From April 1999 to April 2001, a group of patients with Stage III colon cancer were entered into a clinical trial comparing two forms of adjuvant chemotherapy, given after surgical removal of the tumor to try to destroy any remaining cells, preventing recurrence. These patients also completed questionnaires about their diets and lifestyles 4 months after their operation, and again 6-8 months after completing chemotherapy. These patients were then observed for disease-free survival and overall survival.

SOURCE: Alexander Suhorucov in Pexel

The data was analyzed from November 2016 to December 2017, giving about 15 years for differences between groups to become clear. A 2018 article in JAMA Oncology described the results. While there was no difference in outcomes between the two chemotherapy treatment arms, the conclusion states:

“Having a healthy body weight, being physically active, and eating a diet rich in vegetables, fruits, and whole grains after diagnosis of stage III colon cancer was associated with a longer survival.”

SOURCE: Ella Olsson in Pexel

The investigators and commentators on the study were careful to say that these findings are associations and cannot prove causation; only a randomized trial could prove causation. However, randomized trials on lifestyle interventions are difficult to conduct, especially when the diet and lifestyle recommendations are those that are advised for the population anyway. I hope that no one would want to create a clinical trial where some patients were randomized to eat a diet high in sugar, refined grain products, and ultra-processed foods!

I also hope that the results of studies about diet such as this, or about the microbiome will inspire the oncology community to get the junk food out of their offices and treatment rooms, and to be more supportive of their patients’ choices regarding healthy diet.

Finally, I can’t help but be a little sad as I look at these articles. In the same time window that these patients were having information collected about their food choices, 1999 to 2001, Dr. Nicholas Gonzalez and I were struggling to conduct a clinical trial of our methods in patients with pancreatic cancer. We had naively thought that the oncology community would be supportive of our efforts because we were doing the right thing by pursuing clinical trials. Instead, our patients were subjected to incessant negativity by other treating physicians, and adherence to the prescribed treatment was so poor that the data was rendered meaningless. My article Research Battles reviews all this. Perhaps as data accumulates that diet really does matter, such a trial could be considered again.