In particular, people who are yet to undergo cancer treatment still consume a diet full of carbohydrates and various forms of sugar increase their risk of cancer recurrence, and in severe cases, mortality, according to an article in the International Journal of Cancer. In the study, lead author Anna Arthur of the University of Illinois at Urbana–Champaign added that conversely, eating fats and starchy foods in moderation could reduce these risks.
Researchers looked at what cancer patients were eating before and after their treatment and their corresponding health outcomes. The study, which ran for over two years, involved 400 patients from the University of Michigan Head and Neck Specialized Program of Research Excellence (Head and Neck SPORE) who were recently diagnosed and treated for head and neck squamous cell carcinoma (HNSCC).
HNSCC is the collective term for cancers that develop from the squamous cells that line mucosal surfaces inside the head and neck. The usual areas where HNSCC develop include the oral cavity, throat, larynx (or voice box), the paranasal sinuses and sinus cavity, and the salivary glands.
Using the Harvard Food Frequency Questionnaire, the researchers were able to identify which food items, beverages, and supplements patients had taken a year before they were diagnosed with cancer. The team discovered that those who ate the most amounts of total carbohydrates and sugars – especially sucrose, fructose, lactose, and maltose – a year prior to their treatment were most likely to die from any cause during their follow-up period, according to Arthur. In the same vein, these people consumed, on average, at least 4.4 servings of simple carbohydrates, which included refined grains, desserts, and sugar-sweetened beverages – a far cry from the 1.3 servings of those who ate the lowest amounts. Also, the most commonly diagnosed HNSCC types include the tonsils and the base of the tongue including its surrounding tissues, with nearly 70 percent of diagnoses made at the later stages of the disease.
In the follow-up period, more than 17 percent of patients had a recurring case, with 42 patients dying from it. Researchers also noted that 70 participants died from other causes.
Of the results, Arthur explained that the cancer type and stage also played a role in concert with carbohydrate consumption. Those who consumed the highest amounts of carbohydrates and sugars had oral cavity cancer. Likewise, the two factors were also linked to an uptick in mortality risk in people with stages 1-3 cancer, but not stage 4.
"Although in this study we found that higher total carbohydrate and total sugar were associated with higher mortality in head and neck cancer patients, because of the study design we can't say that there's a definitive cause-effect relationship," she added. "The next step would be to conduct a randomized clinical trial to test whether carbohydrate restriction has a protective effect on survival rates."
There's still a silver lining to this study: Eating a moderate amount of various forms of fat and starch after treatment may improve a patient's survival rate and increase his chances of remission, researchers pointed out.
"Our results, along with the findings of other studies, suggest that diet composition can affect cancer outcomes," co-author Amy Goss of the University of Alabama at Birmingham (UAB) explained. "We'd like to determine if this is true using a prospective, intervention study design and identify the underlying mechanisms. For example, how does cutting back on sugar and other dietary sources of glucose affect cancer growth?"
For patients with HNSCC, this is great news: Among all cancers, the five-year survival rates of patients with this type of cancer are low since these are detected in later stages. (Related: Curcumin inhibits cancers of the head and neck.)
"This observational study is noteworthy because it focuses on a serious cancer that is difficult to treat, and little is known about how nutrition can best help a patient battling it," added Dr. Laura Rogers, a co-author of the study and a professor of nutrition sciences at UAB. "This study reiterates the importance of additional intervention studies that test optimal diet recommendations for cancer survivors."