Diet and Cancer: Perils, Prevention Measures, and Additional Insights

Dietary influences on cancer risk, precautions, and further information

In the ongoing quest for understanding the relationship between diet and cancer, numerous studies have been conducted to explore various nutrients and food groups. Here's a summary of some key findings.

The National Institutes of Health's Office of Dietary Supplements recommends that most adults should aim for 600 IU of vitamin D daily. However, evidence from randomized controlled trials suggests that vitamin D supplements do not lower the risk of cancer development overall or of developing specific cancers. In fact, higher vitamin D levels may be associated with an increased risk of prostate and pancreatic cancer.

A healthy diet across the life span may reduce a person's risk of certain cancers, such as breast, colon, and rectal cancers. This diet includes foods high in vitamins, minerals, and other nutrients, vegetables in a variety of colors, fruits, especially whole fruits, in a variety of colors, fiber-rich legumes, whole grains, and limits or does not include processed meats, red meats, highly processed foods, refined grain products, sugar-sweetened beverages, alcohol, and dietary patterns with the most benefits tend to be those based primarily on plant foods, healthy protein sources, and unsaturated fats.

Some evidence suggests that dairy products and calcium may reduce the risk of colorectal and breast cancer, but due to research suggesting dairy products and calcium may increase prostate cancer risk, experts do not make recommendations about the consumption of dairy products for cancer prevention.

Observational studies and randomized controlled trials have explored the association between vitamin D and cancer risk, but the results are not conclusive. On the other hand, the World Cancer Research Fund and the American Institute for Cancer Research suggest that diets high in plant foods and low in refined carbohydrates and animal products may decrease the risk of breast cancer.

Fruits and vegetables, rich in vitamins, minerals, fiber, and other nutrients, may help lower cancer risk. Research is ongoing to determine whether properties in the following fruits and vegetables may prevent cancer: dark green vegetables, cruciferous vegetables, soy products, allium vegetables, legumes, tomato products. Soy, a nutrient-dense source of protein, contains isoflavones and some studies suggest that consuming soy may decrease the risk of prostate and breast cancers.

Avoiding certain foods and beverages can help relieve diarrhea during cancer treatment. These include high fiber foods, sugar-sweetened beverages, fried, fatty, or greasy foods, gas-causing foods, regular milk products, spicy foods, alcohol, sugar-free products sweetened with sorbitol or xylitol, caffeinated foods or drinks, and foods that cause constipation like cocoa, dark chocolate, pureed apple, pureed banana, and strongly brewed black tea.

During cancer treatment, it is advisable to avoid processed, smoked, and cured meats as well as excessive red meat. People with a sore mouth and throat can try avoiding spicy foods, citrus fruits, salty foods, raw vegetables, tomatoes and ketchup, sharp or crunchy foods, alcohol, to help relieve symptoms.

People with dry mouth should avoid alcohol, spicy, salty, hard, sour, or crunchy foods, tobacco products, secondhand smoke, and mouthwash containing alcohol. Consuming alcohol may increase the risk of several types of cancer, including breast, colorectal, endometrial, liver, lung, mouth, throat, and esophageal cancers.

Lastly, drinking coffee may reduce the risk of endometrial cancer, liver cancer, cancers of the mouth, throat, and voice box, basal cell skin cancer, and melanoma, but it is unclear how coffee may reduce cancer risk. A whole grain is a grain that contains all the parts of the original kernel, including the bran, germ, and endosperm. Whole grains are richer in fiber and other nutrients than refined grains. Eating fiber-rich foods decreased the occurrence of chronic diseases, including colorectal cancer, according to a series of systemic reviews and meta-analyses published in 2019.

In conclusion, maintaining a balanced diet rich in fruits, vegetables, whole grains, and fiber-rich foods, while limiting processed meats, red meats, highly processed foods, refined grain products, sugar-sweetened beverages, alcohol, and dietary patterns with the most benefits tend to be those based primarily on plant foods, healthy protein sources, and unsaturated fats, may help reduce the risk of certain cancers. However, more research is needed to fully understand the relationship between specific nutrients and cancer risk.