# Nutrition in metastatic colorectal cancer
Nutritional status and treatment
Patients with metastatic colorectal cancer often struggle with malnutrition, both from the disease itself and from treatment. Malnutrition weakens the immune system and can contribute to fatigue, muscle loss and reduced resistance to infections. Research shows that good nutritional status is associated with better functioning during treatment.
ProveniIncluded in official guidelines, or approved by EMA or FDA
During chemotherapy, hunger and appetite can decrease significantly. This requires adjustments in what and how much you eat, but also attention to the composition of food. A dietitian can help ensure adequate energy and protein intake, even when normal portions are no longer possible.
Protein intake and muscle maintenance
Protein is important for preserving muscle mass, especially since both treatment and disease can lead to muscle loss. Research suggests that adequate protein intake during chemotherapy can help maintain body composition better and improve overall condition.
ProveniIncluded in official guidelines, or approved by EMA or FDA
Protein-rich food can come from many sources: meat, fish, eggs, dairy products, legumes and nuts. When appetite is reduced, protein-rich drinks (such as nutritional supplements) can be a helpful tool. This is discussed in the hospital or in consultation with a dietitian.
Nutritional supplements during chemotherapy
Studies have examined the effect of nutritional supplements on how well patients tolerate chemotherapy and on their overall survival rate. Some studies suggest that supplementary nutrition during chemotherapy can help you eat better, experience fewer side effects, and emerge stronger from treatment.
ResearchediPositive results in clinical studies, not yet standard treatment
This mainly involves nutritional drinks that are specially formulated and given under medical supervision. This differs from home use of vitamin supplements. Whether and which supplements are suitable for your situation is determined together with your treatment team and dietitian.
Bacteria in the gut and nutrition
The gut flora (the collection of beneficial bacteria in your gut) plays a role in how well your body functions and can influence how you respond to treatment. Food influences these bacteria: certain components of food, especially fibre-rich substances, feed beneficial bacteria.
ResearchediPositive results in clinical studies, not yet standard treatment
Research is ongoing into how nutrition and gut health influence each other in cancer patients, but there are not yet many concrete guidelines for this. This is an area where much research is taking place.
Nutrition and chemotherapy side effects
Chemotherapy often causes stomach problems: nausea, vomiting, diarrhoea or constipation. Nutrition can help alleviate certain side effects. Small, regular meals may be better tolerated than large portions. Certain foods can help with nausea or bowel problems.
ProveniIncluded in official guidelines, or approved by EMA or FDA
Which foods work best varies from person to person. What works well for one person can be difficult for another. This is something to explore and adjust together with a dietitian as treatment progresses.
Plant substances and supportive agents
There is increasing research into certain plant substances that may help with cancer. An example is research into substances from seaweed, such as oligofucoidan, and into traditional medicinal herbs used in certain cultures.
ExperimentaliOngoing in study setting, outcome still unknown
These are mainly laboratory findings and early studies. They offer hope, but have not been tested sufficiently in real patients to say anything with certainty. You should not apply this independently without consulting your team.
Interactions between nutrition and medication
Certain nutrients can have interactions with chemotherapy or other medicines you are taking. Grapefruit, certain herbs and even certain vitamin levels can affect how medicines work.
Nutrition with high vitamin K (leafy greens) can affect blood thinners; certain supplements can interfere with chemotherapy. These are important reasons to always discuss your dietary choices with your doctor or dietitian.
ProveniIncluded in official guidelines, or approved by EMA or FDA
Always clearly tell your healthcare provider what you eat, drink, and which supplements you use, including natural or 'mild' things.
Body weight and nutritional status
Both too much weight loss and overweight can cause problems during treatment. Weight loss can lead to weakness; overweight can make certain side effects worse. It's not so much about a specific 'ideal' weight, but about stability and having enough strength for treatment.
ProveniIncluded in official guidelines, or approved by EMA or FDA
Your doctor or dietitian will monitor this and suggest adjustments where necessary.
Timing of food and treatment
If you're receiving chemotherapy, it may be important *when* you eat and drink. Some patients feel better if they eat little shortly before treatment, others have a need for food beforehand. Timing also plays a role after treatment.
This is highly individual and something you'll try out and adjust together with your team.
Practical tips from research
Research into patients undergoing chemotherapy shows that it helps to:
- Eat regularly and in small portions
- Have adequate fluid intake (water, tea, possibly nutritional drinks)
- Fresh food or food that has been kept clean (caution with food infections, because the immune system is weakened by treatment)
- Avoid cold food and things with strong smells in case of nausea
ProveniIncluded in official guidelines, or approved by EMA or FDA
Specific dietary choices should always be discussed with your healthcare provider, especially with metastatic disease where multiple factors play a role.
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_This information never replaces a doctor's judgment. Always discuss your situation with your own healthcare provider._