Researchers followed nearly 2,800 colorectal cancer patients to see if eating foods that fight body damage could help them live longer. They created four different scoring systems to measure how well patients’ diets fought harmful molecules in their bodies. Patients who ate more antioxidant-rich foods—like foods with selenium, omega-3 fatty acids, and vitamin B12—had better survival rates. The study found that two of the scoring systems worked best, and the benefits were especially strong for people with rectal cancer. While these results are promising, they suggest that diet may play an important role in helping cancer survivors, but more research is needed before doctors make official recommendations.

The Quick Take

  • What they studied: Whether eating foods that protect against body damage (called antioxidants) helps colorectal cancer patients live longer and healthier lives
  • Who participated: 2,799 colorectal cancer patients from a cancer registry in Guangdong, China, followed for an average of 5 years
  • Key finding: Patients with the highest scores for eating antioxidant-rich foods had about 24% lower risk of dying from colorectal cancer compared to those with the lowest scores
  • What it means for you: If you have colorectal cancer or are a survivor, eating more selenium-rich foods, omega-3 fatty acids, and vitamin B12 may help improve your chances of living longer, though you should discuss dietary changes with your doctor

The Research Details

This was a prospective cohort study, which means researchers followed real patients over time rather than doing an experiment. They enrolled 2,799 colorectal cancer patients and tracked their health outcomes for about 5 years. The researchers created four different scoring systems to measure how well each patient’s diet fought harmful molecules (called oxidative stress) in their body. These scoring systems combined information about foods and nutrients that either protect the body or damage it. The researchers then used statistical methods to see if patients with higher protective scores lived longer than those with lower scores.

This approach is important because it shows real-world results in actual cancer patients rather than just in laboratory tests. By following patients over several years, researchers could see which dietary patterns were actually linked to better survival. The study also tested multiple scoring systems to find which one worked best, making the results more reliable.

The study is fairly reliable because it included a large number of patients (2,799), had a long follow-up period (5 years), and used well-established statistical methods. However, the study only included patients from one region in China, so results may not apply equally to all populations. The researchers also relied on patients’ memories of what they ate, which can sometimes be inaccurate.

What the Results Show

Two of the four scoring systems (called OBS-2 and OBS-3) showed clear benefits. Patients with the highest scores on these systems had about 24% lower risk of dying from colorectal cancer compared to those with the lowest scores. This means that for every 100 patients with high protective scores, about 24 fewer would die from cancer compared to 100 patients with low scores. The benefits appeared to be consistent across different age groups and were especially strong in patients with rectal cancer specifically. The researchers found that the relationship between diet quality and survival was straightforward—more protective foods meant better outcomes, with no surprising jumps or drops at certain levels.

The other two scoring systems (OBS-1 and OBS-4) showed weaker benefits that were not quite statistically significant. When looking at overall survival (dying from any cause, not just cancer), only one scoring system showed a borderline benefit. The researchers identified three nutrients as the most important protective factors: selenium, omega-3 fatty acids, and vitamin B12. Iron was identified as the main harmful nutrient that increased oxidative stress in the body.

This study adds important new information because previous research on oxidative balance scores and cancer survival has been limited and used different methods. This is one of the first large studies to specifically look at this question in colorectal cancer patients. The findings support earlier research suggesting that antioxidant-rich diets may help cancer patients, but this study provides more specific evidence about which nutrients matter most.

The study only included patients from one region in China, so results may not apply to other populations with different genetics or diets. Patients reported their own food intake from memory, which can be inaccurate. The study couldn’t prove that diet caused better survival—only that it was associated with it. Some patients were lost to follow-up, which could have affected results. The study also couldn’t account for all possible factors that might affect survival, like exercise or stress levels.

The Bottom Line

Based on this research (moderate confidence level), colorectal cancer patients and survivors should consider eating more foods rich in selenium (like nuts, fish, and whole grains), omega-3 fatty acids (like fatty fish and flaxseed), and vitamin B12 (like meat, dairy, and fortified cereals). However, these findings should not replace advice from your oncologist or nutritionist. Discuss any major dietary changes with your healthcare team before making them.

This research is most relevant for people who have been diagnosed with colorectal cancer or are survivors of this disease. It may also be helpful for people at high risk of colorectal cancer. People without colorectal cancer should not assume these specific nutrients will prevent cancer, as more research is needed. Anyone considering major dietary changes should talk to their doctor first.

If you make dietary changes based on this research, you shouldn’t expect immediate results. The benefits in this study appeared over several years of follow-up. It typically takes months to years of consistent healthy eating to see measurable health improvements, so patience and consistency are important.

Want to Apply This Research?

  • Track weekly servings of selenium-rich foods (nuts, fish, whole grains), omega-3 sources (fatty fish, flaxseed, walnuts), and vitamin B12 sources (meat, dairy, fortified cereals). Set a goal of 3-4 servings per week of each category and log them in your nutrition app.
  • Add one new antioxidant-rich food to your weekly meal plan each week. For example: Week 1 add Brazil nuts (selenium), Week 2 add salmon (omega-3), Week 3 add fortified cereal (B12). This gradual approach makes dietary changes easier to maintain long-term.
  • Use your app to create a monthly report showing your average intake of these three key nutrients. Compare your monthly scores to identify trends and celebrate improvements. Share reports with your healthcare provider during check-ups to discuss whether your diet aligns with your health goals.

This research suggests a possible link between antioxidant-rich foods and better colorectal cancer survival, but it does not prove that diet alone can treat or cure cancer. These findings should not replace medical treatment or advice from your oncologist. If you have colorectal cancer or are a survivor, discuss any dietary changes with your healthcare team before making them. This study was conducted in one region of China and may not apply equally to all populations. Always consult with a qualified healthcare provider or registered dietitian before making significant changes to your diet, especially if you have cancer or a serious health condition.