Ralphenia D. Pace

Total phenolics and antioxidant capacity of indigenous vegetables in the southeast United States: Alabama Collaboration for Cardiovascular Equality Project.

Collard greens, mustard greens, kale, okra, green onion, butter beans, butter peas, purple hull peas, rutabagas, and eggplant are frequently consumed by African Americans in the southeast United States. Sweet potato greens and purslane are two novel vegetables in this region. The objective of this study was to analyze total phenolics and antioxidant capacity in these indigenous vegetables. The total phenolic content was analyzed using the Folin–Ciocalteu method and ranged from 7.4 to 53.5 mg gallic acid equivalents per gram of dried sample. The antioxidant capacity was analyzed using the radical DPPH• scavenging capacity assay and oxygen radical absorbance capacity assay (ORAC). At a concentration of 10.0 mg dried vegetable equivalent/ml, the extract of these vegetables was able to quench 13.2–88.5% DPPH• radical in 30 min. The ORAC value ranged from 2.5 to 100.7 µmoles of trolox equivalents per gram of dried sample. The antioxidant capacity of the vegetable samples was highly related to their total phenolic content. The results suggest that these indigenous vegetables consumed by African Americans in the southeastern United States are good sources of the phenolic compounds, which might provide anti-oxidative protection against free radicals in the human body. Consumption of these vegetables might reduce the risk of chronic diseases.

Sweet potato leaves: properties and synergistic interactions that promote health and prevent disease

Sweet potato (Ipomoea batatas) leaves provide a dietary source of vitamins, minerals, antioxidants, dietary fiber, and essential fatty acids. Bioactive compounds contained in this vegetable play a role in health promotion by improving immune function, reducing oxidative stress and free radical damage, reducing cardiovascular disease risk, and suppressing cancer cell growth. Currently, sweet potato leaves are consumed primarily in the islands of the Pacific Ocean and in Asian and African countries; limited consumption occurs in the United States. This comprehensive review assesses research examining the nutritional characteristics and bioactive compounds within sweet potato leaves that contribute to health promotion and chronic disease prevention. Research has affirmed the potential cardioprotective and chemopreventive advantages of consuming sweet potato leaves, thus indicating that increased consumption of this vegetable should be advocated. Since reducing the prevalence of chronic diseases is of public health concern, promoting the consumption of sweet potato leaves warrants further and more intensive research investigation.

Dietary Consumption Practices and Cancer Risk in African Americans in the Rural South

This study describes the dietary consumption practices of a sample of African Americans in the rural South. A qualitative research design involving a cross-sectional food diary was utilized. Complete datasets were collected from 114 participants, 66% female, between the ages of 19 and 79 years. The consumption of a variety of fruits, non-starchy vegetables and unprocessed cereals in daily meals was low in this sample. Frequent consumption of fried foods; fast foods; sugary, carbonated beverages; processed, high-fat and high-sodium foods; and low fruit and non-starchy vegetable intake were evident. The findings are crucial to the development for culturally-specific nutrition education intervention programs for African Americans in the rural South targeted at the modification of not only diet, but food preparation methods to reduce cancer risk.

Trans fat intake lowers total cholesterol and high-density lipoprotein cholesterol levels without changing insulin sensitivity index in Wistar rats

Epidemiologic studies have demonstrated that trans fat intake increases the risk of some chronic diseases. We hypothesize that trans fat intake would increase the risk of cardiovascular disease and type 2 diabetes mellitus by changing the lipid profile in plasma, the secretion of adipokines in adipose tissue, and the insulin sensitivity. Accordingly, the major objective of present study was to investigate the effect of dietary intake of trans fat on lipid profile, insulin sensitivity, and adipokine levels in plasma. Two groups of Wistar rats were fed a diet containing 4.5% trans fat or a control diet containing no trans fat for 16 weeks. Fasting glucose level was monitored every 2 weeks. At the end of feeding experiment, blood, heart, kidney, liver, omental adipose tissue, and semitendinosus muscle were collected. The trans fat content in organs, lipid profile, adipokine, insulin, and glucose levels in plasma were analyzed. The trans fat content in adipose tissue, heart, kidney, liver, and muscle of rats fed trans fat were 169.9, 0.6, 1.2, 1.7, and 2.5 mg/g samples, respectively. The trans fat content in these organs contributed to 15.9%, 1.2%, 2.3%, 4.3%, and 6.1% of the total fat, respectively. The plasma glucose level, insulin level, and insulin sensitivity index were not significantly different between the trans fat and control groups. The results indicated that trans fat intake might not be related to insulin resistance. However, lipid profile and plasma adipokine levels were significantly changed after trans fat feeding. The trans fat fed group showed significantly lower total cholesterol and high-density lipoprotein cholesterol levels than the control group. The decreased high-density lipoprotein cholesterol level may indicate the detrimental effect of trans fat intake on lipid profile. Adiponectin and resistin levels were significantly higher in the trans fat group than the control group. Leptin levels were significantly lower in the trans fat group than the control group. The results indicated that dietary intake of trans fat can significantly change the adipokine levels, but the possible links between adipokine level change caused by trans fat intake and metabolic effects of this change need further investigations.

Use of focus groups to understand African-Americans' dietary practices: implications for modifying a food frequency questionnaire.

OBJECTIVE To generate information about dietary practices, food preferences and food preparation methods from African-Americans in Macon County, Alabama, as a precursor to an intervention designed to modify an existing dietary health questionnaire (DHQ). METHOD African-American males (30) and females (31) ages 20 to 75 years participated in eight focus groups in Macon County Alabama between June and July, 2007. RESULTS The core topics identified were dietary practices; food preferences; food preparation methods; fast food practices; and seasonal/specialty foods. The younger focus group participants reported consuming mostly fast foods such as hamburgers for lunch. Fruits, vegetables, salads, fish, chicken and sandwiches were the most common lunch foods for the older males and females. Across the groups, rice, cornbread and potatoes were reportedly the most commonly consumed starchy foods at dinner. Frying and baking were the most common cooking methods. Fewer participants reported removing the skin when cooking chicken versus those who did not remove. Traditional foods including fried green tomatoes and cracklings were selected for addition to the modified DHQ, while those not commonly consumed, were deleted. CONCLUSIONS Participants described high-fat traditional food preferences, common frying and addition of salted meats to vegetables, which informed the modification of a DHQ.

The impact of high fat diets on physiological changes in euthyroid and thyroid altered rats

The association of adverse health with high fat intake has long been recognized. However, the lack of research focusing on the interrelationship of thyroid and liver function, and the pathogenesis of a high fat diet leaves these topics poorly understood. The objective of this study was to evaluate and compare the physiological changes in euthyroid and thyroid altered animal model fed saturated and unsaturated high fat diets. To achieve this objective adult male Sprague Dawley rats (n = 100) were fed one of five diets; a control or one of four test diets containing 25% saturated or unsaturated, and 37% saturated or unsaturated fats for a period of eight weeks. Each experimental group consisted of ten euthyroid and ten thyroid altered animals. An altered thyroid state was chemically induced with the addition of 0.05% propylthiouracil (PTU) in the drinking water. Euthyroid animals fed high fat diets increased in body weights and body lengths, compared to thyroid altered animals (P < 0.05). Alanine aminotransferase (ALT) and asparte aminotransferase (AST) levels increased across all experimental groups. HbA1C values and urinary glucose values were within normal range for all animals. Liver morphology showed increased hepatic stellate (ito) and vacuole cells in thyroid altered animals. These findings suggest that altered thyroid status negatively impacts growth and weight gain, and simultaneously affected lipid metabolism, resulting in abnormal liver morphology.

Diets containing traditional and novel green leafy vegetables improve liver fatty acid profiles of spontaneously hypertensive rats

BackgroundThe consumption of green leafy vegetables (GLVs) has been demonstrated to reduce the risks associated with cardiovascular and other diseases. However, no literature exists that examines the influence of traditional and novel GLVs on the liver fatty acid profile of an animal model genetically predisposed to developing hypertension. The aim of the present study was to examine the effects of diets containing 4% collard greens, purslane or sweet potato greens on the liver fatty acid profiles of four-week old male spontaneously hypertensive rats (SHRs, N = 44). Following four weeks consumption of the diets, liver fatty acid profiles were determined by gas–liquid chromatography of transesterified fatty acid methyl esters.ResultsSHRs consuming the control diet had greater percentages of liver saturated fatty acid and less omega-3 fatty acid percentages. SHRs consuming the diets containing vegetables had significantly greater liver concentrations of γ- linolenic, docosahexaenoic and docosahexaenoic acids, as well as lower levels of lauric, palmitic and arachidonic acids. SHRs consuming the control diet had significantly greater percentages (p < 0.05) of oleic; significantly less γ-linolenic and docosahexaenoic acids.ConclusionsThis study demonstrates the ability of GLVs to modulate liver fatty acid composition, thus providing protection against elevations in atherogenic fatty acids, which may be involved in CVD pathogenesis. Consequently, dietary recommendations for the prevention of CVD should consider the possible cardioprotective benefits and the subsequent alterations in fatty acid profiles afforded by diets containing collard greens, purslane and sweet potato greens.

Nutritional assessment of transgenic sweetpotato on body weight, lipid, and protein status in hamsters.

The objectives of the present study were to evaluate the nutritional quality of genetically modified sweetpotato (genotype PI318846-3) on growth, lipid metabolism, and protein metabolism of hamsters. Three different diets made with transgenic and nontransgenic sweetpotato protein flour including a control diet with casein were fed to male Golden Syrian hamsters for 28 days. The protein efficiency ratio (1.35±0.01) of the transgenic sweetpotato protein diet was significantly higher (p<0.05) than the nontransgenic sweetpotato and control diets. Plasma albumin and plasma total protein concentrations of hamsters fed the sweetpotato diets were significantly lower (p<0.05) than that of the control. The casein diet (control) produced hypercholesterolemia in hamsters, whereas sweetpotato diets maintained lower plasma and liver total and LDL-cholesterol concentrations in hamsters. Sweetpotatoes contain less amount of protein to maintain the normal animal growth; however, transgenic sweetpotato has good quality protein that supported the growth of hamsters better than nontransgenic sweetpotato.

Bioavailability of calcium from sweetpotato and soy flour supplemented diets in hamsters

The bioavailability of calcium from two varieties of sweetpotatoes and supplementation of sweetpotatoes with soy flour was investigated in hamsters using plasma calcium concentration and femur calcium content as indicators. Five different diets were fed to five groups of animals for 28 days. There was no significant difference in plasma calcium concentrations of hamsters in all the diet groups. However, the femur calcium content of hamsters with transgenic sweetpotato flour (TSPF) and parent nontransgenic (from which transgenic was produced) sweetpotato flour (NTSPF) diets was significantly higher than that of the transgenic sweetotato flour supplemented with soy flour (TSPF+SF) and parent nontransgenic sweetpotato flour supplemented with soy flour (NTSPF+SF) diets. The relative bioavailability of calcium from the control (100%), TSPF+SF (30%), NTSPF+SF (23%), TSPF (57%) and NTSPF (46%) indicated that sweetpotatoes could be the better source of calcium, however, supplementation with soy flour might reduce the bioavailability of calcium.

Strategies for Cardiovascular Disease Prevention in Rural Southern African American Communities

Cardiovascular disease (CVD) is a commonly recognized umbrella term encompassing conditions, disease or disorders of the heart and/or blood vessels that may result in impairment of optimal cardiovascular functioning. CVD is the leading cause of morbidity and mortality in the United States, as well as in both developed and developing nations. Although the risk for CVD in the United States may vary according to and fluctuate within certain demographic, educational, behavioral and socio-economic characteristics, disparities in CVD prevention and treatment continue to ensue, particularly within minority populations. This gap in CVD disparity is further increased in regard to African American women living in rural southern communities. Demographic, socioeconomic and neighborhood characteristics are suggested to converge within rural African American communities to additively influence CVD risk.