Carbohydrates: Separating fact from fiction

Dietary protein intake in midlife in relation to healthy aging - results from the prospective Nurses' Health Study cohort

BACKGROUND

Protein intake plays an important role in maintaining the health status of older adults. However, few epidemiologic studies examined midlife protein intake in relation to healthy aging.

OBJECTIVES

The objective of this study was to evaluate the long-term role of dietary protein intake in healthy aging among female participants in the prospective Nurses' Health Study (NHS) cohort.

METHODS

We included 48,762 NHS participants aged <60 y in 1984. Total protein, animal protein, dairy protein (a subset of animal protein), and plant protein were derived from validated food frequency questionnaires. Healthy aging was defined as being free from 11 major chronic diseases, having good mental health, and not having impairments in either cognitive or physical function, as assessed in the 2014 or 2016 NHS participant questionnaires. We used multivariate logistic regression adjusted for lifestyle, demographics, and health status to estimate the odds ratios (ORs) and 95% confidence intervals for protein intake in relation to healthy aging.

RESULTS

A total of 3721 (7.6%) NHS participants met our healthy aging definition. Protein intake was significantly associated with higher odds of healthy aging. The ORs (95% confidence intervals) per 3%-energy increment with healthy aging were 1.05 (1.01, 1.10) for total protein, 1.07 (1.02, 1.11) for animal protein, 1.14 (1.06, 1.23) for dairy protein, and 1.38 (1.24, 1.54) for plant protein. Plant protein was also associated with higher odds of absence of physical function limitations and good mental status. In substitution analyses, we observed significant positive associations for the isocaloric replacement of animal or dairy protein, carbohydrate, or fat with plant protein (ORs for healthy aging: 1.22-1.58 for 3% energy replacement with plant protein).

CONCLUSIONS

Dietary protein intake, especially plant protein, in midlife, is associated with higher odds of healthy aging and with several domains of positive health status in a large cohort of female nurses.

Plasma fatty acid composition and some markers of dietary habits are associated with cardiovascular disease risk determined by an atherogenic plasma index in postmenopausal women

It is hypothesized that plasma proportion of selected fatty acids (FAs) and dietary habits are linked with the risk of cardiovascular disease (CVD) in postmenopausal women. Therefore, this study was designed to determine the association of plasma FA composition and markers of dietary habits with an atherogenic index of plasma (AIP), a predictor of CVD risk in postmenopausal women. In total, 87 postmenopausal women with an average age of 57 ± 7 years were recruited and their dietary intake, anthropometric and biochemical parameters, and FA status in total plasma lipid proportions were determined, showing that 65.5% of the participants had a high risk of CVD according to their AIP value. After adjusting for some confounders (age, body mass index, and physical activity level), the risk of CVD was only positively associated with the frequency of consumption of animal fat spreads (butter and lard) of terrestrial origin. Regarding the FA profile, CVD risk was positively associated with the percentages of vaccenic acid, dihomo-γ-linolenic acid, and monounsaturated fatty acids (MUFA; mainly n-7) in total FA, as well as the MUFA/SFA ratio in total plasma and stearoyl-CoA desaturase-16 activity (16:1/16:0 ratio). In contrast, the risk of CVD was negatively associated with percentages of α-linolenic acid, total polyunsaturated fatty acids (PUFA), and PUFA/MUFA ratio in total plasma lipid, and the estimated activity of Δ5-desaturase (20:4/20:3 n-6 ratio). These results support the current recommendations to decrease the frequency of animal fat spread intake because it is associated with a reduced CVD risk based on AIP in postmenopausal women. In accordance with these plasma percentages of ALA, vaccenic acid, dihomo-γ-linolenic acid, PUFA, PUFA/MUFA ratio, and 16:1/16:0 ratio may be important parameters in CVD risk assessment.

Prosopis juliflora: nutritional value, bioactive activity, and potential application in human nutrition

Prosopis juliflora is a xerophytic, nitrogen-fixing plant distributed in arid and semi-arid regions. The fruits of this plant are pods, which have seeds inside, and both pods and seeds have high nutritional value and bioactive potential. Different derivatives can be obtained from the pods and seeds: flour, starch, syrup, protein concentrate, and gums. This review aims to gather information from the literature on P. juliflora. It focuses on the nutritional value, bioactive activity, and technological application of pods, seeds, and their derivatives, highlighting their use in human nutrition and new research perspectives. The pod of P. juliflora can be used in several ways, as it has high levels of nutrients. It is used as a food supplement; it has antimicrobial effects and phytochemicals associated with other bioactive activity. Among the pod derivatives, flour is the most studied and can be widely used in bakery products. The seed of P. juliflora also has high nutritional potential and bioactive activity. Among its other derivatives, the gum stands out and can be used for various purposes in the food industry. To expand the use of pods, seeds, and their derivatives in human nutrition, further studies are needed on chemical composition, bioactive activity, toxicity, and nutritional, bioactive, technological, and sensory effects of their application in food products. © 2023 Society of Chemical Industry.

Nutritional strategies to attenuate postprandial glycemic response

Maintaining good glycemic control to prevent complications is crucial in people with type 2 diabetes and in people with prediabetes and in the general population. Different strategies to improve glycemic control involve the prescription of blood glucose-lowering drugs and the modulation of physical activity and diet. Interestingly, lifestyle intervention may be more effective in lowering hyperglycemia than pharmaceutical intervention. Regulation of postprandial glycemia is complex, but specific nutritional strategies can be applied to attenuate postprandial hyperglycemia. These strategies include reducing total carbohydrate intake, consuming carbohydrates with a lower glycemic index, the addition of or substitution by sweeteners and fibers, using food compounds which delay or inhibit gastric emptying or carbohydrate digestion, and using food compounds which inhibit intestinal glucose absorption. Nevertheless, it must be noted that every individual may respond differently to certain nutritional interventions. Therefore, a personalized approach is of importance to choose the optimal nutritional strategy to improve postprandial glycemia for each individual, but this requires a better understanding of the mechanisms explaining the differential responses between individuals.

Metabolism of triglyceride-rich lipoproteins in health and dyslipidaemia

Accumulating evidence points to the causal role of triglyceride-rich lipoproteins and their cholesterol-enriched remnants in atherogenesis. Genetic studies in particular have not only revealed a relationship between plasma triglyceride levels and the risk of atherosclerotic cardiovascular disease, but have also identified key proteins responsible for the regulation of triglyceride transport. Kinetic studies in humans using stable isotope tracers have been especially useful in delineating the function of these proteins and revealing the hitherto unappreciated complexity of triglyceride-rich lipoprotein metabolism. Given that triglyceride is an essential energy source for mammals, triglyceride transport is regulated by numerous mechanisms that balance availability with the energy demands of the body. Ongoing investigations are focused on determining the consequences of dysregulation as a result of either dietary imprudence or genetic variation that increases the risk of atherosclerosis and pancreatitis. The identification of molecular control mechanisms involved in triglyceride metabolism has laid the groundwork for a 'precision-medicine' approach to therapy. Novel pharmacological agents under development have specific molecular targets within a regulatory framework, and their deployment heralds a new era in lipid-lowering-mediated prevention of disease. In this Review, we outline what is known about the dysregulation of triglyceride transport in human hypertriglyceridaemia.