Peanuts and Cancer

Peanut compounds as ingredients for cancer prevention

While dietary patterns that are high in fried foods, sugary drinks, saturated fats, and processed foods increase the risk for many cancers [3], a diet that emphasizes plant foods like peanuts is protective against cancer [4, 5]. Plant-based foods are high in phytochemicals, some of which block the activation of cancer-causing substances and enhance the immune system [6]. In fact, over 25,000 phytochemicals have been identified as cancer-protective substances. Peanuts appear to be particularly effective in cancer protection because they contain a large number of these phytochemicals [7].

For example, resveratrol is a potent antioxidant found in peanuts that protects against breast cancer by preventing toxicity to the cells [7]. Resveratrol is also protective against brain, skin, stomach, and pancreatic cancers [7]. Additionally, peanuts are a source of phytosterols, chemicals that inhibit colon, breast, and prostate cancer cells [8]. These chemicals have blocked prostate cancer cell growth by as much as 40% [6]. And there are even more benefits contained in peanut skins. A 2021 study showed protective effects of peanut skin procyanidins on prostate cancer cell damage [9], and a 2018 study showed that compounds found in the skins inhibit human prostate cancer cells from growing and induce cancer cell death [10].

What about lectins?

Some have wondered, “What about lectins in peanuts—do they have a negative impact on the development of cancer?”

Lectins are naturally-occurring proteins that are widespread in plant foods like peanuts, walnuts, tomatoes, cucumbers, and cherries. As with many foods and even water, consuming large amounts of lectins could be problematic. However, they are largely reduced in the cooking process. Further, eating plant foods like peanuts is consistently associated with reduced cancer risk, inflammation, and other positive health outcomes. You can read more about lectins here.

Evidence on peanut consumption and cancer risk

Research has demonstrated the potential for peanut consumption to impact cancer prevention. A 2020 study published in Advanced Nutrition showed a reduction in risk of cancer incidence and mortality with peanut and tree nut consumption [11]. Another study done in China examined dietary behaviors that impact the risk of esophageal cancer, which is ranked as the top 10th malignancy in China [12]. The study found that those who consumed peanuts 1-3 times per week reduced their esophageal cancer risk by 38%, and those who consumed peanuts 4 times or more per week reduced that risk by as much as 70% [12]. The Netherlands Cohort Study, which followed over 120,000 people for 20 years, showed that men who consumed just 5 grams (1 teaspoon) or more of peanut butter daily had a 47% reduced risk of a pancreatic cancer diagnosis [13]. Data from the same cohort study showed that peanut consumption also reduced the risk for a hard-to-treat strain of breast cancer in older women [14]. These and other studies agree with previous results that have highlighted the protective effects of peanuts. More research is needed to more fully understand the impact of peanut consumption on cancer risk, progression, and mortality.

The good news

The good news is that while cancer may be on the rise, healthy lifestyles that include plant foods like peanuts can help to decrease risk. Including this small nut may not only be a tasty addition to the menu; it can have a significant impact on cancer prevention.

References

1. World Health Organization Cancer: Key Facts. 2018; Available from: http://www.who.int/news-room/fact-sheets/detail/cancer.
2. American Cancer Society. Cancer Facts and Figures 2018. 2018; Available from: https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/annual-cancer-facts-and-figures/2018/cancer-facts-and-figures-2018.pdf.
3.  Abid, Z., A.J. Cross, and R. Sinha, Meat, dairy, and cancer. Am J Clin Nutr, 2014. 100 Suppl 1: p. 386s-93s.
4. Craig, W.J. and A.R. Mangels, Position of the American Dietetic Association: vegetarian diets. J Am Diet Assoc, 2009. 109(7): p. 1266-82.
5. Dreher, M.L., Dietary Patterns, Whole Plant Foods, Nutrients and Phytochemicals in Colorectal Cancer Prevention and Management, in Dietary Patterns and Whole Plant Foods in Aging and Disease. 2018, Springer International Publishing: Cham. p. 521-555.
6. Arya, S.S., A.R. Salve, and S. Chauhan, Peanuts as functional food: a review. J Food Sci Technol, 2016. 53(1): p. 31-41.
7. Anand, P., et al., Cancer is a Preventable Disease that Requires Major Lifestyle Changes. Pharmaceutical Research, 2008. 25(9): p. 2097-2116.
8. Awad, A.B., et al., Peanuts as a Source of β-Sitosterol, a Sterol With Anticancer Properties. Nutrition and Cancer, 2000. 36(2): p. 238-241.
9. Yan, F., et al., Protective effect of procyanidin A-type dimers against H(2)O(2)-induced oxidative stress in prostate DU145 cells through the MAPKs signaling pathway. Life Sci, 2021. 266: p. 118908.
10. Chen, L., et al., Procyanidin from peanut skin induces antiproliferative effect in human prostate carcinoma cells DU145. Chem Biol Interact, 2018. 288: p. 12-23.
11. Naghshi, S., et al., Association of Total Nut, Tree Nut, Peanut, and Peanut Butter Consumption with Cancer Incidence and Mortality: A Comprehensive Systematic Review and Dose-Response Meta-Analysis of Observational Studies. Adv Nutr, 2021. 12(3): p. 793-808.
12. Yanjie, Z., et al., Peanut consumption associated with a reduced risk of esophageal squamous cell carcinoma: A case–control study in a high-risk area in China. Thoracic Cancer, 2018. 9(1): p. 30-36.
13. Nieuwenhuis, L. and P.A. van den Brandt, Total Nut, Tree Nut, Peanut, and Peanut Butter Consumption and the Risk of Pancreatic Cancer in the Netherlands Cohort Study. Cancer Epidemiology Biomarkers & Prevention, 2018. 27(3): p. 274.
14. van den Brandt, P.A. and L. Nieuwenhuis, Tree nut, peanut, and peanut butter intake and risk of postmenopausal breast cancer: The Netherlands Cohort Study. Cancer Causes & Control, 2018. 29(1): p. 63-75.