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Can foods and exercise prevent or lower the risk of cancers?

Foods, vitamins, and certain minerals can help lower the risk of cancers.

Foods, vitamins, and certain minerals can help lower the risk of cancers, such as:

  • Plant-based foods : These foods are high in natural compounds called phytonutrients, such as
    • Carotenoids or carotenes, common in red, orange, yellow, or certain dark green leafy vegetables.
    • Polyphenols in spices, herbs, vegetables, tea, coffee, chocolate, nuts, apples, onions, and berries.
    • Alliums are found in chives, garlic, leeks, and onions.

Phytonutrients in fruits and vegetables can reduce cancer risks by controlling hormones such as estrogens and other substances. They can prevent inflammation, cancer cell growth and decrease free radicals.

Plant-based foods, which are studied and found capable of preventing cancers, consist of:

    • Cruciferous vegetables include broccoli, cauliflower, cabbage, brussels sprouts, bok choy, and kale. Eating these vegetables can help control the cancer-protective enzyme, stop the proliferation of cancer cells, and lower the risk of developing cancers, e.g., head and neck cancer, esophageal cancer, and gastric cancer.
    • Lycopene is found in pink grapefruits, watermelons, and apricots. Studies show that lycopene can lower the risk of developing cancer, e.g., lung cancer, gastric cancer, and prostate cancer; however, there is no direct association.
    • Soybeans contain specific phytonutrients which can prevent some types of cancer, according to a study. The association between soybeans and breast cancer is complicated and unclear. Some research suggests that taking 3 daily servings of soybeans is safe and can reduce the risk of breast cancer. But other studies do not recommend eating soybeans to decrease breast cancer risk. Concentrated isoflavone pills or powder should also be avoided.
  • Vitamins, minerals, and antioxidants include beta-carotene, selenium, vitamin C & E, calcium, iodine, and vitamin A, D, E, K and B. The antioxidants can prevent cell damage from free radicals, which are generated from the normal metabolic process of cells or through external factors such as pollution or smoking.

Our body needs vitamins and minerals for growth and repair. Vitamins and minerals act as antioxidants. However, it is still unclear if antioxidants can prevent cancer.

    1. Beta-carotene: High-dose beta-carotene cannot prevent cancer. Two large-scale studies fail to show risk reduction of high dose beta-carotene for lung cancer in people with an increased risk of developing lung cancer, i.e., those who are smokers or ex-smokers and those exposed to asbestos.
    2. Calcium and vitamin D: Based on a large-scale study of postmenopausal women with healthy nutrition, calcium and vitamin D do not affect the risk of developing colorectal cancer.
    3. Folate: Green leafy vegetables, fruits, fruit juice, and legumes. A study on folate and cancer risk found that people with low folate have an increased risk of breast cancer, colon cancer, and pancreatic cancer. But other studies do not show the benefit of folate supplements in cancer prevention.
    4. Multivitamins: The evidence for cancer risk reduction by taking multivitamins is lacking in most studies. However, one shows a beneficial trend; people taking multivitamins for more than 10 years have a lower risk of developing large bowel polyps, which can lead to colorectal cancer if not removed. Nevertheless, the result is hard to interpret because the study subjects are healthy and receive regular colorectal screening.
    5. Selenium: According to a study, selenium supplement fails to prevent skin cancer, but it can help reduce the risk of prostate, lung, and colorectal cancer. Some studies found an increased risk of diabetes; therefore, one should be cautious with selenium supplement.
    6. Vitamin C: Only certain studies demonstrated gastric cancer prevention by taking vitamin C.
    7. Vitamin E: A large study found that taking vitamin E increases prostate cancer risk. High-dose vitamin C & E increases the risk of head and neck cancer recurrence
  • Dietary fibers increase stool bulk, stimulate bowel movements, and help strengthen the gastrointestinal microbiome, reducing cancer risk. Foods that are rich in dietary fibers are:
    • Whole grains such as barley, kamut, spelt, bulgur, corn, psyllium, and rye.
    • Whole wheat bread and pasta
    • Nuts and legumes
    • Fruits and vegetables
  • Protein: Animal proteins such as beef, fish, poultry, eggs, and dairy products. Limit the intake of red meat, i.e., pork, mutton, and beef, and processed meat, e.g., sausage, ham, bacon, and salami, because their regular consumption increases the risk of colorectal cancer.
  • Alcohols: Drinking alcohols increase the risk of certain cancers such as head and neck, breast, liver, esophageal, and colorectal cancer.

Obesity
People who are overweight or obese have a higher risk of developing various cancers, including breast, uterine, esophageal, gallbladder, bowel, pancreatic, and thyroid cancer. Taking in more than what is needed contributes to weight gain. Food high in sugar and fat lead to obesity, such as:

  • Sweetened beverages such as soft drinks and flavored fruit juice.
  • Dairy products such as full-fat milk and cheese.
  • Fatty meat such as deep-fried chicken skin, duck, bacon, ham, or sausage.

Exercise can reduce the risk of many cancers, for example:

  • Colorectal cancer: In a study comparing people who are physically active versus sedentary people, it is found that people who exercise regularly have a 40-50% lower risk of colorectal cancer.
  • Breast cancer: In women who do moderate exercise or work out more than 3 hours a week, the risk of developing breast cancer decreases by 30-40%; this is also true for those with a family history of breast cancer. Some studies show that high-intensity exercise can reduce cancer risk, though the intensity threshold was not established. Exercise or being physically active can reduce the risk of breast cancer in all age groups.
  • Uterine cancer: Some studies found a correlation between exercise and decreased risk of uterine cancer.
  • Lung cancer: Many studies show that the risk of developing lung cancer is lower in those who exercise regularly.






    Article by
    Dr Siyamol Mingmalairak
    Oncology
    Doctor profile