Cancer
Cancer is a condition in which some body cells proliferate uncontrollably and spread to other regions of the body. Although the mortality rate from cancer has decreased since the early 1990s, it remains the second leading cause of death in the United States. To reduce cancer risk, your patients can eat well, move more, and make healthy choices.
Diet and Cancer
The American Institute for Cancer Research (AICR) recommends selecting plant foods with high nutritional value. For example, consuming nutrient-rich whole plant foods, such as fruits, vegetables, beans, nuts, and whole grains, and restricting sugar-sweetened beverages and ultra-processed foods containing excessive added fats, starches, or sugars. Avocados are a naturally nutrient-dense fruit. According to the AICR, non-starchy vegetables and fruits may protect against cancers of the mouth, pharynx, larynx, esophagus, colon, rectum, and stomach. Avocados are a non-starchy fruit. Moreover, if your patients have cancer, avocado may help if they have nausea because it is easy on the stomach.
Avocado and Cancer
Several peer-reviewed papers have delved into the connection between avocado and its nutrients with respect to cancer. A Harvard study1 of 45,289 men and 67,039 women examined the association between regular weekly avocado consumption of a half cup or half avocado.
Regular avocado intake was linked to a lower risk of total cancer and reduced risk of colorectal, lung, and bladder cancers in men.
Results were mixed for women across the study cohorts. While findings differed among women who consumed the same amount of weekly avocados, no associations were observed with total, endometrial or ovarian cancer risk. A preliminary association between avocado intake and increased risk of breast cancer was seen in post-menopausal women and women without diabetes; however this surprising finding was not replicated in an additional analysis using a more recent database.
Avocados are a good source of vitamin K. In a Danish study2 of 56,048 participants, reported moderate-to-high (87–192 µg/d) vitamin K intake was linked with reduced risk of all-cause mortality, CVD-related mortality, and cancer-related mortality 23 years later. Cancer findings were limited to current/former smokers. Dietary intake was not assessed after baseline and vitamin K was not validated in the food frequency questionnaire.
Avocados are also a good source of folate, providing one third of a medium avocado provides 45 mcg of folate. Two studies have examined the relationship between folate and cancer and found similar findings.
In a meta-analysis3 of over 700,000 participants, researchers identified that women with a daily folate intake of 153-400 mcg is associated with reduced risk of breast cancer. A 100 μg per day increase of dietary folate leads to an ∼9% reduction in breast cancer risk.
Intake of <153 mcg and >400 mcg folate showed mixed results by study type. The findings were limited to women with higher alcohol intake levels. Similarly, in a 12.5 year cohort study4 of 101,700 participants, higher intake of food folate and fortified folic acid in foods was associated with decreased risk of head and neck cancer. The study was not powered to look at cancer subsites.
Other studies have examined the association between unsaturated fats and cancer. Avocados contain 5 grams of MUFA and 1 gram of PUFA per one-third of a medium avocado. A study5 compared how dietary fat, assessed by food frequency questionnaire, impacted risk for hepatocellular carcinoma (HCC) in 1675 hospital patients compared to their cancer-free spouses. Reported intake of monounsaturated fat (MUFA) and Omega-3 polyunsaturated fat (PUFA) were linked with reduced risk for HCC among study participants. HCC was not associated with saturated fat intake. Likewise, a case-control study6 of Jamaican men (209 cases, 226 controls) found higher monounsaturated fatty acid (MUFA) intake was linked to lower prostate cancer risk, along with an inverse association between whole blood oleic acid percentage and prostate cancer in study participants. The results lack causation and need validation in larger, more diverse populations.
Lastly, avocados are a good source of fiber. A systematic review and independent assessment7 by a panel of leading international scientists report there is strong scientific evidence connecting the consumption of foods containing dietary fiber to the decreased risk of colorectal cancer.
The findings from these highlighted studies do not demonstrate causation. Further research is needed to establish causality and translate the findings to a larger, more general population.
Avocado Recipes
Eating a diet rich in some vegetables and fruits, as part of an overall healthy diet, may protect against certain types of cancers. Avocados are a fresh fruit that can enhance the nutrient quality of the diet. The Avocado Nutrition Center provides a selection of avocado recipe ideas designed to meet various dietary preferences. Whether for breakfast or side dishes, these recipes can be incorporated for your patients. Explore the collection of avocado recipes at: https://loveonetoday.com/avocado-recipes/
References:
1. Prospective Study of Avocado Consumption and Cancer Risk in U.S. Men and Women | Cancer Prevention Research | American Association for Cancer Research. Accessed September 26, 2023. https://aacrjournals.org/cancerpreventionresearch/article-abstract/16/4/211/718840/Prospective-Study-of-Avocado-Consumption-and?redirectedFrom=fulltext
2. Palmer CR, Bellinge JW, Dalgaard F, et al. Association between vitamin K1 intake and mortality in the Danish Diet, Cancer, and Health cohort. Eur J Epidemiol. 2021;36(10):1005-1014. doi:10.1007/s10654-021-00806-9
3. Chen P, Li C, Li X, Li J, Chu R, Wang H. Higher dietary folate intake reduces the breast cancer risk: a systematic review and meta-analysis. Br J Cancer. 2014;110(9):2327-2338. doi:10.1038/bjc.2014.155
4. Kawakita D, Lee YCA, Gren LH, Buys SS, La Vecchia C, Hashibe M. The impact of folate intake on the risk of head and neck cancer in the prostate, lung, colorectal, and ovarian cancer screening trial (PLCO) cohort. Br J Cancer. 2018;118(2):299-306. doi:10.1038/bjc.2017.383
5. Moussa I, Day RS, Li R, et al. Association of dietary fat intake and hepatocellular carcinoma among US adults. Cancer Medicine. 2021;10(20):7308-7319. doi:10.1002/cam4.4256
6. Jackson MD, Walker SP, Simpson-Smith CM, et al. Associations of whole-blood fatty acids and dietary intakes with prostate cancer in Jamaica. Cancer Causes Control. 2012;23(1):23-33. doi:10.1007/s10552-011-9850-4
7. Colorectal cancer | What causes colorectal cancer? WCRF International. Accessed February 7, 2024. https://www.wcrf.org/diet-activity-and-cancer/cancer-types/colorectal-cancer/
