Nutrition Research Highlights 1|2014
Keeping consumers and stakeholders up to date
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This newsletter is published by the Nutrition & Health Group of the JRC’s Institute for Health and Consumer Protection. Regularly surveying the top nutrition and medical journals, we select the most recent news on nutrition research, relevant to current societal debates or policies. These are then summarized as “News” items or presented as a “View”, comprising an analysis and expert opinion. Enjoy your reading!
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Much attention has been brought on phosphorus lately. Phosphorus is an essential mineral that is important in the metabolism of carbohydrates, fats and proteins and in bone remodelling (1). The NHANES III* study in the US followed over 9000 healthy adults aged 20-80 years from 1988-1994 (2). Results from the study showed that high dietary phosphate density (0.35mg/kcal) was associated with higher cardiovascular disease (CVD) mortality and higher all-cause mortality. High total phosphorus intake of >1400mg/day was also associated with higher all-cause mortality (2). Although it has been long established that a high level of serum phosphate is related to CVD and mortality in patients with chronic kidney disease (3), it is only recently that the adverse effects have been seen in the general population. Furthermore, the study highlights that excessive intake of phosphorus is not uncommon, as over one-third of the US population had intakes of >1400mg/day (2).
Dietary sources of phosphorus include protein-rich foods such as dairy products, meats, fish and grains. It is also ingested as part of food additives used to preserve processed meats, ready-made meals and fast-foods (1). Evidence is mounting that the dietary phosphorus intake is increasing and that more processed and pre-prepared foods are being consumed (4). Although it is too early to tell whether there is indeed a causal relationship between dietary phosphorus and mortality there is a need for further research determining the appropriate level(s) of dietary phosphorus which are safe. Moreover, because of the popularity of processed foods, there may also be a need to re-assess the use of phosphates as preservatives by the food industry and to raise the public's awareness to limit consumption of processed food products. (TNM)
* NHANES III (The Third National Health and Nutrition Examination Survey) was a survey designed to assess the health and nutritional status of the civilian, non-institutionalised United States population in the years 1988-1994 (2).
A simple weight loss rule often referred to as the 3500-kcal rule has been around for many decades. It stipulates that for every pound of body fat you wish to lose, you just create a calorie deficit of 3500 kcal*. This could be achieved by eating fewer calories, exercising more to burn more calories, or a balanced mix of the two. While reasonably accurate over a few weeks, this static rule is very much at odds with what happens over longer periods and with larger calorie deficits (1, 2). The main issue is that the body slows down its metabolism in response to a calorie deficit, and a lighter body usually requires less energy to maintain its weight. As a result, the real weight curve deviates from the straight line that would be predicted by the rule.
Recently, two teams of researchers have presented new dynamic mathematical models to more accurately predict real life body weight changes in response to varying energy intakes (1, 2). Results are specific for age, gender, body weight and, in part, levels of physical activity. The models were validated using data from various weight loss intervention studies and showed improved predictive value in comparison to the 3500-kcal rule. To facilitate their application, easy-to-use electronic tools based on these new algorithms are now freely available online**. By using these tools, public health experts could assess, for example, to what extent a clinical or policy intervention designed to reduce population energy intakes could help curb the obesity epidemic. Furthermore, individuals can get a better idea of what weight changes they can likely expect based on the number of calories consumed, which may help minimise frustration resulting from unrealistic weight loss expectations. However, one has to bear in mind that the predictions assume that people adhere fully to the energy or lifestyle regime entered into the respective tool (2). Users are also advised to check the accompanying online information and instructions to ensure that they are using the tool most suitable for their needs.
It is important to note that the models and tools have some limitations. Neither of the tools applies to children or adolescents since validated algorithms for these age groups do not exist, and Tool 1** does not account for the impact of higher levels of physical activity. Taken together, the new dynamic models and tools allow more accurate prediction of long-term body weight trajectories than the rigid 3500-kcal rule. We invite you to use the tools following the links below. (SSgB)
** Tool 1: Weight Change Predictor of the US Pennington Biomedical Research Center: http://www.pbrc.edu/sswcp (for individuals) and http://www.pbrc.edu/mswcp (for multiple subjects); Tool 2: Body Weight Simulator of the US National Institutes of Health: http://bwsimulator.niddk.nih.gov
The health benefits of adhering to the Mediterranean Diet are well established (1, 2). More importantly, there is more than just food to a Mediterranean Diet: The promotion of social interaction, respect for the Mediterranean territory and its biodiversity as well as preservation of tradition and cultural identity are other beneficial aspects of the diet as well. Indeed, the Mediterranean Diet is listed as Intangible Cultural Heritage of Humanity by UNESCO (3).
However, these same aspects of the Mediterranean Diet also limit its introduction outside of the region (4). In recognition of this and in order to address the aspects of palatability, regional identity, environmental sustainability and health, the Northern European region has also developed a gastronomically driven, regional, organic and environmentally friendly diet called the New Nordic Diet (4, 5). This diet is characterised by a high content of fruits and vegetables (especially berries, cabbages, root vegetables and legumes), fresh herbs, potatoes, wild plants, whole grains, nuts, fish and seafood, free-range livestock and game (4, 5).
Poulsen and colleagues (4) have now provided the first evidence that in Danish obese female and male volunteers, an ad libitum* New Nordic Diet produces significant weight loss after 6 months. Moreover, additional benefits towards reducing blood pressure and possibly reducing diabetes and cardiovascular risk factors when compared to an average diet were observed. According to the study authors (4), the health effects were comparable to those gained from the Mediterranean Diet as well as from another diet called Dietary Approaches to Reduce Hypertension (DASH). Despite the ad libitum design and a higher satisfaction with the New Nordic Diet over the average Danish diet, subjects following the New Nordic Diet had significantly lower caloric intakes, possibly due to the diet's lower caloric density.
Although not assessed in the study, the authors speculate that the New Nordic Diet had apparently a lasting higher satiation effect compared to the average Danish diet. Further research into health, environmental, social and economic aspects as well as the assessment of Northern European dietary practices will show whether the New Nordic Diet can really be the 'all-in-one diet', creating high satisfaction and regional/cultural identity while being also beneficial for health and the environment in the region. Maybe the UNESCO list of Intangible Cultural Heritage of Humanity will be extended by the New Nordic diet? (JW)
* ad libitum diet: This denotes that study subjects' access to food was free and unlimited, i.e., no restriction of energy or any nutrient was imposed nor were energy/nutrients forced to be constant between diets; subjects had to self-regulate their food intake and food intake was regularly assessed during the study by 3-d weighed dietary records.
Inequalities in Nutrition and Health: 'Do something, do more, do better'*
Health inequality and inequity
"Health inequalities can be defined as differences in health status or in the distribution of health determinants between different population groups. For example, differences in mobility between elderly people and younger populations or differences in mortality rates between people from different social classes. It is important to distinguish between inequality in health and inequity. Some health inequalities are attributable to biological variations or free choice and others are attributable to the external environment and conditions mainly outside the control of the individuals concerned. In the first case it may be impossible or ethically or ideologically unacceptable to change the health determinants and so the health inequalities are unavoidable. In the second, the uneven distribution may be unnecessary and avoidable as well as unjust and unfair, so that the resulting health inequalities also lead to inequity in health."
World Health Organization - Glossary of terms
Health is driven by the conditions in which people are born, grow, live and age (1). A recent report on Health Inequalities in the EU (2) describes the wide health inequalities across the EU27 for specific health outcomes and links them with particular social factors.
The 'social determinants of health' are those social factors that influence people’s health and well-being such as their level of education and educational opportunities, income and living standards, job prospects and security as well as gender, ethnicity, policy frameworks and societal values (3). The current European financial crisis may further exacerbate these health disparities. Sir Michael Marmot, the lead author of the Health Inequalities in the EU report (2), points out that persistently high unemployment rates among young people is a ticking time bomb for public health, and warns EU governments that inaction would worsen the existing social, economic and health burden.
Health and socio-economic inequalities do also exist in nutrition-related behaviours and obesity prevalence. It is suggested that 20-25% of the obesity found in men and 40-50% of the obesity found in women respectively can be attributed to low socio-economic status (SES) (4). The social gradient in the prevalence of obesity is consistent across all EU countries; the association between SES and obesity is stronger in Southern Europe and in women, children and under-educated people (5, 6).
Another study that examined obesity in relation to educational inequalities (that can be seen as an indicator of SES) (7) showed that there is an inverse relationship between level of education and overweight and obesity in Europe**.
Eating behaviours as well as dietary intakes are also related to SES. Although obesity is more prevalent in lower SES groups, this does not necessarily mean that more calories are consumed. Looking closer to the quality of diet is also important: a UK survey among low SES individuals showed that their mean daily caloric intake of total and saturated fat was higher than the dietary recommendation in most age groups (8). Consumption of fibre, fruits and vegetables tends to be higher for people from higher socio-economic groups (5, 9) and data suggest that the lower the income, the higher the proportion of household spending on processed meat and processed fish products (10). Presence of socio-economic disparities is undoubtedly even more important in childhood, the years of life that set the foundation for a healthy adulthood. Obesity and overweight among children is associated with the SES of their parents, especially their mothers (2).
Two large pan-European studies suggest that higher levels of parental education are associated with children's low intakes of sugar-rich and fatty foods (i.e. whole milk, pizza, processed meats, meat-based dishes, fat spreads and sugar-sweetened soft drinks) compared to children from the general population (11, 12). SES and level of education was also found to be positively related to children's nutrition knowledge and physical activity and inversely related to sedentary behaviour in both children and adults (13, 14, 15).
Levelling off the differences in health between and within EU countries is one of the main European public health challenges. These disparities are not just natural differences between populations but rather unfair circumstances that result in ill health. Understanding health inequalities is imperative for people involved in tackling obesity and health-related issues. The European Commission Communication Solidarity in Health: Reducing Health Inequalities in the EU (16) urges all governments to address the social determinants of health such as housing, environment, education and employment, in order to achieve equitable distribution of health. As elegantly put in a recent WHO report (3) the message for all countries seems to be: 'Do something, do more, do better'*! (AL)
* A key message that emerged from the WHO report "Review of social determinants and the health divide in the WHO European Region" (3).
** Percentage of the population that is obese (Body Mass Index (BMI) ≥ 30 kg/m2) by level of education and sex, in selected countries of the European Region. Reproduced from the WHO report "Review of social determinants and the health divide in the WHO European Region". Executive summary. Copenhagen, WHO Regional Office for Europe, 2013, p. 26 (3); with permission from WHO.
January – February 2014
Nutrition Research Highlights is a bi-monthly publication prepared by the Nutrition Team of the DG-Joint Research Centre, Institute for Health and Consumer Protection. Sandra Caldeira, Anastasia Livaniou, Tsz Ning Mak, Theodora Mouratidou, Stefan Storcksdieck genannt Bonsmann and Jan Wollgast contributed to this issue.
The views expressed here do not necessarily reflect the opinion of the European Commission.