Nutrition Research Highlights 1|2012
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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!
We recently held a workshop at the JRC in Ispra with several nutrition experts where we discussed European nutrition research including obesity and its prevention (1). Several of the experts proposed that there should be a focus on research in reducing portion sizes as a way of preventing the energy surplus associated with obesity development (2). In fact, there is evidence that people will eat more when they are served more (3,4). Not only, people also adapt their own food intake to that of their eating companions (5). The measures we discussed at the workshop ranged from actions like reducing the size of plates at the table to campaigns alerting consumers to the size (and caloric content!) of their meals and its consequences. The New York City Department of Health and Mental Hygiene has just done that with the launch of a campaign where portion size is on the spotlight: Cut your portions, cut your risk. The saying goes that 'an image is worth a thousand words' so we can end here by leaving you with one of their powerful images for your own reflection! (SC)
Photo: New York City public campagn against large portion sizes
To fully appreciate our favourite food delicacy, we rely on an intricate cascade of molecular and chemical processes that go from taste receptors (mostly in the tongue) to the brain and then elicit a behavioural response. It is commonly accepted that the sense of taste derives from the perception of 5 different stimuli, sweet, salt, sour, bitter and umami*. The sense of taste is not only a reward for the intake of beneficial nutrients. Umami and sweet do taste “good” and invite us to consume more of nutritious, energy-containing foods but sour and bitter do the opposite cautioning the organism against toxins or acids. Whether fat is also a 'taste' and has a specific taste receptor has been a point of discussion in the field and a recent article by Pepino and colleagues (1), addresses this point in an interesting manner. In the study, 21 people were asked to taste the content of three cups. In one of the cups the researchers included small amounts of a fatty oil while the other cups had fat-free liquids with the same texture. Participants had "to choose the cup that was different" and the researchers ensured their choice was not based on smell or visual cues by using nose clips and testing under red light. Importantly, the people tested carried different versions of a gene called CD36. That particular genetic variation influences the amount of CD36 protein that is produced by the individual. The investigators found that people could indeed detect the presence of fat and that the genetic variations in CD36 affected their ability to taste the fat. In fact, those participants that carried the genetic variant associated with higher production of the CD36 were eight times more sensitive to the presence of fat than those that carried the variant associated with low CD36 levels. Hence, people with less CD36 protein are most likely to be less sensitive to fatty foods. Whether this in turn affects fat preferences and could be exploited to promote healthier food choices is yet to be seen but the study takes us closer to establishing a sixth fat sense…(SC)
* umami is a word derived from the Japanese language that stands for savory or delicious. It corresponds to the taste of the aminoacid L-glutamate, that can be found in many common foods like meat and vegetables.
Stevia rebaudiana is a plant of the Stevia genus which includes plants native to tropical and subtropical regions, mainly from South America. Stevia leaves have a sweet taste, which is due to the presence of steviol glycosides*. In fact, these natural sweeteners are much sweeter than sugar (claimed to be up to 300 times sweeter), which means that considerably less amount is needed to achieve the same sweet taste. On top of that, they are also free of calories, since they are not absorbed by the organism in the intestine. Although stevia plants and their sweet leaves have been known from antiquity to indigenous South American populations, they have been exploited in food technology rather recently. In Japan stevia is safely used as a sweetener since the '70s, while in the rest of the world it is available as a food additive and dietary supplement. In the US, the main steviol glycoside, rebaudioside A has been used without known health issues as a food additive, while stevia leaves and extracts are available as dietary supplements. Steviol glycosides have been evaluated as safe by US Food & Drug Administration (FDA) and by the Food & Agriculture Organization (FAO) / World Health Organisation (WHO) Joint Expert Committee on Food Additives. On the 11th of November 2011 the European Commission (1) also approved the use of steviol glycosides within the European Union for use in foods and beverages as sweeteners. The Commission decision followed the previous positive safety evaluation from the European Food Safety Authority (2), which also established an acceptable daily intake of 4 mg/kg of body weight. Such safety evaluation was necessary because stevia was considered a "novel food", to be introduced for the first time in the EU market, and as such it needed approval according to the novel food regulation (3). Stevia based products have now evolved from sweeteners into low calorie soft drinks, which are marketed by major soft drink companies. As an example, a 330 ml can of a lemon flavoured, stevia-based soft drink has only 69 calories, opposed to 150 calories of standard a lemon-lime type can of the same volume. Zero calorie soft drinks based on stevia have also been marketed. Although the impact of stevia-based products on the EU market and consumers still remains to be seen, don't be too surprised if your eye catches any brand-new, low-calorie, "naturally sweetened" soft drinks in the supermarket shelves. And of course we shouldn't overlook its use as a safe and non-caloric sweetener, especially in light of the recent heated debate cause by a Nature article (4) on the detrimental public health effects of sugar (PM).
February 1st, 2050. A lunch buffet has been prepared to celebrate the annual meeting of the European animal welfare organisation. People are enjoying all sorts of meat products: steaks, cutlets, hamburgers, hot dogs or salmon and tuna. What was unthinkable for a buffet at the animal welfare organisation in the beginning of the 21st century does not unsettle anyone at this forum. Why? Because these meat products are grown in the laboratories and there is no animal distress associated with them. Moreover, livestock breeding has been off the climate debate and meat is not a health concern for anyone as cultured meat is optimised for nutrient composition. Science fiction? Think again! 'In vitro meat' or 'cultured meat' was much in the press recently after Dutch scientists received the funds to make a hamburger from in vitro meat by the end of 2012 (1). The researchers propose to produce meat grown from cells extracted from a tissue biopsy (see photo). Undoubtedly, some technological issues still need to be solved and will need investments. Improvements are needed in developing non-animal based growth media for the cells, reproducing the texture (and taste) of conventional meat as well as scaling up production to industrial level (2). Rough economic analyses estimate that the price of in vitro meat would be twice the price of unsubsidised farmed chicken meat (2, 3) but this difference may be further reduced, depending on technological advances in cultured meat production as well as increasing economic costs for conventional meat stemming from farming animals and exploiting environmental resources to satisfy a doubling global demand for meat by 2050 (4). In fact, a recent study compared the environmental impacts of cultured versus conventional meat and concluded that the impact from cultured meat is substantially lower, in particular for land use, green house gas emissions and water use (5). Only energy use is comparable to conventional meat production due to the high fuel and electricity use during muscle cell cultivation. However, using renewable energy sources could significantly reduce this impact. Other potential benefits of cultured meat relate to the prevention of animal-borne disease and epidemic zoonoses (e.g. salmonellosis, bird flu, mad cow disease etc.) and the possibility to design the nutritional composition of the meat to improve human health, for example reducing saturated fat, increasing omega-3 fatty acids, or adding micronutrients (2, 5). Thus, can we expect cultured meat soon in our grocery stores? We would guess that it will yet take some time as introducing new technologies to foods is often not a smooth path (e.g. GMOs or nanotechnology). The biggest challenge ahead for in vitro meat may well be to convince the consumer to buy and eat it. A starting point may be to find a more palatable label than "in vitro" or "cultured" meat...(JW)
Photo:Cultured meat production. Reprinted by permission from Macmillan Publishers Ltd: Nature 468, 752-753, copyright (2010)
It is hard to imagine that in a world in which one in seven human beings is suffering hunger (as addressed in the previous issue of NRH, 1) there is also so much food being wasted. The numbers are intimidating and in Europe, they point to food waste levels of up to 50% of the food that is produced (2).
To address this issue, the European Parliament has just adopted a resolution (3) that aims to 'halve food waste in the EU by 2025 and improve access to food for needy EU citizens'. It calls for a coordinated EU-wide strategy to improve the food chain and tackle the food waste issue urgently. It highlights the need for better education to raise awareness of the problem, for improving labelling of food products and packaging and stresses the public institutions' responsibility to set the example. If nothing is done, based on anticipated EU population growth and increasing affluence, the food waste is expected to increase 40% by 2020 (2). But what exactly is food waste? Depending on the source, food loss/waste can be defined (2) as the loss of food materials (including vegetable peelings, meat trimmings and spoiling/excess of ingredients) before, during and after meal preparation in the household. Hence, the waste occurs at different stages along the food chain (production, manufacturing, retail, food service (out-of-home) and households). The key causes vary according to product range but are likely to be similar across Europe. They include, among others, misshaped products in production, inappropriate storage or overstocking in retail, high marketing standards causing foods in proper condition to be rejected and difficulties in anticipating client numbers in the food service sector. Marketing strategies that induce people to buy more than needed (pay 2, take 3!) and the offering of ever increasing portion sizes contribute to the problem.
Interestingly, in Europe, it is at the household level where a significant part of the food waste occurs. In fact, 42% of the total food waste occurs at households of which 60% is potentially avoidable (2). While these numbers are astonishingly high, the majority of the people seem to be unaware of the quantity of waste they generate and of the ecological and economical consequences that come along. Food waste in the households stems from a lack of knowledge on storage and preservation, misinterpretation of product labels, poor planning that leads to buying or cooking too much and the consumer's undervalued attitude towards. We note that in low-income countries significantly less food is wasted at the consumer level as described in a recent report on global food waste commissioned by the United Nation's Food and Agricultural Organization (FAO) (4). The consequences that these levels of food waste have for the environment are dramatic and range from unnecessary increases in carbon dioxide and methane emissions, land and water usage and pollution as well as depletion of much essential minerals and nutrients (e.g. phosphorus and nitrogen) (2). The "Adoption of rich countries’ wasteful food-consumption pattern across the world would lead to unsustainable demand for natural resources" said Jose Graziano da Silva (FAO director general) recently (5).
Why does food waste exist? Most people would agree that wasting food is not ethical, as it is, inextricably connected to hunger. Also from an economic point of view food waste should not exist. As there is "no free lunch", people should do whatever possible to reduce food waste - food waste means unnecessary expenses. Therefore we have to understand why people waste food, make producers and consumers aware of the present unsustainable way of consuming and take concrete measures to reduce food waste. Different food waste causes call for different approaches to reduce it. For example, several modifications at the regulatory level regarding food labels, expiration dates or concerning the interpretation of particular measures stipulated in the food hygiene code have been proposed recently in a Dutch report concerning food waste (6).
However, it is us, the regular EU consumer that while shopping or at home is contributing to the largest portion of waste (2). The key issue here is to make the European citizen aware of the significance of its magnitude and changing attitude and behaviour towards food can result in less waste. Our society slowly developed into one that offers perfectly shaped, coloured, sized fruits and vegetables throughout the year, bread on the shelves until closing time and availability of the complete assortment anytime. All this provides us comfort and a pleasurable way of living but contributes to the food waste problem and costs money too as eventually the consumer will be paying the price needed for compensating the farmer or the baker for the food lost. The increase in food prices has greater impact on those households living on low incomes and explains how food waste is related to access to food, both in and outside Europe (as explained in the recent documentary 'Taste the waste' (7).
Different projects have been initiated to raise consumers’ awareness and the UK campaign “Love Food, Hate Waste”, launched in 2007, is an example of a successful initiative, claiming to have reduced the household produced food waste considerably (8). The campaign shows on its website that by doing easy practical everyday things at home, alone will waste less food and, in addition, save money! It also explains food labelling terms (as in 9) like use by (that refers to food safety and means the product must be consumed by this date) or best before (which is not related to the safety of the product but to other attributes as flavour and texture). There are also initiatives like "Last Minute Market" (10) that organises unsold or non-sellable goods from local retail to be redistributed among the deprived people in region. One could argue that in the current financial condition of Europe, people might have other priorities than to be concerned about food waste. However, the financial aspect might actually be an incentive rather than an obstacle for people to start using food more efficiently. Food waste is a waste of money as the potential savings per household are thought to amount to €565 per year (8). In Europe there are 79 million EU citizens living beneath the poverty line and 16 million depending on food aid from charitable institutions (3).
The food waste problem is here and is here to stay unless we do something about it. Resolutions like making 2014 the European Year against Waste and setting goals for its reduction are important, flag the problem and place it high in the political agenda. But the change must come from all of us. There is nothing wrong with a crooked cucumber or eating leftovers from the day before. Plan in advance and think twice before you buy - will you really eat it all? Or why not be creative and use the ingredients that you have in the fridge instead of sticking persistently to the recipe? And if you think about it long enough, what is wrong with taking the food home if you only ate just half your plate at the restaurant? Perhaps replacing the word 'doggy bag' will help to get rid of the taboo and even make it the norm instead of the exception. Your suggestions on how to reduce food waste are very welcome and to be sent to firstname.lastname@example.org (RG)
Photo: United States World War II campaign postcard against food waste: Office for Emergency Management. Office of War Information. Domestic Operations Branch. Bureau of Special Services. (03/09/1943 - 09/15/1945). Source: Wikimedia Commons
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. The Nutrition team is comprised of Sandra Caldeira, Raymond Gemen, Petros Maragkoudakis & Jan Wollgast.
The views expressed here do not necessarily reflect the opinion of the European Commission.
© European Union, 2012. Reproduction of articles (excluding photographs) is authorised, except for commercial purposes, provided that the source is mentioned.