A recent review published in Nutrients has provided an updated overview of the role diet plays in cancer prevention, offering new insights that align with the American Cancer Society (ACS) guidelines.
Key Dietary Patterns and Cancer Risk
The review identifies specific dietary patterns, such as the Mediterranean and vegetarian/pescetarian diets, as being linked to a lower risk of cancer. These diets, which are rich in fruits, vegetables, and healthy fats, appear to reduce the likelihood of developing various types of cancer. On the other hand, factors like excessive fasting and high iron intake may increase cancer risk.
One noteworthy finding is that time-restricted eating, particularly when it involves a long nighttime fast and an early breakfast, could potentially lower the risk of prostate cancer. However, more research is needed to confirm these benefits.
The Mediterranean diet, known for its emphasis on plant-based foods, fish, and olive oil, has been associated with a lower risk of lung and breast cancer. However, the diet’s impact on certain cancer-related compounds, such as trimethylamine N-oxide (TMAO), is still unclear, suggesting the need for further research.
Vegetarian and pescetarian diets, which exclude or limit meat, were also linked to a lower overall risk of cancer, particularly colon cancer. This supports the idea that plant-based or fish-based diets may offer protection against certain cancers.
Interestingly, low-carbohydrate diets were associated with a higher risk of colorectal and lung cancer but a lower risk of gastric cancer. This suggests that the relationship between carbohydrate intake and cancer risk may depend on the type of cancer.
Overall, diets rich in nutrients and low in inflammatory foods were found to reduce the risk of certain cancers, such as squamous cell lung cancer. In contrast, diets with pro-inflammatory properties were linked to an increased risk of lung cancer, highlighting the importance of diet quality in cancer prevention.
Impact of Specific Foods and Nutrients
The review also looked at the role of specific foods and nutrients in cancer risk. Large-scale studies found no clear link between dairy intake and breast cancer risk, suggesting that dairy products may not significantly influence cancer prevention or causation in the context of breast cancer.
Similarly, no significant associations were found between coffee or tea consumption and prostate cancer risk. While the impact of these beverages on other types of cancer remains uncertain, current evidence points to a neutral effect.
Regarding meat consumption, a large UK study found that a high intake of red and processed meat was associated with a higher risk of lung cancer, underscoring the potential dangers of consuming large amounts of these foods. Conversely, diets rich in fruits, vegetables, and whole grains were linked to a lower risk of lung cancer.
The review also highlighted the potential cancer-preventive effects of phytoestrogens, plant compounds that may reduce the risk of lung cancer. These findings support public health recommendations to consume a diet rich in plant-based foods.
Micronutrients and Heavy Metals
Conflicting findings were reported regarding iron intake and lung cancer risk. While heme iron (from animal sources) was linked to an increased risk, non-heme iron (from plant sources) showed a protective effect, although this relationship was influenced by smoking history. The role of iron in cancer risk remains complex and requires further investigation.
Exposure to heavy metals, such as copper, lead, and zinc, was associated with an increased cancer risk. On the other hand, maintaining adequate levels of certain micronutrients, including zinc, selenium, and vitamins C and D, was found to lower cancer risk and potentially improve survival in cancer patients. This highlights the importance of balanced nutrient intake in cancer prevention and management.
Conclusion
The review emphasizes the crucial role of diet in cancer prevention, echoing the recommendations of the ACS. It highlights the protective benefits of the Mediterranean diet, along with fruits and vegetables, while pointing out the potential risks associated with red meat consumption and diets with a high acid load.
Despite these findings, the study also notes gaps in our understanding, particularly regarding the mechanisms by which certain diets, like the Mediterranean diet, influence cancer risk. The review’s strengths lie in its comprehensive analysis of dietary patterns and cancer risk, though it also acknowledges limitations, such as potential bias from the selection of recent studies and reliance on specific databases.
Moving forward, future research should aim to better understand the mechanisms behind diet-related cancer prevention, including the effects of time-restricted eating, alternative diets, and the role of unprocessed carbohydrates. Such research could pave the way for more personalized dietary recommendations and strategies for cancer prevention.
