Nutrition and Cancer

1. Nutrition for Cancer Prevention

Most of the evidence linking diet and cancer comes from large prospective studies and metaanalyses. While no single food guarantees protection, patterns of eating can reduce risk for many tumor types.

Key dietary patterns

• Plantforward diet abundant vegetables, fruits, whole grains, legumes, nuts, and seeds.
• Limited processed red meat consumption of >50g/day of processed meat is associated with higher colorectal cancer risk.
• Moderate alcohol each drink per day adds 510% risk for several cancers; the safest level is none.
• Healthy fats replace saturated and trans fats with monounsaturated (olive oil) and polyunsaturated (fish, nuts) fats.

Micronutrients of interest

• Vitamin D adequate sun exposure and fortified foods may lower colorectal and breast cancer risk.
• Folate found in leafy greens and beans; supports DNA repair.
• Selenium modest amounts in Brazil nuts, seafood; antioxidant role.

2. Nutrition During Active Cancer Treatment

Treatment (surgery, chemotherapy, radiation, immunotherapy) often alters appetite, metabolism, and tolerance of foods. Nutrition therapy aims to maintain body weight, preserve muscle, and support healing.

Common challenges

• Loss of appetite & taste changes chemotherapy can make foods taste metallic or bland.
• Nausea & vomiting antiemetic meds help, but small frequent meals are usually better tolerated.
• Mucositis painful inflamed mucosa; soft, nonacidic foods reduce irritation.
• Diarrhea or constipation may require fiber adjustments.

Nutrition strategies

1. Caloric density use healthy fats (avocado, olive oil) and smoothies to increase calories without large volumes.
2. Protein focus aim for 1.21.5g/kg body weight daily (lean meats, dairy, soy, legumes).
3. Hydration sip water, broths, and electrolyte drinks throughout the day.
4. Meal timing eat 3060minutes before chemo if tolerated; after treatment, prioritize nutritious snacks.
5. Supplements only under professional guidance; highdose antioxidants may interfere with certain therapies.

3. Nutrition in Cancer Survivorship

After completing primary therapy, the focus shifts to longterm health, recurrence prevention, and managing late effects such as fatigue, neuropathy, or cardiotoxicity.

Goals for survivors

• Maintain a healthy body weight (BMI 18.524.9).
• Support cardiovascular health especially after anthracycline or radiation exposure.
• Preserve bone density important for patients on hormonal therapy.
• Promote gut health probiotics or highfiber diets can alleviate lingering GI symptoms.

Evidencebased recommendations

1. Eat a Mediterraneanstyle pattern linked to lower recurrence in breast and colorectal cancers.
2. Limit added sugars & refined grains reduces insulin spikes that may fuel growth pathways.
3. Include omega3 fatty acids found in fatty fish, flaxseed; may reduce inflammation and improve quality of life.
4. Physical activity + nutrition synergy 150min of moderate exercise weekly enhances muscle mass and metabolic health.

4. Practical Tips for Every Stage

• Plan meals ahead of treatment days; keep easytodigest snacks on hand.
• Use herbs, mild spices, and citrus to enhance flavor when taste is altered.
• Keep a foodsymptom diary helps identify triggers for nausea, diarrhea, or constipation.
• Choose wholefood sources over processed mealreplacement products whenever possible.
• Consult a registered dietitian with oncology experience for personalized plans.