Research has shown that diet, including alcohol, is associated with the development of colorectal cancer (CRC),^1–3 and continues to affect health after diagnosis in the form of disease recurrence, physical functioning, and mortality.^4–6 Among CRC survivors, high intake of red and processed meat have been correlated with poorer health outcomes^4,7–9 as has the “Western dietary pattern,” defined by reliance upon red and processed meat, dairy, refined grains, and sweetened desserts.^6,10 Diet is also indirectly implicated in the association between excess body weight and cancer risks.^11,12

A growing body of research has incorporated diet into broader behavioral interventions with CRC survivors, showing benefits to health and well-being from encouraging healthier eating habits and regular exercise.^13–15 Despite these successes, the reach of such efforts has been limited and there remains a need for widespread approaches to educating CRC survivors about the role diet and alcohol play in health. Currently, information is lacking on CRC survivors’ awareness and beliefs about dietary recommendations. Limited information from small studies outside the U.S. suggests that CRC survivors’ understanding of nutrition recommendations is poor¹⁶ and that many survivors do not consider diet to be an important factor in long-term health.¹⁷ More information is needed on what U.S. CRC survivors know about dietary recommendations, what they believe about the benefits of healthy eating and drinking habits, how much support they receive for these practices, and which barriers they encounter in understanding and following dietary recommendations. Collecting this information will better inform public health efforts to develop and disseminate information about diet to cancer survivors.

In the Prevention Among Colorectal Cancer Survivors study,¹⁸ the authors sought to assess the knowledge, attitudes, and practices of CRC survivors regarding preventive health behaviors after cancer. The present analysis examined survivors’ awareness and adherence to dietary guidelines. Specifically, the study aimed to identify which dietary recommendations are most and least well-known and practiced among CRC survivors, what the barriers are to healthy eating after cancer, and to identify characteristics of survivors with the lowest levels of awareness about recommendations.

Prevention Among Colorectal Cancer Survivors study methods have previously been described in detail.¹⁸ This was a cross-sectional survey study of CRC survivors 5–7 years post-diagnosis from the California Cancer Registry. Eligibility criteria included:

All recruitment and study methods were approved by IRBs of CDC, Public Health Institute, California Cancer Registry, and ICF International. Analyses for the present paper were conducted in 2014 and 2015.

A complete explanation of Prevention Among Colorectal Cancer Survivors study recruitment has been reported elsewhere.¹⁸ Briefly, survey packets were mailed to 1,414 survivors, yielding 593 completed surveys, and resulting in an adjusted response rate (which estimates ineligibility in non-response cases) of 46.3%. The cooperation rate, or participation rates among those with confirmed contact, was 64.0%. A separate analysis indicated that being divorced, widowed, or separated; non-Hispanic black, Hispanic, or Asian; and uninsured or having public insurance correlated with non-response (data not shown; JLR, unpublished observations, 2014). Conversely, no differences were found by age, gender, urban/rural residence, stage at diagnosis, or treatment received. Average time since primary diagnosis with CRC was 6.2 years (range, 5.2–7.2 years). As seen in Table 1, there were nearly equivalent male and female respondents, the majority of whom were non-Hispanic white, but sizable percentages of other race/ethnicities were represented. Because only nine participants described themselves as being “other” race, they were combined with the next smallest group, which was “Asian,” and this combined group became the “other” group for analytic purposes. Average age was 73.8 years.

As Figure 1 shows, familiarity with dietary guidelines varied, with 65% being very familiar with some recommendations to under 40% being very familiar with others. The guideline with the highest proportion having never heard of it involved limiting alcohol.

Reliability analysis demonstrated that all eight items assessing familiarity with guidelines fit well together as a measure of awareness (α=0.89). Individual item correlations with the total ranged from 0.56 to 0.72 (data not shown). Findings from the factor analysis showed that loadings for the “approach” factor ranged from 0.62 to 0.84 and loadings for the “avoid” factor ranged from 0.80 to 0.87. The variance explained by each factor was 2.57 and 3.09, respectively (data not shown).

Survivors were more aware of guidelines reflecting “avoid” dietary recommendations (83% aware, 95% CI=79.2%, 86.3%) than “approach” recommendations (66.1% aware, 95% CI=61.4%, 70.5%). Regarding alcohol guidelines, 73.5%, (95% CI=69.1%, 77.4%) were aware. Adjusted and unadjusted associations between demographic characteristics and awareness of recommendations are presented in Table 1. After adjusting for all other variables, greater awareness of “approach” guidelines was significantly associated with being female (74.2% vs 54.3%, p<0.001); age ≥70 years (67.5% vs 56.8%, p<0.05); part of a couple versus not coupled (69.4% vs 54.2%, p<0.01); and in good to excellent health (67.6% vs 50.9%, p<0.01). Additionally, the non-Hispanic other group versus all other race/ethnicity groups was significantly less familiar with “approach” guidelines (p=0.002).

Adjusted demographic characteristics significantly associated with greater awareness of “avoid” recommendations included being female (93.1% vs 69.4%, p<0.001); more educated (with increasing levels: 71.3%, 80.0%, 95.2%; p<0.001); and having private or military insurance (87.4%) versus public insurance (79.6%, p<0.05). Additionally, the non-Hispanic other group versus all other race/ethnicity groups was significantly less familiar with “avoid” guidelines (p=0.027).

The adjusted associations between demographic characteristics and awareness of alcohol recommendations revealed significantly greater awareness with increasing education (65% among less than high school/General Educational Development [GED] test, 75% among some college, 85% among college graduates; p<0.01) (data not shown). No other differences were statistically significant.

As Figure 2 shows, the dietary habit practiced always or most of the time by the largest percentage (72.7%) was choosing meat, poultry, beans, and dairy that are lean, low fat, or fat free. The habit with the highest percentage having never or rarely practiced it (13.9%) involved choosing whole grains instead of processed/refined grains.

More than half (53.5%) did not drink any alcohol in the past 30 days (data not shown). Of those who drank, 83.6% did so within recommended limits whereas 16.4% drank more than recommended. Compared with drinking habits at diagnosis, 23.2% reported currently drinking less, 31.6% the same amount, 0.9% more, and 44.2% abstained at both times.

Most survivors agreed with the statement Eating a healthy diet is important for my health (90.6%), and just more than half (56.5%) agreed that Eating a healthy diet makes me look good (Appendix Figure 1, available online). With regard to barriers, 26% agreed that Eating a healthy diet takes too much effort and only 8% agreed that Eating a healthy diet may cause injury or harm to my body.

Support, perceptions, and beliefs about healthy eating habits and limiting alcohol can be seen in Table 2. The majority (77%) agreed that friends and family supported healthy eating, and 70% said a provider had discussed diet with them. By contrast, 55% agreed that friends and family supported limiting or avoiding alcohol and 48% indicated that a provider had discussed alcohol consumption with them. The majority felt totally or mostly confident in their abilities to eat a healthy diet and avoid or limit alcohol. Most (93%) believed healthy eating habits were beneficial for overall health and well-being. However, 12% believed alcohol was beneficial for health, 58% believed it was harmful, and 30% believed it was neither beneficial nor harmful.

Five to seven years after diagnosis, generally high levels of awareness about dietary guidelines were found among CRC survivors. The recommendation to choose lean, low-fat, and fat-free meat, poultry, beans, and dairy was the most familiar and most practiced by survivors. However, despite having particular relevance for CRC, recommendations regarding limiting processed meats and alcohol consumption were less well known. Survivors received less social support for limiting alcohol than for healthy eating and less than half of survivors recalled medical providers discussing alcohol consumption with them, a finding consistent with the modest estimates found in the general population.²⁶ In addition, this study found interesting patterns of awareness. Recommendations involving specific quantities or proportions, such as limiting fat to “20%–35% of total calories” and eating “3 ounces” of whole grains each day tended to be less well known than were similar recommendations without specific quantities. Survivors were also more aware of recommendations that encouraged the avoidance of certain foods than those that encouraged certain foods. Regarding which survivors were in greatest need of dietary information, those who were male, single, aged ≤69 years, had less education, had public insurance, in worse health, and identified themselves as Asian or “other” race had the lowest awareness about dietary guidelines.

In a time when the long-term health and well-being of cancer survivors has been deemed a public health issue,²⁷ and stakeholders are being called on to intervene using approaches with broader reach,²⁸ this study offers valuable insights into further increasing awareness of dietary guidelines among CRC survivors. Perhaps the guideline in greatest need of increased awareness is that on limiting or avoiding alcohol; a sizable minority had never heard of this recommendation and many were unaware of alcohol’s potential harms to health. Given that alcohol has been deemed a “Group 1,” highest risk carcinogen for more than 25 years²⁹ and is known to contribute specifically to CRC,³⁰ greater awareness of this recommendation is needed among survivors, and also caregivers and medical care providers. Although it is encouraging that very few survivors reported drinking more than recommended, all survivors should be informed of the links between cancer and alcohol. By increasing awareness among several levels of social influence and by reducing confusion about alcohol’s potential health benefits, cancer survivors could become better informed and receive better support, when necessary.

The overarching patterns of awareness observed in this study align with research in health education and cognitive science. Barriers to comprehension and recall from detailed numerical information are inherent to the concepts of health literacy, numeracy, and cognition. The fuzzy trace theory,³¹ for instance, holds that people encode and recall information on gist traces, or the bottom-line meaning of messages, more than verbatim traces, or the exact details/numbers in messages. Likewise, finding that “avoid” recommendations were more familiar than “approach” recommendations is consistent with the negativity bias,³² or people’s tendency to attend to and remember negative over positive information. These findings highlight the importance of cross-disciplinary efforts and can help inform not only which messages need more attention but also how recommendations can be conveyed most effectively. For instance, in developing messages about healthy eating after cancer, high levels of health literacy and numeracy should be avoided³³ in favor of clear, bottom-line messages that will be better understood and recalled.³⁴ Future work could also explore methods for enhancing awareness about “approach” recommendations, perhaps by linking them with more attention-grabbing “avoid” messages or employing other strategies to bolster comprehension and recall.

This study found that awareness differed by survivor characteristics. Efforts to increase awareness among survivor subgroups known to be particularly unaware will need to consider the unique barriers (e.g., social support, gender roles, cost, access, culture, language) certain groups might face in acquiring information. To reach those in particular need, materials could be developed specifically to address known barriers, such as translating materials into other languages, using culturally appropriate dietary references, and tailoring materials for caregivers responsible for purchasing and preparing food. It would also be useful to refer survivors to free or low-cost diet-related resources available online or in the community, such as those available through non-profit organizations or self-management education programs.