Because there is no known cure for mesothelioma, many people who have this form of cancer turn to alternative therapies in hopes of staying healthier for longer. Healthy eating is one simple approach that many cancer patients take to strengthen their immune systems.
Foods containing antioxidants have long been touted as beneficial components of a mesothelioma diet. A spate of scientific studies on humans has cast doubt on this and a 2015 study of mice with melanoma suggests that antioxidants may actually help cancer cells grow and metastasize.
Before we plunge into the science, let’s start with the basics: what are antioxidants and how do they benefit health?
Antioxidants and Free Radicals
We need oxygen to live; too much oxygen, however, can cause damage to our cells or oxidation. Rust is what happens when steel oxidizes; you can think of oxidation as rust eating away at our cells. Oxidative stress is a term for the way excess oxygen can tax our bodies because of an overabundance of free radicals.
That oxygen imbalance within our bodies leads to the creation of cells or molecules that are short on electron or free radicals. To stabilize themselves, these free radicals grab electrons from their neighbors, ripping open cells and creating a chain reaction of instability and damaged cells. Because cell damage is thought to be a precursor to cancer, it seems logical that inhibiting free radicals would help to prevent the spread of cancer.
Enter antioxidants: elements of our diet that bond with free radicals and stop them before they can cut a swath of destruction. Some foods believed to have antioxidant properties include dried beans (kidney, pinto, et al.), berries (blueberry, cranberry, raspberry, strawberry), apples, and plums. Some people also take supplements such as Vitamin E to provide antioxidants.
For those who do not have cancer, antioxidants may have health benefits. Some believe that antioxidants contribute to longevity and counter heart disease and other maladies that become more common as we age.
The story of cancer and antioxidants, however, is not so rosy, nor is it simple.
Lung Cancer Trials
In the 1990s, in search of alternative methods to help heal and prevent cancer, researchers began to study the effectiveness of antioxidants. The first studies were of smokers, who were given high doses of beta-carotene (Vitamin A). A 1994 study found that smokers given the antioxidant vitamin had higher rates of lung cancer (18%). A trial in 1996 was stopped early when results showed a 28% increase in lung cancer among a cohort that included people who had been exposed to asbestos at work as well as smokers.
A 2011 trial looking at the effects of antioxidant Vitamin E on humans found increased risk of prostate cancer. And a 2014 study in which mice were given Vitamin E and an antioxidant drug found that lung tumors grew more quickly and aggressively and the mice died more quickly.
The most recent study, published in October 2015, used mice bred to be more likely to get melanoma, a skin cancer that is known to be affected by free radicals. Some mice were given an antioxidant and some were not. Both sets of mice developed tumors at the same rate; however, the ones that were given antioxidants were two times as likely to have their cancers metastasize.
What Should I Include in My Mesothelioma Diet?
Researchers theorize that antioxidants may help protect cancer cells in some of the same way they protect normal cells. Some scientists have suggested that special, targeted antioxidants could be used to fight specific types of cancer.
Another theory is that pro-oxidants (the opposite of antioxidants) might damage cancer cells and slow or stop the growth of tumors. There are several cancer drugs on the market that act as pro-oxidants.
The research, particularly that relating to lung cancer and people exposed to asbestos, suggests that people with mesothelioma should avoid beta-carotene, Vitamin A, and Vitamin E supplements or take them in very low doses.
A healthy mesothelioma diet may include a variety of fresh fruits and vegetables. You may want to leave the foods that are highest in antioxidants off your plate, including:
- Beans (kidney, pinto, red, black)
- All types of berries
- Green tea
- Apples
- Pecans and other nuts
- Grapes
- Cherries
There are a number of other foods that contain antioxidants, including cacao or chocolate (sorry!). It’s a good idea to do your own research on the antioxidant properties of different fruits and vegetables and make choices based on what feels right for your body and your health.
One word of caution: the trials and studies that showed the negative effects of antioxidants gave their subjects vitamin supplements or antioxidant drugs. The effects of vitamins taken in pill or supplement form may not be the same as when you get that nutrient in a whole food such as a fruit or legume. When it comes to understanding the building blocks of nutrition, science has not yet caught up to Mother Nature.