Maize meal – the staple diet for most people in some parts of the world especially in sub-Saharan Africa – could be the leading cause of oesophageal cancer that appears to be rife in the Eastern Cape Province.
This is the main finding of a research study conducted by Walter Sisulu University to look into why the Eastern Cape has the highest cases of Oesophageal cancer. The study linked the condition to soil contamination with carcinogens agent. Oesophageal cancer is a disease found anywhere in the throat – sometimes called the gullet or food pipe.
Professor Eugene Ndebia, a senior lecturer in the department of human biology confirmed that of all the nine provinces, majority of people who suffer from oesophageal cancer come from the Eastern Cape Province. “There are a lot of causes that have been brought forward for oesophageal cancer in the province. In the 19th century it is said that there were a lot of factories around as a result, soil became polluted. Farm produce from the soil may be contaminated with carcinogens agent. The other causes brought forward was tobacco and alcohol, but now the main reason we have found out that people with this type of cancer have a diet of higher level of carbohydrates- which is maize,” said Professor Ndebia.
He said the Eastern Cape Province is a predominantly rural area and poverty stricken with majority of people living below poverty line. Because of their poor economic situation they buy food in bulk and store them much longer and in the process the quality of the food is compromised. This is largely because when maize is stored in poor conditions and up to four weeks it develops fungal toxin such as Fumonisins, according to Professor Ndebia.
“Maize on its own is not harmful as long as you buy it and use it within a reasonable time period, the problem is when you have stored it for a while that it starts to develop carcinogens agents which become harmful to the oesophagus. It’s those chemicals that cause cancer, not the maize itself. You can buy maize meal and cook it today, that will be fine, but when you cook from the same bag of maize meal after few weeks, it is no longer the same maize,” said Ndebia.
He stressed the importance of knowing how to store maize; saying failure to control humidity and temperature leads to maize contamination with carcinogens. In rural areas the storage of food is usually not in a controlled environment, added Professor Ndebia. Umqombothi, a popular traditional beer made from maize, maize malt, sorghum malt, yeast and water is flagged as one of the causes of oesophageal cancer.
Explained Professor Ndebia: “In the making of traditional beer they are adding a lot of artificial components as ingredient to make it and those components can be carcinogenic and even the containers they use for beer during the fermentation and storage process have an impact. So the problem is not the maize meal, but how you store it, how long you store it and what you add to it when you are cooking.”
Sour taste in the mouth
Explaining how the cancer occurs, Professor Ndebia said diet that is rich in carbohydrate can increase reflux. Reflux is when the content of the stomach moves back into the oesophagus, he said. One may feel a sour taste in mouth when this happens because naturally the stomach content is acid, he said. When it moves to the oesophagus the acid burns and you experience heartburn, added Professor Ndebia. “Heartburn is a warning sign to those people to seek help early and avoid becoming sick. Our research has led us to monitor a rare type of reflux which is not acid, also known as alkaline reflux,” he said.
Surprisingly, he said, the Eastern Cape has the highest number of alkaline reflux in the world because it is alkaline; these reflux do not burn the oesophagus, and therefore there is no warning sign. When you have it, it doesn’t burn you because it’s non-acid. According to the research, alkaline reflux is higher in people with a higher consumption of maize as staple diet. In conclusion, said Professor Ndebia: “Research has shown that alkaline refluxes are very carcinogenic as compared to the traditional acid refluxes. This may be why oesophageal cancer patient are usually diagnosed at an advanced stage of the disease, because nothing warns them to seek for help early.”