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The British Journal of Nutrition Oct 2022Although a decrease in carbohydrate intake and an increase in fat intake among Koreans have been reported, investigations of changes in protein intake have been limited....
Although a decrease in carbohydrate intake and an increase in fat intake among Koreans have been reported, investigations of changes in protein intake have been limited. Thus, this study aimed to explore trends in the dietary intake of total, plant and animal proteins overall and by socio-demographic subgroups in Korea over the past two decades. A total of 78 716 Korean adults aged ≥ 19 years who participated in the seven survey cycles of the Korea National Health and Nutrition Examination Survey 1998-2018 were included. Dietary protein intake, overall and by source, was calculated using a single 24-h dietary recall data. Changes in dietary protein over 20 years were estimated using multiple linear regression analysis after adjusting for potential covariates. For total protein intake, a significant decrease was reported from 1998 to 2016-2018 ( for trend < 0·001), whereas an increasing trend was observed from 2007-2009 to 2016-2018 ( for trend < 0·001). In terms of protein intake by source, plant protein intake decreased while animal protein intake increased over the past two decades, indicating steeper trends during the recent decade ( for trend < 0·001). These trends were more pronounced among younger adults and those with higher household income and education levels. These findings suggest that continuous monitoring of dietary protein intake overall and by source (plant . animal) across socio-demographic group is needed.
Topics: Dietary Proteins; Nutrition Surveys; Diet; Surveys and Questionnaires; Republic of Korea
PubMed: 34763739
DOI: 10.1017/S0007114521004438 -
The American Journal of Clinical... Jan 2022Diet is one of the modifiable risk factors for cognitive decline. However, studies on dietary protein intake and cognitive decline have remained limited and inconclusive.
BACKGROUND
Diet is one of the modifiable risk factors for cognitive decline. However, studies on dietary protein intake and cognitive decline have remained limited and inconclusive.
OBJECTIVES
In this study, we aimed to investigate the associations between long-term dietary protein intake and subsequent subjective cognitive decline (SCD).
METHODS
We included 49,493 women from the Nurses' Health Study (NHS) (1984-2006) and 27,842 men from the Health Professionals Follow-up Study (HPFS) (1986-2002). For the NHS, average dietary intake was calculated from 7 repeated semi-quantitative FFQs (SFFQs), and SCD was assessed in 2012 and 2014. For the HPFS, average dietary intake was calculated from 5 repeated SFFQs, and SCD was assessed in 2008 and 2012. Poisson regression was used to examine the associations between dietary protein, amino acids, and various protein food sources with subsequent SCD.
RESULTS
Higher protein intake compared with total carbohydrates was associated with lower odds of SCD. When substituting 5% energy from protein for the equivalent percentage of energy from total carbohydrates, the pooled multivariable-adjusted ORs (95% CIs) were 0.89 (0.85, 0.94) for total protein, 0.89 (0.84, 0.94) for animal protein, and 0.74 (0.62, 0.88) for plant protein. When substituting 5% of energy from animal protein with plant protein, the OR was 0.84 (95% CI: 0.72, 0.97). For protein food sources, higher intakes of beans/legumes, fish, and lean poultry were significantly associated with lower odds of SCD, but higher intake of hotdogs was associated with higher odds of SCD.
CONCLUSIONS
Higher protein intake was associated with lower odds of SCD when compared isocalorically with carbohydrate. Plant protein sources were also associated with lower odds when compared with animal protein sources. Our findings suggest that adequate protein intake, and choices of protein sources could play a role in the maintenance of cognition and should be studied further.
Topics: Adult; Aged; Cognitive Dysfunction; Diet; Diet Surveys; Dietary Proteins; Eating; Female; Follow-Up Studies; Humans; Male; Middle Aged; Odds Ratio; Risk Factors; United States
PubMed: 34293099
DOI: 10.1093/ajcn/nqab236 -
Current Opinion in Nephrology and... Jan 2022Diet plays an important role in slowing progression of chronic kidney disease in native and transplanted kidneys. There is limited evidence on the association on dietary... (Review)
Review
PURPOSE OF REVIEW
Diet plays an important role in slowing progression of chronic kidney disease in native and transplanted kidneys. There is limited evidence on the association on dietary intake with renal allograft function. Mechanisms of major nutrients and dietary patterns with focusing on a plant-based diet related to kidney transplant health and longevity are reviewed.
RECENT FINDINGS
High dietary protein intake may adversely affect renal allograft. Low protein plant-focused diets such as Dietary Approaches to Stop Hypertension, plant-dominant low-protein diet and Mediterranean diets appear associated with favorable outcomes in slowing renal allograft function decline. The mechanism may be related to a change in renal hemodynamic by decreasing glomerular hyperfiltration from low dietary protein intake and plant-based ingredients. Recent observational studies of association between dietary protein intake and kidney allograft outcomes are conflicting. Although strong evidence is still lacking, a low protein diet of 0.6-0.8 g/kg/day with at least 50% of the protein source from plant-based components in kidney transplant recipients with stable kidney allograft function should be considered as the dietary target.
SUMMARY
Dietary intervention with low-protein plant-focused meals may improve outcomes in kidney transplant recipients, but the evidence remains limited and further studies are warranted.
Topics: Allografts; Dietary Proteins; Humans; Kidney; Kidney Transplantation; Renal Insufficiency, Chronic
PubMed: 34750333
DOI: 10.1097/MNH.0000000000000757 -
Nutrients Feb 2022For design of healthy and sustainable diets and food systems, it is important to consider not only the quantity but also the quality of nutrients. This is particularly... (Review)
Review
For design of healthy and sustainable diets and food systems, it is important to consider not only the quantity but also the quality of nutrients. This is particularly important for proteins, given the large variability in amino acid composition and digestibility between dietary proteins. This article reviews measurements and metrics in relation to protein quality, but also their application. Protein quality methods based on concentrations and digestibility of individual amino acids are preferred, because they do not only allow ranking of proteins, but also assessment of complementarity of protein sources, although this should be considered only at a meal level and not a diet level. Measurements based on ileal digestibility are preferred over those on faecal digestibility to overcome the risk of overestimation of protein quality. Integration of protein quality on a dietary level should also be done based on measurements on an individual amino acid basis. Effects of processing, which is applied to all foods, should be considered as it can also affect protein quality through effects on digestibility and amino acid modification. Overall, protein quality data are crucial for integration into healthy and sustainable diets, but care is needed in data selection, interpretation and integration.
Topics: Amino Acids; Benchmarking; Dietary Proteins; Digestion; Ileum
PubMed: 35267922
DOI: 10.3390/nu14050947 -
Physiology & Behavior Oct 2022Low-protein diets can impact food intake and appetite, but it is not known if motivation for food is changed. In the present study, we used an operant behavioral task -...
Low-protein diets can impact food intake and appetite, but it is not known if motivation for food is changed. In the present study, we used an operant behavioral task - the progressive ratio test - to assess whether motivation for different foods was affected when rats were maintained on a protein-restricted diet (REST, 5% protein diet) compared to non-restricted control rats (CON, 18% protein). Rats were tested either with nutritionally-balanced pellets (18.7% protein, Experiment 1) or protein-rich pellets (35% protein, Experiment 2) as reinforcers. Protein restriction increased breakpoint for protein-rich pellets, relative to CON rats, whereas no difference in breakpoint for nutritionally-balanced pellets was observed between groups. When given free access to either nutritionally-balanced pellets or protein-rich pellets, REST and CON rats did not differ in their intake. We also tested whether a previous history of protein restriction might affect present motivation for different types of food by assessing breakpoint of previously REST animals that were subsequently put on standard maintenance chow (protein-repleted rats, REPL, Experiment 2). REPL rats did not show increased breakpoint, relative to their initial encounter with protein-rich pellets while they were protein-restricted. This study demonstrates that restriction of dietary protein induces a selective increased motivation for protein-rich food, a behavior that disappears once rats are not in need of protein.
Topics: Animals; Appetite; Conditioning, Operant; Diet, Protein-Restricted; Dietary Proteins; Food Preferences; Motivation; Rats
PubMed: 35700813
DOI: 10.1016/j.physbeh.2022.113877 -
Experimental Biology and Medicine... Sep 2019Sedentary lifestyle and aging favor the increasing prevalence of obesity and type 2 diabetes and their comorbidities. The loss of lean body mass reduces muscle strength,... (Review)
Review
UNLABELLED
Sedentary lifestyle and aging favor the increasing prevalence of obesity and type 2 diabetes and their comorbidities. The loss of lean body mass reduces muscle strength, resulting in impaired functional capacity and leading to increased risks of chronic diseases with advancing age. Besides aging, conditions such as inappetence, social isolation, and inadequate dietary intake cause the loss of lean body mass and increased abdominal fatty mass, resulting in sarcopenic obesity and predisposition to type 2 diabetes. Compared to younger people, this condition is more common in the elderly owing to natural changes in body composition associated with aging. Lifestyle changes such as increased physical activity and improved dietary behaviors are effective for preventing the occurrence of comorbidities. Regarding muscle nutrition, besides caloric adequacy, meeting the requirements for the consumption of dietary amino acids and proteins is important for treating sarcopenia and sarcopenic obesity because muscle tissue mainly consists of proteins and is, therefore, the largest reservoir of amino acids in the body. Thus, this review discusses the effects of dietary protein on the preservation of lean body mass, improvements in the functional capacity of muscle tissue, and prevention of chronic diseases such as type 2 diabetes. In addition, we address the effects of regular physical training associated with dietary protein strategies on lean body mass, body fat loss, and muscle strength in the elderly at a risk for type 2 diabetes development.
IMPACT STATEMENT
Diabetes mellitus is a worldwide health problem associated with obesity and sedentary lifestyle, which predisposes affected individuals to mortality and morbidity. Additionally, aging and unhealthy lifestyle behaviors increase inflammation and insulin resistance, contributing to the reduction of cytokines related to muscle nutrition and the suppression of lipogenesis, resulting in the development of sarcopenic obesity. One strategy for the prevention of T2D is the avoidance of secondary aging by participating in healthy action programs, including exercise and nutritional interventions. This minireview of several studies demonstrates the impact of physical activity and nutritional interventions on gaining or preserving muscle mass and on the functional aspects of muscles with aging. It provides information on the effect of protein, leucine, β-hydroxy-β-methylbutyrate (HMB), and creatine supplementation on muscle mass, strength, and volume gain and on the prevention of the progressive decrease in muscle mass with aging in combination with maintaining regular physical activity.
Topics: Aging; Body Weight; Diabetes Mellitus, Type 2; Dietary Proteins; Exercise; Humans; Obesity; Sarcopenia
PubMed: 31307203
DOI: 10.1177/1535370219861910 -
Food & Function Nov 2021Dietary protein has been linked with all-cause and cancer mortality. However, the relationship between dietary protein and the prognosis of hepatocellular carcinoma...
Dietary protein has been linked with all-cause and cancer mortality. However, the relationship between dietary protein and the prognosis of hepatocellular carcinoma (HCC) is still unknown. The purpose of this study was to investigate whether dietary protein intake was related to HCC mortality using data from the Guangdong Liver Cancer Cohort (GLCC), a prospective cohort study of HCC survivors established at the Sun Yat-sen University Cancer Center. Dietary information one year before the diagnosis of HCC was obtained through a 79-item semi-quantitative food frequency questionnaire (FFQ). A total of 883 patients with newly diagnosed HCC who were recruited between September 2013 and April 2017 were included in this study. The hazard ratio (HR) and 95% confidence intervals (95% CIs) were estimated by Cox proportional hazard models. The multivariate-adjusted HRs in the highest the lowest tertile of total protein intake were 0.68 (95% CI: 0.52-0.91, -trend = 0.007) for all-cause mortality and 0.74 (95% CI: 0.55-0.99, -trend = 0.040) for HCC-specific mortality. However, the associations of animal protein intake, plant protein intake, and animal-to-plant protein ratio with all-cause and HCC-specific mortality were not significant (all -trend >0.05). Our research suggests that higher prediagnostic dietary intake of total protein was associated with reduced all-cause and HCC-specific mortality.
Topics: Adult; Carcinoma, Hepatocellular; Diet; Dietary Proteins; Female; Humans; Liver Neoplasms; Male; Middle Aged; Prognosis; Prospective Studies
PubMed: 34709274
DOI: 10.1039/d1fo02013g -
Advances in Experimental Medicine and... 2020Dietary protein digestion is an efficient process resulting in the absorption of amino acids by epithelial cells, mainly in the jejunum. Some amino acids are extensively... (Review)
Review
Dietary protein digestion is an efficient process resulting in the absorption of amino acids by epithelial cells, mainly in the jejunum. Some amino acids are extensively metabolized in enterocytes supporting their high energy demand and/or production of bioactive metabolites such as glutathione or nitric oxide. In contrast, other amino acids are mainly used as building blocks for the intense protein synthesis associated with the rapid epithelium renewal and mucin production. Several amino acids have been shown to support the intestinal barrier function and the intestinal endocrine function. In addition, amino acids are metabolized by the gut microbiota that use them for their own protein synthesis and in catabolic pathways releasing in the intestinal lumen numerous metabolites such as ammonia, hydrogen sulfide, branched-chain amino acids, polyamines, phenolic and indolic compounds. Some of them (e.g. hydrogen sulfide) disrupts epithelial energy metabolism and may participate in mucosal inflammation when present in excess, while others (e.g. indole derivatives) prevent gut barrier dysfunction or regulate enteroendocrine functions. Lastly, some recent data suggest that dietary amino acids might regulate the composition of the gut microbiota, but the relevance for the intestinal health remains to be determined. In summary, amino acid utilization by epithelial cells or by intestinal bacteria appears to play a pivotal regulator role for intestinal homeostasis. Thus, adequate dietary supply of amino acids represents a key determinant of gut health and functions.
Topics: Amino Acids; Dietary Proteins; Gastrointestinal Microbiome; Health; Humans; Intestines
PubMed: 32761567
DOI: 10.1007/978-3-030-45328-2_1 -
The FEBS Journal Mar 2023Dietary choices have a profound impact on the aging process. In addition to the total amount of energy intake, macronutrient composition influences both health and...
Dietary choices have a profound impact on the aging process. In addition to the total amount of energy intake, macronutrient composition influences both health and lifespan. However, the exact mechanisms by which dietary macronutrients influence onset and progression of age-associated features remain poorly understood. Cellular senescence is a state of stable growth arrest characterized by the secretion of numerous bioactive molecules with pro-inflammatory properties. Accumulation of senescent cells is considered one of the basic mechanisms of aging and an important contributor to chronic inflammation and tissue degeneration. Whether dietary macronutrients affect the accumulation and the phenotype of senescent cells with age is still unknown. Here, we show that feeding on diets with varying ratios of dietary macronutrients for 3 months has a significant effect on different senescence-associated markers in the mouse liver. High protein intake is associated with higher expression levels of the two classical senescence-associated growth arrest genes, p21 and p16. Furthermore, the expression of many pro-inflammatory secretory markers was increased in diets enriched in protein and further enhanced by increases in fat content. These results provide preliminary evidence that dietary macronutrients have a significant influence on senescence markers and merit further investigation.
Topics: Animals; Mice; Aging; Cellular Senescence; Phenotype; Dietary Proteins; Liver
PubMed: 34908245
DOI: 10.1111/febs.16292 -
Endocrinology Mar 2020The ability to respond to variations in nutritional status depends on regulatory systems that monitor nutrient intake and adaptively alter metabolism and feeding... (Review)
Review
The ability to respond to variations in nutritional status depends on regulatory systems that monitor nutrient intake and adaptively alter metabolism and feeding behavior during nutrient restriction. There is ample evidence that the restriction of water, sodium, or energy intake triggers adaptive responses that conserve existing nutrient stores and promote the ingestion of the missing nutrient, and that these homeostatic responses are mediated, at least in part, by nutritionally regulated hormones acting within the brain. This review highlights recent research that suggests that the metabolic hormone fibroblast growth factor 21 (FGF21) acts on the brain to homeostatically alter macronutrient preference. Circulating FGF21 levels are robustly increased by diets that are high in carbohydrate but low in protein, and exogenous FGF21 treatment reduces the consumption of sweet foods and alcohol while alternatively increasing the consumption of protein. In addition, while control mice adaptively shift macronutrient preference and increase protein intake in response to dietary protein restriction, mice that lack either FGF21 or FGF21 signaling in the brain fail to exhibit this homeostatic response. FGF21 therefore mediates a unique physiological niche, coordinating adaptive shifts in macronutrient preference that serve to maintain protein intake in the face of dietary protein restriction.
Topics: Animals; Brain; Dietary Carbohydrates; Dietary Proteins; Feeding Behavior; Fibroblast Growth Factors; Homeostasis; Nutrients
PubMed: 32047920
DOI: 10.1210/endocr/bqaa019