Processing Human Milk to Increase Nutrient Density for Preterm Infants.

BACKGROUND: Human milk is the optimal food for newborns. Choices to feed preterm infants in neonatal intensive care units are mother's milk, donor milk, or formula. Preterm infants have better tolerance for human milk, but the lower caloric density of donor milk might not meet preterm infant growth needs. Preterm infants have higher protein and energy requirements with a limited stomach capacity. Therefore, there is a need for human milk with increased nutrient density. RESEARCH AIM: To concentrate donor milk to have a higher caloric and protein density while avoiding side effects of high osmolality by precipitating lactose at low temperatures. METHODS: We investigated the results of volume reduction and lactose removal processes on the lactose, protein, osmolality, and viscosity of human milk. Donor milk was obtained from WakeMed Mothers' Milk Bank. Homogenization and evaporative condensation were applied to samples (N = 36) before they were stored frozen overnight, followed by refrigerated centrifugation for lactose removal at 0 °C. Supernatants were separated and compared to the composition of controls. RESULTS: A significant reduction of lactose (SW = -262, p < .0001) and osmolality (SW = -211.5 p < .01) was achieved in the concentrated milk without a significant protein loss from centrifugation (SW = -44.5, p = .49). A 30%-40% volume reduction is within the American Academy of Pediatrics recommended osmolality for infant feeding. CONCLUSION: Concentrating human milk in a milk bank setting for feeding preterm infants might be a simple and low-cost process to achieve a product with higher nutrient density and no non-human components.

Implementing the 2020-2025 Dietary Guidelines for Americans: Recommendations for a Path Forward.

The Dietary Guidelines for Americans (DGA) provide science-based recommendations for healthy dietary patterns to promote health and reduce risk of chronic diseases. Yet, since their inception in 1980 and updates every 5 y, Americans fall short of meeting dietary recommendations and diet-related chronic diseases continue to be a public health concern. In May of 2021, the Institute of Food Technologists and the Department of Food Science at the University of Massachusetts, Amherst, convened a diverse group of thought leaders in health, nutrition, and food science to identify opportunities and approaches to improve consumer adoption of the DGA recommendations. The invited leaders collaborated in roundtable discussions to develop recommendations and strategies to promote adoption of the DGA recommendations after hearing sessions on the latest consumer trends, advances in food science and technology, and effective communications approaches. Participants agreed that changes in consumer behaviors and heightened interest in health due to the novel coronavirus pandemic have created an opportune time to engage consumers about healthy eating. Communications must be simple, tailored to the consumer, and delivered by influencer(s)/spokesperson(s) who are credible sources and share personal values. Innovations in food science and technology have enabled improvements in the safety, health, acceptability, affordability, and availability of foods, but opportunities to provide more options to enhance consumption of desired food groups, such as fruits, vegetables, and whole grains, remain. Moving Americans toward healthier dietary patterns aligned with DGA recommendations will require collaborations within the food sector and beyond to achieve broad-scale amplification and investment.

Implementing the 2020-2025 Dietary Guidelines for Americans: Recommendations for a path forward.

The Dietary Guidelines for Americans (DGA) provide science-based recommendations for healthy dietary patterns to promote health and reduce risk of chronic diseases. Yet, since their inception in 1980 and updates every 5 years, Americans fall short of meeting dietary recommendations and diet-related chronic diseases continue to be a public health concern. In May of 2021, the Institute of Food Technologists and the Department of Food Science at the University of Massachusetts, Amherst, convened a diverse group of thought leaders in health, nutrition, and food science to identify opportunities and approaches to improve consumer adoption of the DGA recommendations. The invited leaders collaborated in roundtable discussions to develop recommendations and strategies to promote adoption of the DGA recommendations after hearing sessions on the latest consumer trends, advances in food science and technology, and effective communications approaches. Participants agreed that changes in consumer behaviors and heightened interest in health due to the novel coronavirus pandemic have created an opportune time to engage consumers about healthy eating. Communications must be simple, tailored to the consumer, and delivered by influencer(s)/spokesperson(s) who are credible sources and share personal values. Innovations in food science and technology have enabled improvements in the safety, health, acceptability, affordability, and availability of foods but opportunities to provide more options to enhance consumption of desired food groups, such as fruits, vegetables, and whole grains, remain. Moving Americans toward healthier dietary patterns aligned with DGA recommendations will require collaborations within the food sector and beyond to achieve broad scale amplification and investment.

Peanut skin phenolic extract attenuates hyperglycemic responses in vivo and in vitro.

Diabetes affects at least 285 million people globally, and this number continues to increase. Clinical complications include impaired glucose metabolism, hyperglycemia, dyslipidemia, atherosclerosis and non-alcoholic fatty liver disease. Evidence has shown that natural phenolics play a protective effect on both the development and management of type 2 diabetes. This study evaluated effects of the extract from peanut skins containing polyphenols on induced- hyperglycemia using in vivo and in vitro methods. A human hepatocellular liver carcinoma cell line (HepG2) was used to investigate the effect of the peanut skin extract on cell viability after exposure to high glucose concentrations. In vivo, the effect of peanut skin extract on an oral glucose tolerance was investigated in human subjects. Fifteen participants aged 21-32 underwent an oral glucose tolerance test with five treatments: 1) 50-gram glucose solution (reference); 2). 50-gram glucose solution, followed by 12 mg of vegi-capsulated maltodextrin; 3) 50-gram glucose solution, followed by 120 mg of vegi-capsulated maltodextrin-encapsulated peanut skin extract; 4). 50-gram glucose solution, followed by 28 grams of unfortified coated peanuts; 5) 50-gram glucose solution, followed by 28 grams of chili lime coated peanuts fortified with encapsulated peanut skin extract. Glucose levels were measured using a continuous monitor. Peanut skin extract was found to attenuate the decrease in cell viability in high glucose treated HepG2 cells, showing a protective effect against hyperglycemia induced cell death. No difference in the glycemic response area under the curve between any treatments using the tolerance test, but the treatment of the peanut skin extract with the glucose reference resulted in a significantly lower peak blood glucose response at 45 minutes, indicating that it was effective at reducing the glycemic response. The present study shows that the phenolic extract of peanut skins has an antidiabetic effect, further confirming their value as a functional food ingredient.

Storage of Unfed and Leftover Mothers' Own Milk.

OBJECTIVE: The objective was to examine the bacteriological and immunological properties of freshly expressed, previously frozen, and leftover mothers' own milk during storage. MATERIALS AND METHODS: In the first of two pilot studies, 12 mother-infant dyads participated. The milk studied included freshly expressed unfed and freshly expressed leftover milk. Milk samples were stored at 24°C, 4°C, or -20°C. In the second pilot study, 11 mother-infant dyads participated. The milk studied included milk that had been previously frozen, including previously frozen leftover milk. Milk samples were stored at 24°C and 4°C. After storage in both studies, the milk was analyzed for bacteriological and immunological properties. RESULTS: Bacteriological and immunological characteristics of freshly expressed unfed and freshly expressed leftover milk and previously frozen unfed and previously frozen leftover milk remained stable during storage at 4°C for at least 6 days. The quality of all groups of mothers' milk declined when stored at 24°C for longer than 3 hours. CONCLUSIONS: While this study provides evidence that human milk might be safe at longer storage times, storage guidelines should not be revised until more research is performed. This study serves as a call to action for more research on the topic of human milk storage, specifically leftover human milk. The study provides information to inform future study designs on the topic of unpasteurized human milk storage. More research is needed regarding leftover human milk storage with a greater number of participants, determination of the quality of human milk, and the storage of human milk in a real-life setting.

A longitudinal study of human milk composition in the second year postpartum: implications for human milk banking.

While the composition of human milk has been studied extensively in the first year of lactation, there is a paucity of data regarding human milk composition beyond one year postpartum. Policies vary at milk banks around the world regarding how long lactating women are eligible to donate their milk. The primary purpose of this study is to describe longitudinal changes in human milk composition in the second year postpartum to support the development of evidence based guidelines regarding how long lactating women can donate human milk to a milk bank. Nineteen lactating women in North Carolina provided monthly milk samples from 11 months to 17 months postpartum (N = 131), and two non-profit milk banks provided (N = 33) pooled, unpasteurized milk samples from 51 approved donors less than one year postpartum. There was a significant increase (P < 0.05) in the concentration of total protein, lactoferrin, lysozyme, Immunoglobulin A, oligosaccharides and sodium in longitudinal samples of mother's milk between 11 and 17 months postpartum, while zinc and calcium concentrations declined, and no changes were observed in lactose, fat, iron and potassium. Human milk in the second year postpartum contained significantly higher concentrations of total protein, lactoferrin, lysozyme and Immunoglobulin A, than milk bank samples, and significantly lower concentrations of zinc, calcium, iron and oligosaccharides. Accepting milk bank donations beyond one year postpartum is a potential strategy for increasing the supply of donor milk, but may require mineral fortification.

Storage of Unfed and Leftover Pasteurized Human Milk.

OBJECTIVE: To determine the impact of storage on bacterial growth and immunological activity of pasteurized human milk and leftover pasteurized human milk that has been exposed to the microflora in an infant's mouth. MATERIALS AND METHODS: Eighteen mother-infant dyads participated in two separate studies. Mother's milk was pasteurized, and each baby was fed 1 to 2 ounces. Pasteurized and leftover pasteurized milk were stored at room (24°C) and refrigerated temperatures (4°C). After storage, milk was analyzed for bacteria, total protein, lysozyme activity, and secretory immunoglobulin A (SIgA) activity. RESULTS: In pasteurized and leftover pasteurized milk stored in the refrigerator for 7 days, total aerobic bacteria do not increase significantly and total protein and bioactive proteins are stable. At room temperature, there is a significant increase in total aerobic bacteria in leftover pasteurized milk during 12 hours of storage (p < 0.01) and a significant decrease in total protein and SIgA activity in pasteurized milk during 12 hours of storage (p = 0.02 and p = 0.03, respectively). CONCLUSIONS: When stored in the refrigerator, pasteurized and leftover pasteurized milk may be stored for at least 7 days when considering the variables studied. Caution should be used when storing pasteurized and leftover pasteurized milk at room temperature to prevent an increase in bacterial growth and a decrease in total protein and SIgA activity.

Effect of serum cotinine on vitamin D serum concentrations among american females with different ethnic backgrounds.

OBJECTIVE: To investigate the effect of blood serum concentration of cotinine among non-smokers, passive/light smokers and active smoker females in the United States population as it compares to vitamin D blood serum concentrations. MATERIALS AND METHODS: National Health and Nutrition Examination Survey (NHANES) that is designed to assess the health and nutritional status of adults and children in the United States by Centers for Disease Control and Prevention (n=22,196). RESULTS: The analyses demonstrated that among all three smoking categories, black female active smokers have lower vitamin D (13.374 ng/ml), than hispanic (19.213 ng/ml) or white (24.929 ng/ml) females. It was demonstrated that the active smoker black females have the highest percentage of vitamin D deficiency and inadequacy in the population compared to other ethnic females. CONCLUSION: The cotinine blood serum concentrations can also affect vitamin D concentrations in addition to other factors such as gender, ethnicity, dietary supplement intake and sun exposure.

Susceptibility of sweet potato (Ipomoea batatas) peel proteins to digestive enzymes.

Sweet potato proteins have been shown to possess antioxidant and antidiabetic properties in vivo. The ability of a protein to exhibit systemic effects is somewhat unusual as proteins are typically susceptible to digestive enzymes. This study was undertaken to better understand how digestive enzymes affect sweet potato proteins. Two fractions of industrially processed sweet potato peel, containing 6.8% and 8.5% protein and 80.5% and 83.3% carbohydrate, were used as a source of protein. Sweet potato proteins were incubated with pepsin, trypsin, and chymotrypsin and protein breakdown was visualized with SDS-PAGE. After pepsin digestion, samples were assayed for amylase inhibitory activity. Sporamin, the major storage protein in sweet potatoes, which functions as a trypsin inhibitor as well, exhibited resistance to pepsin, trypsin, and chymotrypsin. Sporamin from blanched peel of orange sweet potatoes was less resistant to pepsin digestion than sporamin from outer peel and from extract of the white-skinned Caiapo sweet potato. Trypsin inhibitory activity remained after simulated gastric digestion, with the Caiapo potato protein and peel samples exhibiting higher inhibitory activity compared to the blanched peel sample. Amylase and chymotrypsin inhibitory activity was not present in any of the samples after digestion.

A mixed-methods observational study of human milk sharing communities on Facebook.

OBJECTIVES: The Food and Drug Administration discourages the casual sharing of human milk because of the risk of pathogen transmission. No information is currently available on the prevalence of this practice. The purpose of this mixed-methods observational study is to describe the size and activity of online milk sharing communities. MATERIALS AND METHODS: Data for 3 months were extracted from nine public Facebook pages that facilitate the exchange of human milk. The numbers of participants, interactions, and comments were analyzed. RESULTS: We observed 954 individuals participating in milk sharing. The number of interactions per individual ranged from none to 16 (mean, 1.74 ± 1.65). Top reasons that participants requested milk included "lactation problems" (69.4%) and "child health problems" (48.5%). Nearly half of donors were offering 100 ounces or more, which is the minimum to be eligible to donate to nonprofit milk banks. CONCLUSIONS: Milk sharing networks in the United States are active, with thousands of individuals participating in the direct exchange of raw human milk. Public health issues include increasing the supply of pasteurized donor milk for fragile infants, increasing breastfeeding support, and helping milk sharing families appropriately manage risks.

The nutritive and immunoprotective quality of human milk beyond 1 year postpartum: are lactation-duration-based donor exclusions justified?

Donor human milk is critical for the fragile preterm infant who does not have access to his or her mother's milk, improving survival rates and quality of survival and decreasing hospital stay. Despite the opening of donor milk banks around the world, shortages continue as demand for donor milk exceeds supply. One potential means of increasing supply is by reducing exclusion criteria that prohibit mothers from donating milk based on duration of lactation. Minimal research has been done on the composition of human milk during the second year of lactation, with most research focusing on the nutritive compounds and not the immunoprotective compounds. Several immunoprotective compounds, including lysozyme, lactoferrin, secretory immunoglobulin A, and oligosaccharides, are abundant in human milk compared to bovine-based infant formula and are partially or fully retained during Holder pasteurization, making them an important differentiating feature of donor milk. A PubMed search was conducted to review studies in human milk composition during the second year of lactation. Limitations of existing research include sample collection protocols, small study sizes, and use of populations that may have been at risk for nutritional deficiencies. Stable concentrations of several components were reported including protein, lactose, iron, copper, lactoferrin, and secretory immunoglobulin A. Lysozyme concentration increased during extended lactation, while zinc and calcium concentrations declined into the second year. Conflicting findings were reported on fat content, and no information was available regarding oligosaccharide content. More research is needed to create evidence-based guidelines regarding the nutritive and immunoprotective value of donor milk throughout the course of lactation.

Bioavailability of Oil-Based and ß -Lactoglobulin-Complexed Vitamin A in a Rat Model.

ß -Lactoglobulin is capable of binding fat-soluble compounds including vitamin A palmitate and is suggested to specifically enhance intestinal uptake of retinol. In this study, bioavailability of a vitamin-A-retinyl palmitate complex in skim milk and in water-based liquids was investigated in vitamin-A-depleted rats. First, rats were fed a vitamin-A-free pellet diet for 6 wk and were thereafter gavage-fed with vitamin A in oil, vitamin-A- ß -lactoglobulin complex, vitamin A in oil + skim milk, and vitamin-A- ß -lactoglobulin + skim milk for 2 wk and 42 wk. Vitamin A repletion, as judged by vitamin A accumulation in serum and liver, occurred in all the treatments. Vitamin-A- ß -lactoglobulin complex treatments had statistical equivalence with oil-based vitamin A treatments. In a second experiment, vitamin-A-depleted rats were fed UHT-processed skim milk fortified with either oil-based or freeze-dried ß -lactoglobulin-complexed retinyl palmitate. Liver and serum vitamin A were analyzed by HPLC to indicate vitamin A status in the rats. Results showed no significant difference in bioavailability of retinyl palmitate from milk made with either regular oil-based or ß -lactoglobulin-complexed fortifiers. The vitamin-A- ß -lactoglobulin complex, being water soluble, may be useful for fortification of nonfat products.

Chemical optimization of protein extraction from sweet potato (Ipomoea batatas) peel.

UNLABELLED: Proteins isolated from sweet potatoes (Ipomoea batatas) have been shown to possess antidiabetic, antioxidant, and antiproliferative properties. The objective of this study was to chemically optimize a process for extracting proteins from sweet potato peel. The extraction procedure involved mixing peel with saline solvent to dissolve proteins and then precipitating with CaCl(2). Quadratic and segmented models were used to determine the optimum NaCl concentration and peel to solvent ratio to maximize protein solubility while minimizing solvent usage. A segmented model was also used to optimize the concentration of CaCl(2) used for precipitation. The highest yield was obtained by mixing blanched peelings with 59.7 mL of 0.025 mM NaCl per g peel and then precipitating with 6.8 mM CaCl(2). The results of this study show that potentially valuable proteins can be extracted from peel generated during processing of sweet potatoes and industrial costs can be minimized by using these optimum conditions. PRACTICAL APPLICATION: Potentially valuable proteins can be extracted from sweet potato peel, a waste product of sweet potato processing.

Effect of added calcium, phosphorus, and infant formula on calcium and phosphorus dialyzability in preterm donor human milk.

OBJECTIVES: We studied the effect of preparing donor human milk (DHM) with commonly used nutritional additives on the dialyzability of calcium and phosphate. We hypothesized that the additives to DHM would decrease the dialyzability of calcium and phosphate when prepared according to hospital protocols. METHODS: An in vitro system simulating premature infant digestion was developed to measure dialyzability of calcium and phosphate in DHM. Dialyzable calcium and phosphate were measured after in vitro digestion in DHM before and after preparation of DHM with the following additives according to hospital protocols: calcium glubionate, sodium potassium phosphate, calcium glubionate and sodium potassium phosphate added together, Similac human milk fortifier, Similac NeoSure, or Enfamil Enfacare. RESULTS: The percentage of dialyzable calcium in DHM with added calcium and calcium and phosphate together was greater than the percentage of dialyzable calcium in DHM with added powdered infant formulas (P<0.0001). Dialyzable calcium was greater in DHM with added calcium and with added calcium and phosphate than in all other treatment groups (P<0.0001). Dialyzable calcium in DHM without additives was not different from dialyzable calcium in DHM with added phosphate or with added powdered infant formulas. Dialyzable phosphate did not differ between the treatment groups. CONCLUSIONS: The addition of calcium alone or calcium and phosphate together increased calcium dialyzability in DHM significantly, whereas the addition of powdered human milk fortifier or formulas did not. The addition of calcium or calcium with phosphate together to DHM may provide the most dialyzable calcium.

Utilization of dairy byproduct proteins, surfactants, and enzymes in frozen dough.

Use of natural additives is gaining popularity among the masses as they are becoming more conscious about their diet and health. Frozen dough products are one of the recent examples of value-added cereal products which face stability problems during extended storage periods of times. Dairy whey proteins, surfactants, and certain enzymes are considered important natural additives which could be used to control the water redistribution problem in the dough structure during the storage condition. They interact with the starch and gluten network in a dough system and thus behave as dough improvers and strengtheners. These natural additives not only help to bind extra moisture but also to improve texture and sensory attributes in frozen dough bakery products.

Pro-thrombotic and pro-oxidant effects of diet-induced hyperhomocysteinemia.

Elevated plasma homocysteine levels are associated with the risk of atherosclerosis and arterial and venous thrombosis. We have previously demonstrated that rabbits rendered hyperhomocysteinemic by parenteral administration of homocysteine develop a dysfibrinogenemia that is associated with the formation of fibrin clots that are abnormally resistant to fibrinolysis. We suggested that this acquired dysfibrinogenemia contributes to the thrombotic tendency in hyperhomocysteinemia. However, it was possible that the homocysteine-associated dysfibrinogenemia was an artifact of the parenteral administration model. Therefore, the goals of the current study were to develop a diet-induced model of homocysteinemia in rabbits and determine whether a dysfibrinogenemia and evidence of oxidative stress develop in this model as they do when homocysteine is injected. We found that rabbits fed a diet severely deficient in folate and mildly deficient in choline develop mild hyperhomocysteinemia: 14.8+/-4.0 microM in deficient rabbits compared to 9.0+/-1.7 microM in controls. The deficient rabbits also develop evidence of oxidant stress: increased lipid peroxidation in liver, impaired mitochondrial enzyme activities in liver and elevated caspase-3 levels in plasma. Most importantly, the deficient rabbits also develop a dysfibrinogenemia characterized by increased resistance to fibrinolysis. We believe that this dietary model of homocysteinemia is clinically relevant and reproduces many features associated with hyperhomocysteinemia in previous work using in vitro and in vivo models. Our findings suggest that an acquired dysfibrinogenemia could play a role in the increased risk of atherothrombotic disease in mildly hyperhomocysteinemic human subjects.

Determination of membrane lipid differences in insulin resistant diabetes mellitus type 2 in whites and blacks.

OBJECTIVES: Insulin resistance in diabetes mellitus type 2 (DM2) can result from membrane lipid alterations. Blacks are at a higher risk of developing DM2; therefore, we investigated whether membrane lipid differences exist between blacks and whites and if differences contribute to impaired insulin binding in diabetes. METHODS: Subjects were recruited from four groups: white control (n = 10), black control (n = 10), white diabetic (n = 5), and black diabetic (n = 10). Diabetic subjects who had DM2 with insulin resistance on insulin monotherapy were matched by age and sex. The following determinations were made: fasting serum glucose, fasting serum insulin, plasma lipid profile, red blood cell (RBC) membrane lipids and cholesterol, and RBC insulin binding. RESULTS: The membrane lipid analysis showed racial differences in phosphatidyl ethanolamine (PE) and phosphatidyl choline (PC). The plasma membrane of whites showed higher PE and lower PC levels than that in blacks. The RBC rheologic (PE/phosphatidyl serine) properties (deformability) were lower in diabetics and black subjects. The saturated nature of RBC ([sphingomyelin + PC)/(PE + phosphatidyl serine]) was the lowest in white control subjects (P < 0.056). CONCLUSION: The combination of increased saturated/polyunsaturated fatty acids, increased saturated nature, and increased cholesterol/phospholipid can contribute to decreased membrane fluidity, resulting in insulin resistance. Also, decreased RBC deformability can make oxygen delivery through the capillaries difficult, create tissue hypoxia, and contribute to some of the known complications of diabetes. Membrane lipid alteration may be one of the reasons for a higher incidence of diabetes among blacks.

Muscadine grape products intake, diet and blood constituents of non-diabetic and type 2 diabetic subjects.

OBJECTIVE: Red wines and grape juices contain polyphenolics with antioxidant and antiplatelet properties that may be protective against oxidative stress leading to hypertension, insulin resistance, and type 2 diabetes (T2D). This study evaluated the effects of supplementing meals of subjects with 150 mL of muscadine grape juice (MJ), muscadine grape wine (MW), and dealcoholized muscadine grape wine (Dz-W) on glycemic indices, blood constituents, lipid profile, anthropometric, and nutrient intakes of healthy and T2D subjects over a 28-d period. METHODS: Subjects with T2D were assigned to take MJ, MW, or Dz-W. Non-diabetics consumed MJ and controls were given no test drinks. Several metabolic indicators associated with diabetic conditions were measured at baseline and repeated after 28 d. RESULTS: Diabetics given MW and Dz-W showed lower levels of blood glucose, insulin, and glycated hemoglobin, indicating better glycemic control. Elevated dietary vitamin C and E levels were observed in diabetics given Dz-W, indicating improved antioxidant status. Decreased red blood cell membrane saturated fatty acids and increased mono- and polyunsaturated fatty acids for subjects with T2D given MW suggested improved membrane fluidity. Lower sodium and chloride values for subjects T2D given MW suggested lower risk for developing hypertension. Improved hepatic conditions were noted by decreases in alanine aminotransferase and aspartate aminotransferase among subjects with T2D given MW, indicating better insulin sensitivity and decreased tendency toward impaired liver function. CONCLUSION: Daily intake of 150 mL of MW or Dz-W with meals improved several metabolic responses among diabetics compared with diabetics given MJ.

Differences in the metabolic response to exogenous homocysteine in juvenile and adult rabbits.

Homocysteine has recently received a lot of attention as an independent risk factor for atherosclerotic and thrombotic cardiovascular disease. Plasma homocysteine levels tend to rise with age, but are also greatly influenced by nutritional factors. Early reports suggested that there were differences in the metabolism of homocysteine in adult and immature animals. The current work tests the hypothesis that adult and juvenile animals respond differently to chronic administration of homocysteine. We have previously found that adult rabbits given homocysteine parenterally twice daily for seven weeks developed progressive folate deficiency and concurrently developed an impairment of homocysteine metabolism. We now report that juvenile rabbits do not develop folate deficiency with chronic homocysteine loading and do not have progressively higher trough levels of homocysteine, as do the adults. In addition, juvenile rabbits that have been chronically pre-treated with homocysteine exhibit a lower peak homocysteine level after a single dose than do juvenile rabbits that have never received homocysteine. This adaptation did not occur in the adult rabbits. In addition, adult homocysteine-treated rabbits had evidence of oxidative stress as evidenced by higher levels of malondialdehyde in liver tissue than adult controls. The homocysteine-treated juvenile rabbits had the same levels of malondialdehyde as the juvenile control rabbits. We conclude that the plasma elimination kinetics are altered in juvenile rabbits in response to homocysteine pre-treatment. The difference in metabolism of homocysteine may protect the juvenile rabbits from the damaging effects of homocysteine. Future studies are planned to elucidate the mechanism of this adaptive response.

Fatty acids, diet, and body indices of type II diabetic American whites and blacks and Ghanaians.

OBJECTIVE: This research was designed to study the diet, lipid profile, and metabolic and body indices of type II diabetic and non-diabetic subjects among American white and black and Ghanaian populations. METHODS: Fifty-one type II diabetic and non-diabetic volunteers were recruited through medical clinics. Data collected included food intake and anthropometric measurement. Blood samples were taken for glucose and serum lipid analyses. Serum non-esterified fatty acids, very low-density lipoproteins, low-density lipoproteins, high-density lipoproteins, total cholesterol, and triacylglycerols levels were measured. RESULTS: The Ghanaian subjects had lower body mass indexes than did the American white and black subjects (P < 0.01), although they recorded the highest carbohydrate intake. Dietary fat intake was not significantly correlated with body fat level or body mass index among the different observational groups. The serum ratio of saturated to polyunsaturated fat was higher in all diabetics than in controls and higher in Ghanaians than in Americans. Total cholesterol, triacylglycerols, and lipoproteins were within normal ranges for diabetic and non-diabetic subjects. The ratio of total cholesterol to high-density lipoprotein cholesterol was slightly elevated among the white diabetics (P < 0.05). CONCLUSIONS: The data showed a higher metabolism of carbohydrate for energy in the Ghanaian group than in the other groups. In addition, fat metabolism may differ between Americans and Ghanaians. For many variables, black Americans were more similar to white Americans than to Ghanaians. These observations imply that cultural factors may contribute more than ethnic origin to the etiology of diabetes.