High Animal Protein Intake Research Articles

Animal source food intake and association with blood cholesterol, glycerophospholipids and sphingolipids in a northern Swedish population

BackgroundThe high intake of game meat in populations with a subsistence-based diet may affect their blood lipids and health status.ObjectiveTo examine the association between diet and circulating levels of blood lipid levels in a northern Swedish population.Study designWe compared a group with traditional lifestyle (TLS) based on reindeer herding (TLS group) with those from the same area with a non-traditional lifestyle (NTLS) typical of more industrialized regions of Sweden (NTLS group). The analysis was based on self-reported intake of animal source food (i.e. non-game meat, game meat, fish, dairy products and eggs) and the serum blood level of a number of lipids [total cholesterol (TC), low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), triglycerides (TG), glycerophospholipids and sphingolipids].ResultsThe TLS group had higher cholesterol, LDL and HDL levels than the reference group. Of the TLS group, 65% had cholesterol levels above the threshold for increased risk of coronary heart disease (≥240 mg/dl), as compared to 38% of the NTLS group. Self-reported consumption of game meat was positively associated with TC and LDL.ConclusionsThe high game meat consumption of the TLS group is associated with increased cholesterol levels. High intake of animal protein and fat and low fibre is known to increase the risk of cardiovascular disease, but other studies of the TLS in northern Sweden have shown comparable incidences of cardiovascular disease to the reference (NTLS) group from the same geographical area. This indicates that factors other than TC influence disease risk. One such possible factor is dietary phospholipids, which are also found in high amounts specifically in game meat and have been shown to inhibit cholesterol absorption.

Dietary acid load and metabolic acidosis in renal transplant recipients.

Acidosis is prevalent among renal transplant recipients (RTRs) and adversely affects cardiometabolic processes. Factors contributing to acidosis are graft dysfunction and immunosuppressive drugs. Little is known about the potential influence of diet on acidosis in RTRs. This study examined the association of metabolic acid load with acidosis and with cardiovascular risk factors in RTRs and aimed to identify dietary factors associated with acidosis. DESIGN, PARTICIPANTS, SETTING, & MEASUREMENTS: 707 RTRs were included. Metabolic acid load was assessed by measuring 24-hour urinary net acid excretion (NAE; i.e., titratable acid + ammonium - bicarbonate). Acidosis was defined as serum [HCO(3)(-)] < 24 mmol/L. BP and insulin resistance, reflected by hemoglobin A1c, were among cardiovascular risk factors. Diet was assessed with food-frequency questionnaires. Linear regression analysis was applied to investigate association between NAE and acidosis and between dietary factors and acidosis. Mean age ± SD was 53 ± 13 years; 57% of patients were male. Acidosis was present in 31% of RTRs. NAE was associated with acidosis (serum HCO(3)(-): β=-0.61; serum pH: β=-0.010; both P<0.001). Patients with high intake of animal protein (i.e., from meat, cheese, and fish) and low intake of fruits and vegetables had significantly lower serum HCO(3)(-) and serum pH. No associations were observed between NAE and cardiovascular risk factors, such as hypertension and insulin resistance. In addition to conventional factors contributing to acidosis, diet might influence acid-base homeostasis in RTRs. Higher intake of fruits and vegetables and lower animal protein intake is associated with less acidosis in RTRs.

Long‐term high animal protein diet reduces body weight gain and insulin secretion in diet‐induced obese rats

The effects of a high protein diet on insulin secretion and glucose metabolism have been quite controversial. The aim of this study was to evaluate the effects of long-term isocaloric high animal protein intake on insulin secretion in diet-induced obese rats. After the experimental period (24 weeks), the high-fat diet-induced obese rats that were fed isocaloric high-protein diets (HP) had lower body weight gain (P < 0.01) and lower visceral fat (P < 0.05) than normal protein (NP) rats. Fasting plasma glucagon-like peptide-1 (GLP-1) was also reduced significantly (P < 0.05), as well as serum insulin levels at 5 min and 10 min by intravenous insulin releasing test. In addition, insulin mRNA and pancreatic duodenal homeodomain-1 (PDX-1), GLP-1 protein expression were both markedly lower in HP rats (P < 0.05), while PDX-1 mRNA in HP rats had no difference from NP rats. These results suggest that long-term isocaloric high animal protein intake reduces the acute insulin response in obese rats and the decrease of insulin is associated with both reduced weight gain and inhibition of PDX-1 expression. GLP-1 might be a negative feedback for the balance of energy metabolism secondary to changes of body weight and visceral fat.

Association between dietary protein intake and benign prostatic hyperplasia

Objective To examine the association between the intakes of dietary protein,milk and dairy products and the risk of benign prostatic hyperplasia(BPH).Methods A case-control study was conducted among 360 men who were aged 50-90 years and surgically treated for BPH between 2007 and 2009 and 360 gender and age-matched controls who were admitted to the same hospital for diseases other than prostatic conditions.The cases and controls were interviewed during their hospitalization with a standardized structured questionnaire.Data on diet were obtained via a valid semi-quantitative food frequency questionnaire(FFQ).Odds ratios(OR) and corresponding 95% confidence intervals(CI) of the variables were estimated using unconditional multiple logistic regression model.Results The proportion of the cases living in the rural area was significantly higher than that of in the controls(28.3% vs 16.7%,P0.05).After adjusting for age and energy intake,the total protein intake was inversely related to BPH(χ2=8.567,P=0.036).Men in the highest quartile of total protein intake were nearly a half less likely to report BPH(OR=0.615,95%CI=0.014-0.930).The consumptions of animal protein and milk and dairy products were inversely related with BPH(χ2=10.572,P=0.014 and OR=0.731,95%CI:0.545-0.981,respectively).The relation was attenuated among the subjects with high intake of animal protein(OR=0.638,95%CI:0.418-0.972 and OR=0.636,95%CI:0.292-0.835,respectively).Conclusion Dietary protein,especially animal protein,was inversely related to BPH.But the relation was attenuated by high intake of animal protein.

Dietary Risk Factors in Relation to Colorectal Adenoma

The role of dietary risk factors in colorectal carcinogenesis remains unclear. We investigated the association between dietary intakes and colorectal adenomas who visited a health promotion center for a routine health check-up colonoscopy. We conducted a retrospective case-control study using data from individuals who had colonoscopy at Seoul National University Hospital Healthcare System Gangnam Center from October 2003 to December 2007. The subjects were 242 patients (162 males and 80 females) with histopathologically confirmed colorectal adenoma, and 464 (272 males and 192 females) controls. Dietary data were obtained via 24 hour dietary recall, assisted by a registered dietitian. The student's t-test and the chi-square test were performed for the statistical comparison of means and proportions among groups. Multivariate analyses using logistic regression were performed to assess the relation between dietary intake and colorectal adenoma. The total average energy intake of the patients (male: 2,407.5±429.2 kcal, female: 1,901.3±316.9 kcal) was higher than the controls (male: 2,249.6±430.4 kcal, female: 1,752.4±275.0 kcal; p=0.001). High energy intake (male: OR=4.13, 95% CI=1.70-10.05, p=0.002; female: OR=4.00, 95% CI=1.51-10.61, p=0.005) and animal protein intake (male: OR=3.97, 95% CI=1.66-9.49, p=0.002; female: OR=5.76, 95% CI=1.99-16.169, p=0.001) were found to be associated with the risk of colorectal adenoma after adjusting for confounders such as age, BMI, waist circumference, metabolic syndrome and smoking. In summary, high energy intake and animal protein were associated with colorectal adenoma.

Protein intake and fracture risk in elderly people: A case-control study

We investigated whether protein intake (PI) is related to osteoporotic fractures (OP) in the elderly by analyzing vegetable protein intake (VPI), animal protein intake (API), and animal/vegetable protein intake ratio (AVR) and by calcium intake (CaI). A 1:1 matched by age and sex case-control study with 167 cases was carried out at the Hospital of Jaen (Spain). Cases were patients aged ≥65 years with a low-energy fracture. Controls were people without previous fractures. Diet was assessed by a food frequency questionnaire. Multivariable analyses were fitted using analysis of covariance (for comparison of adjusted means) and conditional logistic regression (estimating adjusted odds ratios [ORs]). The control-group showed a higher API (p=0.046) even when CaI was <800mg/day (p=0.041). ORs for AVR were 0.68 (0.38-1.19) and 0.38 (0.15-0.98), respectively with a p for trend=0.046. A PI<15% of the total energy intake showed an OR of 2.86 (1.10-7.43). Patients with fracture history have lower API suggesting that high API reduce the occurrence of OP in elderly even if CaI is <800mg/day. A PI<15% of total calories were associated with an increased risk of OP in elderly.

Urbanization of black South African women may increase risk of low bone mass due to low vitamin D status, low calcium intake, and high bone turnover

Globally, rural to urban migration is accompanied by changes in dietary patterns and lifestyle that have serious health implications, including development of low bone mass. We hypothesized that serum 25 (OH) vitamin D3 (25[OH]D3) levels will be lower, bone turnover higher, and nutrition inadequate in urban postmenopausal black women, increasing risk for low bone mass. We aimed to assess the prevalence of risk factors for low bone mass in 1261 black women from rural and urban areas in the North West Province of South Africa (Prospective Urban and Rural Epidemiology-South Africa project). Fasting blood samples were taken; and participants were interviewed to complete questionnaires on self-reported diseases, fractures, and dietary intakes. Bone health markers were assessed in a subgroup of 658 women older than 45 years. Specific lifestyle risk factors identified were inactivity, smoking, injectable progestin contraception use, and high alcohol consumption. Dietary risk factors identified were low calcium and high animal protein, phosphorous, and sodium intakes. The 25(OH)D3 and C-terminal telopeptide (CTX) levels were significantly higher in the rural vs the urban women older than 50 years. Parathyroid hormone (PTH) levels increased with age in both groups. The 25(OH)D levels were inversely correlated with CTX and PTH in rural women. In urban women, PTH and CTX were correlated while dietary calcium was inversely correlated with CTX and PTH with 25(OH)D3. The combination of low dietary calcium (<230 mg/d), marginally insufficient 25(OH)D3 status, and raised PTH may result in increased bone resorption. Further research is required to assess bone health and fracture risk in black African women.

High beverage sugar as well as high animal protein intake at infancy may increase overweight risk at 8 years: a prospective longitudinal pilot study

BackgroundCombined effects of early exposure to beverage sugar and animal protein and later life overweight risk have not been studied.MethodsA prospective longitudinal study was initiated in 2001 with 226 infants between 4 and 13 months of age. Dietary intake was assessed with a 2 day food record. Also information on infant body weight and socio-economic status was obtained at baseline. At 8 year follow-up in 2009, children were surveyed again. Main outcome measure was overweight at 8 years as defined by BMIsds > = +1.0. Also maternal BMI, present dietary intake and physical activity, were obtained by questionnaire and 2-day food record.ResultsAt the 8 year follow up, 120 children (53%) were surveyed again. Of those, questionnaires and food records were completed for 63 children, for the other 57 children only weight and height at 8 years was available; 20 out of 120 children (17%) were self-reported overweight at 8 years of age. Unadjusted odds ratios (ORs; 95% CI) for overweight at 8 years were 1.10 (1.02, 1.18) for beverage sugar intake per one percent of energy intake and 4.06 (1.50, 11.00) for the highest tertile of animal protein intake at infancy compared to the lowest two tertiles. After adjustment for sex, age, infant weight, breastfed at intake assessment, and socio-economic status, odds ratios were 1.13 (1.03, 1.24) for beverage sugar, and 9.67 (2.56, 36.53) for highest tertile of animal protein intake. In the subgroup with completed questionnaire (n = 63) ORs were also adjusted for current maternal overweight, more than 2 months full breastfeeding, physical activity, and energy intake, but ORs remained significantly associated with overweight at 8 years.ConclusionsA high intake of sugar containing beverages as well as animal protein in the first year of life may increase the risk of overweight at 8 years. The results of this pilot investigation should be confirmed in a larger cohort.

Vegetarianism, bone loss, fracture and vitamin D: a longitudinal study in Asian vegans and non-vegans

The effect of vegan diet on bone loss has not been studied. The aim of this study was to examine the association between veganism and bone loss in postmenopausal women. The study was designed as a prospective longitudinal investigation with 210 women, including 105 vegans and 105 omnivores. Femoral neck (FN) bone mineral density (BMD) was measured in 2008 and 2010 by dual-energy X-ray absorptiometry (Hologic QDR4500). The incidence of vertebral fracture was ascertained by X-ray report. Serum levels of C-terminal telopeptide of type I collagen (βCTX) and N-terminal propeptide of type I procollagen (PINP) were measured by Roche Elecsys assays. Serum concentration of 25-hydroxyvitamin D and parathyroid hormone were measured by electrochemiluminescence. Among the 210 women who initially participated in the study in 2008, 181 women had completed the study and 29 women were lost to follow-up. The rate of loss in FN BMD was -1.91±3.45%/year in omnivores and -0.86±3.81%/year (P=0.08) in vegans. Lower body weight, higher intakes of animal protein and lipid, and corticosteroid use were associated with greater rate of bone loss. The 2-year incidence of fracture was 5.7% (n=5/88) in vegans, which was not significantly different from omnivores (5.4%, n=6/93). There were no significant differences in βCTX and PINP between vegans and omnivores. The prevalence of vitamin D insufficiency in vegans was higher than in omnivores (73% versus 46%; P=0.0003). Vegan diet did not have adverse effect on bone loss and fracture. Corticosteroid use and high intakes of animal protein and animal lipid were negatively associated with bone loss.

Body-mass index and mortality among white adults.

n engl j med 364;8 nejm.org february 24, 2011 781 Gimenez-Perez raises potential long-term safety concerns about high-protein, low-carbohydrate diets as well as the source of protein (animal vs. vegetable) and asks whether this might have an effect on deaths from any cause, cardiovascular disease, and cancer, given the conclusions of a recent article on a low-carbohydrate diet with a high intake of animal protein. In our study, which did not involve low-carbohydrate diets, the total dietary protein originated both from animal and vegetable sources, partly varying according to differences in dietary habits in the involved countries. Information about the dietary strategies was reported previously.1 Thomas Meinert Larsen, Ph.D.

Body-Mass Index and Mortality among White Adults

n engl j med 364;8 nejm.org february 24, 2011 781 Gimenez-Perez raises potential long-term safety concerns about high-protein, low-carbohydrate diets as well as the source of protein (animal vs. vegetable) and asks whether this might have an effect on deaths from any cause, cardiovascular disease, and cancer, given the conclusions of a recent article on a low-carbohydrate diet with a high intake of animal protein. In our study, which did not involve low-carbohydrate diets, the total dietary protein originated both from animal and vegetable sources, partly varying according to differences in dietary habits in the involved countries. Information about the dietary strategies was reported previously.1 Thomas Meinert Larsen, Ph.D.

High animal protein intake linked to long-term weight gain

High animal protein intake linked to long-term weight gain

Dietary protein and risk of hypertension in a Dutch older population: the Rotterdam study

Several observational studies suggest an inverse association of protein with blood pressure (BP). However, little is known about the role of dietary protein from specific sources in BP. We examined the relation between several types of dietary protein (total, plant, animal, dairy, meat, grain, fish, soy, and nut) and incident hypertension in 2241 participants from the Rotterdam Study, aged at least 55 years, who were free of hypertension at baseline. Hazard ratios, with 95% confidence intervals (CIs), for incident hypertension during 6 years of follow-up were obtained per standard deviation (SD) of energy-adjusted intake of protein. Hazard ratios were adjusted for age, sex, body mass index (BMI), baseline systolic blood pressure (SBP) smoking, educational level, alcohol, intake of carbohydrates, other nutrients, and other types of protein (if applicable). We conducted stratified analyses by age (cut-off 70 years), sex, and BMI (cut-off 25 kg/m). The risk of hypertension in the total cohort (1113 cases) was not related to intake of total protein or types of protein (all hazard ratios ∼1.00 per SD). Sex and BMI did not significantly modify the associations of dietary protein with hypertension. In 559 participants aged at least 70 years, the intake of animal protein was positively related to risk of hypertension (hazard ratio 1.37 per SD, 95% CI 1.09-1.72). For participants aged below 70 years no association was found (hazard ratio 0.92, 95% CI 0.81-1.06). Total dietary protein or types of protein are not related to incident hypertension in this older population. In the more aged, however, high intake of animal protein may increase the risk of hypertension, which warrants further investigation.

Dietary protein and risk of ischemic heart disease in middle-aged men

Prospective studies in US women have suggested an inverse relation between dietary protein and risk of ischemic heart disease (IHD). However, no large-scale prospective studies have been conducted in US men. The objective was to examine the association between dietary protein and risk of IHD in a prospective study of US men. Intakes of protein and other nutrients were assessed by using a validated food-frequency questionnaire at 4 time points during follow-up of 43,960 men participating in the Health Professionals Follow-Up Study. Cox proportional hazards models were used to calculate multivariable-adjusted relative risks (RRs) and 95% CIs. During 18 y of follow-up, we documented 2959 incident cases of IHD. The RR of IHD was 1.08 (95% CI: 0.95, 1.23; P for trend = 0.30) comparing the top with the bottom quintile of percentage of energy from total protein. RRs for animal and vegetable protein were 1.11 (95% CI: 0.97, 1.28; P for trend = 0.18) and 0.93 (95% CI: 0.78, 1.12; P for trend = 0.49), respectively. When the population was restricted to "healthy" men (those free of hypertension, hypercholesterolemia, and diabetes at baseline), the RR of IHD was 1.21 (95% CI: 1.01, 1.44; P for trend = 0.02) for total protein, 1.25 (95% CI: 1.04, 1.51; P for trend = 0.02) for animal protein, and 0.93 (95% CI: 0.72, 1.19; P for trend = 0.65) for vegetable protein. We observed no association between dietary protein and risk of total IHD in this group of men aged 40-75 y. However, higher intake of animal protein may be associated with an increased risk of IHD in "healthy" men.

Evaluación metabólica y nutricional en litiasis renal

Los pacientes con litiasis renal requieren de investigaciones para identificar las condiciones médicas subyacentes y otras anomalías metabólicas predisponentes. Los resultados de estas investigaciones se utilizan para guiar el tratamiento preventivo. La profundidad del estudio necesario depende de varios factores, incluyendo la edad, la historia clínica de la persona y el número y la frecuencia de los cálculos. Una variedad de factores dietéticos y metabólicos pueden contribuir o causar la formación de litiasis renal. Los factores dietéticos incluyen una alta ingesta de proteínas animales, oxalato y sodio, y una baja ingesta de líquidos y de productos cítricos que contienen potasio. Las alteraciones metabólicas más frecuentemente asociadas a litiasis son la hipercalciuria, la hipocitraturia, la gota, la hiperoxaluria y la hiperuricosuria. Las modificaciones en la dieta deben aplicarse en todos los pacientes con litiasis renal, y consisten en una elevada ingesta de líquidos, la restricción de oxalato y sodio, una dieta balanceada en proteínas animales y complementadas por una ingesta adecuada de frutas y verduras. Cuando las modificaciones en la dieta no son suficientes en prevenir la formación de litiasis o en la presencia de alteraciones metabólicas importantes, es necesaria una intervención farmacológica especifica. People who form kidney stones require investigations to identify underlying medical conditions and to detect other predisposing metabolic abnormalities. The results of these investigations can also be used to help guide therapy to prevent future stone formation. The extent of testing required depends on several factors including age and medical history of the person and the number and frequency of stones. A variety of dietary and metabolic factors may contribute or cause stone formation in nephrolithiasis. Dietary factors include a high intake of animal proteins, oxalate and sodium, and a low intake of fluids and potassium-containing citrus products. Some of the metabolic causes of stones are hypercalciuria, hypocitraturia, gout, hyperoxaluria, and hyperuricosuria. Dietary modification, to be applied in all patients with stones includes a high fluid intake, restriction of oxalate and sodium, and balanced diet with animal proteins complemented by adequate intake of fruits and vegetables. When dietary modification is ineffective in controlling stone formation or in the presence of severe metabolic derangements, a pharmacologic intervention may be necessary.

High Intake of Animal Protein Tied to IBD Risk

High Intake of Animal Protein Tied to IBD Risk

High Intake of Animal Protein Tied to IBD Risk

High Intake of Animal Protein Tied to IBD Risk

Prepubertal Adrenarchal Androgens and Animal Protein Intake Independently and Differentially Influence Pubertal Timing

Whether adrenarche impacts on pubertal development is controversial. The objective of the study was to examine the associations of adrenal androgen (AA) secretion with early and late pubertal markers, independent of potential influences of dietary animal protein intake. This was a prospective cohort study of healthy free-living Caucasian children (n = 109) who provided both 24-h urine samples and 3-d weighed dietary records 1 and 2 yr before the biological age at take-off of the pubertal growth spurt (ATO). Twenty-four-hour excretion rates of androgen (C19) metabolites quantified by gas chromatography-mass spectrometry were measured. ATO, age at peak height velocity (APHV), age at menarche/voice break, duration of pubertal growth acceleration, and ages at Tanner stage 2 for breast (girls) and genital (boys) development (B2-G2) and pubic hair (PH2). Higher adrenarchal C19 steroids predicted earlier ages at Tanner stage 2 for pubic hair (P < 0.0001) and B2-G2 (P = 0.009) as well as a shorter pubertal growth acceleration period (P = 0.001), independently of animal protein intake. Children with a higher AA secretion had a 1.5-yr earlier beginning of pubarche and a 0.8-yr earlier beginning of B2-G2 than those with a lower AA excretion. Furthermore, animal protein intake was independently negatively associated with ATO and APHV (P < 0.05 each) and tended to be negatively associated with age at menarche/voice break (P = 0.07). A higher animal protein intake may be involved in an earlier attainment of ATO and APHV, whereas a more intensive adrenarchal process may precipitate a shorter pubertal growth spurt and a notably earlier onset of breast and genital development in girls and boys, respectively.

Biochemical and histological assessment of Alkali therapy during high animal protein intake in the rat

The Westernized diet is acidogenic due to the high content of sulfur-containing amino acids and relative deficiency of potassium organic anions. Chronic acid loads result in hypercalciuria and negative calcium balance often associated with loss of bone mineral. Alkali therapy tends to reverse the hypercalciuria but little is known regarding its effect on bone as assessed by bone histomorphometry. The present study utilized dynamic bone histomorphometry to evaluate the effects of alkali therapy on acid-induced changes in bone turnover. Serum and urine analyses and bone histomorphometry were assessed in adult rats after 2 months of either a low casein (LC) or high casein (HC) diet supplemented with either potassium chloride (KCl) or potassium citrate (KCit). Compared to animals on LC-KCl diet, HC-KCl diet delivered a substantial acid load as shown by significant increases in urinary sulfate, ammonium, and net acid excretion, and a lower urinary pH and citrate excretion without detectable changes in serum parameters. The acid load also resulted in hypercalciuria. Dynamic and static bone histomorphometry disclosed a significant reduction in cancellous bone volume and trabecular number associated with a 2.5-fold increase in eroded and a 3.5-fold increase in osteoclastic surfaces. There was also a near 2-fold increase in bone formation rate in rats on the HC-KCl diet. When animals on the HC diet were given KCit instead of KCl, all of the aforementioned changes in urine biochemistry and bone turnover were significantly attenuated or entirely prevented. These findings underscore the deleterious effects of high animal protein intake in promoting hypercalciuria and increasing bone turnover. Co-administration of potassium alkali attenuates or prevents these changes. In this animal model of high dietary animal protein intake, the major skeletal effect of alkali therapy is to reduce bone resorption, with little or no effect on bone formation.

Increased protein intake on controlled oxalate diets does not increase urinary oxalate excretion

High animal protein intake is a risk factor for calcium oxalate stone disease. The effect of dietary protein on the urinary excretion of calcium, acid and citrate is well established. However, its effect on oxalate excretion is unclear, due in part to an inadequate control of dietary oxalate intake in previous studies. This relationship warrants clarification due to the proposed important role of the metabolism of amino acids in endogenous oxalate synthesis. In this study, 11 normal subjects consumed controlled oxalate diets containing 0.6, 1.2 and 1.8 g protein/kg body weight/day. The analysis of 24 h urine collections confirmed that as protein intake increased, urinary calcium and glycolate increased and urinary pH and citrate decreased. The increased glycolate excretion was due in part to an increased hydroxyproline, but not glycolate consumption. Total daily urinary oxalate excretion did not change. When indexed to creatinine there was a small but significant decrease in oxalate excretion. This is most likely due to hyperfiltration. These results indicate that as dietary protein intake increases, the catabolism of diet-derived amino acids is not associated with an increased endogenous oxalate synthesis in normal subjects.