Projects per year
Numerous guidelines are available for the prevention of cancer. Optimal nutrition after a cancer diagnosis may increase survival, reduce the risk of recurrence, limit side-effects and improve recovery and quality of life. However, cancer survivors often do not receive nutritional information, and health professionals are often not trained to provide such advice (chapter 1). This thesis aims to improve nutritional information provision for cancer survivors, the general public and health professionals by investigating whether adherence to dietary recommendations is associated with improved quality of life; investigating the importance of information provision on nutrition and cancer by assessing nutritional beliefs, assessing information needs of cancer survivors and whether survivors change their dietary behaviour when they receive information on nutrition and cancer, by assessing the ideas of oncology nurses and by developing a website.
In chapter 2, the association between adherence to the World Cancer Research Fund/American Institute of Cancer Research (WCRF/AICR) recommendations and health related quality of life (HRQL) among colorectal cancer (CRC) survivors was investigated. All CRC survivors stage I-IV, diagnosed between January 2000 and June 2009 in the southern area of the Netherlands were sampled via the Netherlands Cancer Registry (NCR). Questionnaires about dietary intake, body height/weight, physical activity and HRQL were sent out. WCRF/AICR adherence scores (range 0-8, with a higher score for better adherence) were calculated using the questionnaires on dietary intake, physical activity, and body mass index (BMI). 1,096 CRC survivors with a mean WCRF/AICR adherence score of 4.81 ± 1.04 were included (response rate 67%). Higher WCRF/AICR scores were associated with better global health status, physical, role, cognitive and social functioning, and with less fatigue. Physical activity seemed to be the main contributor.
In chapter 3, the association between nutritional information provision and beliefs on nutrition and cancer was investigated. Questionnaires were filled out by 326 CRC survivors one month after surgery on general characteristics, nutritional information provision by health care professionals, nutritional information needs, satisfaction with nutritional information and patients’ beliefs on nutrition and cancer. Most respondents who received information strongly believe nutrition influences feelings of well-being (59%) and recovery after cancer (62%). 62% of respondents received information from one or more health professionals. Respondents who received information from three health professionals, had stronger beliefs on the influence of nutrition on cancer outcomes than those who did not receive information about nutritional complaints after treatment (PR 3.2; 95% CI 1.5-6.9), recovery after cancer (PR 1.8; 95% CI 1.2-2.9) and about recurrence of cancer (PR 2.9; 95% CI 1.3-6.4).
In chapter 4, it was investigated whether obtaining nutritional information influences reported changes in dietary behaviour in 239 cancer survivors and their relatives and how this association is. It was then investigated whether nutritional information needs influenced this association. This panel completed a survey about their experiences with nutritional information provision by healthcare professionals in the period after diagnosis, their information needs regarding nutrition and cancer, and whether they changed their dietary behaviour since diagnosis. The survey showed that 56% of respondents obtained nutritional information, mostly during treatment. Respondents who obtained nutritional information more often reported to have altered their dietary behaviour after diagnosis in a positive way (less products that promote weight gain, increased intake of plant foods, decreased meat and alcohol use), regardless whether they had nutritional information needs or not.
Chapter 5 investigated if oncology nurses perceived themselves as having insufficient knowledge to provide advice on nutrition and/or physical activity, and which characteristics were associated with this perception. 355 oncology nurses provided advice on nutrition and of these, 327 provided advice on physical activity. Of these oncology nurses, 43% perceived themselves as having insufficient knowledge to provide advice on nutrition, and 46% perceived insufficient knowledge to provide advice on physical activity. In particular, younger oncology nurses and oncology nurses with an intermediate vocational education more often perceived themselves as having insufficient knowledge to give these advices.
In Chapter 6, the development of a website to make scientific information available for cancer survivors was described. Initially, the website was filled with answers to frequently asked questions provided by cancer organizations and the Dutch Dietetic Oncology Group, and by responding to various fiction and facts published in the media. Furthermore, an opportunity for visitors to submit specific questions regarding nutrition and cancer was included. The answers to these visitors’ questions were consequently published on the website.
Chapter 7 discusses that healthy lifestyle screening should be implemented in all phases of cancer care; that dieticians are responsible for nutritional support and information provision for all cancer patients; that a cancer diagnosis is not the window of opportunity for sustained lifestyle changes and that physicians are the ones to stress the importance of a healthy diet to cancer survivors, but should refer to experts for the actual advice. Future research should focus on the need for cancer survivors to better adhere to the recommendations for a healthy lifestyle, with better information provision by health professionals. For public health and clinical practice, available information sources should be promoted and implemented in health care.
Based on the results of this thesis as well as existing literature, it can be concluded that evidence based nutritional information should be provided to cancer survivors. To be able to do so, health professionals should receive more nutritional training to emphasize the important role of nutrition in cancer and to properly refer and advice cancer survivors about nutrition and cancer. The dietician must have the lead in this process. This is important, since correct nutritional information might positively influence cancer survivors’ beliefs about the role of nutrition in cancer and stimulate cancer survivors to positively alter their dietary behaviour. The newly developed website voedingenkankerinfo.nl on diet and cancer fills a gap in the provision of information about nutrition and cancer for both patients, the general public and health professionals.
|Qualification||Doctor of Philosophy|
|Award date||18 Sep 2019|
|Place of Publication||Wageningen|
|Publication status||Published - 2019|