We all know that what we eat affects how we feel, and a healthy diet is key to preventing many diseases. Laura Kerwin, MS, RDN, CD, registered dietitian, Parkview Regional Medical Center, shares some thoughts on the role of diet in cancer prevention and treatment and what foods to avoid.

Diet to prevent cancer.

Although no single food or food alone can prevent cancer, studies have shown that foods rich in vegetables, fruits, whole grains, beans, and legumes can reduce the risk of several types of cancer. Some foods contain substances and chemicals that help prevent cancer. Phytochemicals that occur naturally in plants reduce inflammation (which can increase cancer risk), strengthen the immune system, and provide many other cancer-fighting chemicals.

Antioxidants destroy chemicals known as free radicals, which damage cells and increase the risk of cancer. A variety of antioxidants are found in certain foods and beverages. Examples of dietary antioxidants are lycopene, beta-carotene, and vitamins A, C, and E found in various fruits and vegetables. Antioxidants called catechins found in tea reduce the risk of cancer. Fiber-rich foods have been shown to significantly reduce the risk of colorectal cancer, especially when associated with colon carcinogens.

Many studies have shown that many vitamins, minerals and phytochemicals have anti-cancer effects, but there is evidence that many common dietary compounds are beneficial for certain types of cancer.

When combined with a balanced diet, the five foods mentioned below can help prevent various types of cancer.

Brussels sprouts, broccoli and other cruciferous vegetables

Dark green vegetables including spinach

Berry

Bright orange vegetables and fruits, including sweet potatoes, carrots and green peppers

White garlic

Avoid food.

Almost any food is relatively safe when eaten in moderation, but studies have shown that some foods may increase the risk of certain types of cancer. Although these may cause a small increase in your risk of cancer, replacing these foods with healthy foods in your diet will not only lower your cancer risk but also improve your overall health. For example, processed foods have little or no nutritional value. Anyone with or without cancer can generally benefit from focusing on healthy eating and avoiding processed foods when possible.

Another example is sugar. Our body needs sugar (glucose) to function. Glucose in the body provides the energy we need to carry out our daily activities. Healthy sources of sugar include fruits, some vegetables, whole grain bread products, and low-fat dairy products. When people eat a lot of things like candy, fast food, and sugary drinks, it can lead to weight gain. Too much fat puts people at risk of diseases such as cancer, diabetes, heart disease and obesity.

The way food is prepared also affects risk factors. Most people don’t realize that fried or undercooked meat increases the risk of cancer. Prolonged cooking of meat, especially at high temperatures, releases carcinogens such as heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs).Cooking meat above 300 degrees F and using direct heat (such as a grill) increases the amount of this carcinogen. Cooking methods such as boiling, boiling and frying can significantly reduce the amount of these carcinogens. If you overcook the meat in the oven or on the stove, you can always cut off the burnt parts.

Tips to reduce exposure to these carcinogens include: avoiding deep frying, using microwave ovens to reduce cooking time before roasting meat at high temperatures, and continuous frying of meat.

Top 5 foods that increase the risk of cancer:

Red meat is good

Prepared meats, including packaged sausages, cold cuts, bacon, sausages and hams

AlcoholHigh-fat foods such as fried foods and potato chips

More sugar

Diet during cancer diagnosis.

Just as there are foods that can help prevent cancer, there are also foods (or herbs) that can help reduce the side effects of treatment. Any patient taking herbal remedies is advised to consult an oncologist before starting treatment. In general, depending on the location of the tumor, it is important for people to eat a healthy, nutritious diet.

Some foods are hard to name when they cause cancer. The location of the cancer makes certain foods intolerable, and not everyone will experience the side effects of chemotherapy. Patients will benefit from seeing a nutritionist before, during and after treatment to ensure a personalized diet.

Nutrition during cancer treatment

From chemotherapy, radiation therapy and surgery to immunotherapy, hormone therapy and clinical trials, there have never been more options for treating cancer. Additional treatment options may have additional side effects. Most of these side effects can be treated with proper nutritional therapy. The main foods to consider during cancer treatment are protein, carbohydrates, fats, water, vitamins and minerals.

Protein requirements are generally increased for muscle strength and repair, infection prevention, disease recovery, and tissue repair. Carbohydrate sources are important, and choosing whole grains and complex carbohydrates over simple carbohydrates and sugary foods will promote sustained energy and nutrition. “Healthy” monounsaturated and polyunsaturated fats are better for treating heart disease and controlling cholesterol than “unhealthy” saturated and trans fats. Hydration is especially important if vomiting or diarrhea occurs, requiring more than 64 ounces of fluid per day to maintain balance and restore cell health.

Fluid requirements are not limited to water, but include soups, stews, milk, and gelatin. Vitamin and mineral requirements may increase, especially if appetite is reduced, so a multivitamin or mineral supplement may be a suitable alternative source of nutrients needed to boost energy in the body’s systems.

Reference

https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/cancer-and-food#:~:text=Summary&text=High%2Dfat%2C%20low%2Dfibre,the%20risk%20of%20many%20cancers.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9414571/

https://www.americanoncology.com/blogs/the-nutrition-and-cancer-prevention-understanding-the-role-of-diet

https://pubmed.ncbi.nlm.nih.gov/32543948/

https://www.parkview.com/blog/the-role-of-food-for-cancer-prevention-and-treatment

https://www.mdanderson.org/prevention-screening/manage-your-risk/diet.html

The Importance of Nutrition in Cancer Prevention & Treatment

https://www.helpguide.org/wellness/nutrition/cancer-prevention-diet

Preventing Cancer

https://www.researchgate.net/publication/362724326_The_Role_of_Diet_and_Nutrition_in_Cancer_Prevention_Treatment_and_Survival

https://acsjournals.onlinelibrary.wiley.com/doi/10.3322/canjclin.46.6.325

https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/diet-and-cancer