« Recent studies on cancer and diet »
Based on impressive evidence, the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) recommends eating more vegetables and fruits (V&F) as part of a healthy diet to prevent various types of cancer. Evidence on the role of diet in cancer prognosis is still limited but there are three recent studies (out of four) showing that survival may be improved by greater intake of V&F. Not surprisingly, attempts at improving V&F intake continue, in the general population and among cancer survivors. Pollán et al. show in a recent case-control study a protective effect of a Spanish Mediterranean diet on breast cancer; the diet includes a high intake of fish, legumes and olives together with V&F and boiled potatoes and a low intake of juices. Benefit was seen particularly against triple-negative breast tumors but this needs to be confi rmed in a prospective study.
Freedman et al. report on a multi-agency cooperation to facilitate a foodsystems approach to increasing V&F. The agencies involved were Cooperative Extension Services (community-focused outreach programs of US universities), public health systems and community health centers. Growers and sellers of V&F were involved and structural changes instituted – e.g., a farmers’ market – to improve both awareness and access to V&F. Although it is not yet established that this approach yields the desired results and although the agencies involved are United States specifi c, this could provide a model to be used elsewhere for multi-agency approaches to increase V&F.
Coleman et al. examined the role of depressive symptoms, hope, social support and quality of life in relation to V&F intake among cancer survivors and showed a modest association with social support. There is no sociologic or causal model in this paper so it is hard to understand exactly what is being reported, especially when the response proportion was less than 25 per cent. Perhaps the clearest message that can be extracted is that some benefi cial circumstances cluster to infl uence cancer survival. Such clusters may, in turn, be related to socioeconomic status, education, etc.
Benefi ts of high V&F consumption are clear but further research must continue to explore what works to increase intakes. These recent papers provide a few more clues and directions for further research and intervention. However, V&F have low profi t margins and receive very little advertising (compared especially with high-fat, high-sugar foods). It is an uphill battle to change community norms in the face of the power of corporate food empires but there is no option but to continue the struggle.