Now, the European EPIC study carried out by researchers from 10 countries has shown that, in the case of lung cancer, the important thing is not just the quantity but also the variety of fruit consumed, which can reduce the risk by up to 23%.
"This research looks more deeply into the relationship between diet and lung cancer", Maria Jose Sanchez Perez, co-author of the study and director of the Granada Cancer Registry at the Andalusian School of Public Health, tells SINC.
She says: "Aside from the amount consumed, it's also important to take into account the variety. A varied diet reduces the risk of developing this cancer, above all in smokers".
The results of this study, which have been published in the journal Cancer Epidemiology, Biomarkers & Prevention, show that eating "more than eight sub-groups" of vegetables cuts this risk by 23% compared with eating "less than four sub-groups". In addition, this risk falls by a further 4% for each unit added to the diet from another sub-group.
"A significant link was only found in smokers", the researcher stresses. "For every two additional units of different kinds of fruits and vegetables in the diet, the risk of lung cancer falls significantly by 3%. So if smokers increase the variety of fruit they eat they could have a lower risk of developing this type of cancer".
The European Prospective Investigation into Cancer and Nutrition (EPIC) involves 23 centers from 10 European countries (Germany, Denmark, Spain, France, Greece, Holland, Italy, Norway, the United Kingdom and Sweden, working with a sample of 500,000 European subjects (41,000 of whom live in the Spanish regions of Asturias, Granada, Guipuzcoa, Murcia and Navarre).
Lung cancer continues to be one of the most common cancers in developed countries. For this reason, despite the encouraging results of this study, Sanchez Perez concludes that "the most effective way of preventing it continues to be reducing the prevalence of tobacco consumption among the populace".
The effect by type of cancerous tissue
Greater variety in fruit and vegetable consumption is associated with a lower risk of developing epidermoid carcinoma of the lung, with an additional two units of fruit and vegetable consumption leading to a 9% reduction in risk. This effect is clearer among smokers (where the risk falls by 12%).
No significant association between fruit and vegetable consumption and the risk of developing lung cancer was seen for the other kinds of tissues affected (adenocarcinoma and small and large cell carcinoma).
Frederike L. Buchner, H. Bas Bueno-de-Mesquita, Martine M. Ros, Kim Overvad, Christina C. Dahm, Louise Hansen, Anne Tjonneland, Francoise Clavel-Chapelon, Marie-Christine Boutron-Ruault, Marina Touillaud, Rudolf Kaaks, Sabine Rohrmann, Heiner Boeing, Ute Nathlings, Antonia Trichopoulou, Dimosthenis Zylis, Vardis Dilis, Domenico Palli, Sabina Sieri, Paolo Vineis, Rosario Tumino, Salvatore Panico, Petra H.M. Peeters, Carla H. van Gils, Eiliv Lund, Inger T. Gram, Tonje Braaten, Maria-Jose Sanchez, Antonio Agudo, Nerea Larraaaga, Eva Ardanaz, Carmen Navarro, Marcial V. Arguelles, Jonas Manjer, Elisabet Wirfalt, Garan Hallmans, Torgny Rasmuson, Tim J. Key, Kay-Tee Khaw, Nick Wareham, Nadia Slimani, Anne-Claire Vergnaud, Wei W. Xun, Lambertus A.L.M. Kiemeney, and Elio Riboli. "La variedad en el consumo de frutas y verduras disminuye el riesgo de desarrollar cancer de pulmon entre las personas fumadoras". Cancer Epidemiol Biomarkers Prev; 19(9); 22780 - septiembre de 2010.