Truths and Myths about Food and Cancer

A common concern in modern day society is health and how to maintain a healthy lifestyle free of sickness and disease. The main way in which to do this is through having a healthy, balanced diet which reduces the chances of contracting sicknesses and diseases and makes one healthy overall.  A seminar conducted by the Sri Lanka Medical Association (SLMA) on March 9  tackled this issue and discussed the relationship between food and cancer. 

This seminar was organised by the Expert Committee on Non-Communicable Diseases of the SLMA, featuring Dr. Jayantha Balawardane (Senior Lecturer and Senior Consultant in Oncology and Radiotherapy) and Dr. Renuka Jayatissa (Consultant Nutritionist) as the keynote speakers at the event. It was held at the Lionel Memorial Auditorium in Colombo and was also made accessible to a virtual audience through Zoom and Facebook.
Starting off the seminar, Dr. Balawardane engaged in a discussion of how the food we consume may be related to the development of cancer cells in the body.  He stated that many epidemiology studies have shown that 30% of Human Cancers may be related to food and nutrition. Evidence of this relationship dates back to shortly after the end of the Second World War following which large groups of Japanese individuals migrated to the West. In comparison to those who remained in Japan, the group of individuals who had migrated showed more signs of having developed cancers more such as colorectal, prostrate, breast and lung cancer which are more common occurrences among the European community. Further research showed that the main contribution to this trend was the change in diet of the migrants. The discussion also included an explanation of six sub-categories of food and their impact on the chances of incidence of cancer in an individual. The sub-categories identified included macronutrients, micronutrients, food additives, fruits and vegetables, salt and food preservatives and contaminants.  

Macronutrients, more specifically carbohydrates, and fats, are found to be more likely to promote carcinogenesis (the transformation of normal cells into cancer cells), when consumed in excess. They are also a major contributor to the onset of obesity which in turn has shown to increase the risk of carcinogenesis. Dr. Balawardane also mentioned that the types of cancers caused by macronutrients such as those mentioned above include colon, breast, prostate, kidney and liver cancer among many others. He also emphasised the fact that food additives (chemicals used to change the colour, texture, taste and stability of certain foods) are also carcinogenic, as are contaminants such as fungi due to poor storage conditions, although these have not been found to be a major contributing factor. Additionally, foods with a higher salt or preservative content have also been found to cause cancers such as stomach and colorectal cancers. Another major contributor to carcinogenesis, as mentioned in Dr. Balawardane’s speech was alcohol, consumption, which causes cancers such as oesophagus, pharyngeal and laryngeal cancer among others because it only contains calories which are not balanced out by other nutrients.  Dr. Balawardane also highlighted the fact that diets rich with micronutrients (vitamins and minerals), and fruits and vegetables interfere with and reduce the carcinogen metabolism, lowering the risk of cancer. Dr. Balawardane concluded his discussion by encouraging the attendees to adopt a more Ketogenic diet into their lifestyles, consisting of more proteins and fats and very few carbohydrates as such diets lead to the reduction of sugar and fat reserves and insulin, help to reduce body weight balances the free radicals and antioxidants in the body. 

The discussion was then taken over by Dr. Renjuka Jayatissa, who emphasised on the fact that diets with an excess of calories leads to weight gain, resulting in the increase in risk of multiple cancers. She also brought to light the fact the more than 40% of the population in most regions are overweight/obese and that obesity in girls between the ages of 10 and 14 has shown a significant increase from 2003 to 2017. She also showed the major increase in the total calorie count in food seen between 1961 and 2017, emphasising the extent to which calorie consumption and in turn obesity has increased over time, an occurrence showing that despite an overall reduction in physical activity, there has been an increase in the need for and consumption of bodily energy. 

She then went on to provide recommendations on how to adjust our diet in a way that is more healthy and beneficial to the body. She first recommended that maintaining a healthy weight or staying lean will be effective in reducing the risk of developing medical issues. The second recommendation made by Dr. Renuka was to limit one’s sugar intake as evidence shows that there is an increased risk of weight gain which in turn causes further medical complications. She also emphasised that foods with a smaller glycemic load are more beneficial to the body and also emphasised on the fact that artificially produced beverages should be replaced with water or fresh juices containing 100% fruit with no additives. The next recommended step was to limit the intake of high fat and processed food such as fried foods, bacon, salami and sausages. Such foods have proved to have largely negative impacts on health, with a greater risk seen in children and adolescents.

 Dr. Renuka’s fourth recommendation for a healthier diet was to consume at least 500g of fruits and vegetables of varying kinds per day whilst limiting the consumption of fried and starchy vegetables
She also suggested that a diet consisting of unpolished rice (also known as brown rice), with less refined flour and at least 3 cups of pulses per week has shown a 9% lower risk of colon cancer with other health benefits such as improved gut health and reduced bowel stasis. Dr. Renuka’s next recommendation was a reduction of alcohol consumption, emphasising on the fact that water and fresh drinks are the highly recommended beverages 
She also recommended that relying on naturally occurring nutrients instead of supplements are more effective in protecting against cancer with further recommendations to minimise the consumption of food high in free radicals, which are damaging byproducts of oxygen and cause progressive injury to DNA and tissues in the body. Foods high in free radicals include those with a high glycemic index, red meats, processed food and alcohol among others. Dr. Renuka’s expert recommendation was to replace such foods with foods that have a higher antioxidant count such as fruits and vegetables, milk, nuts and seafood.

The last two recommendations provided by Dr. Renuka was to increase the consumption of fish because an inverse relationship had been found between fish intake and the occurrence of cancers such as rectal and colon cancer, with the final recommendation being to maintain proper dietary patterns by taking into consideration her other recommendations. Dr Renuka concluded her discussion by stating that paying attention to your diet and maintaining a balanced healthy diet can lead to the prevention of cancer.

Time was then allocated for questions to be put forward to the two speakers by the members of the physical and virtual audience, where it was mentioned that there have been an increase in the number of cancer patients in the country which may have been caused for various reasons including more awareness among the population, better detection methods and also an inclination towards western trends. Dr Renuka suggested the consumption of home-cooked meals as much as possible while making sure that consumption of meals is regular. She also suggested that physical exercise is highly effecting in maintaining a healthy lifestyle. Dr Balawardane added to this and mentioned the fact that consumption of food with added chemicals, for instance agro-chemicals increases the risk of carcinogenesis. The final question asked was about whether the government had taken any measures in relation to the issue of food and its contribution to causing cancer. The speakers addressed this by affirming that the Ministry of Health has conducted various workshops on healthy eating patterns in schools, advised new mothers on how to maintain a balanced diet and also that the use of harmful additives and preservatives have been banned in the country, emphasising on the fact that routine checks are carried out on the use of agro-chemicals on foods, ensuring they are used in accordance with legal and health restraints. The event was concluded with the speakers highlighting that as individual citizens, we should take the responsibility for maintaining a healthy and balanced diet and be aware of facts and myths pertaining to food to have a happy, cancer free life.