A recent study by the American Cancer Society (ACS) provides jarring insights into the connection between diet and cancer. While dietary risk factors might statistically appear to play a minor role in overall cancer risk— being linked to 4.2% of all cancer cases and 4.3% of all cancer deaths— their impact on specific types of cancer is far more significant. In fact, unhealthy dietary habits can be linked to up to 35% of certain cancer types.
Case in point: while low dietary fiber may only account for 0.9% of all cancers in women, this risk factor is responsible for a substantial 11.8% of colorectal cancer cases. In men, poor consumption of fruits and vegetables causes just 2% of all cancers, yet it is the primary risk factor behind a staggering 30.7% of laryngeal cancer cases.
The study, published in CA: A Cancer Journal for Clinicians, highlights the influence of fruit and vegetable intake, red and processed meat consumption, dietary fiber, and calcium on cancer risk. Despite the omission of sugary drinks, consumption of saturated and trans fats, and salt intake in the analysis of risk factors, the findings are compelling and suggest that diet-related cancers are a preventable reality.
Colorectal Cancer: The Diet-Cancer Link That Can’t Be Ignored
Among all cancer types, colorectal cancer has the strongest link to dietary factors. The ACS study found that a staggering 54.2% of colorectal cancer cases could be prevented through lifestyle changes, with diet playing the most significant role. Remarkably, 35% of all colorectal cancer cases are directly linked to dietary choices.
Processed meat tops the list of dietary risk factors, responsible for 12.8% of all colorectal cancer cases, and 14.6% of colorectal cancer cases among men. For women, low dietary fiber intake is the biggest dietary contributor, accounting for 11.8% of cases. Red meat and low calcium intake also play substantial roles, contributing to 7.3% and 4.2% of cases, respectively.
In 2019, colorectal cancer was the second leading cause of diet-related cancer deaths in men over 30 and the third in women. The connection between diet and colorectal cancer is so strong that some studies, like one published in The BMJ, found that men who consumed high amounts of ultra-processed foods were 29% more likely to develop this type of cancer.
But there’s good news.
“Colorectal cancer ranks as the third most prevalent cancer globally and is the second most lethal. But in many instances colorectal cancer is preventable,” says Guido Baechler, CEO of Mainz Biomed (NASDAQ: MYNZ), developer of ColoAlert— a rapid detection at-home screening test for colorectal cancer that is currently under review by the FDA for Breakthrough Device Designation for its non-invasive Next Generation colorectal cancer product.
Baechler says that society’s shift to diets that are high in additives and preservatives is a likely contributor to the surge in colorectal cancer cases and urges Americans to consider dietary modifications that are more reflective of a Mediterranean diet.
“Adopting a plant-based diet rich in whole grains, fruits, vegetables, seafood, beans, and nuts can help lower your cancer risk,” says Baechler.
“Early detection is crucial— survival rates exceed 90% if colorectal cancer is caught early. Consider non-invasive at-home stool DNA tests, like ColoAlert, starting at age 45.”
Upper Aerodigestive Tract Cancers: The Power of Fruits and Vegetables
Low consumption of fruits and vegetables is the most critical dietary risk factor associated with incidence and death across all types of cancer, accounting for 1.4% of all cancers and 2.2% of all cancer deaths. In the case of cancers of the upper aerodigestive tract, the influence of this risk factor on cancer incidence and death increases significantly.
According to the ACS study, low fruit and vegetable intake contributes to 30.7% of cancers of the oral cavity, esophagus, pharynx, and larynx, as well as 30.7% of all cancer deaths associated with these types of cancer.
These findings suggest that the protective compounds in fruits and vegetables could play a vital role in reducing cancer risk.
According to the American Institute for Cancer Research, the special plant compounds in cruciferous vegetables may protect the body from cancers of the mouth, pharynx, larynx and esophagus.
Another study, led by researchers from the University of Bristol and the International Agency for Research on Cancer (IARC) and published in in the European Journal of Nutrition found that eating 10% more of ultra-processed foods (UPFs) may be associated with a 23% higher risk of developing cancers of upper aerodigestive tract (including the mouth, throat and oesophagus).
The ACS study reveals that 83.7-89.9% of cancers of the oral cavity, esophagus, pharynx and larynx could be prevented through healthier lifestyle choices. In addition to increasing fruit and vegetable consumption, the impact of reducing intake of UPFs is clear.
Says Dr Helen Croker, Assistant Director of Research and Policy at the World Cancer Research Fund, “The association between a higher consumption of UPFs and an increased risk of developing upper-aerodigestive tract cancer supports our Cancer Prevention Recommendations to eat a healthy diet, rich in whole grains, vegetables, fruit, and beans.”
Breast Cancer: A Variety Of Dietary Risks
While the link between diet and breast cancer is not highlighted in the ACS study, a significant amount of research points to the influence of dietary factors on breast cancer risk.
According to a paper published in Contemporary Oncology, diet can impact breast cancer development and progression in a multitude of ways. Dietary iron, for example, can cause oxidative stress and DNA damage, potentially increasing risk, and certain fats, as well as low folate intake are linked to higher risk of breast cancer. A study reported in the journal, Frontiers, reveals that each 10% increase in UPF consumption is related to a 5% higher risk of breast cancer risk, emphasizing the importance of dietary choices in prevention.
Fruit and vegetable consumption has been found to reduce breast cancer risk, with a 27% lower risk of certain breast cancer types among those with high vegetable intake. Phytoestrogens and vitamin D are also noted for their potential protective effects.
The Bigger Picture: Diet, Lifestyle, and Cancer
The combined impact of excess body weight, alcohol consumption and inactivity— in tandem with diet— has the strongest link to increased cancer risk, when compared to all other preventable risk factors. This group of combined risk factors accounts for 15.3% of cancer cases in men (second only to smoking and second-hand smoke) and 22.5% of cancer cases among women (followed by smoking and secondhand smoke) resulting in more than 17% of all cancer related deaths, according to the ACS study.
Rising rates of obesity, coupled with declining fruit and vegetable consumption, underscore the need for broad public health initiatives. Strategies like increasing access to affordable, nutritious food, establishing farmers’ markets, and promoting educational programs can make a significant difference in reducing cancer risk across populations. Early detection is also key.
Dr. Farhad Islami, senior scientific director, cancer disparity research at the American Cancer Society, and lead author of the study notes, “We also need more implementation research for broad application of known interventions, especially for excess body weight, unhealthy diet, alcohol consumption, and physical inactivity, and to identify tailored and mutually reinforcing interventions, as they are more likely to mitigate these risk factors, especially in historically marginalized populations.”
While diet alone may not be the sole factor in cancer prevention, it is a powerful tool in the fight against this deadly disease. By making informed dietary choices, the risk of certain cancers can be significantly reduced.
