Michael Douglas suffers throat cancer

Editor's note: This is an updated version that adds more information on how a person's diet may help prevent throat cancer.

On Tuesday night, Michael Douglas, a well-known American movie star and film producer, revealed on David Letterman's "Late Show" that he was diagnosed with stage 4 throat cancer earlier this summer and has been receiving chemotherapy and radiotherapy for a week.

Mr. Douglas suspected something was amiss when he felt a persistent sore throat that wouldn’t heal.  But it took a few months for Michael Douglas's doctors to finally diagnose the disease, which understandably made Douglas's wife Catherine Zeta-Jones, an award winning actress, furious.

Douglas told Letterman's audience that his doctors told him his survival rate is 80 percent, even though the prognosis is generally poor for a stage 4 throat cancer, which can be one of several forms of head and neck cancers, including cancers of the oral cavity, pharynx and larynx.

It remains unknown what type of throat cancer Mr. Douglas suffered. But he was cited as saying that the malignancy was caused by smoking and drinking, both of which are major, known risk factors for throat cancer.

Many lifestyle parameters can affect a person's risk of throat cancer, although drinking, smoking, and infection of sexually transmitted HPV virus (unfortunately nearly half of Americans will get it sooner or later - fortunately it will not cause cancer in every one of those infected) can all cause the disease.  A person's diet or what he eats may also play a role in the risk.

A few studies are cited below for those food consumers who are interested in learning how a person's diet may affect his risk of throat cancer. There is strong evidence that dietary patterns and certain foods have been associated with throat cancer risk.

One study, led by De Stefani E. and colleagues from Universidad de Clínicas, Facultad de Medicina in Montevideo, Uruguay and published in March 2009 in International Journal of Cancer, suggests that the prudent diet is negatively associated with cancers of the upper aerodigestive tract, including throat cancer.

The prudent diet consists of high amounts of fruits, vegetables, whole grains, and low amounts of sweets and processed meats. This diet is often recommended to prevent heart disease. But studies show that this diet is so healthful that is also offers other benefits, such as preventing breast cancer.

Another case-control study, which analyzed 800 patients with confirmed cancers of the oral cavity and pharynx, was led by Garavello W. and colleagues from Istituto di Ricerche Farmacologiche Mario Negri in Milan, Italy. This study revealed that a diversity of fruits and vegetables is associated with a 38 and 33 percent reduced risk of the oral and pharyngeal cancer, respectively.

Still another study found that consumption of dairy products was negatively associated with cancers of the larynx and the esophagus while the consumption of yellow/orange vegetables was inversely linked with oral/pharyngeal and laryngeal cancer. 

Preserved vegetables, on the other hand, were associated with an increased risk of oral/pharyngeal and laryngeal cancer.

The study was conducted by Sapkota A. and colleagues of the International Agency for Research on Cancer in Lyon, France and published in the Dec 2008 issue of Cancer Causes and Control.

The protective effect of fruits and vegetables on throat cancer risk has been known for a long time.  

Deborah M. Winn and colleagues from the National Cancer Institute and published a study in 1983 in Cancer Research that shows a high intake of fruits like citrus fruit and vegetables including green vegetables, cruciferous vegetables, and yellow vegetables was associated with a lower risk.

The study was based on data from 227 women in North Carolina with oral cavity or pharyngeal cancer with 405 matched controls.

Specifically, those who ate moderate amounts of fruits and vegetables were 35 percent less likely to have the cancer and the risk for those who ate high amounts was reduced by 48 percent, the researchers found. 

Low risk was also found in those who had higher bread and cereal intake, whereas meat and fish consumption was correlated with increased risk of oral and pharynx cancer;dairy products and eggs, on the other hand, were not associated with the cancer risk.

The researchers speculated that the vitamin C and/or beta-carotene intake may be responsible for the reduction in the risk of the oral and pharyngeal cancer.

Other Foods that may help cut the risk of throat cancer include allium vegetables like onions and n-3 polyunsaturated fatty acids, according to early studies.

Jimmy Downs and editing by Rachel Stockton