Is it safe to eat bacon? Does eating processed meats increase the risk of cancer? Dietitian Emer Delaney looks into the research behind the recent headlines.
Recently, news headlines have focused on the health implications of eating red and processed meat. But should we really be worried about tucking into the occasional bacon sarnie? Is there any evidence that we should switch to buying nitrate-free products? We asked dietitian Emer Delaney to explain the research behind the headlines and separate fact from fiction.
What is the latest research into processed meats and cancer?
In 2015 the International Agency for Research on Cancer, an independent agency of the World Health Organisation (WHO), reported that processed meat was carcinogenic to humans. This was based on an expert review article which was summarised in the prestigious scientific journal – Lancet Oncology. The WHO defines processed meats as products that have undergone salting, curing, fermentation or smoking to enhance flavour or improve preservation. This includes products such as bacon, salami, hot dogs, ham and corned beef. WHO found that eating 50g of processed meats a day would increase the risk of developing bowel cancer by 18% over a lifetime – a statistic that increases with the amount of processed meat eaten. In fact, recent research found that people eating around 76g of red and processed meat a day had an increased risk of developing bowel cancer compared to those who ate about 21g a day.
As a result, the NHS recommends limiting intake of red and processed meats to 70g per day – although you may choose to eat less.
What are nitrates and what do they do?
Nitrates are food additives that are used to improve the look and quality of bacon and some other processed meats. They are sometimes included for food safety to protect against microbes such as botulism. However, they have been reported to be sources of carcinogens as they form something called nitrosocompounds (NOS). A carcinogen is any chemical substance or form of radiation that either damages DNA or disrupts the metabolism of an organism.
Read more about the WHO's classification of red and processed meat as carcinogens.
Are nitrates bad for you?
Unfortunately, it’s not as simple as saying that nitrates are bad for you and cause cancer. There are a multitude of factors that affect the formation of NOS. These include the quality of the meat, how it’s cooked, the fat content, the processing and maturation of the meat.
Adding vitamin C and E to processed meats has been reported to reduce the formation of these harmful NOS. One recent study looked at the impact of vitamin C on the effects of NOC exposure and colorectal cancer in women. They concluded that overall nitrate intake was not associated with the risk of developing colorectal cancer. However, women who had a lower than recommended vitamin C intake and hence a higher exposure to NOCs, had a higher risk of developing colorectal cancer.
Is it better to buy nitrate-free bacon and other processed meats?
The evidence is pretty strong and consistent that a higher consumption of processed meat is associated with increased cancer risk. We know bacon and other processed meats contain nitrates, however according to some experts, including additional vitamins negates these potential negative properties. The truth is, we cannot confidently say what happens to nitrates in the body for numerous reasons such as the presence of gut bacteria, oxygen in the blood, dietary antioxidants, fat and alcohol. We cannot, therefore, definitively say that the presence of nitrates in processed meats is the sole reason for increased cancer risk.
What we do know is that, based on the evidence available, processed meats should be reduced to a minimum and only eaten occasionally. We should aim to eat plenty of fruit and vegetables whether fresh, frozen or tinned and eat wholegrain foods as often as possible. This is the best dietary advice to follow – coupled with eating fish twice a week (once of which should be oily), limiting red meat to once a week, including pulses as often as possible and keeping alcohol intake to a minimum.
Discover how to eat a balanced diet.
How much bacon is safe to eat?
Keeping your bacon intake to a minimum is recommended and only eating it every couple of weeks is best. The current advice from the NHS recommends that if you currently eat more than 90g (cooked weight) of red and processed meat a day, that you cut down to 70g a day. This is equivalent to two or three rashers of bacon, or a little over two slices of roast lamb, beef or pork, with each about the size of half a slice of bread. In light of the more recent evidence, it's best to reduce your intake of all processed meats to once every couple of weeks.
Read more: How much red meat is safe to eat?
What are your top tips to cut down on bacon?
- Swap bacon for lentils, chickpeas, kidney beans, peas, butter beans, baked beans or haricot beans.
- Try bacon alternatives such as turkey, tofu or tempeh rashers.
- Add small salmon fillets to your meal instead.
- Buy meat less frequently but make it the best quality you can afford.
- Cut thin slices of avocado and add it to your sandwich.
- Portobello and porcini mushrooms have a very rich, meaty feel and flavour, so adding these to dishes can work.
- Paprika and chipotle peppers both have a smoky flavour and can add depth to dishes.
This article was last reviewed on 9th October 2019.
Emer Delaney BSc (Hons), RD has an honours degree in Human Nutrition and Dietetics from the University of Ulster. She has worked as a dietitian in some of London's top teaching hospitals and is currently based in Chelsea.
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