Antonis Vlassopoulos

Changing distributions of body size and adiposity with age.

Background:Adiposity and health risks are better indicated by waist circumference than body mass index (BMI). Patterns of change with age are incompletely documented.Methods:Adults aged 18–92 years in the Scottish and English Health Surveys of 1994–96 and 2008–10 were divided into fifteen 5-year age bands. Sex-specific prevalences of overweight/obesity and of increased/high waist circumference against age were compared using analysis of covariance.Results:Data available for 7932 Scottish and 55 925 English subjects in 1994–96, and for 27 391 Scottish and 30 929 English in 2008–10, showed generally similar patterns of change in the two countries. Prevalences of both elevated BMI and waist circumference rose with age for longer in 2008–10 than in 1994–96, reaching higher peaks at greater ages, particularly among men. Between 1994–96 and 2008–10, maximum prevalences of BMI>30 increased from 25 to 38% (larger increases in men than women), reaching a peak at age 60–70 years in both sexes. This peak prevalence was 5–10 years later than in 1994–96 for men and remained unchanged for women. Between 1994–96 and 2008–10, maximum prevalences of high waist circumference (men>102 cm, women>88 cm) increased from 30 to –70% in both sexes, peaking in 2008–10 at ages 80–85 years (men) and 65–70 years (women). In 2008–10, proportions of adults with ‘normal’ BMI (18.5–25) fell with age to 15–20% at age 60–70 years (men) and 75 years (women). Among all those with BMI=18.5–25, aged>65 years, the proportions with unhealthily elevated waist circumference were 30 (men>94 cm) and 55% (women>80 cm).Conclusions:Almost 40% of men and women are now becoming obese. People are growing fatter later in life, with waist circumference rising more persistently than BMI, which may indicate increased loss of muscle mass and sarcopenia in old age. Among older people, few now have ‘normal’ BMI, and of these up to half have elevated waist circumference, raising questions for the suitability of BMI as a measure of adiposity in this age group.

Role of oxidative stress in physiological albumin glycation: a neglected interaction.

Protein glycation is a key mechanism involved in chronic disease development in both diabetic and nondiabetic individuals. About 12-18% of circulating proteins are glycated in vivo in normoglycemic blood, but in vitro studies have hitherto failed to demonstrate glucose-driven glycation below a concentration of 30mM. Bovine serum albumin (BSA), reduced BSA (mercaptalbumin) (both 40g/L), and human plasma were incubated with glucose concentrations of 0-30mM for 4 weeks at 37°C. All were tested preoxidized for 8h before glycation with 10nM H2O2 or continuously exposed to 10nM H2O2 throughout the incubation period. Fructosamine was measured (nitroblue tetrazolium method) at 2 and 4 weeks. Oxidized BSA (both preoxidized and continuously exposed to H2O2) was more readily glycated than native BSA at all glucose concentrations (p = 0.03). Moreover, only oxidized BSA was glycated at physiological glucose concentration (5mM) compared to glucose-free control (glycation increased by 35% compared to native albumin, p < 0.05). Both 5 and 10mM glucose led to higher glycation when mercaptalbumin was oxidized than when unoxidized (p < 0.05). Fructosamine concentration in human plasma was also significantly higher when oxidized and exposed to 5mM glucose, compared to unoxidized plasma (p = 0.03). The interaction between glucose concentration and oxidation was significant in all protein models (p < 0.05). This study has for the first time demonstrated albumin glycation in vitro, using physiological concentrations of albumin, glucose, and hydrogen peroxide, identifying low-grade oxidative stress as a key element early in the glycation process.

Modeled Dietary Impact of Pizza Reformulations in US Children and Adolescents.

Background and Objective Approximately 20% of US children and adolescents consume pizza on any given day; and pizza intake is associated with higher intakes of energy, sodium, and saturated fat. The reformulation of pizza products has yet to be evaluated as a viable option to improve diets of the US youth. This study modeled the effect on nutrient intakes of two potential pizza reformulation strategies based on the standards established by the Nestlé Nutritional Profiling System (NNPS). Methods Dietary intakes were retrieved from the first 24hr-recall of the National Health and Nutrition Examination Survey (NHANES) 2011–12, for 2655 participants aged 4–19 years. The composition of pizzas in the NHANES food database (n = 69) were compared against the NNPS standards for energy, total fat, saturated fat, sodium, added sugars, and protein. In a reformulation scenario, the nutrient content of pizzas was adjusted to the NNPS standards if these were not met. In a substitution scenario, pizzas that did not meet the standards were replaced by the closest pizza, based on nutrient content, that met all of the NNPS standards. Results Pizzas consistent with all the NNPS standards (29% of all pizzas) were significantly lower in energy, saturated fat and sodium than pizzas that were not. Among pizza consumers, modeled intakes in the reformulation and substitution scenarios were lower in energy (-14 and -45kcal, respectively), saturated fat (-1.2 and -2.7g), and sodium (-143 and -153mg) compared to baseline. Conclusions Potential industry wide reformulation of a single food category or intra-category food substitutions may positively impact dietary intakes of US children and adolescents. Further promotion and support of these complimentary strategies may facilitate the adoption and implementation of reformulation standards.

Nutrient profiling for product reformulation: public health impact and benefits for the consumer

The food industry holds great potential for driving consumers to adopt healthy food choices as (re)formulation of foods can improve the nutritional quality of these foods. Reformulation has been identified as a cost-effective intervention in addressing non-communicable diseases as it does not require significant alterations of consumer behaviour and dietary habits. Nutrient profiling (NP), the science of categorizing foods based on their nutrient composition, has emerged as an essential tool and is implemented through many different profiling systems to guide reformulation and other nutrition policies. NP systems should be adapted to their specific purposes as it is not possible to design one system that can equally address all policies and purposes, e.g. reformulation and labelling. The present paper discusses some of the key principles and specificities that underlie a NP system designed for reformulation with the example of the Nestlé nutritional profiling system. Furthermore, the impact of reformulation at the level of the food product, dietary intakes and public health are reviewed. Several studies showed that food and beverage reformulation, guided by a NP system, may be effective in improving population nutritional intakes and thereby its health status. In order to achieve its maximum potential and modify the food environment in a beneficial manner, reformulation should be implemented by the entire food sector. Multi-stakeholder partnerships including governments, food industry, retailers and consumer associations that will state concrete time-bound objectives accompanied by an independent monitoring system are the potential solution.

Testing the capacity of a Multi-Nutrient profiling system to guide food and beverage reformulation : Results from five national food composition databases

Nutrient profiling ranks foods based on their nutrient composition, with applications in multiple aspects of food policy. We tested the capacity of a category-specific model developed for product reformulation to improve the average nutrient content of foods, using five national food composition datasets (UK, US, China, Brazil, France). Products (n = 7183) were split into 35 categories based on the Nestlé Nutritional Profiling Systems (NNPS) and were then classified as NNPS ‘Pass’ if all nutrient targets were met (energy (E), total fat (TF), saturated fat (SFA), sodium (Na), added sugars (AS), protein, calcium). In a modelling scenario, all NNPS Fail products were ‘reformulated’ to meet NNPS standards. Overall, a third (36%) of all products achieved the NNPS standard/pass (inter-country and inter-category range: 32%–40%; 5%–72%, respectively), with most products requiring reformulation in two or more nutrients. The most common nutrients to require reformulation were SFA (22%–44%) and TF (23%–42%). Modelled compliance with NNPS standards could reduce the average content of SFA, Na and AS (10%, 8% and 6%, respectively) at the food supply level. Despite the good potential to stimulate reformulation across the five countries, the study highlights the need for better data quality and granularity of food composition databases.

Industry Approach to Nutrition-Based Product Development and Reformulation in Asia

In the recent years there has been a proliferation of initiatives to classify food products according to their nutritional composition (e.g., high in fat/sugar) to better guide consumer choices and regulate the food environment. This global trend, lately introduced in Asia as well, utilizes nutrient profiling (NP) to set compositional criteria for food products. Even though the use of NP to set targets for product reformulation has been proposed for years, to date only two NP systems have been specifically developed for that purpose. The majority of the NP applications, especially in Asia, focus on marketing and/or health claim regulation, as well as front-of-pack labeling. Product reformulation has been identified, by the World Health Organization and other official bodies, as a key tool for the food industry to help address public health nutrition priorities and provide support towards the reduction of excessive dietary sugar, salt and fats. In the United Kingdom, the Responsibility Deal is an excellent example of a public-private collaborative initiative that successfully reduced the salt content of products available in the supermarkets by 20-30%, resulting in an estimated 10% reduction in salt intake at the population level. Validation of NP systems targeted towards reformulation supports the hypothesis that, by adopting them, the industry can actively support existing policies in the direction of lowering consumptions in public health-sensitive nutrients. The symposium presented a discussion on the current NP landscape in Asia, the importance of reformulation for public health and the Nestlé approach to improve the food environment in Asia through NP.

Inhibition of protein glycation by phenolic acids: physiological relevance and implication of protein-phenolic interactions

Protein glycation is central to tissue damage occurring as part of the pathogenic process of several non-communicable diseases. There is a limited body of work on the antiglycative function of (poly)phenols, relying on supra-physiological concentrations and use of non-bioavailable compounds. To inform the design of a physiologically relevant in-vitro study, a systematic literature review of dietary interventions quantifying plasma phenolic acids was carried out, to inform selection of physiologically relevant concentrations. Bovine Serum Albumin (BSA), either native (no treatment), pre-oxidised (incubated with 10nM H2O2, 22 for 8 hours) or incubated with a phenolic acid mixture, for 8 hours) was glycated. Glycation was carried out with i) glucose only (0, 5, or 10 mM), ii) glucose (0, 5, or 10 mM) plus H2O2 (10 nM), or iii) glucose (0, 5, or 10 mM) plus phenolic acids (10–160 nM). Fructosamine was measured using the nitroblue tetrazolium method. Following (high) dietary polyphenol intake, 3-hydroxyphenylacetic acid is the most abundant phenolic acid in peripheral blood (up to 338 μM) with concentrations for other phenolic acids ranging from 13 nM–200 μM. Presence of six phenolic acids with BSA during in-vitro glycation did not lower fructosamine formation. However, when BSA was pre-incubated with phenolic acids, significantly lower concentration of fructosamine was detected under glycoxidative conditions (glucose 5 or 10 mM plus H2O2 10 nM) (p< 0·001 vs. native BSA). Protein pre-treatment, either with oxidants or phenolic acids, is an important regulator of subsequent glycation in a physiologically relevant system. High quality in-vitro studies under conditions closer to physiology are feasible and should be employed by default.

Serum levels of advanced glycation end-products (AGEs) and the decoy soluble receptor for AGEs (sRAGE) can discriminate non-alcoholic fatty liver disease in age-, sex- and BMI-matched normo-glycemic adults

BACKGROUND Non-alcoholic fatty liver disease (NAFLD) is a serious health problem affecting ~25% of the global population. While NAFLD pathogenesis is still unclear, multiple NAFLD parameters, including reduced insulin sensitivity, impaired glucose metabolism and increased oxidative stress are hypothesised to foster the formation of advanced glycation end-products (AGEs). Given the link of AGEs with end organ damage, there is scope to examine the role of the AGE/RAGE axis activation in liver injury and NAFLD. METHODS Age, sex and body mass index matched normo-glycemic NAFLD adults (n = 58) and healthy controls (n = 58) were enrolled in the study. AGEs were analysed by liquid chromatography-mass spectrometry (CML, CEL), fluorescence (pentosidine, AGE fluorescence), colorimetry (fructosamine) and ELISA (sRAGE). Their association with liver function, inflammation, fibrosis and stage of NAFLD was examined. RESULTS Early and advanced glycation end-products, except Nε-carboxymethyl-L-lysine (CML), were 10-30% higher, sRAGE levels 1.7-fold lower, and glycation/sRAGE ratios 4-fold higher in the NAFLD cases compared to controls. While AGEs presented weak to moderate correlations with indices of liver function and damage (AST/ALT, HOMA-IR, TNF-α and TGF-β1), including sRAGE to characterize the AGEs/sRAGE axis strengthened the associations observed. High glycation/sRAGE ratios were associated with 1.3 to 14-fold likelihood of lower AST/ALT ratios. The sum of AGEs/sRAGE ratios accurately distinguished between healthy controls and NAFLD patients (area under the curve of 0.85). Elevated AGEs/sRAGE (>7.8 mmol/pmol) was associated with a 12-fold likelihood of the presence of NAFLD. CONCLUSION These findings strengthen the involvement of AGEs-RAGE axis in liver injury and the pathogenesis of NAFLD.

Erratum: Unraveling the effect of adiposity on health: the epidemiology paradoxes

Obesity (2016) 24:1212. doi:10.1002/oby.21530 In the paper listed above, the first sentence of the second paragraph has been amended from: ‘In 2013, Flegal et al. generated major academic and media excitement from a cross-sectional analysis of BMI status by concluding that “overweight” (i.e., BMI 25–30 kg/m) might be protective against all-cause mortality, making a case for an “obesity paradox” [2].’ to: ‘In 2013, Flegal et al. generated major academic and media excitement with an analysis of longitudinal data of BMI status by concluding that “overweight” (i.e., BMI 25–30 kg/m) might be protective against all-cause mortality, which was seen as making a case for an “obesity paradox” [2].’

Unraveling the effect of adiposity on health: The epidemiology paradoxes.

In this issue of Obesity, Hulsegge et al. (1) produce evidence from Dutch data that a rising body mass index (BMI) during a 15-year follow-up is strongly linked to increases in oxidative stress and inflammation markers compared with a stable BMI. Although that is true within the same generation, that is, people born in the same year, greater BMI across generations at the same age was not associated with greater oxidative stress or inflammation.