Fruits
Fruits are the ripened ovaries of flowering plants, commonly known for their sweet and fleshy parts that are a significant part of the human diet. Examples of popular fruits include cherries, peaches, plums, apples, strawberries, and oranges. They are not only enjoyed for their flavor but also for their health benefits, particularly due to their rich content of phytochemicals, which may help protect against certain cancers. Compounds like carotenoids, vitamins (especially C and E), and dietary fiber found in fruits play crucial roles in antioxidant activity, immune system support, and the maintenance of cellular health.
Research indicates a strong link between fruit consumption and reduced cancer risk, although findings can be inconsistent. Regular intake of fruit is associated with benefits such as improved cell differentiation, lower estrogen levels, and enhanced immune function. While no single fruit can guarantee cancer prevention, incorporating a variety of fruits into a balanced diet is recommended for overall health. Generally, fruits are safe to consume, though excessive intake may lead to gastrointestinal discomfort for some individuals.
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Fruits
DEFINITION: Botanically, fruit is defined as the ripened ovary of an angiosperm or flowering plant. In the human diet, fruit generally refers to the sweet and fleshy parts of certain plants. Examples of fruits include cherries, peaches, plums, apples, strawberries, and oranges.
How phytochemicals work: Fruits contain many phytochemicals that are believed to have an inverse relationship to cancer incidence or at least act as a protective agent against cancer-causing substances in the human body. Some of these chemicals believed to be active include allium compounds, carotenoids, coumarins, dietary fiber, dithiolthiones, bioflavonoids, folic acid, endole-3-carbinol, inositol hexaphosphate, isoflavones, isothiocyanates, D-limonene, phytosterols, protease inhibitors, saponins, selenium, and vitamins, especially vitamins C and E.
Carotenoids, including alpha- and beta-carotene, lutein, and lycopene, are found in yellow and orange vegetables and fruits and act as antioxidants to maintain the functioning of the immune system. Antioxidants bind to free radicals in the human body. Free radicals are unstable molecules that lack a sufficient number of electrons and can damage genetic material and proteins. This disrupts cell molecules and chemical processes, making cells more susceptible to cancer. When the amount and availability of free radicals in cells and tissues are decreased, the likelihood of cells becoming cancerous is similarly decreased. Studies have also suggested that carotenoids stimulate the manufacture of detoxifying enzymes and inhibit the formation of cancer cells by regulating communication between cancer cells. Ascorbic acid, or vitamin C, functions in a similar manner and can be found in citrus fruits and strawberries. Folic acid, also found in citrus fruits, is involved in the synthesis, repair, and function of deoxyribonucleic acid (DNA), while dietary fiber encourages peristalsis and, in turn, the elimination of harmful wastes and estrogens.
How fruits help: Overall, the benefits of moderate fruit intake in the diet include cell differentiation (which decreases cell proliferation), antioxidant potential, increase in activity of naturally protective enzymes, lower estrogen levels, and enhanced immune function.
Research shows a strong relationship between overall health and fruit consumption. Total cancer risk may decrease in populations that receive adequate amounts of fruit per day, although study findings are inconsistent. The correlation may even be stronger than the results indicate, as studies on the relationship between increased fruit intake and reduced cancer rates must track a healthy person over many years to assess the relationship to subsequent cancer incidence, which involves reliance on memory before the cancer diagnosis. Additional studies analyzing the relationship between increased fruit intake and the reduction of various specific cancers have been ongoing for decades, but the American Cancer Society suggests consuming adequate amounts of fruit may help prevent bowel, mouth, throat, stomach, and lung cancer. While researchers state there is no one fruit that could completely prevent cancer, eating fruit as part of an overall healthy lifestyle could lead to fewer cancer cases.
Side effects: Generally, no side effects are experienced from eating fruit. However, excessive dietary intake of fruit may cause gastrointestinal discomfort in some individuals and increase the incidence or extent of diarrhea in others.
Bibliography
“Antioxidants and Cancer Prevention.” National Cancer Institute, 6 Feb. 2017, www.cancer.gov/about-cancer/causes-prevention/risk/diet/antioxidants-fact-sheet. Accessed 12 June 2024.
Campo, Nikki. “Can Certain Foods Reduce Cancer Risk? Which Ones Experts Recommend.” The New York Times, 29 Nov. 2023, www.nytimes.com/2023/11/27/well/eat/food-diet-cancer-risk.html. Accessed 12 June 2024.
“Diet Choices to Prevent Cancer - familydoctor.org.” FamilyDoctor.org, 19 Aug. 2022, familydoctor.org/cancer-diet-choices-to-prevent-cancer. Accessed 12 June 2024.
Tanaka, Takuji, Masahito Shnimizu, and Hisataka Moriwaki. "Cancer Chemoprevention by Carotenoids." Carotenoids. Spec. Issue of Molecules, vol. 17.3, 2012, pp. 3202–42.
“Tips for Eating Healthier - Eating to Reduce Cancer Risk.” American Cancer Society, 18 Oct. 2021, www.cancer.org/cancer/risk-prevention/diet-physical-activity/eat-healthy/add-fruits-and-veggies-to-your-diet.html. Accessed 12 June 2024.
Xia Wang, et al. "Fruit and Vegetable Consumption and Mortality from All Causes, Cardiovascular Disease, and Cancer: Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies." British Medical Journal, vol. 349.g4490, 2014, pp. 1–14.