Frequently asked questions

We answer your questions on cancer and lifestyle

  • Q: Do artificial sweeteners increase cancer risk?
  • A: Artificial sweeteners are used in a wide variety of foods and drinks so almost everyone in developed countries consumes them, whether they know it or not. Because of this, any potential impact on cancer risk would be very far-reaching. But overall, studies on artificial sweeteners have not found that they increase the risk of cancer.1

    Saccharin is one of the best studied artificial sweeteners. Some studies in the 1980s found that it could cause bladder cancer in rats, but we now know that these effects were specific to rats and not relevant to humans.

    Aspartame, another sweetener, was also the subject of a cancer scare. This was because of an article linking it to rising brain tumour rates. The article had very little scientific basis and many subsequent studies showed that Aspartame was safe for humans.

    Published in Winter 2015 issue


    1. Cancer Research UK. Food controversies. 2015.

  • Q: Does stress cause cancer?
  • A:  Some people believe that stress can directly affect cancer risk, but this is a common misconception. At World Cancer Research Fund UK we focus on the link between diet, physical activity, weight and cancer, so we don’t normally review the evidence on stress. However experts in this field have found little evidence to support the idea that stress can increase the risk of cancer.1

    Stress can have a negative impact on other aspects of your health, such as blood pressure and sleep quality, and it can encourage unhealthy behaviours, such as smoking, heavy drinking and overeating. These behaviours are all linked to a number of different cancers, which is why it is important that people find other ways to cope with stress that are not harmful to their health. For example, being physically active can improve mood, relieve stress and lower cancer risk.2

    Published in Summer 2015 issue


    1. Cancer Research UK, Stress and Cancer. 2015.

    2. NHS Choices, Exercise to relieve stress. 2013.

  • Q: Can drinking coffee increase your risk of cancer?
  • A: In the past there have been media reports that linked coffee to a number of lifestyle-related diseases including cancer, so it’s no wonder that some people believe that drinking coffee could increase their risk. However, this is not supported by recent research, in fact, evidence now shows that drinking coffee could reduce the risk of womb (endometrial) and liver cancer.1

    Although there is strong evidence that coffee has a protective effect against some cancers, we cannot make any specific recommendations because there are too many unanswered questions – for example, are the benefits a result of drinking coffee regularly, or in large amounts? We are also unsure of the effects of adding milk and/or sugar, and drinking caffeinated, decaffeinated, instant or filter coffee. We must also consider whether there are any harmful effects for other health conditions before making recommendations on coffee. Therefore we cannot give specific advice on coffee consumption for cancer prevention, but we can say that drinking coffee does not seem to increase the risk of developing cancer. 

    Safety of caffeine

    In May 2015, the European Food Safety Authority (EFSA) concluded that for healthy adults (with the exception of pregnant women) single doses of caffeine up to 200 mg (approximately 2.5 espressos or four cups of tea) and total daily caffeine consumption of up to 400 mg are safe. Read the full report.

    Published in Autumn 2015 issue


    1. World Cancer Research Fund UK. Cancer types. 2015.

  • Q: Are all sausages classed as processed meat?
  • A: We advise people to eat as little processed red meat as possible, as it is strongly linked to bowel cancer. When we talk about processed meat we are referring to meat that has been smoked, cured or salted, or contains added preservatives (such as nitrates). If sausages are not smoked, and made fresh with no preservatives, then they are not considered processed and would count as fresh meat. This is true even if a small amount of salt is added for flavour.

    Processed meats usually contain added nitrates and nitrites, which are thought to cause cancer. Processing changes the composition of the meat, which may also play a role. There is also strong evidence to suggest that high-salt diets are linked to stomach cancer.

    Preservative-free sausages made from red meat, such as pork, should still be eaten in moderation, as there is strong evidence to show that eating more than 500g (cooked weight) of red meat a week is also linked to bowel cancer.

    As for processed white meats and fish, there is currently not enough research available on whether they increase cancer risk. As we base our recommendations on the available evidence, we don’t give any advice these foods.

    Published in Spring 2015 issue

  • Q: Is being a vegetarian the best way to lower your risk of cancer?
  • A: There is no evidence that links fish or lean poultry to an increased cancer risk, so we don’t suggest cutting out meat and other animal products altogether to lower the risk of cancer. Instead, we recommend a balanced diet that includes plenty of wholegrains, pulses, vegetables and fruits and limits red meat consumption to no more than 500g (cooked weight) per week. We recognise that meat and fish provide an important source of nutrients as part of a balanced and healthy diet, but a vegetarian diet can also be healthy providing it’s nutritionally balanced. Our advice is for people to follow the two-thirds/one-third rule by filling two-thirds or more of their plate with plant foods and one-third or less with animal foods like meat, fish and dairy.

    Published in Winter 2014 issue

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