Instruct: Given a question, retrieve relevant passages that answer the question.
Query: A/V ratio
Diet may represent a modifiable prostate cancer (CaP) risk factor, but a vegetable-based prostate-healthy diet is a major change for most men. We used a ratio of animal:vegetable proteins (A:V ratio) to evaluate whether a comprehensive dietary change was self-sustaining following completion of 11 weekly dietary and cooking classes that integrated mindfulness training (MT). Thirty-six men with recurring CaP were randomized to the intervention or wait-list control. Assessments were at baseline, three months and six months. Of the 17 men randomized to the intervention, 14 completed the requirements. Nineteen were randomized to control and 17 completed requirements. Compared to controls, a significant post-intervention (3 months) decrease in A:V ratio in the intervention group (p=.01) was self-maintained 3 months post-intervention (p=0.049). At each assessment, the A:V ratio was correlated with lycopene, fiber, saturated fat, and dietary cholesterol; four dietary components linked to clinically relevant outcomes in CaP. Change in A:V ratio was also significantly correlated with changes in fiber, saturated fat and dietary cholesterol intake. Participants reported regular MT practice and there was a significant correlation between MT practice and changes in both initiation and maintenance of the change in the A:V ratio. These pilot results provide encouraging evidence for the feasibility of a dietary program that includes MT in supporting dietary change for men with recurrent CaP and invite further study to explore the possible role of MT as a means of supporting both initiation of dietary changes and maintenance of those changes over time.
Apple cider vinegar products are advertised in the popular press and over the Internet for treatment of a variety of conditions. After an adverse event was reported to the authors, eight apple cider vinegar tablet products were tested for pH, component acid content, and microbial growth. Considerable variability was found between the brands in tablet size, pH, component acid content, and label claims. Doubt remains as to whether apple cider vinegar was in fact an ingredient in the evaluated products. The inconsistency and inaccuracy in labeling, recommended dosages, and unsubstantiated health claims make it easy to question the quality of the products.
Measuring food prices per gram, rather than per calorie, is one way to make healthful vegetables appear less expensive. However, a better measure of affordability would take the nutrient content of vegetables into account. This study, based on analyses of US Department of Agriculture datasets, aimed to identify which vegetables, including juices and soups, provided the most nutrients per unit cost. Nutrient density was measured using the Nutrient Rich Foods (NRF) index, based on nine nutrients to encourage: protein; fiber; vitamins A, C, and E; calcium; iron; magnesium; and potassium; and on three nutrients to limit: saturated fat, added sugar, and sodium. Food cost in dollars was calculated per 100 g, per 100 kcal, per serving, and per nutrient content. One-way analyses of variance with post hoc tests were used to determine statistical significance. Results showed that tomato juices and tomato soups, dark green leafy and nonleafy vegetables, and deep yellow vegetables, including sweet potatoes, had the highest NRF scores overall. Highest NRF scores per dollar were obtained for sweet potatoes, white potatoes, tomato juices and tomato soups, carrots, and broccoli. Tomato sauces, raw tomatoes, and potato chips were eaten more frequently than were many other vegetables that were both more affordable and more nutrient-rich. These new measures of affordable nutrition can help foodservice and health professionals identify those vegetables that provide the highest nutrient density per unit cost. Processed vegetables, including soups and juices, can contribute to the quality and the affordability of the diet. Copyright © 2013 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.
The thermal stability of virulent hepatitis E virus (HEV) and hepatitis A virus (HAV) was compared. Fecal suspensions of virus were heated to temperatures between 45 degrees C and 70 degrees C, and residual infectivity was determined in a cell culture system that was permissive for both viruses. Although HEV was less stable than was HAV, some HEV would most likely survive the internal temperatures of rare-cooked meat.
BACKGROUND: Several epidemiologic studies found no effect of egg consumption on the risk of coronary heart disease. It is possible that the adverse effect of eggs on LDL-cholesterol is offset by their favorable effect on HDL cholesterol. OBJECTIVE: The objective was to review the effect of dietary cholesterol on the ratio of total to HDL cholesterol. DESIGN: Studies were identified by MEDLINE and Biological s searches (from 1974 to June 1999) and by reviewing reference lists. In addition, we included data from a more recently published study. Studies were included if they had a crossover or parallel design with a control group, if the experimental diets differed only in the amount of dietary cholesterol or number of eggs and were fed for > or =14 d, and if HDL-cholesterol concentrations were reported. Of the 222 studies identified, 17 studies involving 556 subjects met these criteria. RESULTS: The addition of 100 mg dietary cholesterol/d increased the ratio of total to HDL cholesterol by 0.020 units (95% CI: 0.010, 0.030), total cholesterol concentrations by 0.056 mmol/L (2.2 mg/dL) (95% CI: 0.046, 0.065 mmol/L; 1.8, 2.5 mg/dL), and HDL-cholesterol concentrations by 0.008 mmol/L (0.3 mg/dL) (95% CI: 0.005, 0.010 mmol/L; 0.2, 0.4 mg/dL). CONCLUSIONS: Dietary cholesterol raises the ratio of total to HDL cholesterol and, therefore, adversely affects the cholesterol profile. The advice to limit cholesterol intake by reducing consumption of eggs and other cholesterol-rich foods may therefore still be valid.
We assessed the relation of risk factors for cardiovascular disease to early atherosclerotic lesions in the aorta and coronary arteries in 35 persons (mean age at death, 18 years). Aortic involvement with fatty streaks was greater in blacks than in whites (37 vs. 17 percent, P less than 0.01). However, aortic fatty streaks were strongly related to antemortem levels of both total and low-density lipoprotein cholesterol (r = 0.67, P less than 0.0001 for each association), independently of race, sex, and age, and were inversely correlated with the ratio of high-density lipoprotein cholesterol to low-density plus very-low-density lipoprotein cholesterol (r = -0.35, P = 0.06). Coronary-artery fatty streaks were correlated with very-low-density lipoprotein cholesterol (r = 0.41, P = 0.04). Mean systolic blood-pressure levels also tended to be higher in the four subjects with coronary-artery fibrous plaques than in those without them: 112 mm Hg as compared with 104 (P = 0.09). These results document the importance of risk-factor levels to early anatomical changes in the aorta and coronary arteries. The progression of fatty streaks to fibrous plaques is uncertain, but these data suggest that a rational approach to the prevention of cardiovascular disease should begin early in life.
Our understanding of coronary artery disease risk and the atherosclerotic process has changed greatly in recent years. For example, it is now known that angiographically apparent coronary artery plaque is not the major cause of myocardial infarction (MI). Rather, it is unstable, soft plaque that cannot be seen angiographically that is prone to rupture and result in infarction. Also important are changes in vascular reactivity resulting from diet. Cholesterol levels by themselves reveal little about a patient's coronary artery disease risk. Most infarctions occur in patients who have normal total cholesterol levels. At-risk patients can be identified using the ratio of total-to-high-density lipoprotein (HDL) cholesterol levels. The ratio of triglyceride to HDL cholesterol levels is also important. Simple steps to assess patients' risk in practice are outlined. Primary prevention trials demonstrate that coronary artery disease risk can be lowered dramatically with diet and drug therapy.
The art of the musical anus is reviewed in the light of its most prominent performers and of anorectal physiological aspects related to this specific musical performance.
This systematic review collated seventy-eight studies exploring waist-to-height ratio (WHtR) and waist circumference (WC) or BMI as predictors of diabetes and CVD, published in English between 1950 and 2008. Twenty-two prospective analyses showed that WHtR and WC were significant predictors of these cardiometabolic outcomes more often than BMI, with similar OR, sometimes being significant predictors after adjustment for BMI. Observations from cross-sectional analyses, forty-four in adults, thirteen in children, supported these predictions. Receiver operator characteristic (ROC) analysis revealed mean area under ROC (AUROC) values of 0·704, 0·693 and 0·671 for WHtR, WC and BMI, respectively. Mean boundary values for WHtR, covering all cardiometabolic outcomes, from studies in fourteen different countries and including Caucasian, Asian and Central American subjects, were 0·50 for men and 0·50 for women. WHtR and WC are therefore similar predictors of diabetes and CVD, both being stronger than, and independent of, BMI. To make firmer statistical comparison, a meta-analysis is required. The AUROC analyses indicate that WHtR may be a more useful global clinical screening tool than WC, with a weighted mean boundary value of 0·5, supporting the simple public health message 'keep your waist circumference to less than half your height'.
The effectiveness of high-temperature, short holding time (HTST) pasteurization and homogenization with respect to inactivation of Mycobacterium avium subsp. paratuberculosis was evaluated quantitatively. This allowed a detailed determination of inactivation kinetics. High concentrations of feces from cows with clinical symptoms of Johne's disease were used to contaminate raw milk in order to realistically mimic possible incidents most closely. Final M. avium subsp. paratuberculosis concentrations varying from 102 to 3.5 × 105 cells per ml raw milk were used. Heat treatments including industrial HTST were simulated on a pilot scale with 22 different time-temperature combinations, including 60 to 90°C at holding (mean residence) times of 6 to 15 s. Following 72°C and a holding time of 6 s, 70°C for 10 and 15 s, or under more stringent conditions, no viable M. avium subsp. paratuberculosis cells were recovered, resulting in >4.2- to >7.1-fold reductions, depending on the original inoculum concentrations. Inactivation kinetic modeling of 69 quantitative data points yielded an Ea of 305,635 J/mol and an lnk0 of 107.2, corresponding to a D value of 1.2 s at 72°C and a Z value of 7.7°C. Homogenization did not significantly affect the inactivation. The conclusion can be drawn that HTST pasteurization conditions equal to 15 s at ≥72°C result in a more-than-sevenfold reduction of M. avium subsp. paratuberculosis.
BACKGROUND: Abdominal aortic aneurysm (AAA) disease is an insidious condition with an 85% chance of death after rupture. Ultrasound screening can reduce mortality, but its use is advocated only for a limited subset of the population at risk. METHODS: We used data from a retrospective cohort of 3.1 million patients who completed a medical and lifestyle questionnaire and were evaluated by ultrasound imaging for the presence of AAA by Life Line Screening in 2003 to 2008. Risk factors associated with AAA were identified using multivariable logistic regression analysis. RESULTS: We observed a positive association with increasing years of smoking and cigarettes smoked and a negative association with smoking cessation. Excess weight was associated with increased risk, whereas exercise and consumption of nuts, vegetables, and fruits were associated with reduced risk. Blacks, Hispanics, and Asians had lower risk of AAA than whites and Native Americans. Well-known risk factors were reaffirmed, including male gender, age, family history, and cardiovascular disease. A predictive scoring system was created that identifies aneurysms more efficiently than current criteria and includes women, nonsmokers, and individuals aged <65 years. Using this model on national statistics of risk factors prevalence, we estimated 1.1 million AAAs in the United States, of which 569,000 are among women, nonsmokers, and individuals aged <65 years. CONCLUSIONS: Smoking cessation and a healthy lifestyle are associated with lower risk of AAA. We estimated that about half of the patients with AAA disease are not eligible for screening under current guidelines. We have created a high-yield screening algorithm that expands the target population for screening by including at-risk individuals not identified with existing screening criteria.
OBJECTIVE: In 1976, the Royal College of Physicians and the British Cardiac Society recommended eating less fatty red meat and more poultry instead because it was lean. However, the situation has changed since that time, with a striking increase in fat content of the standard broiler chicken. The aim of the present study was to report a snapshot of data on fat in chickens now sold to the public. DESIGN: Samples were obtained randomly between 2004 and 2008 from UK supermarkets, farm shops and a football club. The amount of chicken fat was estimated by emulsification and chloroform/methanol extraction. SETTING: Food sold in supermarkets and farms in England. SUBJECTS: Chicken samples. RESULTS: The fat energy exceeded that of protein. There has been a loss of n-3 fatty acids. The n-6:n-3 ratio was found to be as high as 9:1, as opposed to the recommendation of about 2:1. Moreover, the TAG level in the meat and whole bird mostly exceeded the proportion of phospholipids, which should be the higher for muscle function. The n-3 fatty acid docosapentaenoic acid (DPA, 22 : 5n-3) was in excess of DHA (22 : 6n-3). Previous analyses had, as usual for birds, more DHA than DPA. CONCLUSIONS: Traditional poultry and eggs were one of the few land-based sources of long-chain n-3 fatty acids, especially DHA, which is synthesized from its parent precursor in the green food chain. In view of the obesity epidemic, chickens that provide several times the fat energy compared with protein seem illogical. This type of chicken husbandry needs to be reviewed with regard to its implications for animal welfare and human nutrition.
AV119 is a patented blend of two sugars from avocado that can induce human beta-defensin-2 production by normal human keratinocytes. In this study, we analysed the effect of AV119 on growth and invasiveness of Malassezia furfur, a dimorphic, lipid-dependent yeast that is part of the normal human cutaneous commensal flora. The ability to modulate the expression of the proinflammatory and immunomodulatory cytokines in normal human keratinocytes was also investigated. Microbiological assay demonstrated that this sugar induced the aggregation of yeast cells and inhibited the invasiveness of M. furfur, without affecting its growth. Real-time PCR analysis demonstrated that AV119 was able to modulate the HBD-2 response in treated keratinocytes, reaching a maximum after 48-h treatment, and to induce the recovery of a satisfactory proinflammatory response in human keratinocytes. As AV119 can induce aggregation of yeast cells, thus inhibiting their penetration into the keratinocytes, the sugar could be used in the preparation of cosmetics or pharmacological drugs to inhibit colonization of the skin by pathogenic strains of M. furfur.
Phytochemicals are recognized as playing an important role in cancer prevention by fruits and vegetables. The avocado is a widely grown and consumed fruit that is high in nutrients and low in calories, sodium, and fats. Studies have shown that phytochemicals extracted from the avocado fruit selectively induce cell cycle arrest, inhibit growth, and induce apoptosis in precancerous and cancer cell lines. Our recent studies indicate that phytochemicals extracted with chloroform from avocado fruits target multiple signaling pathways and increase intracellular reactive oxygen leading to apoptosis. This review summarizes the reported phytochemicals in avocado fruit and discusses their molecular mechanisms and targets. These studies suggest that individual and combinations of phytochemicals from the avocado fruit may offer an advantageous dietary strategy in cancer prevention.
Purpose To explore the association between consumption of fruits and vegetables and the presence of glaucoma in older African American women. Design Cross-sectional study. Methods Disc photographs and suprathreshold visual fields were obtained from the 662 African American participants in the Study of Osteoporotic Fractures. Masked, trained readers graded all discs, and two glaucoma specialists reviewed photos and visual fields. The Block Food Frequency Questionnaire assessed food consumption. Relationships between selected fruit/vegetable/nutrient consumption and glaucoma were evaluated using logistic regression models after adjusting for potential confounders. Results After excluding women missing Food Frequency Questionnaire and disc data, 584 African American women (88.2% of total African American cohort) were included. Glaucoma was diagnosed in at least one eye in 77 subjects (13%). Women who ate 3 or more servings/day of fruits/fruit juices were 79% (odds ratio [OR]=0.21; 95% confidence interval [CI]: 0.08–0.60) less likely to have glaucoma than women who ate less than one serving/day. Women who consumed more than 2 servings/week of fresh oranges (OR=0.18; 95%CI: 0.06–0.51) and peaches (OR=0.30; 95%CI: 0.13–0.67) had a decreased odds of glaucoma compared to those consuming less than one serving/week. For vegetables, >1 serving/week compared to ≤1 serving/month of collard-greens/kale decreased the odds of glaucoma by 57% (OR=0.43; 95%CI: 0.21–0.85). There was a protective trend against glaucoma in those consuming more fruit/fruit juices (p=0.023), fresh oranges (p=0.002), fresh peaches (p=0.002), and collard greens/kale (p=0.014). Higher consumption of carrots (p=0.061) and spinach (p=0.094) also showed some associations. Individual nutrient intake from food sources found protective trends with higher intakes of vitamin A (p=0.011), vitamin C (p=0.018), and α-carotene (p=0.021), and close to statistically significant trends with β-carotene (p=0.052), folate (p=0.056), and lutein/zeaxanthin (p=0.077). Conclusion Higher intake of certain fruits and vegetables high in Vitamins A and C and carotenoids may be associated with a decreased likelihood of glaucoma in older African American women. Randomized controlled trials are needed to determine whether the intake of specific nutrients changes the risk of glaucoma.
OBJECTIVE: To evaluate the efficacy of preparations with avocado-soybean unsaponifiables (ASUs) in osteoarthritis (OA) patients using meta-analysis on randomized controlled trials (RCTs). METHOD: RCTs from systematic searches were included if they explicitly stated that hip and/or knee OA patients were randomized to either ASU or placebo. The co-primary outcome was reduction in pain and Lequesne index, leading to effect size (ES), calculated as the standardized mean difference. As secondary analysis, the number of responders to therapy was analyzed as odds ratios (ORs). Restricted maximum likelihood methods were applied for the meta-analyses, using mixed effects models. RESULTS: Four trials--all supported by the manufacturer--were included, with 664 OA patients with either hip (41.4%) or knee (58.6%) OA allocated to either 300 mg ASU (336) or placebo (328). Average trial duration was 6 months (range: 3-12 months). Though based on heterogeneous results, the combined pain reduction favored ASU (I(2) = 83.5%, ES = 0.39 [95% confidence intervals: 0.01-0.76], P=0.04). Applying the Lequesne index also favored ASU (I(2) = 61.0%, ES = 0.45 [0.21-0.70], P = 0.0003). Secondarily, the number of responders following ASU compared to placebo (OR = 2.19, P = 0.007) corresponded to a number needed to treat of six (4-21) patients. CONCLUSIONS: Based on the available evidence, patients may be recommended to give ASU a chance for e.g., 3 months. Meta-analysis data support better chances of success in patients with knee OA than in those with hip OA.
Vitamin A deficiency (VAD) has been recognized as a public-health issue in developing countries. Economic constraints, sociocultural limitations, insufficient dietary intake, and poor absorption leading to depleted vitamin A stores in the body have been regarded as potential determinants of the prevalence of VAD in South Asian developing countries. VAD is exacerbated by lack of education, poor sanitation, absence of new legislation and enforcement of existing food laws, and week monitoring and surveillance system. Several recent estimates confirmed higher morbidly and mortality rate among children and pregnant and non-pregnant women of childbearing age. Xerophthalmia is the leading cause of preventable childhood blindness with its earliest manifestations as night blindness and Bitot's spots, followed by blinding keratomalacia, all of which are the ocular manifestations of VAD. Children need additional vitamin A because they do not consume enough in their normal diet. There are three general ways for improving vitamin A status: supplementation, fortification, and dietary diversification. These approaches have not solved the problem in South Asian countries to the desired extent because of poor governmental support and supervision of vitamin A supplementation twice a year. An extensive review of the extant literature was carried out, and the data under various sections were identified by using a computerized bibliographic search via PubMed, Web of Science, and Google Scholar. All abstracts and full-text articles were examined, and the most relevant articles were selected for screening and inclusion in this review. Conclusively, high prevalence of VAD in South Asian developing countries leads to increased morbidity and mortality among infants, children, and pregnant women. Therefore, stern efforts are needed to address this issue of public-health significance at local and international level in lower- and middle-income countries of South Asia.
Avian leukosis/sarcoma viruses (ALSV) infect and cause cancers in chickens. Poultry workers are exposed to ALSV and other infectious agents in the workplace. This study examines if industrial hygiene assessment of antibody levels in poultry workers can identify risky job tasks at the higher exposure risk to an infectious agent, i.e., ALSV. We compared ALSV antibody levels in poultry workers and control subjects. Occupational and demographical factors were examined for an association with the exposure risk in poultry workers. We found that the antibody levels were significantly higher in poultry workers than in control subjects. Job category and age together were significantly associated with the antibody levels in workers. Certain job tasks were identified with significantly higher antibody levels as compared to others, implying that recommendations should be made to protect workers at these jobs. The findings of this study indicate that the measurement of antibody levels in workers can be useful for industrial hygiene assessment of exposure to infectious agents.
Measurements of cerebral spinal fluid pressure, arterial pressure, and internal carotid artery blood flow were obtained in a series of patients during a Valsalva maneuver. During straining (phase II), an 11% reduction in mean arterial pressure was associated with a 21% decrease in internal carotid flow from control values; and following release (phase IV), the 19% increase in mean arterial pressure produced a 22% increase in internal carotid artery flow. Perfusion pressure computed as the mean arterial pressure minus cerebral spinal fluid pressure and internal carotid artery blood flow were used to calculate an index of cerebral vascular resistance. The data indicate that a modest but significant decrease in vascular resistance occurred during phases II and III followed by return to control levels during phase IV. These changes in vascular resistance were not rapid enough or of sufficient magnitude to maintain constant cerebral perfusion during the Valsalva maneuver.
Cytomegalovirus (CMV) retinitis is the most common cause of vision loss in patients with acquired immunodeficiency syndrome (AIDS). CMV retinitis afflicted 25% to 42% of AIDS patients in the pre-highly active antiretroviral therapy (HAART) era, with most vision loss due to macula-involving retinitis or retinal detachment. The introduction of HAART significantly decreased the incidence and severity of CMV retinitis. Optimal treatment of CMV retinitis requires a thorough evaluation of the patient’s immune status and an accurate classification of the retinal lesions. When retinitis is diagnosed, HAART therapy should be started or improved, and anti-CMV therapy with oral valganciclovir, intravenous ganciclovir, foscarnet, or cidofovir should be administered. Selected patients, especially those with zone 1 retinitis, may receive intravitreal drug injections or surgical implantation of a sustained-release ganciclovir reservoir. Effective anti-CMV therapy coupled with HAART significantly decreases the incidence of vision loss and improves patient survival. Immune recovery uveitis and retinal detachments are important causes of moderate to severe loss of vision. Compared with the early years of the AIDS epidemic, the treatment emphasis in the post- HAART era has changed from short-term control of retinitis to long-term preservation of vision. Developing countries face shortages of health care professionals and inadequate supplies of anti-CMV and anti-HIV medications. Intravitreal ganciclovir injections may be the most cost effective strategy to treat CMV retinitis in these areas.
The incidence of colorectal cancer (CRC) is dramatically higher in African Americans (AAs) than in Native Africans (NAs) (60:100,000 vs. <1:100,000) and slightly higher than in Caucasian Americans (CAs). To explore whether the difference could be explained by interactions between diet and colonic bacterial flora, we compared randomly selected samples of healthy 50- to 65-y-old AAs (n = 17) with NAs (n = 18) and CAs (n = 17). Diet was measured by 3-d recall, and colonic metabolism by breath hydrogen and methane responses to oral lactulose. Fecal samples were cultured for 7-alpha dehydroxylating bacteria and Lactobacillus plantarum. Colonoscopic mucosal biopsies were taken to measure proliferation rates. In comparison with NAs, AAs consumed more (P < 0.01) protein (94 +/- 9.3 vs. 58 +/- 4.1 g/d) and fat (114 +/- 11.2 vs. 38 +/- 3.0 g/d), meat, saturated fat, and cholesterol. However, they also consumed more (P < 0.05) calcium, vitamin A, and vitamin C, and fiber intake was the same. Breath hydrogen was higher (P < 0.0001) and methane lower in AAs, and fecal colony counts of 7-alpha dehydroxylating bacteria were higher and of Lactobacilli were lower. Colonic crypt cell proliferation rates were dramatically higher in AAs (21.8 +/- 1.1% vs. 3.2 +/- 0.8% labeling, P < 0.0001). In conclusion, the higher CRC risk and mucosal proliferation rates in AAs than in NAs were associated with higher dietary intakes of animal products and higher colonic populations of potentially toxic hydrogen and secondary bile-salt-producing bacteria. This supports our hypothesis that CRC risk is determined by interactions between the external (dietary) and internal (bacterial) environments.
Even when adults meet physical activity guidelines, sitting for prolonged periods can compromise metabolic health. TV time and objective-measurement studies show deleterious associations, and breaking up sedentary time is beneficial. Sitting time, TV time, and time sitting in automobiles increase premature mortality risk. Further evidence from prospective studies, intervention trials, and population-based behavioral studies is required.
An evidence-based systematic review of acai (Euterpe oleracea) by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.
The serum concentration of high-density lipoprotein cholesterol and the proportion it constitutes of total serum cholesterol are high in children and low in sufferers from coronary heart disease (CHD). Studies in elderly black Africans in Western Transvaal showed them to be free of CHD. HDL concentrations measured at birth and in groups of 10- to 12-year-olds, 16- to 18-year olds, and 60- to 69-year-olds showed mean values of 0.96, 1.71, 1.58, and 1.94 mmol/l (36, 66, 61, and 65 mg/100 ml) respectively; these concentrations constitued about 56%, 54%, and 45%, and 47%, of total cholesterol. Values thus did not fall from youth to age as they did in whites. Rural South African blacks live on a diet high in fibre and low in animal protein and fat; children are active; and adults remain active even when old. These high values of HDL may well be representative for a population that is active, used to a frugal traditional diet, and free from CHD.
PURPOSE OF REVIEW: This review discusses recent evidence that suggests a significant underestimation of protein requirements in adult humans. RECENT FINDINGS: Traditionally, total protein requirements for humans have been determined using nitrogen balance. The recent Dietary Reference Intake recommendations for mean and population-safe intakes of 0.66 and 0.8 g/kg/day, respectively, of high-quality protein in adult humans are based on a meta-analysis of nitrogen balance studies using single linear regression analysis. We reanalyzed existing nitrogen balance studies using two-phase linear regression analysis and obtained mean and safe protein requirements of 0.91 and 0.99 g/kg/day, respectively. The two-phase linear regression analysis is considered more appropriate for biological analysis of dose-response curves. Considering the inherent problems associated with the nitrogen balance method, we developed an alternative method, the indicator amino acid oxidation technique, to determine protein requirements The mean and population-safe requirements in adult men were determined to be 0.93 and 1.2 g/kg/day and are 41 and 50%, respectively, higher than the current Dietary Reference Intakes recommendations. SUMMARY: The indicator amino acid oxidation-based requirement values of 0.93 and 1.2 g protein/kg/day and the reanalysis of existing nitrogen balance studies are significantly higher than current recommendations. Therefore, there is an urgent need to reassess recommendations for protein intake in adult humans.