The myth of increased lactose intolerance in African-Americans

Executive summary: The role of dairy food intake for improving health among Black Americans across the life continuum

Given the complex relationships that many Black individuals have with dairy foods, due to issues with lactose intolerance or other cultural factors, the National Medical Association has made considerable efforts to examine the role that dairy foods play in the health and well-being of Black Americans. Over the last two decades, the National Medical Association and its partners have produced multiple reports on the value of including adequate milk and dairy foods in the diets of Black Americans. These publications have highlighted the impact that inadequate consumption of dairy foods and nutrients have on chronic disease risks. Past publications have also provided evidence-based recommendations for the proper diagnosis and management of lactose intolerance. This new series of evidence reviews focuses on dairy's role in improving nutrition and health among Black Americans across the life course and covers an extensive amount of new research that highlights additional health disparities and provides further evidence-based strategies for the management of lactose intolerance. Much like the 2020-2025 Dietary Guidelines for Americans, this work utilizes a life course approach to better address dairy intake on health outcomes for different ages and life stages: 1) pregnancy, fetal development, and lactation, 2) infants, toddlers, and young children, 3) older children and adolescents, 4) adults, and 5) geriatric populations. Overall, the findings and conclusions from this series of evidence reviews continue to indicate that higher dairy intake is associated with reduced risk for many of the most commonly occurring deficiencies and diseases impacting each life stage, and that Black Americans would receive significantly greater health benefits by increasing their daily dairy intake levels to meet the national dietary recommendations than they would from continuing to fall short of these recommendations. However, these recommendations must be considered with appropriate context and nuance as the intake of different dairy products can have different impacts on health outcomes. For instance, vitamin D fortified dairy products and fermented dairy products like yogurt - which are low in lactose and rich in live and active cultures - tend to show the greatest impacts for reducing disease risk across the life continuum, while whole-fat dairy foods may be most beneficial in early life for optimal brain development, and more protein-rich options may be most beneficial in later life to help maintain muscle mass and function.

A review of dairy food intake for improving health among black infants, toddlers, and young children in the US

Adequate nutrition is paramount for proper growth and musculoskeletal, neurocognitive, and immunological development in infants, toddlers, and young children. Among breastfeeding mother-child dyads, this critical window of development, is impacted by both maternal and offspring dietary patterns. For mothers, their dietary patterns impact not only their own health and well-being, but also the nutrition of their breast milk - which is recommended as the sole source of food for the first 6 months of their infant's life, and as a complementary source of nutrition until at least 2 years of age. For infants and toddlers, the breast milk, formulas, and first foods they consume can have both short-term and long-term effects on their health and well-being - with important impacts on their taste perception, microbiome composition, and immune function. According to dietary intake data in the US, infants and young children meet a greater number of nutrient requirements than older children and adults, yet numerous disparities among socially disadvantaged racial/ethnic groups still provide significant challenges to achieving adequate nutrition during these early life stages. For example, Black children are at greater risk for disparities in breastfeeding, age-inappropriate complementary feeding patterns, nutrient inadequacies, food insecurity, and obesity relative to most other racial/ethnic groups in the US. For infants who do not receive adequate breast milk, which includes a disproportionate number of Black infants, dairy-based infant formulas are considered the next best option for meeting nutritional needs. Fermented dairy foods (e.g., yogurt, cheese) can serve as ideal first foods for complementary feeding, and cow's milk is recommended for introduction during the transitional feeding period to help meet the nutrient demands during this phase of rapid growth and development. Low dairy intake may put children at risk for multiple nutrient inadequacies and health disparities - some of which may have lifelong consequences on physical and mental health. A burgeoning body of research shows that in addition to breast milk, cow's milk and other dairy foods may play critical roles in supporting physical growth, neurodevelopment, immune function, and a healthy gut microbiome in early life. However, most of this research so far has been conducted in White populations and can only be extrapolated to Black infants, toddlers, and young children. Therefore, to better understand and support the health and development of this population, greater research and education efforts on the role of milk and dairy products are urgently needed. This review presents the current evidence on health disparities faced by Black children in the US from birth to four years of age, and the role that dairy foods can play in supporting the normal growth and development of this vulnerable population.

The role of dairy food intake for improving health among black Americans across the life continuum: A summary of the evidence

Decades of health data show major health disparities occurring at every life stage between Black and White Americans. These disparities include greater mortality rates among Black mothers and their offspring, higher levels of malnutrition and obesity among Black children and adolescents, and a higher burden of chronic disease and lower life expectancy for Black adults. Although nutrition is only one of many factors that influence human health and well-being across the life continuum, a growing body of research continues to demonstrate that consuming a healthy dietary pattern is one of the most dominant factors associated with increased longevity, improved mental health, improved immunity, and decreased risk for obesity and chronic disease. Unfortunately, large percentages of Black Americans tend to consume inadequate amounts of several essential nutrients such as vitamin A, vitamin D, calcium, and magnesium; and simultaneously consume excessive amounts of fast foods and sugar-sweetened beverages to a greater degree than other racial/ethnic groups. Therefore, strategies that can help improve dietary patterns for Black Americans could make up a major public health opportunity for reducing nutrition-related diseases and health disparities across the life course. A key intervention strategy to improve diet quality among Black Americans is to focus on increasing the intake of nutrient-rich dairy foods, which are significantly underconsumed by most Black Americans. Compared to other food group, dairy foods are some of the most accessible and affordable sources of essential nutrients like vitamin A, D, and B12, calcium, magnesium, potassium, selenium, and zinc in the food supply, as well as being some of the primary sources of several health-promoting bioactive compounds, including polar lipids, bioactive proteins and peptides, oligosaccharides, and live and active cultures in fermented products. Given the complex relationships that many Black Americans have with dairy foods, due to issues with lactose intolerance, and/or negative perceptions about the health effects of dairy foods, there is still a need to examine the role that dairy foods play in the health and well-being of Black Americans of all ages and life stages. Therefore, the National Medical Association and its partners have produced multiple reports on the value of including adequate dairy in the diet of Black Americans. This present summary paper and its associated series of evidence reviews provide an examination of an immense amount of research focused on dairy intake and health outcomes, with an emphasis on evidence-based strategies for improving the health of Black Americans. Overall, the findings and conclusions from this body of research continue to indicate that higher dairy intake is associated with reduced risk for many of the most commonly occurring deficiencies and diseases impacting each life stage, and that Black Americans would receive significantly greater health benefits by increasing their daily dairy intake levels to meet the national recommendations than they would from continuing to fall short of these recommendations. However, these recommendations must be considered with appropriate context and nuance as the intake of different dairy products can have different impacts on health outcomes. For instance, vitamin D fortified dairy products and fermented dairy products like yogurt - which are low in lactose and rich in live and active cultures - tend to show the greatest benefits for improved health. Importantly, there are significant limitations to these research findings for Black Americans, especially as they relate to reproductive and child health, since most of the research on dairy intake and health has failed to include adequate representation of Black populations or to sufficiently address the role of dairy intake during the most vulnerable life stages, such as pregancy, lactation, fetal development, early childhood, and older age. This population and these life stages require considerably more research and policy attention if health equity is ever to be achieved for Black Americans. Sharing and applying the learnings from this summary paper and its associated series of evidence reviews will help inform and empower nutrition and health practitioners to provide more evidence-based dietary recommendations for improving the health and well-being of Black Americans across the life course.

Lactose intolerance in children and adults

Lactose is a disaccharide found in milk and dairy products. Children and adults with lactose intolerance are unable to tolerate significant amounts of lactose because of an inadequate amount of the enzyme lactase. The condition occurs in three main types: primary, secondary, and primary adult-type hypolactasia. The use of milk in the diet of these individuals may lead to appearance of the irritable bowel syndrome. In persons with lactose intolerance symptoms include diarrhoea, dominated by abdominal colic, loud peristaltic sounds, increased flatulence and meteorism. A diagnosis of lactose intolerance can usually be made with a careful history, elimination of lactose from the diet, lactose tolerance test, hydrogen breath test and genetic testing. In the absence of appropriate tests in patients with suspected primary adult-type hypolactasia, diagnosis can be made as in patients with food allergy. Treatment is based on the restriction of lactose intake with the use of fermented milk products. However, especially for children, if milk and dairy products are eliminated from the diet, it is important to ensure D vitamin and calcium supplementation.

Prospective Study of Lactose Intolerance as a Potential Cause of Gas Bloat Syndrome in Patients Treated Surgically for Gastroesophageal Reflux

Introduction. The high incidence of lactose intolerance leads us to consider that many of our patients could suffer from this alteration. Therefore, as its main sign (even when asymptomatic) is increased intestinal gas, patients recovering from a Nissen fundoplication have a significant probability of suffering from gas bloat syndrome. Materials and Methods. This prospective study was conducted from November 2012 to January 2017, we included all the patients who had been treated by the Nissen technique for gastroesophageal reflux disease with gas bloat syndrome detected during follow-up and tested positive for lactose intolerance. The study participants were then prescribed a lactose-poor diet to be followed for 3 months. The patients were asked to complete quality of life and symptomatology questionnaires before and after diet. The pre- and post-diet results were then compared. Results. The pre- and post-diet results showed statistically significant improvements in both questionnaires. Conclusion. Lactose intolerance may account for the symptoms presented by a significant number of patients with gas bloat syndrome following antireflux surgery; these patients could benefit from consuming a lactose-free diet, which we expect to alleviate or, in some cases, eliminate the above symptoms.

Milk intake and mammographic density in premenopausal women

PURPOSE

Mammographic density is a strong risk factor for breast cancer. Although diet is associated with breast cancer risk, there are limited studies linking adult diet, including milk intake, with mammographic density. Here, we investigate the association of milk intake with mammographic density in premenopausal women.

METHODS

We analyzed data from 375 cancer-free premenopausal women who had routine screening mammography at Washington University School of Medicine, St. Louis, Missouri in 2016. We used Volpara to measure volumetric percent density, dense volume, and non-dense volume. We collected information on recent milk intake (past 12 months), and categorized skim milk and low/reduced-fat milk intake into 4 groups: < 1/week, 1/week, 2-6 times/week, ≥ 1/day, while whole and soy milk intake were categorized into 2 groups: < 1/week, ≥ 1/week. We used multivariable linear regression model to evaluate the associations of milk intake and log-transformed volumetric percent density, dense volume, and non-dense volume.

RESULTS

In multivariable analyses, volumetric percent density was 20% (p-value = 0.003) lower in the 1/week group, 14% (p-value = 0.047) lower in the 2-6/week group, and 12% (p-value = 0.144) lower in the ≥ 1/day group (p-trend = 0.011) compared with women who consumed low/reduced-fat milk < 1/week. Attenuated and non-significant associations were observed for low/reduced-fat milk intake and dense volume. There were no associations of whole, skim, and soy milk intake with volumetric percent density and dense volume.

CONCLUSIONS

Recent low/reduced-fat milk intake was inversely associated with volumetric percent density in premenopausal women. Studies on childhood and adolescent milk intake and adult mammographic density in premenopausal women are needed.

The incidence of vitamin D deficiency in the obese: a retrospective chart review

Objective

To determine whether the obese population is more likely to be vitamin D deficient compared to healthy and overweight individuals.

Patients and methods

A retrospective chart review was performed for patients seen in two ambulatory clinics in South Florida over a 1-year period (n=402). Patients’ vitamin D levels drawn during annual wellness visits were analyzed. Subjects were categorized based on body mass index (BMI) as normal (BMI <24.9), overweight (BMI 25.0–29.9), and obese (BMI >30.0). Their 25-OH vitamin D status was defined as normal (>30 ng/mL), insufficient (20.0–29.9 ng/mL), and deficient (<20 ng/mL). The study included both men and women of black, white, Hispanic, and Asian races. Other variables in the study included age, history of hypertension, and diabetes. Patients with conditions leading to vitamin D malabsorption (chronic pancreatitis, celiac disease, Crohn's disease, cystic fibrosis, ileocecal resection) were excluded. Patients with prior vitamin D supplementation were also excluded.

Results

The results of the study indicated a significant association of vitamin D deficiency and obesity (p<0.05). Patients who were obese had a relative risk of 3.36 (95% CI: 1.50–7.54) for vitamin D deficiency compared to subjects with normal BMI. The study also showed a significant association between vitamin D levels and obesity when controlling for age, race, and presence of hypertension (p <0.05), with Asians and blacks more likely to be vitamin D deficient.

Conclusion

These results demonstrated that obesity was a risk factor for vitamin D deficiency in all races, especially the Asian and black populations. This suggests that physicians should screen for vitamin D deficiency in the obese populations, especially among Asian and black races.

A new medical research model: ethically and responsibly advancing health for humans and animals

With the increasing use of genomics, computational analytics, emerging technologies, and personalized medicine, the possibility of a new research model is emerging. Using the clues from thousands of species living on our planet, scientists from many disciplines (medicine, veterinary medicine, wildlife) must collaborate, prioritize, and strategize on how to address causes of health and disease. Such clues should guide disease prevention, as well as the development of innovative, efficacious, and gentler therapies. Geographic and language barriers must be broken down, and scientists--even within a single academic, corporate, or government research site--must be vigilant in seeking the help of nonmedical disciplines of colleagues from whence answers might come. The public will become more interested in and demanding of such a model, desiring that all family members (humans and animals) have an opportunity for a long and healthy life. Above all, such activities will be humanely conducted with outcomes having the greatest chance for success.

The association between fracture rates and neighborhood characteristics in Washington, DC, children

BACKGROUND

Effects of neighborhood contextual features have been found for many diseases, including bone fractures in adults. Our study objective was to evaluate the association between neighborhood characteristics and pediatric bone fracture rates. We hypothesized that neighborhood indices of deprivation would be associated with higher fracture rates.

MATERIALS AND METHODS

Pediatric bone fracture cases treated at a tertiary, academic, urban pediatric emergency department between 2003 and 2006 were mapped to census block groups using geographical information systems software. Fracture rates were calculated as fractures per 1000 children in each census block. Exploratory factor analysis of socioeconomic indicators was performed using 2000 census block data. Factor scores were used to predict odds of bone fracture at the individual level while adjusting for mean age, sex composition, and race/ethnicity composition at census block level using our sample data.

RESULTS

We analyzed 3764 fracture visits in 3557 patients representing 349 distinct census blocks groups. Fracture rates among census blocks ranged from 0 to 207 per 1000 children/study period. Logistic regression modeling identified 2 factors (race/education and large families) associated with increased fracture risk. Census variables reflecting African American race, laborer/service industry employment, long-term block group residence, and lower education levels strongly loaded on the race/education factor. The large families factor indicated the children-to-families ratio within the block group. The poverty factor was not independently associated with fracture risk.

CONCLUSIONS

Thus, neighborhood characteristics are associated with risk for fractures in children. These results can help inform translational efforts to develop targeted strategies for bone fracture prevention in children.

The uncertain significance of low vitamin D levels in African descent populations: a review of the bone and cardiometabolic literature

Vitamin D levels in people of African descent are often described as inadequate or deficient. Whether low vitamin D levels in people of African descent lead to compromised bone or cardiometabolic health is unknown. Clarity on this issue is essential because if clinically significant vitamin D deficiency is present, vitamin D supplementation is necessary. However, if vitamin D is metabolically sufficient, vitamin D supplementation could be wasteful of scarce resources and even harmful. In this review vitamin D physiology is described with a focus on issues specific to populations of African descent such as the influence of melanin on endogenous vitamin D production and lactose intolerance on the willingness of people to ingest vitamin D fortified foods. Then data on the relationship of vitamin D to bone and cardiometabolic health in people of African descent are evaluated.

Status of vitamin D in children with sickle cell disease living in Madrid, Spain

Patients with sickle cell disease have vitamin D deficiency and poor bone health which makes them prone to have an increased risk of fractures and osteoporosis in adulthood. We performed a prospective, cross-sectional study in children diagnosed with sickle cell disease living in Madrid, Spain. The purpose of this study was to evaluate the status of vitamin D of these children. Patients 0-16 years old were enrolled between 2008 and 2011. We studied demographics, calcium metabolism, and bone health, especially by measuring levels of 25-hydroxyvitamin D (25(OH)D), during different seasons of the year, and bone densitometry (beyond 4 years of age). Seventy-eight children were included in the study. Mean age was 4.8 ± 4.3 years, and mean serum 25(OH)D level was 21.50 ± 13.14 ng/ml, with no differences in 25(OH)D levels within different seasons. Fifty-six percent of children had levels of 25(OH) vitamin D of <20 ng/ml, whereas 79 and 18 % of them had levels of <30 and <11 ng/ml, respectively. Secondary hyperparathyroidism was observed in 25 % of children. Densitometry was performed in 33 children, and an abnormal z-score was seen in 15.2 % of them with no correlation with levels of 25(OH)D.

CONCLUSIONS

Vitamin D deficiency is highly prevalent in children with sickle cell disease, who are residing in Madrid, Spain, and it is detected at a young age. We propose that early intervention may increase the possibility of an adequate bone density later in life.

Bone mineral density and vitamin D status among African American children with forearm fractures

OBJECTIVE

To determine whether African American children with forearm fractures have decreased bone mineral density and an increased prevalence of vitamin D deficiency (serum 25-hydroxyvitamin D level ≤ 20 ng/mL) compared with fracture-free control patients.

METHODS

This case-control study in African American children, aged 5 to 9 years, included case patients with forearm fracture and control patients without fracture. Evaluation included measurement of bone mineral density and serum 25-hydroxyvitamin D level. Univariable and multivariable analyses were used to test for associations between fracture status and 2 measures of bone health (bone mineral density and 25-hydroxyvitamin D level) while controlling for other potential confounders.

RESULTS

The final sample included 76 case and 74 control patients. There were no significant differences between case and control patients in age, gender, parental education level, enrollment season, outdoor play time, height, or mean dietary calcium nutrient density. Cases were more likely than control patients to be overweight (49.3% vs 31.4%, P = .03). Compared with control patients, case patients had lower whole body z scores for bone mineral density (0.62 ± 0.96 vs 0.98 ± 1.09; adjusted odds ratio 0.38 [0.20-0.72]) and were more likely to be vitamin D deficient (47.1% vs 40.8%; adjusted odds ratio 3.46 [1.09-10.94]).

CONCLUSIONS

These data support an association of lower bone mineral density and vitamin D deficiency with increased odds of forearm fracture among African American children. Because suboptimal childhood bone health also negatively impacts adult bone health, interventions to increase bone mineral density and correct vitamin D deficiency are indicated in this population to provide short-term and long-term benefits.

Calcium intake and body composition in African-American children and adolescents at risk for overweight and obesity

This study examined the role of calcium intake on body composition in 186 African-American adolescents at risk for overweight and obesity. The average weight of 89.8 kg ± 23.6 (SD) had a mean BMI z score of 2.2. Females with a calcium intake of <314 mg/day had higher percent fat mass compared to those with the highest calcium intakes that were ≥634 mg/day. Compared to those with a low calcium intake (<365 mg/day), those with the highest calcium intake of >701 mg/day had higher intake of thiamin, folate, cobalamin, vitamin D, phosphorus, iron, zinc.

An update on the epidemiology of pediatric fractures

Despite public health measures to prevent childhood injuries, the incidence of pediatric fractures is increasing. This fracture incidence is dependent on many demographic factors, the various contributors to bone health, and an individual's risk-taking behavior. Although traditional play activities continue to be the prevalent causes for fractures, there is an evolving array of new sport and recreation activities that carry significant fracture risk. The following review article outlines the developing epidemiology of pediatric fractures by analyzing some of the individual risk factors that influence fracture incidence as well as the variety of activities that are associated with these fractures.

Body fat and dairy product intake in lactase persistent and non-persistent children and adolescents

Background

Lactase non-persistent (LNP) individuals may be lactose intolerant and therefore on a more restricted diet concerning milk and milk products compared to lactase persistent (LP) individuals. This may have an impact on body fat mass.

Objective

This study examines if LP and LNP children and adolescents, defined by genotyping for the LCT-13910 C > T polymorphism, differ from each other with regard to milk and milk product intake, and measures of body fat mass.

Design

Children (n=298, mean age 9.6 years) and adolescents (n=386, mean age 15.6 years), belonging to the Swedish part of the European Youth Heart Study, were genotyped for the LCT-13910 C > T polymorphism. Dietary intakes of reduced and full-fat dairy varieties were determined.

Results

LNP (CC genotype) subjects consumed less milk, soured milk and yoghurt compared to LP (CT/TT genotype) subjects (p<0.001). Subsequent partitioning for age group attenuated this observation (p=0.002 for children and p=0.023 in adolescents). Six subjects were reported by parents to be ‘lactose intolerant’, none of whom were LNP. LNP children and adolescents consumed significantly less reduced fat milk and milk products than LP children and adolescents (p=0.009 for children and p=0.001 for adolescents).

Conclusions

We conclude that LP is linked to an overall higher milk and dairy intake, but is not linked to higher body fat mass in children and adolescents.

Prevalence of vitamin D insufficiency in African American children with forearm fractures: a preliminary study

OBJECTIVES

Forearm fractures account for a significant proportion of childhood injuries and seem to be increasing in incidence. Poor vitamin D status increases overall fracture risk in infants with rickets and adults with osteoporosis. Children with vitamin D insufficiency (serum 25-hydroxy vitamin D level <20 ng/mL) have decreased bone mineral density (BMD) compared with children having normal vitamin D status. The relationship between vitamin D status and childhood forearm fracture has not been investigated.

METHODS

This prospective study enrolled African American children, aged 5 to 9 years, with a forearm fracture. Bone health evaluation included measurement of serum 25-hydroxy vitamin D level and BMD by dual energy x-ray absorptiometry scan. Univariable analyses were used to test the associations between fracture status and the independent variables, serum vitamin D level and BMD.

RESULTS

Vitamin D levels were available for 17 cases. The mean (+/-SD) 25-hydroxy vitamin D level was 20.1 (+/-7.3) ng/mL with a range of 10 to 38 ng/mL. The mean of this group was at the cut point for vitamin D insufficiency. Ten cases (59%) were vitamin D insufficient. Dual energy x-ray absorptiometry scan results for these patients were consistent with normal bony mineralization for age.

CONCLUSIONS

A significant proportion of African American children with fractures in our study have vitamin D insufficiency. Analysis of serum 25-hydroxy vitamin D levels and BMD in additional cases and controls will determine the significance of these findings.

CLINICAL RELEVANCE

Vitamin D insufficiency may play a previously unrecognized role in childhood fractures. Strong consideration should be given to routine vitamin D testing in African American children with forearm fractures.

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.

Ethnic differences in dairy and related nutrient consumption among US adults and their association with obesity, central obesity, and the metabolic syndrome

BACKGROUND

Recent studies suggest dairy consumption and associated nutrients may be protective against some of the components of the metabolic syndrome (MetS).

OBJECTIVES

We examined the association between consumption of a variety of dairy products and their related nutrients with obesity, central obesity, and MetS, and attempted to explain some of the ethnic differences in metabolic outcomes through dairy consumption using national data.

DESIGN

Nationally representative indicators of obesity, central obesity, and MetS among US adults were constructed from National Health and Nutrition Examination Survey 1999-2004 data, including direct anthropometric assessments, blood pressure, and laboratory tests. Sample sizes ranged from 4519 for MetS to 14 618 for obesity. Associations between diet (assessed using 24-h recalls) and metabolic and other outcomes were tested using multivariate linear and logistic models and structural equation models.

RESULTS

We found a significant inverse association between intake of whole milk, yogurt, calcium, and magnesium and metabolic disorders. Odds ratios for one more daily serving of yogurt and 100 mg Mg for MetS were 0.40 (95% CI: 0.18, 0.89) and 0.83 (95% CI: 0.72, 0.96), respectively. The opposite was found for intakes of cheese, low-fat milk, and phosphorus. Using structural equation models, ethnic differences in some MetS outcomes, such as body mass index and systolic blood pressure, were partly explained by variations in dairy-related nutrients.

CONCLUSIONS

Various dairy products may have differential associations with metabolic disorders, including obesity. Ethnic differences in dairy consumption may explain in part the ethnic disparities in metabolic disorders in the US population.

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.

Low micronutrient intake may accelerate the degenerative diseases of aging through allocation of scarce micronutrients by triage

Inadequate dietary intakes of vitamins and minerals are widespread, most likely due to excessive consumption of energy-rich, micronutrient-poor, refined food. Inadequate intakes may result in chronic metabolic disruption, including mitochondrial decay. Deficiencies in many micronutrients cause DNA damage, such as chromosome breaks, in cultured human cells or in vivo. Some of these deficiencies also cause mitochondrial decay with oxidant leakage and cellular aging and are associated with late onset diseases such as cancer. I propose DNA damage and late onset disease are consequences of a triage allocation response to micronutrient scarcity. Episodic shortages of micronutrients were common during evolution. Natural selection favors short-term survival at the expense of long-term health. I hypothesize that short-term survival was achieved by allocating scarce micronutrients by triage, in part through an adjustment of the binding affinity of proteins for required micronutrients. If this hypothesis is correct, micronutrient deficiencies that trigger the triage response would accelerate cancer, aging, and neural decay but would leave critical metabolic functions, such as ATP production, intact. Evidence that micronutrient malnutrition increases late onset diseases, such as cancer, is discussed. A multivitamin-mineral supplement is one low-cost way to ensure intake of the Recommended Dietary Allowance of micronutrients throughout life.