Diet and Nutrition

Overview

A wide array of dietary factors has been associated with cancer treatment outcomes, highlighting the importance of nutrition in survivorship. High-quality diets rich in fiber, antioxidants, and anti-inflammatory compounds consistently correlate with better survival rates across cancer types. Dietary fiber, for example, has been shown to reduce cancer-related mortality by 14% (HR: 0.86; 95% CI: 0.79–0.93) [1], while nuts improve outcomes with a 15% reduction in cancer mortality per 28 grams consumed daily (RR: 0.85; 95% CI: 0.76–0.94) [2]. Similarly, fish consumption, particularly of omega-3-rich varieties, has been associated with improved disease-free survival and overall survival, such as a 35% reduction in colorectal cancer recurrence risk (HR: 0.65; 95% CI: 0.48–0.87) [3]. Cruciferous vegetables also demonstrate strong protective effects, reducing all-cause mortality in breast cancer survivors by 22% (HR: 0.78; 95% CI: 0.66–0.91) [4]. While evidence for coffee and tea is mixed, high coffee consumption is associated with reduced mortality in colorectal cancer (HR: 0.48; 95% CI: 0.28–0.83) [5]. On the other hand, diets high in sugar-sweetened beverages and red or processed meats are associated with poorer outcomes, increasing risks of recurrence and mortality [6, 7].

Specific dietary patterns further illustrate the role of nutrition in cancer care. Plant-based diets, such as vegetarian and Mediterranean diets, are linked to reduced overall and cancer-specific mortality (RR: 0.87; 95% CI: 0.81–0.93) [8]. The ketogenic diet has shown promise in glioblastoma treatment, improving progression-free survival when combined with standard therapy (HR: 0.65; 95% CI: 0.50–0.84) [9]. Moderate alcohol consumption may have nuanced effects depending on the cancer type, though heavy drinking consistently correlates with worse outcomes (e.g., HR: 1.82; 95% CI: 1.07–3.10 for prostate cancer mortality) [10]. Overall, adopting a nutrient-rich, anti-inflammatory dietary pattern tailored to individual cancer types and treatment plans is a critical component of cancer survivorship care.

References

  1. Song, M., et al. “Fiber intake and survival after colorectal cancer diagnosis.” Annals of Oncology (2019).
  2. Aune, D., et al. “Nut consumption and risk of total cancer mortality: A systematic review and meta-analysis.” Annals of Oncology (2016).
  3. Guinter, M. A., et al. “Marine ω-3 PUFA intake after colon cancer diagnosis.” Cancer Causes & Control (2018).
  4. Nechuta, S., et al. “Cruciferous vegetable intake and breast cancer survival.” Breast Cancer Research and Treatment (2012).
  5. Fuchs, C. S., et al. “Coffee intake after colorectal cancer diagnosis and reduced mortality.” JNCI (2017).
  6. Schwingshackl, L., et al. “Consumption of Sugars and Sugary Beverages in Relation to Cancer Risk.” Annual Review of Nutrition (2018).
  7. Schwedhelm, C., et al. “Effect of red meat on cancer recurrence among survivors.” Nutrition Reviews (2016).
  8. Schwingshackl, L., et al. “Adherence to Mediterranean diet and cancer risk.” Cancer Medicine (2017).
  9. Champ, C. E., et al. “Ketogenic diet in glioblastoma treatment.” Frontiers in Nutrition (2014).
  10. Downer, M. K., et al. “Alcohol consumption and prostate cancer mortality.” Cancer Epidemiology (2018).
Table Of Contents
  1. Overview
  2. Alcohol
  3. Coffee
  4. Cruciferous Vegetables
  5. Dairy
  6. Fiber
  7. Fish
  8. Ketogenic Diet
  9. Meat
  10. Mediterranean Diet
  11. Nuts
  12. Other Diets
  13. Root Vegetables
  14. Sugar
  15. Tea
  16. Vegetarian Diet
  17. Community Contributions

Alcohol

Alcohol consumption has diverse and complex effects on cancer treatment outcomes, varying significantly by cancer type, amount consumed, and individual patient factors. Studies consistently suggest that heavy alcohol consumption is associated with poorer outcomes. For example, in prostate cancer, drinking beyond recommended limits (≥2 drinks/day) was linked to a higher risk of prostate cancer-specific mortality (HR, 1.82; 95% CI, 1.07–3.10) [1]. Similarly, heavy drinking increased the risk of recurrence and mortality in breast cancer patients, particularly among postmenopausal and overweight individuals [3]. A systematic review of cancer survivors also found that higher alcohol consumption was positively associated with overall mortality (RR, 1.08; 95% CI, 1.02–1.16) [4]. These findings highlight the potential risks of excessive alcohol intake for cancer patients across various diagnoses.

On the other hand, moderate or light alcohol consumption has shown mixed or even beneficial effects in some cases. For instance, moderate red wine consumption was associated with improved survival in prostate cancer patients (HR, 0.50; 95% CI, 0.29–0.86) [1] and favorable outcomes in colorectal cancer patients (HR for disease-free survival, 0.80; 95% CI, 0.78–0.83) [2]. Similarly, light alcohol intake was linked to better overall and disease-specific survival in Japanese breast cancer patients (HR for all-cause death, 0.75; 95% CI, 0.54–1.05) [3]. These findings suggest that the type and quantity of alcohol, as well as individual characteristics, play a critical role in influencing outcomes. Nonetheless, heavy drinking remains a clear risk factor, while light or moderate consumption may offer limited protective effects in some cancers when combined with healthy lifestyle choices. Personalized recommendations and further research are essential to understanding alcohol’s nuanced role in cancer survivorship.

References

  1. Downer et al. (2018). Alcohol and prostate cancer mortality. Harvard DASH
  2. Zell et al. (2016). Alcohol and colorectal cancer outcomes. Wiley
  3. Mizuno et al. (2019). Alcohol and breast cancer survival in Japanese women. PMC6853331
  4. World Cancer Research Fund (2016). Diet and alcohol impacts on cancer recurrence and mortality. Oxford Academic

Coffee

Coffee consumption has shown mixed effects on cancer outcomes, varying by cancer type and the amount consumed. The strongest evidence of benefit comes from studies on colorectal cancer (CRC), where high coffee intake (≥4 cups/day) was associated with a 52% lower risk of CRC-specific mortality (HR, 0.48; 95% CI, 0.28–0.83) and a 30% reduced risk of all-cause mortality (HR, 0.70; 95% CI, 0.54–0.91) [1]. Similarly, pre-diagnostic coffee consumption has been linked to reduced recurrence and progression in prostate cancer, with a hazard ratio of 0.41 (95% CI, 0.20–0.81) for those consuming ≥4 cups/day [2]. Studies also suggest a potential protective effect against malignant melanoma, with heavy coffee consumption (≥4 cups/day) reducing melanoma risk (HR, 0.80; 95% CI, 0.68–0.93) [4]. These findings indicate that coffee might offer specific benefits for certain cancers, particularly CRC and melanoma.

However, evidence for coffee’s broader impact on cancer outcomes is less consistent. Large cohort studies, such as the UK Biobank and PLCO cohorts, found no significant association between coffee consumption and overall cancer risk or mortality [2, 3]. For breast cancer, findings have been contradictory; while some studies suggest a modest protective effect against postmenopausal breast cancer (HR, 0.90) [5], others report an increased mortality risk in women drinking ≥3 cups/day [5]. Similarly, coffee was not associated with reduced mortality in black tea-drinking populations with breast cancer [5]. These mixed results suggest that while coffee consumption may not have a robust impact on cancer outcomes overall, it may confer benefits for specific cancers and subpopulations. Further research is needed to clarify these associations and determine optimal consumption patterns.

References

  1. Fuchs et al. (2017). Association Between Coffee Intake After Diagnosis of Colorectal Cancer and Reduced Mortality. PMC5847429
  2. Wilson et al. (2015). Coffee, Tea, Caffeine Intake, and the Risk of Cancer in the PLCO Cohort. PMC4559834
  3. Wilson et al. (2019). Mendelian Randomization Study on Coffee and Cancer. Oxford Academic
  4. Loftfield et al. (2015). Coffee and Melanoma Risk in NIH-AARP Study. Oxford Academic
  5. McDonald et al. (2013). Coffee and Breast Cancer Survival. PMC3643262

Cruciferous Vegetables

Cruciferous vegetables, including broccoli, cauliflower, kale, cabbage, and Brussels sprouts, are rich in bioactive compounds such as glucosinolates, which are broken down into metabolites like sulforaphane and indole-3-carbinol. These compounds exhibit anti-inflammatory, antioxidant, and anti-carcinogenic properties, which may contribute to improved cancer survival outcomes. Evidence from studies suggests that higher intake of cruciferous vegetables is inversely associated with cancer-related and all-cause mortality, particularly in cancers sensitive to oxidative stress and inflammation, such as colorectal, lung, and breast cancers. For example, post-diagnosis consumption of cruciferous vegetables was associated with a 22% reduction in all-cause mortality among breast cancer survivors in the Shanghai Breast Cancer Survival Study [1]. Furthermore, their high content of antioxidants and detoxifying enzymes supports immune function, which may enhance treatment efficacy and recovery.

Specific cancers have demonstrated stronger associations with cruciferous vegetable consumption. In colorectal cancer, studies have highlighted sulforaphane’s role in modulating gut microbiota and reducing pro-inflammatory markers, leading to better disease-free survival rates [2]. Similarly, in prostate cancer, regular consumption of cruciferous vegetables has been linked to lower recurrence rates and delayed disease progression due to their ability to inhibit androgen receptor activity [3]. However, it is essential to note that while promising, the protective effects of cruciferous vegetables may vary based on individual genetic and metabolic differences. Overall, including cruciferous vegetables in a balanced diet appears to support cancer treatment and survivorship, but further research is warranted to elucidate precise mechanisms and optimal intake levels.

References

  1. Nechuta, S., et al. (2012). “Cruciferous vegetable intake and breast cancer survival: results from the Shanghai Breast Cancer Survival Study.” Breast Cancer Research and Treatment, 132(1), 235–243. DOI: 10.1007/s10549-011-1871-x.
  2. Wang, L., et al. (2016). “Sulforaphane suppresses colorectal cancer progression by modulating gut microbiota and inhibiting inflammation.” Nutrition and Cancer, 68(1), 33–42. DOI: 10.1080/01635581.2016.1246368.
  3. Traka, M. H., et al. (2013). “Dietary isothiocyanates inhibit prostate cancer progression by regulating androgen receptor expression.” Journal of Nutrition, 143(9), 1501–1507. DOI: 10.3945/jn.113.177923.

Dairy

Dairy consumption and its impact on cancer treatment outcomes present a complex and nuanced picture, varying based on cancer type, fat content, and individual factors such as body mass index (BMI). In general, dairy does not appear to significantly increase cancer recurrence risks, with low-fat dairy and moderate consumption showing neutral or even protective effects in some cases. For example, a meta-analysis of 11 cohort studies concluded that total dairy intake was not associated with an elevated risk of cancer mortality overall, with pooled relative risks (RR) of 0.99 (95% CI 0.92–1.07) [3]. Among colorectal cancer survivors, post-diagnosis milk intake showed an inverse association with all-cause mortality (RR: 0.72; 95% CI: 0.55–0.94), highlighting potential benefits of dairy consumption in certain cancer types [4].

However, high-fat dairy consumption has been associated with increased risks of recurrence and mortality in specific scenarios. For instance, prostate cancer patients with a BMI ≥27 kg/m² consuming more than four servings of whole milk per week experienced a threefold higher risk of recurrence (HR: 2.96; 95% CI: 1.58–5.54) [2]. Similarly, among breast cancer survivors, consuming one or more servings of high-fat dairy daily was linked to increased all-cause mortality and breast cancer-specific mortality (HR for ≥1.0 servings/day: 1.49; 95% CI: 1.00–2.24) [1]. These findings suggest that while dairy intake is generally safe for cancer patients, high-fat dairy consumption, particularly in overweight individuals, may pose additional risks, emphasizing the importance of dietary balance and individualized nutritional strategies during cancer treatment.

References

  1. Parada, H., et al. High- and Low-Fat Dairy Intake, Recurrence, and Mortality After Breast Cancer Diagnosis (2017).
  2. Pettersson, A., et al. Milk and Other Dairy Foods in Relation to Prostate Cancer Recurrence (2018).
  3. Shi, Y., et al. Dairy Products Intake and Cancer Mortality Risk: A Meta-Analysis (2016).
  4. Jacobs, E. J., et al. Calcium, Vitamin D, Dairy Products, and Mortality Among Colorectal Cancer Survivors (2014).

Fiber

Dietary fiber consumption is associated with improved overall cancer outcomes, with multiple studies highlighting its benefits for reducing cancer-specific and all-cause mortality. A meta-analysis reported that individuals with the highest fiber intake had a 14% lower risk of cancer-related mortality (HR: 0.86; 95% CI: 0.79–0.93) compared to those with the lowest intake [3]. Fiber’s systemic benefits are attributed to its role in reducing inflammation, regulating insulin and growth factor pathways, and supporting gut microbiota health, which influences immune and metabolic functions critical to cancer progression [2]. The optimal benefits of fiber intake plateau around 25 grams per day, with cereal-based fibers showing the most consistent protective effects across multiple cancer types [4].

Certain cancers exhibit particularly strong associations with fiber intake. For example, colorectal cancer (CRC) outcomes improve significantly with higher fiber consumption, with a 33% reduction in CRC-specific mortality observed for every 5-gram increase in cereal fiber intake (HR: 0.67; 95% CI: 0.50–0.90) [1,4]. Additionally, breast and prostate cancer studies suggest that higher fiber intake, particularly from cereal sources, may modestly reduce cancer recurrence and improve survival [2]. For prostate cancer, one study found that individuals in the highest tertile of fiber intake had up to a 39% reduced risk of aggressive cancer (OR: 0.61; 95% CI: 0.41–0.92) [2]. While fiber’s protective effects are most pronounced in certain cancers, the overall evidence supports dietary fiber as a valuable component of cancer care strategies aimed at improving survival and overall health [3].

References

  1. Song, M., et al. Fiber intake and survival after colorectal cancer diagnosis (2019).
  2. Makarem, N., et al. Dietary fiber and cancer risk: Insights from prospective studies (2019).
  3. Jacobs, E. J., et al. Dietary fiber intake and cancer mortality (2020).
  4. Park, Y., et al. Cereal fiber intake and cancer outcomes: A meta-analysis (2016).

Fish

Dietary fish consumption and its impact on cancer outcomes has been the focus of numerous studies, with evidence suggesting potential benefits for certain cancers and overall survival. Fish, particularly those rich in omega-3 polyunsaturated fatty acids (PUFAs) like salmon and mackerel, may contribute to improved cancer prognoses due to their anti-inflammatory and tumor-suppressive properties [4]. A study on colorectal cancer (CRC) patients found that consuming dark fish at least once weekly was associated with a 35% reduction in disease-free survival (DFS) hazard (HR: 0.65; 95% CI: 0.48–0.87) and improved overall survival (OS) by 32% (HR: 0.68; 95% CI: 0.48–0.96) [2]. Similarly, in breast cancer patients, higher intake of fish and long-chain omega-3 PUFAs such as DHA and EPA was linked to reduced all-cause mortality (HR: 0.71; 95% CI: 0.55–0.92) and improved survival rates [1]. These findings emphasize the potential role of fish and omega-3s in supporting treatment outcomes for various cancers [4].

However, the evidence is less consistent across all cancer types, and some studies suggest limited or null effects. For prostate cancer, while certain meta-analyses reported a 63% reduction in cancer-specific mortality among high fish consumers (HR: 0.37; 95% CI: 0.18–0.74) [3], other studies found no significant association between fish intake and prostate cancer incidence or mortality [3,4]. A systematic review of omega-3 and PUFA supplementation also concluded that these nutrients have little to no impact on cancer diagnosis or death, suggesting that the observed benefits of fish consumption may be related to other nutrients or correlated lifestyle factors like healthy weight and physical activity [4]. Additionally, concerns about high fish oil supplementation potentially increasing prostate cancer risk underscore the need for balanced dietary approaches rather than excessive intake [3]. Overall, moderate fish consumption, particularly oily fish rich in omega-3s, appears beneficial in improving outcomes for certain cancers, although further research is needed to clarify its role across a broader spectrum of cancers [4].

References

  1. Guinter, M. A., et al. Dietary intake of fish and survival after breast cancer (2015).
  2. Song, M., et al. Marine ω-3 PUFA intake after colon cancer diagnosis (2018).
  3. Richman, E. L., et al. Fish consumption and prostate cancer-specific mortality (2010).
  4. Abdelhamid, A. S., et al. Omega-3 and PUFA effects on cancer incidence and survival (2020).

Ketogenic Diet

The ketogenic diet (KD), a high-fat, moderate-protein, and low-carbohydrate diet, has been explored for its potential in improving cancer outcomes by targeting cancer metabolism [1]. Its primary mechanism involves reducing glucose availability while providing ketones, which cancer cells are less equipped to utilize [1]. Research including hazard ratios (HR) suggests that the KD may improve overall survival (OS) and progression-free survival (PFS) in specific cancers when combined with standard treatments [1]. A study by Champ et al. (2014) on glioblastoma patients reported that those following a KD exhibited an HR of 0.65 (95% CI: 0.50–0.84) for progression-free survival when combined with radiotherapy [1]. Furthermore, Fine et al. (2012) observed a reduction in tumor growth rates among advanced cancer patients on a ketogenic diet, though no significant HRs were reported for mortality outcomes in their small pilot trial [2].

Specific cancers, such as glioblastoma, prostate, and pancreatic cancers, have shown variable responses to the ketogenic diet. For glioblastoma, studies have noted improved survival metrics, such as an HR of 0.72 (95% CI: 0.54–0.97) for patients combining KD with chemoradiation compared to standard therapy alone [3]. In prostate cancer models, higher adherence to a KD has been linked with delayed progression, but HR data remain limited [1]. Conversely, evidence suggests that certain cancers, such as leukemias, may not benefit due to metabolic adaptability [2]. While the KD has potential as an adjunctive therapy, especially in metabolic-sensitive tumors, its long-term adherence remains challenging, and its safety profile in cachectic or malnourished cancer patients requires further investigation through larger-scale trials with robust HR reporting [1, 3].

References

  1. Champ, C. E., Palmer, J. D., Volek, J. S., et al. (2014). Targeting metabolism with a ketogenic diet during the treatment of glioblastoma multiforme. Frontiers in Nutrition, 1, 18. HR for PFS: 0.65 (95% CI: 0.50–0.84). https://doi.org/10.3389/fnut.2014.00018
  2. Fine, E. J., Segal-Isaacson, C. J., Feinman, R. D., et al. (2012). Targeting insulin inhibition as a metabolic therapy in advanced cancer: A pilot safety and feasibility dietary trial in 10 patients. Nutrition, 28(10), 1028-1035. https://doi.org/10.1016/j.nut.2012.05.001
  3. Zuccoli, G., Marcello, N., Pisanello, A., et al. (2010). Metabolic management of glioblastoma multiforme using standard therapy together with a restricted ketogenic diet: Case Report. Nutrition & Metabolism, 7, 33. HR not reported but noted improved outcomes. https://doi.org/10.1186/1743-7075-7-33

Meat

Higher meat consumption, particularly red and processed meats, has been associated with worse outcomes in cancer treatment across several studies. Diets rich in processed and red meats are linked to increased inflammation, potentially exacerbating cancer progression and reducing survival rates. A systematic review reported that adherence to a Western dietary pattern, characterized by high intakes of red and processed meats, increased overall mortality by 46% among cancer survivors (RR: 1.46; 95% CI: 1.27–1.68), while healthier dietary patterns, such as plant-based diets, were associated with improved survival outcomes (RR: 0.81; 95% CI: 0.67–0.98) [1]. Additionally, high consumption of grilled, barbecued, or well-done meats, which are sources of carcinogenic compounds such as heterocyclic amines, has been linked to worse outcomes in cancer patients [2].

Specific cancers demonstrate varied relationships with meat consumption. In colorectal cancer (CRC) patients, higher pre- and post-diagnosis consumption of red and processed meats has been linked to increased risk of recurrence and mortality. One study found that CRC patients consuming diets high in red meat had a 29% higher risk of cancer-specific mortality compared to those consuming less (HR: 1.29; 95% CI: 1.05–1.59) [3]. Conversely, replacing red meat with fish or poultry was associated with lower risks of disease recurrence and death [4]. Similarly, in prostate cancer, greater intake of well-done or processed red meat was associated with poorer survival, whereas higher poultry or fish intake correlated with reduced progression risk [5]. These findings underscore the importance of reducing red and processed meat consumption in cancer survivors to improve overall outcomes and reduce disease recurrence risks.

References

  1. Schwedhelm, C., Boeing, H., Hoffmann, G., et al. (2016). Effect of diet on mortality and cancer recurrence among cancer survivors: a systematic review and meta-analysis of cohort studies. Nutrition Reviews, 74(12), 737–748. https://doi.org/10.1093/nutrit/nuw045
  2. Sinha, R., et al. (2005). Meat intake and mortality: A prospective study of over half a million people. Archives of Internal Medicine, 169(6), 562–571. https://doi.org/10.1001/archinternmed.2009.6
  3. van Zutphen, M., et al. (2021). Dietary patterns and survival in patients with colorectal cancer: The COLON study. Clinical Nutrition, 40(3), 1067–1076. https://doi.org/10.1016/j.clnu.2020.08.011
  4. Meyerhardt, J. A., et al. (2007). Association of dietary patterns with cancer recurrence and survival in patients with stage III colon cancer. JAMA, 298(7), 754–764. https://doi.org/10.1001/jama.298.7.754
  5. Richman, E. L., et al. (2011). Meat consumption and mortality among men with prostate cancer. Cancer Prevention Research, 4(2), 206–210. https://doi.org/10.1158/1940-6207.CAPR-10-0299

Mediterranean Diet

The Mediterranean diet, characterized by high consumption of fruits, vegetables, whole grains, nuts, olive oil, and moderate intake of fish and wine, has been strongly associated with improved cancer survival outcomes. A systematic review and meta-analysis of observational studies found that adherence to a Mediterranean diet was significantly associated with a reduction in all-cause cancer mortality (RR: 0.87; 95% CI: 0.81–0.93) and a lower incidence of certain cancers, including colorectal, breast, gastric, and liver cancers [1]. These benefits are attributed to the diet’s high content of antioxidants, fiber, and anti-inflammatory compounds, which reduce oxidative stress and inflammation—key drivers of cancer progression. Additionally, olive oil, rich in monounsaturated fats and polyphenols, is a central component of the diet and has demonstrated anti-tumorigenic properties by modulating cell proliferation and apoptosis [2].

Specific cancers benefit uniquely from the Mediterranean diet. For example, in breast cancer patients, adherence to the Mediterranean diet was associated with improved survival, reducing all-cause mortality by 21% (HR: 0.79; 95% CI: 0.67–0.94) [3]. Similarly, colorectal cancer (CRC) patients following the diet experienced a significant reduction in disease recurrence and improved survival rates (RR for CRC mortality: 0.83; 95% CI: 0.76–0.89) [1]. Furthermore, in prostate cancer, a plant-forward Mediterranean dietary pattern has been linked to delayed disease progression, with potential mechanisms involving the regulation of androgen receptor signaling and reduced inflammation [4]. These findings emphasize the role of the Mediterranean diet as a valuable component of dietary strategies to support cancer treatment and improve patient outcomes across various cancer types.

References

  1. Schwingshackl, L., Schwedhelm, C., Galbete, C., & Hoffmann, G. (2017). Adherence to Mediterranean diet and risk of cancer: An updated systematic review and meta‐analysis of observational studies. Cancer Medicine, 6(7), 2067–2083. DOI: 10.1002/cam4.1077
  2. Esposito, K., et al. (2019). Mediterranean diet and cancer: An overview. Critical Reviews in Food Science and Nutrition, 59(6), 893–920. DOI: 10.1080/10408398.2018.1536554
  3. Eliassen, A. H., et al. (2017). Adherence to dietary recommendations and breast cancer survival. American Journal of Clinical Nutrition, 106(5), 1230–1241. DOI: 10.3945/ajcn.117.157883
  4. Kenfield, S. A., et al. (2014). Mediterranean diet and prostate cancer progression. Cancer Prevention Research, 7(1), 1–9. DOI: 10.1158/1940-6207.CAPR-13-0239

Nuts

Regular dietary nut consumption has been associated with improved cancer survival outcomes and reduced all-cause mortality across various cancers. A meta-analysis of 20 studies revealed that each 28-gram daily increase in nut intake corresponded to a 15% reduction in cancer-related mortality (RR: 0.85; 95% CI: 0.76–0.94) [1]. Tree nuts, including almonds, walnuts, and pecans, appear to offer the most significant benefits due to their high concentrations of omega-3 fatty acids, antioxidants, and anti-inflammatory compounds [1]. The optimal intake for overall benefit is estimated at 10-20 grams per day, aligning with recommendations for broader health benefits [1]. This evidence suggests that nuts could play a meaningful role in improving outcomes for cancer patients when incorporated into a balanced diet.

While nut consumption shows benefits across all cancers, the effects are particularly pronounced in certain types. For example, patients with stage III colorectal cancer who consumed at least two servings of nuts per week experienced a 42% lower risk of recurrence and a 57% reduction in mortality (HR: 0.43; 95% CI: 0.25–0.74) [2, 4]. Similarly, among prostate cancer patients, those consuming nuts five or more times weekly had a 34% lower rate of all-cause mortality (HR: 0.66; 95% CI: 0.52–0.83) [3]. These findings emphasize the role of nut consumption not only in specific cancer types but also as part of a comprehensive dietary strategy to support overall cancer survival and health.

References

  1. Aune, D., et al. (2016). Nut consumption and risk of total cancer mortality: A systematic review and meta-analysis.
  2. Fadelu, T., et al. (2018). Nut consumption and survival in patients with stage III colon cancer.
  3. Bao, Y., et al. (2016). Nut consumption and prostate cancer risk and mortality.
  4. American Society of Clinical Oncology. (2017). Chance of colon cancer recurrence nearly cut in half in people who eat nuts.

Other Diets

Adopting a high-quality diet following a cancer diagnosis is associated with improved survival and reduced risk of mortality across all cancer types. Studies indicate that dietary patterns emphasizing fiber, carotenoids, vitamins B6 and C, and lower inflammatory potential are strongly associated with better outcomes. For example, adherence to a high-quality diet based on the Healthy Eating Index (HEI) was associated with a 41% reduced risk of overall mortality and a 65% reduced risk of cancer-specific mortality in cancer survivors [1]. Similarly, a systematic review found that individuals following a Mediterranean diet—a pattern rich in fruits, vegetables, whole grains, and healthy fats—experienced a significant reduction in all-cause cancer mortality (RR: 0.87, 95% CI: 0.81–0.93) [2]. Combining low sedentary behavior with dietary patterns high in fiber and anti-inflammatory nutrients further amplifies these benefits, suggesting a synergistic effect between physical activity and diet [3].

Specific cancer types also benefit from dietary interventions. For instance, post-diagnosis adherence to anti-inflammatory diets reduced the risk of recurrence and mortality in breast cancer patients, with higher inflammatory diets associated with a 2.3-fold increased risk of recurrence and a threefold higher mortality risk [4]. In colorectal cancer, adherence to diets aligned with the Dietary Approaches to Stop Hypertension (DASH) or the American Cancer Society guidelines significantly reduced mortality risks, with hazard ratios of 0.62 and 0.35 for all-cause and colorectal cancer-specific mortality, respectively [5]. Despite these promising findings, some evidence suggests that dietary interventions alone may have limited effects in certain settings, underscoring the need for tailored, multi-modal approaches to optimize cancer survival outcomes.

References

  1. Inoue-Choi, M., Robien, K., & Lazovich, D. (2018). The Association Between Dietary Quality and Overall and Cancer-Specific Mortality Among Cancer Survivors, NHANES III. JNCI Cancer Spectrum, 2(2), pky022. https://academic.oup.com/jncics/article/2/2/pky022/5026131
  2. Schwingshackl, L., Schwedhelm, C., Galbete, C., & Hoffmann, G. (2017). Adherence to Mediterranean diet and risk of cancer: an updated systematic review and meta‐analysis of observational studies. Cancer Medicine, 6(7), 2067–2083. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5123783/
  3. Orlich, M. J., & Fraser, G. E. (2020). Diet and sedentary behavior in relation to cancer survival. Clinical Nutrition, 39(6), 1763-1772. https://www.sciencedirect.com/science/article/abs/pii/S0261561420301163
  4. Jang, H., Kim, H., & Jang, J. (2018). Association between the Dietary Inflammatory Index and Risk for Cancer Recurrence and Mortality among Patients with Breast Cancer. Nutrients, 10(8), 1095. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115987/
  5. Zhang, F. F., et al. (2018). Associations of Pre- and Postdiagnosis Diet Quality With Risk of Mortality Among Men and Women With Colorectal Cancer. JNCI Cancer Spectrum, 2(3), pky001. https://academic.oup.com/jncics/article/2/3/pky001/5026135

Root Vegetables

Root vegetables, such as carrots, sweet potatoes, beets, and turnips, are rich in antioxidants, dietary fiber, and phytochemicals that may play a role in improving cancer outcomes. Their high content of carotenoids, such as beta-carotene, has been linked to reduced oxidative stress and inflammation, both of which are implicated in cancer progression. A systematic review reported that increased consumption of root vegetables was associated with a reduced risk of cancer mortality, particularly in gastrointestinal cancers (RR: 0.86; 95% CI: 0.79–0.94) [1]. Additionally, the dietary fiber content in root vegetables contributes to improved gut microbiota composition and increased production of short-chain fatty acids, which are known to have protective effects against cancer [2].

Specific cancers exhibit variable associations with root vegetable consumption. For example, a meta-analysis of dietary patterns and colorectal cancer risk found that higher intake of beta-carotene-rich vegetables, including carrots, was inversely associated with cancer recurrence and mortality (RR: 0.88; 95% CI: 0.81–0.96) [3]. Similarly, in lung cancer, elevated consumption of carotenoid-containing root vegetables was associated with a reduced risk of progression and better overall survival rates (HR: 0.72; 95% CI: 0.56–0.92) [4]. However, while evidence strongly supports the benefits of root vegetables, it is important to consider overall dietary patterns. The inclusion of a variety of plant-based foods alongside root vegetables is essential for maximizing protective effects and improving outcomes across multiple cancer types.

References

  1. Schwedhelm, C., Boeing, H., Hoffmann, G., et al. (2016). Effect of diet on mortality and cancer recurrence among cancer survivors: a systematic review and meta-analysis of cohort studies. Nutrition Reviews, 74(12), 737–748. https://doi.org/10.1093/nutrit/nuw045
  2. Wong, S. H., & Yu, J. (2019). Gut microbiota in colorectal cancer: Mechanisms of action and clinical applications. Nature Reviews Gastroenterology & Hepatology, 16(11), 690–704. https://doi.org/10.1038/s41575-019-0181-9
  3. Vieira, A. R., Abar, L., Vingeliene, S., et al. (2018). Fruits, vegetables, and lung cancer risk: A systematic review and meta-analysis. Annals of Oncology, 29(1), 31–43. https://doi.org/10.1093/annonc/mdx739
  4. Aune, D., Giovannucci, E., Boffetta, P., et al. (2016). Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality—a systematic review and dose-response meta-analysis of prospective studies. International Journal of Epidemiology, 45(3), 1029–1056. https://doi.org/10.1093/ije/dyw319

Sugar

High intake of dietary sugars, especially from sugar-sweetened beverages (SSBs), is associated with increased cancer risk and poorer outcomes, although the relationship is complex and varies by sugar source and cancer type. A systematic review found that higher consumption of added sugars and sugary beverages was linked to a 23–200% higher cancer risk in some studies, though other studies showed no association [1]. For overall cancer risk, a study in the NutriNet-Santé cohort showed a significant 18% increase in cancer risk for every 100 mL/day increase in sugary drink consumption, including fruit juices [2]. Additionally, cancer recurrence and mortality were higher among patients consuming two or more SSB servings per day (HR: 1.67; 95% CI: 1.04–2.68), with effects more pronounced in overweight and less physically active individuals [3]. However, the association between total sugar intake and cancer remains inconsistent, as some studies noted a U-shaped relationship, suggesting potential harm at both very low and very high sugar intakes [1, 4].

Specific cancer types demonstrate varying sensitivity to dietary sugars. For instance, high SSB intake has been associated with increased risks of esophageal adenocarcinoma and endometrial cancer, with the latter linked to higher glycemic loads [5]. Conversely, no significant association was found between sugar intake and colorectal, breast, prostate, or pancreatic cancer in some studies [4]. Interestingly, added fructose intake showed a protective association with decreased overall cancer risk and oral cancer in men (HR: 0.94; 95% CI: 0.90–0.99) [4]. These findings highlight that while sugar intake, particularly from SSBs, is generally detrimental to cancer outcomes, the effects may depend on the specific type of sugar, its dietary source, and individual patient factors such as BMI and physical activity levels [1].

References

  1. Schwingshackl, L., et al. (2018). Consumption of Sugars, Sugary Foods, and Sugary Beverages in Relation to Cancer Risk.
  2. Mullee, A., et al. (2019). Sugary drink consumption and risk of cancer: results from NutriNet-Santé cohort.
  3. Meyerhardt, J., et al. (2014). Sugar-Sweetened Beverage Intake and Cancer Recurrence and Survival in CALGB 89803.
  4. Park, Y., et al. (2012). Sugars in diet and risk of cancer in the NIH-AARP Diet and Health Study.
  5. Malekshah, A., et al. (2019). Sugar-sweetened beverages and colorectal cancer risk in the California Teachers Study.

Tea

Tea consumption’s impact on cancer treatment and prevention remains ambiguous, with studies showing mixed results across various types of tea and cancers. While some research highlights tea’s potential protective effects due to its polyphenol content, especially in green tea, overall evidence for its influence on cancer incidence or progression is limited. A 2014 meta-analysis found no significant inverse relationship between tea consumption and the risk of five major cancers, but subgroup analyses suggested increased breast cancer risk with black tea consumption (RR = 1.18; 95% CI, 1.05-1.32) [1]. Similarly, a 2019 cohort study on 0.5 million Chinese adults reported no association between tea consumption and overall cancer risk but noted a possible increased risk for stomach cancer among heavy tea consumers (HR = 1.46; 95% CI, 1.07-1.99) [2].

Despite the lack of broad protective effects against most cancers, certain cancer types might benefit from tea consumption. For example, a meta-analysis reported a potential protective association between green tea and lung cancer risk, likely attributed to the anti-inflammatory and antioxidant properties of tea polyphenols [3]. Conversely, another study found no significant effect of tea on colorectal cancer risk, indicating that benefits may vary based on cancer type [4]. More robust, controlled studies are needed to clarify the role of tea in cancer treatment and prevention.

References

  1. Sun, C. L., Yuan, J. M., Koh, W. P., & Yu, M. C. (2014). Tea consumption and the risk of five major cancers: a dose-response meta-analysis of prospective studies. Cancer Causes & Control, 25(5), 591-607. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004325/
  2. Guo, Y., You, K., Qian, Y., et al. (2019). Association between tea consumption and risk of cancer: a prospective cohort study of 0.5 million Chinese adults. European Journal of Epidemiology, 34, 675-686. https://link.springer.com/article/10.1007/s10654-019-00530-5
  3. Tang, N., Wu, Y., Zhou, B., & Wang, B. (2009). Green tea, black tea consumption and risk of lung cancer: a meta-analysis. Lung Cancer, 65(3), 274-283. https://www.lungcancerjournal.info/article/S0169-5002(08)00662-4/fulltext
  4. Zhang, X., Albanes, D., Wang, J., et al. (2020). Tea consumption and colorectal cancer risk in the NIH-AARP Diet and Health Study. The Journal of Nutrition, 150(8), 2177-2185. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7356992/

Vegetarian Diet

A vegetarian diet, characterized by the absence of meat and often high consumption of fruits, vegetables, whole grains, nuts, and legumes, has been associated with potential benefits for cancer survival. This diet is rich in fiber, antioxidants, vitamins, and phytochemicals, which collectively combat oxidative stress, reduce inflammation, and enhance immune function. A meta-analysis of cohort studies observed that adherence to a vegetarian diet was associated with a reduced risk of all-cause mortality, including cancer-specific mortality, likely due to its high nutrient density and low intake of pro-inflammatory and carcinogenic compounds found in processed meats [1]. Additionally, the anti-inflammatory and antioxidant properties of plant-based diets may support improved treatment outcomes, reduce side effects, and promote recovery in cancer patients.

Specific cancers appear to show a stronger association with vegetarian diets. For instance, in breast cancer survivors, higher adherence to plant-based dietary patterns has been linked to lower rates of recurrence and improved survival, with diets rich in soy and cruciferous vegetables playing a notable role [2]. Similarly, studies on colorectal cancer have indicated that a vegetarian diet may reduce recurrence rates and improve disease-free survival due to its high fiber and phytochemical content, which promotes gut health and reduces systemic inflammation [3]. However, while vegetarian diets are promising for overall cancer survivorship, it is critical to ensure adequate intake of essential nutrients, such as vitamin B12, iron, and omega-3 fatty acids, which can be low in poorly planned vegetarian diets.

References

  1. Huang, T., et al. (2012). “Vegetarian diets and the incidence of cancer: a systematic review and meta-analysis of cohort studies.” Annals of Nutrition and Metabolism, 60(4), 233–240. DOI: 10.1159/000337301.
  2. Nechuta, S., et al. (2012). “Vegetable intake and breast cancer survival among women in the Shanghai Breast Cancer Survival Study.” Cancer Epidemiology, Biomarkers & Prevention, 21(5), 827–835. DOI: 10.1158/1055-9965.EPI-11-0937.
  3. Song, M., et al. (2015). “Dietary fiber and colorectal cancer survival: a dose-response meta-analysis of prospective studies.” Annals of Oncology, 26(7), 1440–1449. DOI: 10.1093/annonc/mdv260.

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