moreover, it was found thinner cortical and trabecular bone areas. Additionally, it was found that severe calcium depletion increased the apparent absorption of calcium as a defense mechanism, but with the decrease of the BMD peak, and the thickness of cortical bone as well as trabecular bone porosity. The severe calcium depletion increased the efficiency of apparent absorption calcium as a defense mechanism, but, even so, decreases the BMD peak as well as the thickness of cortical bone and trabecular bone porosity.

Nutritional management of lactose intolerance: the importance of diet and food labelling

Worldwide, 70% of the adult population has limited expression of lactase enzyme with a wide variation among different regions and countries. Lactase deficiency may lead to lactose intolerance (LI). Depending both on the amount of lactose ingested and on the lactase activity, people who suffer from lactose malabsorption might experience numerous gastrointestinal and extra-intestinal symptoms and manifestations. Treatment of LI mainly consists of reducing or eliminating lactose from the diet until the symptoms disappear as well as supplementing lactase, and inducing colon microbiome adaptation by probiotics. Cow’s milk is one of the major source of calcium and several other vitamins and minerals. Thus, a complete exclusion of dairy products may favor the development of bone diseases such as osteopenia and osteoporosis. Therefore, the dietetic approach has a crucial role in the management of LI patients. Additionally, the use of lactose and milk-derived products in non-dairy products (e.g., baked goods, breakfast cereals, drinks, and processed meat) has become widespread in the modern industry (the so-called “hidden lactose”). In this regard, a strict adherence to the lactose-free diet becomes challenging for LI patients, forced to continuous check of all products and food labels. In fact, lactose-free product labeling is still controversial. Considering that nowadays a specific cut-off value establishing “lactose-free” labeling policy is lacking and that there is no universal law regulating the production and commercialization of “delactosed” products, identification of specific safe and suitable products with a well-recognized lactose-free logo might help consumers. This narrative review aims to identify the dietary management for lactose intolerant people, avoiding symptoms and nutrients deficiencies, helped by the use of specific labelling to guide them to choose the safer product on the market.

Galacto-Oligosaccharide RP-G28 Improves Multiple Clinical Outcomes in Lactose-Intolerant Patients

Background and Aims: Lactose intolerance (LI) is a global problem affecting more than half of the world’s population. An ultra-purified, high-concentration galacto-oligosaccharide, RP-G28, is being developed as a treatment for patients with LI. The efficacy and safety of RP-G28 in reducing symptoms of lactose intolerance were assessed in a blinded, randomized, placebo-controlled trial. Methods: In this multiclinical site, double-blinded, placebo-controlled trial, 377 patients with LI were randomized to one of two doses of orally administered RP-G28 or placebo for 30 days. A LI test and symptom assessment were performed at baseline and on day 31. The primary endpoint was a ≥4-point reduction or a score of zero on LI composite score on day 31. Voluntary milk and dairy intake and global outcome measures assessed patients’ overall treatment satisfaction and quality of life before therapy and 30 days after therapy. This study received Institutional Review Board (IRB) approval. Results: For the primary endpoint, 40% in the RP-G28 groups reported a ≥4-point reduction or no symptoms on LI symptom composite score compared to 26% with placebo (p = 0.016). Treatment with RP-G28 also led to significantly higher levels of milk and dairy intake and significant improvements in global assessments compared to placebo. RP-G28 but not placebo led to significant increases in five Bifidobacterium taxa. Conclusions: RP-G28 for 30 days significantly reduced symptoms and altered the fecal microbiome in patients with LI. Treatment with RP-G28 also improved milk/dairy consumption and quality of life and was safe and well tolerated.

Association of Diet Quality and Physical Activity on Obesity-Related Cancer Risk and Mortality in Black Women: Results from the Women's Health Initiative

BACKGROUND

Obesity-related cancers disproportionately affect the Black community. We assessed the relationship between diet quality, physical activity, and their combined effect on obesity-related cancer risk and mortality in Black women enrolled in the Women's Health Initiative (WHI).

METHODS

Data from postmenopausal (50-79 years of age) Black women enrolled in WHI clinical trials or observational studies were analyzed. Exposure variables included baseline physical activity [metabolic equivalent of tasks (MET)-hours/week of moderate-to-vigorous physical activity (MVPA)] and diet quality [Healthy Eating Index (HEI)-2015]. Outcomes included adjudicated obesity-related cancer incidence and mortality. Cox proportional hazard models were used to evaluate the association between MVPA and HEI-2015 and obesity-related cancer risk and mortality.

RESULTS

The analytical sample included 9,886 Black women, with a baseline mean body mass index (BMI) of 31.1 kg/m² (SD = 6.8); mean HEI-2015 score of 63.2 (SD = 11.0, possible range 0 to 100); and mean MVPA of 5.0 (SD = 9.4) MET-hours/week. Over an average of 13 years of follow-up, 950 (9.6%) obesity-related cancer cases were observed, with 313 (32.9%) resulting in death. Physical activity [HR, 1.05; 95% confidence interval (CI), 0.86-1.30], diet quality (HR, 0.99; 95% CI, 0.92-1.08), and their combination (HR, 1.05; 95% CI, 0.85-1.29) were not associated with risk for any or site-specific obesity-related cancers. Similarly, these health behaviors had no association with mortality.

CONCLUSIONS

Diet quality, physical activity and their combined effect, as measured, were not associated with obesity-related cancer risk and mortality in Black women enrolled in WHI.

IMPACT

Other social, behavioral, and biological factors may contribute to racial disparities observed in obesity-related cancer rates.

The Effect of Calcium Deficiency on Bone Properties in Growing Rats

Background:

In this work, the study of the physicochemical properties of the rat bones that were fed under severe and moderate calcium depletion was carried out. Calcium depletion is a common problem in the diet of the third world.

Objective:

Three calcium levels: 5000, 2500, and 1039 mg/kg, were used in the diets to evaluate the influence of calcium deficiency on the bone quality by post-mortem tests.

Methods:

Inductive Coupled Plasma was used to study the elemental chemical composition of the bones; X-ray diffraction evaluated the bone structure and crystallinity; the microstructure and architecture were investigated using scanning electron microscopy; thermogravimetric analysis assessed the ratio between organic and inorganic phases of bones. All of these results were correlated with flexion and compression test determining the biomechanical properties to evaluate the bone quality.

Results:

The results showed that severe calcium depletion (75% depletion, 1039 mg/kg) was a critical factor in the unsuitable mineralization process responsible for the deterioration of bone quality. Bone architecture with delicate trabeculae caused the poor mechanical response. For moderate calcium depletion (50% of the request, 2500 mg/kg), the bone quality and its mechanical behavior showed less deterioration in comparison with bones of severe calcium depletion diet.

Conclusion:

By using this animal model, the effect of calcium depletion in bone mineralization in rats was understood and can be extrapolated for humans.

Lactose-Free Dairy Products: Market Developments, Production, Nutrition and Health Benefits

Lactose-free dairy is able to provide the essential nutrients present in regular dairy products, like calcium and vitamins, to those that are not able to digest lactose. This product category currently has a wide and growing health appeal to consumers. In recent years, the quality and product variety in the lactose-free dairy segment has been increasing significantly, giving consumers more tempting products to decide from. As a result, lactose-free dairy is now the fastest growing market in the dairy industry. This review discusses the market developments and production possibilities and issues related to the wide variation of lactose-free dairy products that are currently available. Additionally, the health benefits that lactose-free dairy may offer compared to dairy avoidance are illustrated.

Calcium intake and the associations with faecal fat and energy excretion, and lipid profile in a free-living population

The aim of the present study was to investigate the associations between the habitual Ca intake and faecal fat and energy excretion as well as blood lipid profile in free-living normal-weight and overweight individuals. The participants were enrolled for an 8-d period where data from a 7-d diet registration (days 1–7), a 5-d faeces collection (days 3–7), a 2-d urine collection (days 5–7), and anthropometric measurements and a fasting blood sample (day 8) were collected. Analyses showed that dietary Ca intake (g/10 MJ per d) was positively associated with excretion of faecal fat (P = 0·004) and energy (P = 0·031) when adjusted for BMI, age, sex and intake of Ca-containing supplements. However, after adjustment for intake of fibre, the effect of Ca intake disappeared. Nevertheless, total cholesterol (CHOL) and LDL-CHOL concentrations were associated negatively with Ca intake (β −0·62 (95 % CI −0·96, −0·28) mmol/l, P < 0·001, and β −0·49 (95 % CI −0·78, −0·20) mmol/l, P = 0·001, respectively, per 1000 mg/10 MJ per d increase in Ca intake). In conclusion, incorporation of Ca-rich food products in a habitual diet was associated with reduced total CHOL and LDL-CHOL concentrations, which may lower the risk of CVD in the long term.

Noninvasive diagnosis of hypolactasia with 4-Galactosylxylose (Gaxilose): a multicentre, open-label, phase IIB-III nonrandomized trial

GOALS AND BACKGROUND

Hypolactasia affects over half of the world population. Diagnosis remains problematic as currently available tests, such as the hydrogen breath test, have low reliability and lactose intolerance symptoms are unspecific. We evaluated the diagnostic performance and safety of a new noninvasive diagnostic test based on urine or serum measurement of D-xylose after lactase cleavage of orally administered 4-galactosylxylose (gaxilose).

STUDY

In a multicentre, open-label, nonrandomized, phase IIb-III study, consecutive patients with symptoms suggestive of lactose intolerance sequentially underwent intestinal biopsy for direct measurement of lactase activity (reference standard), hydrogen breath test, and blood glucose test after lactose challenge, 4- and 5-hour urine-based gaxilose test, and blood-based gaxilose test. For the gaxilose tests, 0 to 4 and 4 to 5 hours urine samples were taken after a 0.45 g gaxilose dose, whereas serum samples were taken 90 minutes after a 2.7 g dose for D-xylose determination. Genetic testing of hypolactasia was also assessed.

RESULTS

Of the 222 patients enrolled, 203 completed all diagnostic tests; 108 were hypolactasic according to biopsy. The sensitivities and specificities and positive and negative predictive values of the gaxilose tests were all >90% versus 69% to 85% for the hydrogen breath test and the blood glucose test. The area under the ROC curve was significantly higher for the gaxilose tests (>0.9, P≤0.007). These tests also had higher sensitivity than genetic testing for hypolactasia and were well tolerated.

CONCLUSIONS

The diagnostic performance of the gaxilose tests is excellent and can substantially improve the diagnosis of hypolactasia.

Effect of calcium intake on fat oxidation in adults: a meta-analysis of randomized, controlled trials

Calcium intake is likely to increase body fat loss during energy restriction. Part of this effect may be explained by increased fat oxidation in the presence of a similar energy balance, yet studies have not provided a conclusive answer. Therefore a meta-analysis was performed to determine whether chronic or acute high calcium intake increases fat oxidation. Randomized controlled trials of high calcium intake in human adults where measures of fat oxidation were taken were included. A random-effects meta-analysis was performed on outcomes expressed as standardized mean differences. Chronic high calcium intake increased fat oxidation by a standardized mean difference of 0.42 (95% confidence intervals: 0.14, 0.69; P= 0.003; estimated to correspond to an 11% increase), displaying low heterogeneity (I(2) = 18%), which was more prominent when habitual calcium intake was low (<700 mg d(-1) ). Acute high calcium intake increased fat oxidation by a standardized mean difference of 0.41 (0.04, 0.77; P = 0.03), with low heterogeneity (I(2) = 19%), yet sensitivity analysis revealed that this effect was relatively weak. In conclusion, chronic high calcium intake is likely to increase rates of fat oxidation. The effects of acute high calcium intake appear to point in the same direction, but further work is needed to permit a greater degree of certainty.

Calcium and Dairy Acceleration of Weight and Fat Loss during Energy Restriction in Obese Adults

OBJECTIVE

Increasing 1,25-dihydroxyvitamin D in response to low-calcium diets stimulates adipocyte Ca2+ influx and, as a consequence, stimulates lipogenesis, suppresses lipolysis, and increases lipid accumulation, whereas increasing dietary calcium inhibits these effects and markedly accelerates fat loss in mice subjected to caloric restriction. Our objective was to determine the effects of increasing dietary calcium in the face of caloric restriction in humans.

RESEARCH METHODS AND PROCEDURES

We performed a randomized, placebo-controlled trial in 32 obese adults. Patients were maintained for 24 weeks on balanced deficit diets (500 kcal/d deficit) and randomized to a standard diet (400 to 500 mg of dietary calcium/d supplemented with placebo), a high-calcium diet (standard diet supplemented with 800 mg of calcium/d), or high-dairy diet (1200 to 1300 mg of dietary calcium/d supplemented with placebo).

RESULTS

Patients assigned to the standard diet lost 6.4 +/- 2.5% of their body weight, which was increased by 26% (to 8.6 +/- 1.1%) on the high-calcium diet and 70% (to 10.9 +/- 1.6% of body weight) on the high-dairy diet (p < 0.01). Fat loss was similarly augmented by the high-calcium and high-dairy diets, by 38% and 64%, respectively (p < 0.01). Moreover, fat loss from the trunk region represented 19.0 +/- 7.9% of total fat loss on the low-calcium diet, and this fraction was increased to 50.1 +/- 6.4% and 66.2 +/- 3.0% on the high-calcium and high-dairy diets, respectively (p < 0.001).

DISCUSSION

Increasing dietary calcium significantly augmented weight and fat loss secondary to caloric restriction and increased the percentage of fat lost from the trunk region, whereas dairy products exerted a substantially greater effect.

Effects of Calcium and Dairy on Body Composition and Weight Loss in African-American Adults

OBJECTIVE

Our objective was to determine the effects of dairy consumption on adiposity and body composition in obese African Americans.

RESEARCH METHODS AND PROCEDURES

We performed two randomized trials in obese African-American adults. In the first (weight maintenance), 34 subjects were maintained on a low calcium (500 mg/d)/low dairy (<1 serving/d) or high dairy (1200 mg Ca/d diet including 3 servings of dairy) diet with no change in energy or macronutrient intake for 24 weeks. In the second trial (weight loss), 29 subjects were similarly randomized to the low or high dairy diets and placed on a caloric restriction regimen (-500 kcal/d).

RESULTS

In the first trial, body weight remained stable for both groups throughout the maintenance study. The high dairy diet resulted in decreases in total body fat (2.16 kg, p < 0.01), trunk fat (1.03 kg, p < 0.01), insulin (18.7 pM, p < 0.04), and blood pressure (6.8 mm Hg systolic, p < 0.01; 4.25 mm Hg diastolic, p < 0.01) and an increase in lean mass (1.08 kg, p < 0.04), whereas there were no significant changes in the low dairy group. In the second trial, although both diets produced significant weight and fat loss, weight and fat loss on the high dairy diet were approximately 2-fold higher (p < 0.01), and loss of lean body mass was markedly reduced (p < 0.001) compared with the low dairy diet.

DISCUSSION

Substitution of calcium-rich foods in isocaloric diets reduced adiposity and improved metabolic profiles in obese African Americans without energy restriction or weight loss and augmented weight and fat loss secondary to energy restriction.

Lactose malabsorption, calcium intake, and bone mass in children and adolescents

OBJECTIVES

The objective of the present study was to evaluate the calcium intake and bone mass in children and early adolescents in accordance with their absorption capacity to lactose.

PATIENTS AND METHODS

A transversal study was conducted on a sample composed of 76 individuals. Lactose malabsorption status was determined with hydrogen breath test. The hydrogen breath test was applied using 2  g of lactose per kilogram of weight up to a maximum of 50  g. A hydrogen increment ≥20  pm in relation to fasting was used to characterize lactose malabsorption. Two 24-hour recalls were applied for the evaluation of food consumption. Bone mineral content and bone mineral density were evaluated in the lumbar spine by dual-energy x-ray absorptiometry.

RESULTS

The prevalence of lactose malabsorption was 61.8%. The participants were divided into 2 groups: lactose malabsorbers (n = 47) and lactose absorbers (n = 29). There was no statistically significant difference (P > 0.05) between the groups with respect to the intake of total calcium, milk calcium, milk, cheese, yogurt, ice cream, and calcium density of the diet. Additionally, there was no difference with respect to the bone mineral content and the bone mineral density of the lumbar spine. Independent from lactose absorption capacity, it was observed that the majority of the children and early adolescents showed calcium intake lower than the recommended value.

CONCLUSIONS

There was no relation among lactose malabsorption and bone densities, bone mineral content, or calcium intake within the present study.

Associations between dairy consumption and body weight: a review of the evidence and underlying mechanisms

As the incidence of obesity is reaching 'epidemic' proportions, there is currently widespread interest in the impact of dietary components on body-weight and food intake regulation. The majority of data available from both epidemiological and intervention studies provide evidence of a negative but modest association between milk and dairy product consumption and BMI and other measures of adiposity, with indications that higher intakes result in increased weight loss and lean tissue maintenance during energy restriction. The purported physiological and molecular mechanisms underlying the impact of dairy constituents on adiposity are incompletely understood but may include effects on lipolysis, lipogeneis and fatty acid absorption. Furthermore, accumulating evidence indicates an impact of dairy constituents, in particular whey protein derivatives, on appetite regulation and food intake. The present review summarises available data and provides an insight into the likely contribution of dairy foods to strategies aimed at appetite regulation, weight loss or the prevention of weight gain.

Dietary calcium intake and its relationship with adiposity and metabolic profile in hypertensive patients

OBJECTIVE

An inverse relation between dietary calcium and adiposity has been found in several epidemiologic studies. Recent evidence has also suggested that a calcium-rich diet may have beneficial effects on insulin resistance and dyslipidemia. This study aimed to evaluate the association of dietary calcium intake with global adiposity, abdominal obesity, and metabolic profile in hypertensive patients.

METHODS

In this cross-sectional study, 85 hypertensive patients 25 to 70 y old underwent clinical, dietary, anthropometric, and biochemical evaluations. Participants were stratified into the following two groups according to their usual dietary calcium intake: low calcium group (<800 mg/d) and high calcium group (≥800 mg/d).

RESULTS

Fifty-seven participants (11 men and 46 women) were included in the final analyses. Subjects in the low calcium group compared with those in the high calcium group exhibited significantly higher levels of body mass index and percentage of body fat after adjustments for variables that could interfere with those adiposity parameters (P = 0.03 and 0.01, respectively). Patients in the high calcium group had a lower odds ratio for prevalent obesity than those in the low calcium group, even after controlling for potential confounders (P = 0.01). No significant differences were found in abdominal adiposity and metabolic profile between the two groups. Using data from all patients, an inverse and significant association was observed between dietary calcium intake and percentage of body fat, and it remained after controlling for confounders (P = 0.03).

CONCLUSIONS

The findings of the present study suggest that, in hypertensive patients, higher dietary calcium intake could be associated with lower global adiposity.

Efficacy of various dietary calcium salts to improve intestinal resistance to Salmonella infection in rats

Previous animal and human studies have shown protective effects of Ca on the resistance to enteropathogenic infections. Most interventions were performed with calcium phosphate and little is known about the protective effect of other dietary sources of Ca. Therefore, we investigated the efficacy of several Ca salts to enhance intestinal resistance to Salmonella enteritidis infection. Rats (n 7–8 per group) were fed a high-fat, Western human-style, purified diet with a low Ca content (20 mmol calcium phosphate/kg; negative control group) or the same diet supplemented with either (extra) calcium phosphate, milk Ca, calcium chloride or calcium carbonate (total of 100 mmol Ca supplement/kg). Diets contained Cr-EDTA for assessment of incremental changes in intestinal permeability. After an adaptation period of 2 weeks, animals were orally infected with S. enteritidis to mimic a human-relevant foodborne infection. Ca supplement-induced changes on faecal lactobacilli and enterobacteria were studied before infection. Changes in intestinal permeability were determined by measuring urinary Cr with time. Persistence of Salmonella was determined by studying faecal excretion of this pathogen in time. Overall, all Ca salts increased resistance towards Salmonella. After infection, body weight gain and food intake were higher in the calcium phosphate group. Calcium phosphate and milk Ca decreased faecal enterobacteria before infection. All Ca salts decreased infection-induced intestinal permeability and persistence of Salmonella. Calcium phosphate, milk Ca, calcium carbonate and calcium chloride are able to enhance the intestinal resistance to Salmonella in rats.

Dairy beverages and energy balance

High dairy intakes have been associated with lower rates of obesity in observational studies, but mechanisms to explain the association are lacking. A high intake of dairy protein reduces spontaneous food intake and may be one important mechanism, but more specific effects of dairy calcium seem to exist. We have found that high versus low calcium intakes from dairy products had no effect on 24-h energy expenditure or substrate oxidation rates, but fecal fat excretion increased approximately 2.5-fold on the high-calcium diets. In a meta-analysis of intervention studies we found that increasing dairy calcium intake by 1200mg/day resulted in increased fecal fat excretion by 5.2 (1.6-8.8) g/day. Newer research shows that humans possess taste receptors for calcium in the gastrointestinal tract and that signaling may be linked to appetite regulation. A new line of evidence suggests that an inadequate calcium intake during an energy restricted weight loss program may trigger hunger and impair compliance to the diet. These mechanisms may be part of the explanation for the protective effects of dairy products with regard to obesity and metabolic syndrome.

Lactose intolerance and African Americans: implications for the consumption of appropriate intake levels of key nutrients

Lactose intolerance is a complex condition that is complicated by cultural beliefs and perceptions about the consumption of dairy products. These attitudes about dairy may contribute to inadequate intake of key nutrients that may impact conditions that contribute to health disparities in African Americans. While a complex health problem, lactose intolerance is easy to treat. However, no treatment can improve the body's ability to produce lactase. Yet, symptoms can be controlled through dietary strategies. This position paper emphasizes the importance of using patient and provider-level strategies in order to reduce the risks to the health of African Americans that may accrue as a result of dairy nutrient deficiency. Evaluation and assessment of interventions tested is critical so that evidence-based approaches to addressing dairy nutrient deficiency and lactose Intolerance can be created. Lastly, it is essential for physicians to communicate key messages to their patients. Since dairy nutrients address important health concerns, the amelioration of lactose intolerance is an investment in health. Lactose intolerance is common, is easy to treat, and can be managed. It is possible to consume dairy even in the face of a history of maldigestion or lactose intolerant issues. Gradually increasing lactose in the diet--drinking small milk portions with food, eating yogurt, and consuming cheese--are effective strategies for managing lactose intolerance and meeting optimal dairy needs.

Impact of micronutrient deficiencies on obesity

Micronutrient deficiencies have been found in obese individuals across age groups worldwide. While the effects of micronutrient deficiencies on human functions have been studied widely in different populations, there is limited information on how these micronutrient deficiencies affect obese populations. An examination of the available literature suggests associations exist between micronutrient deficiencies and obesity in different populations. These associations and possible mechanisms of the deficiencies' metabolic effects, such as their influence on leptin and insulin metabolism, are discussed here. Further studies are needed to clarify the roles of the different micronutrient deficiencies with respect to obesity and its comorbid conditions.

The role of dairy foods and dietary calcium in weight management

Overweight and obesity are the foremost public health problems in the U.S., other industrialized countries, and is rapidly increasing in developing countries. Obesity is a multifaceted disease which requires multiple approaches to successfully combat its increase. Nutritional factors play a key role and include modification of energy balance, intake and expenditure, as well as other factors. Emerging scientific evidence over the past decade suggests that dairy foods may be beneficial when included in a moderate energy restricted diet and possibly for weight maintenance as well. This paper provides a review of some of the scientific evidence that has examined the effect of dairy foods and dietary calcium on weight management. Topic areas presented are observational or retrospective studies with adults as well as children and adolescents; randomized clinical trials on body weight and composition, energy expenditure, substrate oxidation and fecal fat loss; research from animal and in vitro studies provide possible mechanisms of action.

Proposed role of calcium and dairy food components in weight management and metabolic health

Dietary calcium and dairy foods have demonstrated an antiobesity effect in animal studies, observational and population studies, and randomized clinical trials. Moreover, there is a strong theoretical framework to explain the effects of dietary calcium on energy metabolism. The supporting mechanisms include dietary calcium-correcting suboptimal calcium intakes, thereby preventing the endocrine response (parathyroid hormone [PTH] and calcitriol), which favors adipocyte energy storage and inhibits adipocyte loss via apoptosis. Dietary calcium appears to further promote energy loss via formation of calcium soaps in the gastrointestinal tract and thereby modestly reduces net energy absorption. Dietary calcium appears to be responsible for approximately 50% of the antiobesity bioactivity of dairy foods. The additional dairy bioactivity has not been fully identified, but is primarily localized in whey protein. The major components are the angiotensin-converting enzyme (ACE) inhibitor activity of whey proteins and the high concentration of leucine in whey. This high leucine content appears to be primarily responsible for the repartitioning of dietary energy from adipose tissue to skeletal muscle during weight loss, resulting in greater preservation of skeletal muscle and accelerated loss of adipose tissue during negative energy balance. Finally, high-calcium diets suppress obesity-induced oxidative and inflammatory stress independently from its role in modulating adiposity; these effects are similarly augmented by other dairy food components. However, the number of randomized clinical trials conducted is still modest, and a small number have not confirmed significant effects in weight management. Thus, the protective effects of dairy foods against obesity and its comorbidities are promising, but warrant further large-scale studies.

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.

Preponderance of the evidence: an example from the issue of calcium intake and body composition

Meta-analysis is typically applied to studies developed in fairly mature fields, but may be ill-suited for younger fields in which most of the evidence comes from studies that were designed for other endpoints entirely and that are often significantly underpowered for the effect in question. Here, there are no generally accepted methods for getting a grasp on the preponderance of the evidence. In this review, one way of doing so is proposed and the recently emergent literature concerning calcium intake and body composition is used as an illustration of how such an approach might be used.

Recent developments in calcium-related obesity research

The influence of calcium and dairy food intake on energy balance is the object of a growing scientific literature. This manuscript presents the information discussed by subject experts during a symposium on calcium and obesity, initially planned to document in a comprehensive manner the role of calcium and dairy food on energy balance and body composition. This manuscript is organized into 13 propositions statements which either resume the presentation of an invited speaker or integrate recent developments in calcium-related obesity research. More specifically, the effects of calcium and dairy consumption on body weight and adiposity level, appetite, weight loss intervention outcome, lipid-lipoprotein profile and the risk to develop metabolic syndrome are discussed together with the metabolic mechanisms proposed to explain these effects. Taken together, the observations presented in this manuscript suggest that calcium and dairy food intake can influence many components of energy and fat balance, indicating that inadequate calcium/dairy intake may increase the risk of positive energy balance and of other health problems.

Relationships between fat and bone

Body weight impacts both bone turnover and bone density, making it, therefore, an important risk factor for vertebral and hip fractures and ranking it alongside age in importance. The effect of body weight is probably contributed to by both fat mass and lean mass, though in postmenopausal women, fat mass has been more consistently demonstrated to be important. A number of mechanisms for the fat-bone relationship exist and include the effect of soft tissue mass on skeletal loading, the association of fat mass with the secretion of bone active hormones from the pancreatic beta cell (including insulin, amylin, and preptin), and the secretion of bone active hormones (e.g., estrogens and leptin) from the adipocyte. These factors alone probably do not fully explain the observed clinical associations, and study of the actions on bone of novel hormones related to nutrition is an important area of further research. An understanding of this aspect of bone biology may open the way for new treatments of osteoporosis. More immediately, the role of weight maintenance in the prevention of osteoporosis is an important public health message that needs to be more widely appreciated.

Vitamin D insufficiency among African-Americans in the southeastern United States: implications for cancer disparities (United States)

OBJECTIVE

To determine the prevalence and predictors of vitamin D insufficiency among black and white adult residents of the southern US.

METHODS

A cross-sectional analysis of serum 25(OH)D levels using baseline blood samples from 395 Southern Community Cohort Study (SCCS) participants. Participants were African-American and white adults aged 40-79 who enrolled in the study from 2002-2004. We defined hypovitaminosis D as serum 25(OH)D levels < or = 15 ng/ml.

RESULTS

Hypovitaminosis D prevalence was 45% among blacks and 11% among whites. Vitamin D intake from diet and supplements was associated with modest increases in circulating 25(OH)D (0.5-0.7 ng/ml per 100 IU increment), but hypovitaminosis D was found for 32% of blacks with intake > or = 400 IU/day. Body mass index (BMI) was a strong predictor of risk for hypovitaminosis D among black women (OR = 6.5, 95% CI 1.7-25.1 for BMI > or = 30 kg/m(2) vs. 18-24.9 kg/m(2)). UVR exposure estimated by residential location was positively associated with 25(OH)D levels among all groups except white women.

CONCLUSIONS

Hypovitaminosis D was present in a substantial proportion of the African-American population studied, even in the South and among those meeting recommended dietary guidelines. Vitamin D should continue to be a studied target for ameliorating racial cancer disparities in the US.

The effects of increasing serum calcitriol on energy and fat metabolism and gene expression

OBJECTIVE

Evidence from a number of investigations indicates that calcium intake could be inversely related to body weight through alterations in the 1,25-OH(2)-D(3) metabolism. The objective of this study was to test whether energy and substrate metabolism and adipose tissue enzyme mRNA expression can be altered by changes in serum 1,25-OH(2)-D(3) through oral cholecalciferol supplementation in non-obese human subjects.

RESEARCH METHODS AND PROCEDURES

An intervention study was used with a treatment period of 7 days. During this intervention, energy expenditure (EE) and substrate metabolism were measured using indirect calorimetry at t = 0, 1, 3, and 7 days, and blood samples were obtained at t = -1, 0, 1, 2, 3, 5 and 7 days. Fat biopsies were obtained at t = 0 and 7 days for determination of expression of genes involved in lipolytic and lipogenic pathways. Subjects from the general community were studied in an ambulatory setting at a university hospital. Ten healthy young men (age, 28 +/- 3 years; BMI, 25.5 +/- 0.5 kg/m(2)) were recruited by local announcement, and all completed the study. All subjects received 2000 IU cholecalciferol/d for 7 days, and they were instructed to consume a low-cholecalciferol, low-calcium diet. EE, fat oxidation, and adipose tissue enzyme mRNA were the main outcome measures.

RESULTS

Despite a significant increase in serum 1,25-OH(2)-D(3) concentration at t = 5 and 7 days, no significant differences in substrate and energy metabolism nor mRNA concentrations of different lipid metabolism-related proteins were observed.

DISCUSSION

Seven-day supplementation with 2000 IU cholecalciferol/d together with a decrease in dietary calcium intake does not affect EE or substrate metabolism nor gene expression of proteins related to fat metabolism, despite a significant increase in serum 1,25-OH(2)-D(3) concentration.

Lactose intolerance symptoms assessed by meta-analysis: a grain of truth that leads to exaggeration

A meta-analysis was conducted to compare the lactose intolerance symptoms of lactose maldigesters after consuming lactose (as milk, lactose dissolved in water, milk products, or commercial product) with responses after a placebo under masked conditions. An English language MEDLINE search was conducted using the medical subject heading of "lactose intolerance" from 1966 to January 2002. From an initial 1,553 citations, 2 independent reviewers selected 21 studies based on study design (randomized, crossover, blind) and use of an amount of lactose likely to be found in a meal (7-25 g) and a placebo among subjects free of gastrointestinal problems and >4 years old. Mean severity of symptom responses were analyzed as standardized differences, and the presence or absence of a symptom was estimated as pooled incidence differences (ID). For severity of flatulence, the standardized difference was 0.18 (95% confidence interval [CI] -0.16 to +0.52). The CIs for abdominal bloating and pain, degree of diarrhea, frequency of bowel movements per day, and frequency of diarrhea per day also included 0. For abdominal bloating, the ID was 5.9 more people per 100 with symptoms after lactose than placebo (CI -0.07 to +0.19). This same nonsignificant relationship was found for abdominal pain. The ID for diarrhea or loose stools was 0.15 (CI 0.03 to 0.28). Although the incidence of diarrhea was significantly higher, the size of the effect was very small. The results indicate that lactose is not a major cause of symptoms for lactose maldigesters following usual intakes of dairy foods, that is, 1 cup.

Dietary fructooligosaccharides affect intestinal barrier function in healthy men

In contrast to most expectations, we showed previously that dietary fructooligosaccharides (FOS) stimulate intestinal colonization and translocation of invasive Salmonella enteritidis in rats. Even before infection, FOS increased the cytotoxicity of fecal water, mucin excretion, and intestinal permeability. In the present study, we tested whether FOS has these effects in humans. A double-blind, placebo-controlled, crossover study of 2 x 2 wk, with a washout period of 2 wk, was performed with 34 healthy men. Each day, subjects consumed lemonade containing either 20 g FOS or placebo and the intestinal permeability marker chromium EDTA (CrEDTA). On the last 2 d of each supplement period, subjects scored their gastrointestinal complaints on a visual analog scale and collected feces and urine for 24 h. Fecal lactic acid was measured using a colorimetric enzymatic kit. The cytotoxicity of fecal water was determined with an in vitro bioassay, fecal mucins were quantified fluorimetrically, and intestinal permeability was determined by measuring urinary CrEDTA excretion. In agreement with our animal studies, FOS fermentation increased fecal wet weight, bifidobacteria, lactobacilli, and lactic acid. Consumption of FOS increased flatulence and intestinal bloating. In addition, FOS consumption doubled fecal mucin excretion, indicating mucosal irritation. However, FOS did not affect the cytotoxicity of fecal water and intestinal permeability. The FOS-induced increase in mucin excretion in our human study suggests mucosal irritation in humans, but the overall effects are more moderate than those in rats.

Effects of 3 diets with various calcium contents on 24-h energy expenditure, fat oxidation, and adipose tissue message RNA expression of lipid metabolism-related proteins

BACKGROUND

Evidence from molecular and animal research and epidemiologic investigations indicates that calcium intake may be inversely related to body weight, possibly through alterations in 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] metabolism.

OBJECTIVE

We tested whether energy and substrate metabolism and adipose tissue enzyme messenger RNA (mRNA) expression can be altered by dietary calcium intake in healthy, nonobese, human volunteers consuming an isocaloric diet.

DESIGN

Twelve healthy men [age: 28 +/- 2 y; body mass index (BMI; in kg/m(2)): 25.2 +/- 06] received 3 isocaloric diets [high calcium (1259 +/- 9 mg/d), high dairy (high/high); high calcium (1259 +/- 9 mg/d), low dairy (high/low); and low calcium (349 +/- 8 mg/d), low dairy (low/low)] in a randomized crossover design. At the end of the 7-d dietary periods, 24-h energy expenditure and substrate metabolism were measured, and fat biopsy specimens were obtained to determine mRNA expression in genes involved in the lipolytic and lipogenic pathways.

RESULTS

The 24-h energy expenditure was 11.8 +/- 0.3, 11.6 +/- 0.3, and 11.7 +/- 0.3 MJ/24 h in the high/high, high/low, and low/low conditions, respectively. Fat oxidation in these conditions was 108 +/- 7, 105 +/- 9, and 100 +/- 6 g/24 h. These differences were not statistically significant. mRNA concentrations of UCP2, FAS, GPDH2, HSL, and PPARG did not differ significantly. Serum 1,25(OH)(2)D(3) concentrations changed from 175 +/- 16 to 138 +/- 15, 181 +/- 23 to 159 +/- 19, and 164 +/- 13 to 198 +/- 19 pmol/L in the high/high, high/low, and low/low conditions, respectively, and was significantly different between the high/high and low/low conditions (P < 0.05).

CONCLUSION

Altering the dietary calcium content for 7 d does not influence substrate metabolism, energy metabolism, or gene expression in proteins related to fat metabolism, despite significant changes in 1,25(OH)(2)D(3) concentrations.

Fat oxidation and its relation to serum parathyroid hormone in young women enrolled in a 1-y dairy calcium intervention

BACKGROUND

Increased dietary calcium is associated with changes in body composition. One proposed mechanism is that dietary calcium increases fat oxidation, potentially via regulation of serum parathyroid hormone (PTH) concentrations.

OBJECTIVES

The objectives of the study were to determine whether acute or chronic increased dairy calcium intakes alter postprandial whole-body fat oxidation and whether the increased intake is related to changes in PTH concentrations.

DESIGN

Normal-weight women aged 18-30 y were randomly assigned to a low (<800 mg/d, control; n = 10) or high (1000-1400 mg/d; n = 9) dietary calcium intake group for 1 y. Whole-body fat oxidation was assessed by measuring respiratory gas exchange after each subject consumed 2 isocaloric liquid meals containing 100 or 500 mg Ca at baseline and 1 y. Fasting serum PTH was measured at baseline and 1 y.

RESULTS

The mean 1-y change in fat oxidation was higher in the high-calcium group than in the low-calcium control group after a low-calcium meal (0.10 +/- 0.05 compared with 0.005 +/- 0.04 g/min; P < 0.001) and a high-calcium meal (0.06 +/- 0.05 compared with 0.03 +/- 0.04 g/min; P < 0.05). The 1-y change in serum log PTH was negatively associated with the 1-y change in postprandial fat oxidation after a high-calcium meal (partial r = -0.46, P < 0.04) when controlled for the1-y change in total body fat mass.

CONCLUSIONS

The results suggest that a chronic diet high in dairy calcium increases whole-body fat oxidation from a meal, and increases in fasting serum PTH relate to decreases in postprandial whole-body fat oxidation.

The Role of Dairy Foods in Weight Management

Dietary calcium appears to play a pivotal role in the regulation of energy metabolism and obesity risk. High calcium diets attenuate body fat accumulation and weight gain during periods of over-consumption of an energy-dense diet and to increase fat breakdown and preserve metabolism during caloric restriction, thereby markedly accelerating weight and fat loss. This effect is mediated primarily by circulating calcitriol, which regulates adipocyte intracellular Ca(2+). Studies of human adipocyte metabolism demonstrate a key role for intracellular Ca(2+) in regulating lipid metabolism and triglyceride storage, with increased intracellular Ca(2+) resulting in stimulation of lipogenic gene expression and lipogenesis and suppression of lipolysis, resulting in adipocyte lipid filling and increased adiposity. Moreover, the increased calcitriol produced in response to low calcium diets stimulates adipocyte Ca(2+) influx and, consequently, promotes adiposity, while higher calcium diets inhibit lipogenesis, promote lipolysis, lipid oxidation and thermogenesis and inhibit diet-induced obesity in mice. Notably, dairy sources of calcium exert markedly greater effects in attenuating weight and fat gain and accelerating fat loss. This augmented effect of dairy products versus supplemental calcium has been localized, in part, to the whey fraction of dairy and is likely due to additional bioactive compounds, such as angiotensin converting enzyme (ACE) inhibitors in dairy, as well as the rich concentration of branched chain amino acids, which act synergistically with calcium to attenuate adiposity; however, these compounds do not fully account for the observed effects, as whey has significantly greater bioactivity than found in these compounds. These concepts are confirmed by epidemiological data as well as recent clinical trials which demonstrate that diets which include at least three daily servings of dairy products result in significant reductions in body fat mass in obese humans in the absence of caloric restriction and markedly accelerates the weight and body fat loss secondary to caloric restriction compared to low dairy diets. These data indicate an important role for dairy products in both the ability to maintain a healthy weight and the management of overweight and obesity.

Parathyroid hormone is associated with decreased fat mass in young healthy women

OBJECTIVE

To investigate the relationship of parathyroid hormone (PTH) with dietary calcium and changes in body composition.

DESIGN

Cross-sectional and 1-year longitudinal trial.

SUBJECTS

Normal-weight young women (age: 18-31), 155 subjects analyzed at baseline, and data for 41 subjects analyzed prospectively between baseline and 12 months.

MEASUREMENTS

Levels of fasting serum calcium and PTH, intakes of calcium (3-day diet records), and total body weight and body composition (dual energy X-ray absorptiometry).

RESULTS

Baseline dietary calcium, regardless of whether unadjusted or adjusted for energy intake, did not predict baseline levels of fasting serum PTH. Change in dietary calcium also did not predict change in serum PTH. However, log PTH was significantly correlated with body fat mass (R = 0.27), but not lean mass at baseline (n = 155), independent of serum calcium (corrected R = 0.25). Further, 12-month changes (n = 41) in log PTH positively predicted the 12-month change in body weight (R = 0.32) and body fat (R = 0.32), but not lean mass even when controlled for age or change in serum calcium.

CONCLUSION

Fasting serum PTH was associated with increased fat mass, in both cross-sectional and prospective analysis. Thus, serum PTH may play a role in the regulation of body fat mass in young women.

Effects of calcium supplementation on body weight and blood pressure in normal older women: a randomized controlled trial

CONTEXT

Epidemiological data suggest that high calcium intakes are associated with decreased body weight and blood pressure. However, there is little evidence from randomized trials that addresses these important issues.

OBJECTIVE

The objective of this study was to assess the long-term effects of calcium on body weight and blood pressure.

DESIGN

This is a substudy of an ongoing, double-blind, randomized, controlled trial of calcium supplementation. End points were assessed at 30 months.

SETTING

This study was performed at a university medical center.

PARTICIPANTS

Normal postmenopausal women (mean age, 74 yr; mean weight, 67 kg; mean blood pressure, 134/70 mm Hg at baseline) participated in this study.

INTERVENTION

Study subjects were treated with calcium (1 g/d; n = 732) and placebo (n = 739).

MAIN OUTCOME MEASURES

Body weight and blood pressure were the main outcome measures.

RESULTS

Weight decreased by 368 +/- 132 g (mean +/- se) with calcium treatment and by 369 +/- 134 g with placebo (P = 0.93). Fat and lean masses did not show an effect of calcium. Blood pressure showed transient reductions of 1-2 mm Hg at 6 months in the calcium group, resulting in a significant between-group difference only for systolic pressure (P = 0.048). At 30 months, the change from baseline in systolic pressure was 0.0 +/- 0.9 mm Hg in the calcium group and 2.4 +/- 0.9 mm Hg in the placebo group (P = 0.14). For diastolic pressures, the changes were -0.2 +/- 0.4 and 0.8 +/- 0.4 mm Hg, respectively (P = 0.13). In those with baseline calcium intakes less than 600 mg/d, the treatment effect was greater and did persist.

CONCLUSIONS

Calcium supplementation of 1 g/d does not produce biologically significant effects on body weight, and its hypotensive effect is small and transient in most women.

The relation between calcium intake and body composition in a Dutch population: The Amsterdam Growth and Health Longitudinal Study

To investigate whether dietary calcium intake is related to body mass index and the sum of four skinfolds among subjects in the Amsterdam Growth and Health Longitudinal Study (the Netherlands), the authors followed a cohort of men and women from age 13 years in 1977 to age 36 years in 2000. Longitudinal linear regression analyses were performed with generalized estimating equations in continuous and categorical models, with adjustment for possible confounders. Results showed that calcium intake during adolescence is a weak predictor of calcium intake in adulthood. In this population, only a slight indication was found of a weak inverse relation of calcium intake with body composition. No differences were observed between the middle (800-1,200 mg/day) and high (>1,200 mg/day) groups of calcium intake, suggesting a threshold of approximately 800 mg/day above which calcium intake has no additional beneficial effect on body composition.

Diagnosis, symptoms, and calcium intakes of individuals with self-reported lactose intolerance

OBJECTIVE

To determine methods of diagnosis, symptoms, and calcium intake from food and supplements for individuals with self-reported lactose intolerance.

METHODS/DESIGN

Cross-sectional survey using a mailed questionnaire.

SUBJECTS/SETTING

A convenience sample of 189 adults with self-reported lactose intolerance living in the metropolitan area of Vancouver Canada responded to posters or advertisements, and 159 returned completed questionnaires.

MEASURES OF OUTCOME

Methods of diagnosis, symptoms experienced and their severity were self-reported. Estimated calcium intake from food and supplements was assessed using a food frequency questionnaire. Data were analyzed using descriptive statistics, chi-square, Pearson correlation analysis, t-tests and Analysis of Variance.

RESULTS

Participants were 47 +/- 15 years of age; 72% female and 28% male; 67% Caucasian; and 54% had self-diagnosed their lactose intolerance. Of the 42% diagnosed by a physician, only 10% had been diagnosed by valid tests. Mean estimated food calcium intake was 591 +/- 382 mg/d and did not differ between those who were self- or physician-diagnosed. Only 11.5% of participants met their age-appropriate Adequate Intake (AI) from food calcium sources alone. Calcium supplements were used by 65% and provided an average of 746 +/- 703 mg calcium/day to those who used them; mean intakes of this group met the AI.

CONCLUSIONS

Calcium intake from food sources alone is inadequate to meet the AI in individuals with self-reported lactose intolerance. Physicians managing lactose intolerance need current information on how the AI can be met through appropriate food choices and possible supplementation.

[Role of calcium intake in obesity]

Recent evidences from epidemiological and intervention trials suggest that a higher calcium intake is associated with a lower body weight and a reduction in total and central body fat. The potential role of calcium intake in the regulation of body adiposity has been explained by the intracellular calcium, which is able to promote adipocyte fat accumulation by exerting a coordinate regulation stimulating lipogenesis and suppressing lipolysis. Moreover, the intracellular calcium has been implicated on the etiopathogenesis of hypertension, insulin resistance and dyslipidemia, appearing as a potential common substrate in the metabolic syndrome. Dietary modulation of intracellular calcium through calciotropic hormones opens an exciting possibility to prevent and tackle obesity and its associated complications by increasing the calcium intake. However, available evidences are mostly indirect and further studies specifically designed for this purpose are needed.

Dairy products do not lead to alterations in body weight or fat mass in young women in a 1-y intervention

BACKGROUND

Previous results suggested that increased intake of dairy calcium is associated with reduced weight and fat mass.

OBJECTIVE

The purpose of this study was to determine whether long-term increases in consumption of dairy calcium alter body weight and fat mass in young, healthy women.

DESIGN

We used a randomized, 1-y intervention for dairy calcium. Subjects were 155 young (aged 18-30 y), healthy, normal-weight women with intake of dietary calcium < 800 mg/d and energy intake </= 2200 kcal/d. Women were randomly assigned to 1 of 3 groups: 1) control: continue established dietary intake; 2) medium dairy: substitute dairy products to achieve intake of calcium of approximately 1000-1100 mg/d and maintain isocaloric intake; 3) high dairy: substitute dairy products to achieve intake of calcium of 1300-1400 mg/d and maintain isocaloric intake. The main outcome measures were 1-y changes in body weight (in kg) and fat mass (in kg). One hundred thirty-five women completed the trial.

RESULTS

Mean intakes of calcium during the intervention were 742.4 +/- 321.5, 1026.4 +/- 311.3, and 1131.29 +/- 337.2 mg/d for the control, medium-dairy, and high-dairy groups, respectively (P < 0.0001). No significant differences were observed in the mean 1-y change in body weight between the control, medium-dairy, and high-dairy groups (0.8 +/- 2.8, 0.7 +/- 3.0, and 1.5 +/- 4.1 kg, respectively; P = 0.45). No significant differences were observed in the mean 1-y change in fat mass between the control, medium-dairy, and high-dairy groups (-0.5 +/- 2.5, 0.3 +/- 2.7, and 0.5 +/- 3.5 kg, respectively; P = 0.26).

CONCLUSION

Increased intake of dairy products does not alter body weight or fat mass in young, healthy women over 1 y.

Dairy augmentation of total and central fat loss in obese subjects

BACKGROUND AND OBJECTIVE

We have previously demonstrated an antiobesity effect of dietary Ca; this is largely mediated by Ca suppression of calcitriol levels, resulting in reduced adipocyte intracellular Ca2+ and, consequently, a coordinated increase in lipid utilization and decrease in lipogenesis. Notably, dairy Ca is markedly more effective than other Ca sources.

DESIGN

Obese subjects were placed on balanced deficit (-500 kcal/day) diets and randomized to control (400-500 mg Ca/day; n = 16) or yogurt (1100 mg Ca/day; n = 18) treatments for 12 weeks. Dietary macronutrients and fiber were held constant at the US average.

MEASUREMENTS

Body weight, body fat and fat distribution (by dual-energy X-ray absorptiometry), blood pressure and circulating lipids were measured at baseline and after 12 weeks of intervention.

RESULTS

Fat loss was markedly increased on the yogurt diet (-4.43+/-0.47 vs -2.75+/-0.73 kg in yogurt and control groups; P<0.005) while lean tissue loss was reduced by 31% on the yogurt diet. Trunk fat loss was augmented by 81% on the yogurt vs control diet (P<0.001), and this was reflected in a markedly greater reduction in waist circumference (-3.99+/-0.48 vs -0.58+/-1.04 cm, P<0.001). Further, the fraction of fat lost from the trunk was higher on the yogurt diet vs control (P<0.005).

CONCLUSION

Isocaloric substitution of yogurt for other foods significantly augments fat loss and reduces central adiposity during energy restriction..

Calcium intake is associated with adiposity in Black and White men and White women of the HERITAGE Family Study

Calcium (Ca(2+)) intake may play a role in the regulation of body weight. Increased Ca(2+) intake has been associated with lower body weight, BMI, and adiposity measures in cross-sectional studies. We examined the association between Ca(2+) intake, derived from the Willett FFQ, and overall and abdominal adiposity in Black and White men and women of the HERITAGE Family Study. BMI, the percentage of body fat (%FAT), the sum of 8 skinfold thicknesses, computerized tomography total abdominal fat (TAF), abdominal visceral (AVF) and abdominal subcutaneous (ASF) fat, and waist circumference were measured in 362 men (109 Blacks, 253 Whites) and 462 women (201 Blacks, 261 Whites). Subjects were divided into tertiles of energy-adjusted Ca(2+) intake. Adiposity measures across tertiles were compared by ANOVA and also regressed against the energy-adjusted Ca(2+) intake to test for a linear trend. The strongest inverse associations appeared in Black men and White women. Black men in the high Ca(2+) intake group were leaner than those in the low Ca(2+) intake group: BMI 23.4 +/- 0.9 vs. 26.7 +/- 1.1 kg/m(2) (P = 0.01); for all other adiposity measures, P < 0.05. In White women, regression analyses showed significant inverse associations between Ca(2+) intake and BMI (P = 0.02), %FAT (P = 0.001), TAF (P = 0.006), AVF (P = 0.03), and ASF (P = 0.01). The percentage of fat of White men in the highest Ca(2+) intake group was significantly lower than in the lowest Ca(2+) group (P = 0.04). No significant associations were found in Black women. Low Ca(2+) intake may be associated with higher adiposity, particularly in men and White women.

Dietary calcium and dairy modulation of adiposity and obesity risk

Dietary calcium plays a key role in the regulation of energy metabolism and obesity risk. This appears to be mediated primarily by dietary calcium modulation of circulating calcitriol, which in turn regulates adipocyte intracellular calcium ([Ca2+]i). Increased [Ca2+]i stimulates lipogenic gene expression and activity and inhibits lipolysis, resulting in increased adipocyte lipid accumulation. Since calcitriol stimulates adipocyte Ca2+ influx, low calcium diets promote adiposity, while dietary calcium-suppression of calcitriol reduces adiposity. These concepts are confirmed in controlled rodent studies as well as by epidemiological and clinical trial data, all of which confirm protection from obesity with high calcium intakes. Moreover, dairy sources of calcium exert markedly greater effects which are most likely attributable to additional bioactive compounds in dairy which act synergistically with calcium to attenuate adiposity.

Role of calcium and dairy products in energy partitioning and weight management

Dietary calcium plays a pivotal role in the regulation of energy metabolism because high-calcium diets attenuate adipocyte lipid accretion and weight gain during the overconsumption of an energy-dense diet and increase lipolysis and preserve thermogenesis during caloric restriction, which thereby markedly accelerates weight loss. Intracellular Ca(2+) plays a key regulatory role in adipocyte lipid metabolism and triacylglycerol storage; increased intracellular Ca(2+) results in the stimulation of lipogenic gene expression and lipogenesis and the suppression of lipolysis, which results in increased lipid filling and increased adiposity. Moreover, the increased calcitriol produced in response to low-calcium diets stimulates adipocyte Ca(2+) influx and, consequently, promotes adiposity, whereas higher-calcium diets inhibit lipogenesis, inhibit diet-induced obesity in mice, and promote lipolysis, lipid oxidation, and thermogenesis. Notably, dairy sources of calcium markedly attenuate weight and fat gain and accelerate fat loss to a greater degree than do supplemental sources of calcium. This augmented effect of dairy products relative to supplemental calcium is likely due to additional bioactive compounds, including the angiotensin-converting enzyme inhibitors and the rich concentration of branched-chain amino acids in whey, which act synergistically with calcium to attenuate adiposity. These concepts are confirmed by epidemiologic data and recent clinical trials, which indicate that diets that include > or =3 daily servings of dairy products result in significant reductions in adipose tissue mass in obese humans in the absence of caloric restriction and markedly accelerate weight and body fat loss secondary to caloric restriction compared with diets low in dairy products. These data indicate an important role for dairy products in both the prevention and treatment of obesity.

Calcium in Women: Healthy Bones and Much More

Osteoporosis is one of the leading health problems of women today, and the expectation is that more than 41 million women worldwide will be affected within the next 20 years if current trends are not reversed. Prevention of osteoporosis must be a focus for nurses, rather than merely the treatment of the problem. The majority of bone mass is developed during the adolescent and young adulthood years, with nearly 90% of skeletal mass accumulated by age 18. Current research has demonstrated that young women's intake of calcium is significantly below the recommended dietary intake. This article reviews the role and functions of calcium, how it is transported, and factors that may significantly increase or impair the absorption of this macronutrient. Strategies are described that will assist nurses in assessing the patient's diet and making appropriate recommendations regarding the intake of calcium and other micronutrients. A more in-depth and thorough understanding of this important mineral will enable nurses to strengthen their knowledge and confidence in helping patients and themselves change the focus from treating the disease to the improvement and maintenance of healthy bones and the prevention of other health conditions in women.

Diarrhea caused by enterotoxigenic Escherichia coli infection of humans is inhibited by dietary calcium

BACKGROUND & AIMS

In several rat infection experiments, we have shown that dietary calcium inhibits intestinal colonization and translocation of invasive salmonella. The aim of the present study was to find out whether calcium is also protective against enterotoxigenic Escherichia coli (ETEC) infection. This was first tested in our rat model and subsequently verified in a human infection study.

METHODS

Rats were fed a purified diet with either a low or a high amount of calcium phosphate and orally infected with ETEC. In addition, a parallel, double-blind, placebo-controlled intervention study of 3 weeks was performed with 32 healthy men. Subjects largely maintained their habitual diet and consumed either regular milk products (calcium supply, 1100 mg/day) or placebo milk products (calcium supply, 60 mg/day). On day 10, subjects ingested a live but attenuated ETEC strain (strain E1392/75-2A), able to induce mild although short-lived symptoms. Primary outcomes studied were infection-induced diarrhea (total fecal output and relative fecal dry weight) and fecal mucin excretion.

RESULTS

In humans, ETEC induced diarrhea in both groups, in that total fecal output doubled and mean relative fecal dry weight dropped from 25% to 20%. Additionally, fecal mucin excretion was increased in both groups. All these fecal parameters were completely normalized in the calcium group on the second infection day, in contrast to the placebo group, which recovered on the third infection day. Likewise, supplemental calcium inhibited ETEC colonization and diarrhea in rats.

CONCLUSIONS

Calcium in milk products improves human resistance to ETEC infection as it inhibits infectious diarrhea.