The relationship between health and nutrition has been one of the spearheads from the start at the Brightlands Campus Greenport in Venlo. At the former Floriade site, researchers, suppliers, horticultural entrepreneurs and Limburg policymakers will gather at the research and innovation center in mid-November for the closing symposium of the project ‘The value(s) of fruit and vegetables’.
From the Top Sector Horticulture and Propagation Materials, thirteen companies and three knowledge institutions have spent four years examining issues relating to the health values of fruit and vegetables and the effect of tomatoes, cabbage or berries on the body.
‘The value of healthy fruit and vegetables has only increased as a result of the corona pandemic, the food crisis due to the war in Ukraine and the nitrogen crisis’, project leader Herman Peppelenbos kicked off the meeting. He is a lecturer in Green Health at the HAS green academy.
Welfare diseases
Fruit and vegetables in particular appear to be an important key in the fight against diseases of affluence, such as type 2 diabetes and cardiovascular disease. Firstly because people exchange fruit and vegetables for unhealthy food and secondly because of the specific ingredients, such as lycopene in carrots and tomatoes.
Healthy eating is often accompanied by healthy lifestyle
The researchers who started the project also saw a number of obstacles: the measurements of ingredients are expensive, recognized health claims seem hopeless and the variation in nutritional value is great. Lecturer-researcher Tamara Verhoeven, who works at the HAS green academy, and the project partners focused on the use of fast, reliable and affordable measurement methods to map the amount of ingredients.
‘For us it really is measuring is knowing’, she reported. ‘We were the first to improve the extraction method with which we isolate the ingredients. We also used the fast method Near Infrared Spectroscopy, which we use to immediately measure the amount of lycopene in fresh vegetables using light.’
Lycopeengehaltes
One of the main conclusions from the measurements is that even within the group of tomatoes, lycopene levels vary widely. Not only between varieties such as plum tomatoes or the much more expensive and much more lycopene-rich small cherry tomatoes. As a result of different cultivation methods and conditions in the greenhouse, the proportion of useful ingredients also varies greatly within varieties. Not to mention the effects of preparing vegetables.
The focus in the top sector project was on phytonutrients, or nutrients that a plant produces itself. These are substances such as anthocyanins that are found in blueberries, carotenoids in carrots, for example, and glucosinolates that are found in cabbage varieties such as broccoli. The substances are antioxidants and can prevent damage in body cells caused by oxidation. Or they play a role in combating chronic inflammation, often in the run-up to diseases of affluence.
Hidde van Steenwijk, PhD student at the Food Claims Center Venlo, recently developed a model of an innovative method to determine the health effects of fruit and vegetables related to inflammation in the body in a short period of time. ‘Healthy eating often goes hand in hand with healthy living behaviour,’ he indicated. ‘That’s why we wanted to look for the causal relationship, ie the real effects of the ingredients.’
Healthy eating works like exercising
Test subjects were given both healthy products and an unhealthy high-calorie drink in two sessions. Urine and blood samples were then taken. According to Van Steenwijk, the short-term effects are measurable and therefore the very beginning of many diseases of affluence. ‘Healthy eating works in much the same way as exercising; you build up condition and thus build up resistance with nutrition.’
The long-term effects are also clear to Van Steenwijk. ‘Although we are still working on the investigation and not everything is clear to us.’ This also brought criticism from the horticulturists present at the Brightlands Campus Greenport. Panel member and horticultural entrepreneur Rob Baan was surprised that the project is called a ‘closing symposium’. ‘We are only at the very beginning and really need to get to work quickly and together. In a country like Japan they are much further ahead with ingredients.’
Rob Baan (with microphone) thinks that the horticultural sector and researchers should get to work. © Michael Elands
Limburg grower Toon Janssen, founder of Tasty Tom, responded from the audience. ‘I have been seeing research into ingredients for many years. Why isn’t there more collaboration with other knowledge institutes and making use of all available information?’
New questions arose
Food scientist Alie de Boer of Maastricht University concluded that ‘questions have been answered in recent years, but many more new ones have arisen’. ‘Especially when you consider that we want to have a picture of many more substances from many more vegetables and fruit and also want to understand the effects that combinations of substances have in the body, then we still have a long way to go.’
Professor Peppelenbos is satisfied after four years of research. ‘With the results we can contribute to keeping people healthy. As a result, lifestyle diseases are reduced, health care costs are reduced and people get a healthier lifestyle.’
‘Actively offering works to eat more fruit and vegetables’
Whatever figures you use, the majority of the Dutch do not consume the 250 grams of vegetables per day recommended by the Netherlands Nutrition Centre. ‘Only a quarter of all children and 16 percent of adults eat enough fruit and vegetables,’ says Herman Peppelenbos, professor of Green Health at the HAS green academy. ‘Moreover, the appreciation for these fresh products is low.’ How can you change that? Offer more fruit and vegetables, especially from a young age, and make that choice automatic and easy, advises scientist Coosje Dijkstra, affiliated with VU University Amsterdam. She has done a lot of research into the eating behavior of people. The price is also an important factor. If healthy choices become cheaper and unhealthy choices more expensive, that really makes a difference.’ There is therefore praise for the Limburg initiative ‘The healthy primary school of the future’. In addition to healthy living and plenty of exercise, attention is also paid to nutrition. Children leave the lunch box at home and receive a healthy school lunch and snack. The lunch is composed according to the rules of the Netherlands Nutrition Center. Especially little sugar and fat and lots of vitamins, proteins and fiber. At least 80 percent of the products served come from the Wheel of Five. ‘Behavioural change is difficult,’ says Dijkstra. ‘Actively offering works to get people to eat more fruit and vegetables. The environment is also important, but we have not yet found a holy grail. We make a lot of food choices and they are mostly impulsive.’