Cancer & Food Controversies
If you are anything like me, you have read many articles regarding various foods or nutrients that supposedly either increase or decrease the risk of cancer.
You will also find many articles that claim that certain foods are so-called ‘superfoods’ that can prevent or cure cancer merely by eating them.
While nature does contain certain natural remedies, and while eating or not eating certain foods may be good for one’s health, it is unlikely that specific ‘superfoods’, on their own, could directly affect the risk of cancer.
Unfortunately there are still those who insist on spreading stories about what is good, not good, what is carcinogenic, and what can/will or cannot/will not cause or cure cancer.
This article will hopefully bring you some clarity on some of the most talked-about foods or nutrients.
Most of us do not know what acrylamide is by name, although we probably partake of it more than once a day…
Acrylamide is a chemical that is created naturally when many foods, particularly starchy foods, are cooked at high temperatures for long periods (e.g. baking, frying, toasting and roasting); it is found in foods such as biscuits, coffee, bread, and fried potato products (like crisps and chips).
While some animal studies show that acrylamide has the potential to interact with the DNA in the cells, so could be linked to cancer, evidence from human studies has shown that, for most cancer types, there is no link between acrylamide and cancer risk.
Even food industry workers, who are exposed to twice as much acrylamide as other people, do not have higher rates of cancer.
If you want to be on the safe side, you can reduce your exposure to acrylamide aiming for a golden yellow colour or lighter when frying, baking, toasting or roasting starchy foods like potatoes and bread, as the duration and temperature of cooking determines the amount of acrylamide produced.
Follow a healthy balanced diet and reduce your intake of crisps, chips and biscuits (major sources of acrylamide).
Artificial sweeteners are used in a wide variety of foods and drinks, and the controversy surrounding their use is ongoing. Once again, while there have previously been questions over their safety after early animal studies, large studies in humans have provided strong evidence that artificial sweeteners do not increase the risk of cancer.
Saccharin was the subject of a cancer scare after studies in the 1980s found that it could cause bladder cancer in rats. We now know that these effects were specific to rats and not relevant to humans.
In the mid-1990s an article linked the artificial sweeter aspartame to rising brain cancer rates, however, this article had very little scientific basis and many later studies showed that aspartame was safe for humans.
In 2006, another study in rats suggested a link to cancer but the European Food Safety Authority (EFSA) found that the study had some major flaws and concluded that aspartame does not increase the risk of cancer below the daily recommended level.
Large studies looking at humans have now provided strong evidence that artificial sweeteners do not increase the risk of cancer. For example, one study looked at almost half a million people and found that aspartame does not increase the risk of leukaemia, lymphoma or brain cancer.
Green tea and cancer risk has been extensively studied. Results from large human studies have shown no strong evidence that green tea could reduce the risk of pancreatic, lung, breast, prostate, stomach, bowel, thyroid, liver, endometrial, laryngeal, bladder, oral, ovarian, kidney, or oesophageal cancers.
Green tea contains a high amount of a group of chemicals called catechins. Green tea has higher levels of catechins than black tea.
While laboratory studies have found that catechins could block the growth of cancer cells, and stop cancer-causing chemicals being activated, human studies have not shown any strong evidence linking green tea and cancer risk.
Milk & Dairy Products
Milk and dairy are good sources of calcium and protein which are needed as part of a healthy, balanced diet. Calcium is important for teeth and bone health.
Studies looking into the link between cancer and dairy products have not given clear results. There is evidence that dairy products could reduce the risk of bowel cancer, but we cannot say for sure that this is the case. There is no strong evidence linking dairy products to any other types of cancer.
Further research is needed to find out more about the links between dairy products and cancer risk.
In some countries, a hormone called bovine somatotrophin (BST) is used to speed up or increase the production of milk or meat. Farmers are banned from using this hormone in some countries, but this is on animal welfare grounds and not because there is any proven effect on human health.
Independent health bodies including the European Union Scientific Committee have reviewed the evidence on BST and found it does not pose any harm to human health.
Pesticides & Organic Foods
Pesticides are widely used in agriculture. High doses of some pesticides can cause cancer in animals, but the levels found in foods are tightly regulated to make sure they are well below this dose.
Fruit and vegetables sometimes contain minute amounts of pesticides on the surface, but there is no evidence that these small amounts increase the risk of cancer in people who eat them. There is also evidence that eating organic food – which usually doesn’t use pesticides – does not affect cancer risk.
Fruit and vegetables are an important part of a balanced diet, providing vitamins, minerals and fibre – individuals who eat plenty of fruit and vegetables may have a slightly lower cancer risk.
There is some evidence that individuals such as agricultural workers and farmers who are exposed to higher levels of pesticides as part of their job, for example in industry or through farming, may be at slightly higher risk of cancer.
The International Agency for Research into Cancer (IARC) has looked at the evidence and said that regularly spraying pesticides as part of your job “probably” slightly increases the risk of cancer.
Pesticides which research has clearly shown to be dangerous, such as DDT and lindane, have been banned by various regulatory agencies.
Glyphosate is a broad spectrum herbicide (weed killer). It is the main active ingredient in Roundup, and is widely used in agriculture as well as home gardening. There is some evidence that people who are exposed to the highest levels of glyphosate may have a small increased risk of certain types of cancer.
Soy (or soya) products such as tofu and soy milk are made from soybeans, and contain a group of chemicals called isoflavones, which are plant-based oestrogens which have a similar structure to the human oestrogen, but with much milder effects.
Laboratory studies have shown that these isoflavones can mimic the effects of oestrogen in our bodies, which scientists think could reduce the risk of some hormonal cancers.
The effect of soy in human studies is less clear, however; some studies have shown that diets high in soy could reduce the risk of prostate cancer, but it is not clear if this is really the case. There is no strong evidence for a link between soy and any other cancer type.
Also, many of the studies which look at the effect of soy on cancer risk take place in Asian countries, where people generally have more soy in their diets than in Western countries, so it is not clear whether these results are relevant to Western countries.
The term ‘superfood’ is used to describe foods with apparently special health-related powers. These often include blueberries, broccoli, raspberries, green tea and many more. Typically, such foods are hailed as having the power to prevent or even cure many diseases, including cancer.
Many so-called ‘superfoods’ contain natural chemicals that have been shown to have positive health effects in laboratory studies. These include antioxidants, vitamins and minerals. It is true that some of these ingredients can affect cancer cells in a laboratory setting, including killing them and stopping them from growing.
The problem, however, is that foods contain many chemicals, and laboratory studies are usually carried out using a purified ingredient from a particular food. So if researchers want to test the effect of an antioxidant contained in blueberries, they will use a purified version of that chemical rather than fresh blueberries.
Scientists have to use very large doses, which are much higher than what we would actually get in our diet, of these purified compounds to see any effects in their studies. This means that even eating very large portions of a ‘superfood’ might not provide enough of a specific ingredient to have any effect on our health.
Tomatoes contain a chemical called lycopene. Lycopene is an antioxidant, which are also known as a “free radical scavenger,” – chemicals that interact with and neutralise free radicals, thus preventing them from causing damage.
Lycopene is found in all forms of tomatoes and tomato products including fresh, tinned, paste, juice and tomato sauce.
In human studies it’s unclear if lycopene can reduce the risk of prostate cancer. More research is needed to say for sure whether lycopene can affect cancer risk.
Even so, eating tomatoes still counts towards your five-a-day, and they’re also an excellent source of vitamins A, C and E.
Vitamin & Mineral Supplements
Vitamin supplements do not have the same benefits as getting naturally-occurring vitamins in your food. It is thought that in fruit and vegetables, vitamins andnutrients interact with other chemicals to produce positive effects. On their own, they could be much less beneficial.
Several clinical trials have found that very high doses could actually increase the risk of cancer.
The best way to get your full range of vitamins and minerals is to eat a healthy, balanced diet, with a variety of fruit and vegetables.
Source: Cancer Research UK
Posted on 18 July, 2017, in Blog, nutrition and tagged acrylamide, artificial sweeteners, cancer, cancer fighting foods, cancer nutrition, childhood cancer, Children with Cancer, dairy products, green tea, LFCT, Little Fighters Cancer Trust, pesticides, soya, superfood, supplements, tomatoes. Bookmark the permalink. Leave a comment.