Food and diet as CANCER TRIGGERS

CANCER TRIGGERS IN DETAIL

The majority of individuals are aware of and often even clued up on health. Take away the distractions, the everyday rush and the amount of things we have on our plates, many of us do know what to do and what not to do in order to maintain a healthy lifestyle.

Yet, according to the WCRF and the AICR, chronic disease in South Africa accounts for 53.9 per cent of deaths, while infectious diseases, and maternal, perinatal and nutritional conditions account for 40.2 per cent. We are not a healthy country. And it is not just us. Although cancer patterns and trends vary in different parts of the world, every year there are more than ten million new cases of cancer recorded worldwide and nearly seven million cancer deaths. ‘By 2020 these figures are estimated to rise to over 16 million new cases with 10 million deaths.’14 We are not a healthy world.

Considering that the majority of cancers are caused by environmental factors rather than genetics, it is important to understand how each lifestyle factor contributes to health and risk of illness.

Food and diet

Understanding how food plays a role in cancer and how nutrition can affect or damage cells is not so clear-cut. Ernest Hawk, vice president and division head of Cancer Prevention and Population Sciences at the University of Texas MD Anderson Cancer Center explains that research efforts in the
ecological, observational, experimental and clinical realms involving the general population, those at risk for cancer, cancer patients and survivors is difficult because of challenges in assessing the complexity and heterogeneity of diets within and across individuals, especially in our time. The most compelling data, he says, is observational. When talking about his home country, Hawk says: ‘Approximately 30 to 40 per cent of cancer is believed to be related to the broad concept of energy imbalance in the American population – specifically, 20 per cent to overweight/obesity, which is by far the most important issue, 5 to 10 per cent to physical inactivity, 5 per cent to unhealthy diets.’

To make matters worse, there is no hard and fast rule when it comes to knowing exactly what you should be eating for your body type to avoid or treat cancer. People’s bodies react differently to certain things, which is what makes it so difficult to understand why some get cancer and others do not.

Moreover, different diets may apply to different cancers. What all of this really means is that the most crucial thing to understand is that the individual is key.

Scientific research into the food we eat and its contribution to cancer is something dietitian Catherine Boome has extensively investigated. ‘Cancer results from the interaction of genetic risks and environmental exposures.

Environmental factors include many aspects of how we live, from how active we are, our diet, our lifestyle habits such as smoking, alcohol consumption and our stress levels,’ she says.

According to Boome, modern society has a huge impact on how we eat, and often leads to obesity, which can enhance our cancer risk. She adds that obesity and excess weight have been linked to breast cancer among postmenopausal women. It could also influence cancer in the colon, endometrium, oesophagus, kidneys and possibly many other sites as well.

‘Nutrition can influence cancer risk, directly due to carcinogens in foods or indirectly by hormonal and metabolic responses to obesity,’ she explains. We will look at weight in more detail in the next section.

Another factor is what goes into our food. There is extensive research out there – if you know where to look – that can make understanding food constituents and their relationship to cancer risk a little easier. According to Boome: ‘Nutrient and toxicant exposures are important contributors to the risk of some cancers. The ACS has compiled research on many components of the human base of diet and its risk on cancer development.’

Boome herself addresses some of the common questions pertaining to the components in our food and their effects, if any, on cancer risk:

Nitrates and agents used in meat processed by methods involving smoking, salting and curing to enhance flavour and colour and to prevent bacterial overgrowth have been linked to certain cancers such as colorectal and stomach cancers. It is important to avoid exposure to these foods or eat them in limited quantities.

Food additives added to foods to preserve them and to enhance colour, flavour and texture must be cleared by the Department of Health before entering the food supply. Additives are usually present in very small quantities, however, and no convincing evidence has shown that any additive at these levels causes human cancers.

Aspartame is a low-calorie artificial sweetener that is about 200 times sweeter than sugar. Current evidence does not show any link between aspartame use and increased cancer risk.

Genetically modified foods are made by adding genes from other plants or organisms to crops to make them more resistant to pests and to slow spoilage. Some genes improve flavour and nutrient composition, or make food easier to transport. In theory, these added genes might create substances that could cause harmful reactions among sensitised or allergic individuals. But there is no evidence at this time that the substances found in bioengineered foods currently on the market are harmful or that they either increase or decrease cancer risk.

Pesticides can be toxic when used improperly in industrial, agricultural or other occupational settings. In South Africa, the departments of health and agriculture set maximum residue limits for the levels of pesticides used in food production, and these are usually way in excess of actual intakes.

Although vegetables and fruit sometimes contain low levels of these chemicals, overwhelming scientific evidence supports the overall health benefits and cancer-protective effects of eating vegetables and fruit. At present there is no evidence that residues of pesticides and herbicides at the low doses found in foods increase the risk of cancer, but fruit and vegetables should be washed thoroughly before eating.

The food you eat on a daily basis affects how you feel, as well as your energy levels. In terms of general health, another Johannesburg-based dietitian, Nathalie Mat, says the most important thing to remember is that if you do not eat balanced meals at regular intervals, you will not have consistently good energy levels. If you do not have good energy levels, you will not be able to operate at full capacity. ‘You do not need to completely make over your lifestyle – adopt small changes that will become habits. Concentrate on daily healthy eating behaviours like getting a minimum of three servings of vegetables a day, choosing unrefined starches instead of products made with refined flours, and on doing exercise when you can. These behaviours will become part of your daily routine, at which point you can create new health goals.’