How Safe are Animal Products from the USA?

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This article was first published in the December 2018/January 2019 edition of NHD Magazine (you can download the PDF of the original article at the end of this post).

Due to the possibility of a trade deal between the USA and UK, there is a lot of discussion about how safe it is to consume meat, poultry and dairy products from the US.

This article examines this topic, which a specific focus on the chlorine-washing chicken and the use of antibiotics and hormones in meat and dairy production.

Chlorine-Washed Chicken

Therefore poultry from the US is sometimes washed with chlorine in order to disinfect it before it is sold. Some suggest that this use is related to lower animal welfare and hygiene standards in farming the US as compared with the EU. For example, chickens can be crammed together in small spaces which increases the risk of contamination and disease.

However, experts in chicken farming in the US disagree with this and describe chlorine-washing as “one tool in the tool box to keep chicken as safe as possible before reaching consumers”.

According to the European Food Safety Authority (EFSA), the chlorine washing itself does not seem to pose any health risks to humans.

But there is a precautionary ban on chlorine washed products in the EU, because relying on this method could lead to lower hygiene standards, and the EU emphasises food quality and food safety during all stages of production ‘from farm to fork’.

As chlorine washing is deemed as a process rather than an ingredient, chicken imported from the US might not be labelled as to whether it had been chlorine washed or not.

However, it is estimated that only 10% of chicken-processing plants in the US use chlorine-washing. Furthermore, no chlorine in found in the chicken itself by the time it reaches the shops.

Summary: Chlorine washed chicken does not seem to pose a risk to human health, and no chlorine is found in the chicken when it is being sold. But there is a precautionary ban on this practice in the EU, in case this may lead to poorer hygiene standards in chicken farming.

Hormones Used in Cattle Farming

Steroid growth hormone implants are used in US cattle to increase weight gain and meat production.

The ‘beef war’ between the EU and the US began in 1989 when the EU banned meat from the US and Canada which contained artificial growth hormones. This was a safety measure due to the potential health risk to humans related to hormone residue in meat; although the use of some hormones was allowed under the supervision of a vet. This lead to a legal dispute involving the World Trade Organization in 1997. This was won by the US and Canada on the basis that the risk assessment by the EU was inadequate. Then in 2008, a mixed ruling was given which allowed the EU to continue its ban on hormone treated meat, and also allowed the US and Canada to continue trade sanctions on the EU.

The most recent review of this topic by EFSA reported that there is not enough data to conclude whether there is a causal relationship between consumption of hormone-treated meat and the development of hormone-dependant cancers (such as breast, endometrial, ovary, testicular and prostate cancer).

This report also highlighted there are environmental concerns related to hormone treated meat; such as disturbance to wild fish populations as a result of contamination of rivers near farms with hormone-treated cattle.

Summary: Growth hormone implants can be used by farmers in the US to increase weight gain in cattle. There is no strong evidence that hormone-treated meat poses a risk to human health, but as there is some uncertainty about this, meat containing certain hormones are banned in the EU – which led to a trade dispute between the EU and US.

Hormone Use in Dairy Production

A growth hormone called recombinant bovine somatotropin (rBST – also called “bovine growth hormone” or BGH) is used to increase milk production in cows.

The US Department of Agriculture reported in 2005 that only about 17% of dairy producers in the US use rBST.

rBST is banned from use in the EU, Australia, New Zealand, Canada, Japan, Israel and Argentina. The main reason for this ban is because meta-analysis studies have linked its use to harming animals – causing lameness, decreased fertility, lactation problems and udder infections; however results of a more recent meta-analysis have contradicted this.

There is also a concern that the increase in udder infections as a result of rBST increases the use of antibiotics. This increases the development of antibiotic-resistant bacteria (i.e. ‘superbugs’) which is a worldwide public health concern.

However it is less clear to what extent these antibiotics have a direct effect on human health.

The food and drug association (FDA) in the US report that pasteurised milk (regular and organic) is tested for antibiotic residue to ensure it does not contain dangerous amounts of antibiotics before being sent to shops.

Milk used to make products like butter and cheese does not have to undergo this testing, but most of it does meet this standard.

There is a theory that because rBST treated dairy contains higher levels of insulin-like growth factor 1(IGF-1), that consuming this may increase the risk of cancer. rBST is not active in humans and it is destroyed in the digestive system, but IGF-1 from dairy is not destroyed by pasteurization; with the exception of the specific heat treatment used to produce infant formula).

Studies have found that IGF-1 intake from dairy has no significant activity in humans, which may be because the level of IGF-1 in milk is much lower than the level which is found in the digestive juices which are already present in our body. But IGF-1 levels have been found to increase slightly after milk consumption. For example, a randomised trial from the US found that regular milk drinking was associated with 10% higher IGF-1 levels, but this study only involved rBST treated dairy so it is unclear whether this was related to milk in general or the use of rBST.

An increase in IGF-1 in the blood may be associated with an increased risk of prostate cancer; but the American Cancer Society report that the evidence is inconclusive about this and that more research is needed.

However, rBST use does have environmental benefits. For example, it has been found that 8% fewer cows are needed to product the same amount of milk when rBST treated cows were compared with conventional non-rBST treated cows. In contrast, organic dairy production requires 25% more cows to produce the same amount of dairy as conventional dairy production (without using rBST).

Summary: rBST can cause harm to cows. There is no strong link between drinking milk produced using rBST and harm to human health, but more research is needed to look into this. rBST can increase the use of antibiotics to treat udder infections, this contributes to the global issue of antibiotic-resistant bacteria development. But milk sold in shops is very unlikely to contain antibiotics.

Antibiotic Use in Cattle Farming

Antibiotics are used as part of meat production to treat and prevent diseases from occurring in the animals. Antibiotics can also be fed to animals in small doses in order to improve growth. This practice has been banned in the EU since 2006, and was also banned in the US in 2017. Currently in the US, a Veterinary Feed Directive (VFD) or a prescription is needed for all medically important antibiotics which are used in feed or water for animals.

However, a recent report by the Alliance to Save our Antibiotics found that farms in the US still use roughly 5 times more antibiotics as compared with UK farms.

When this was broken down by specific animals, antibiotic use in the US was roughly:  

  • Twice as high compared to use in UK pigs
  • Three times as high compared to use in UK chickens
  • Five times as high compared to use in UK turkeys
  • 9-16 times as high compared to use in UK cattle

The main concern with this high use of antibiotics is that it promotes the development of antibiotic resistant bacteria, which in turn leads to increased medical costs, longer hospital stays, and a higher risk of death as antibiotics become less effective.

For example, in the US more than 23,000 people die every year as a result of antibiotic resistant bacteria.

As the largest use of antibiotics globally is for the production of meat and dairy for human consumption, the World Health Organisation (WHO) has urged the farming sector to:

  • Only give antibiotics to animals under veterinary supervision.
  • Not use antibiotics for growth promotion or to prevent diseases in healthy animals.
  • Vaccinate animals to reduce the need for antibiotics and use alternatives to antibiotics when available.
  • Promote and apply good practices at all steps of production and processing of foods from animal and plant sources.
  • Improve biosecurity on farms and prevent infections through improved hygiene and animal welfare.

There is also a risk that antibiotic resistant bacteria can be passed to humans through the food supply. Ground beef is one of the most common foods which is associated with antibiotic‐resistant outbreaks. But the risk related to this is very low because cooking food properly destroys the harmful bacteria. The FDA also has strict testing procedures in place to prevent meat products being sold which contain unapproved or unsafe drugs, including antibiotics.

So the risk of consuming antibiotics from meat in the US is low.

Summary: Overuse of antibiotics in meat production poses a serious risk on a public health level, as this promotes the development of antibiotic resistant bacteria. The US is working towards reducing its overuse of antibiotics in animals. However, the chance of consuming antibiotics or antibiotic resistance bacteria via meat is very low overall.

Organic Meat and Dairy

The USDA ‘100% Organic’ logo can be used on products from the US which have not been made using growth hormones or antibiotics. However, organic and ‘antibiotic free’ produce can still contain antibiotic resistant bacteria, but this tends to be in slightly lower levels than conventional produce.

A study from 2015 found that organically produced chicken contained 31% antibiotic resistance bacteria as compared to conventionally produced chicken which contained 43.6%.

Poultry and eggs which are labelled as organic by the USDA can be chlorine washed, but these are then rinsed with water which is deemed safe for drinking.

But as mentioned previously, the chances of ingesting hormones or antibiotics from conventionally produced meat and dairy is already very low due to testing by the FDA.

For more information about organic food, check out this article I wrote for The Food Medic Educational Hub.

Summary: Meat and Dairy products which are labelled as ‘100% Organic’ by the USDA are not produced using hormones or antibiotics. Chickens and eggs which use this label can be chlorine washed, as long as they are rinsed with water afterwards which is of drinking standard.


There is no good evidence to suggest that consuming chlorine washed chicken is a health risk. Similarly, eating meat or dairy products which were produced using growth hormones or antibiotics doesn’t seem to pose a direct risk to human health. This is likely to be related to the fact that meat and dairy products are rigorously tested to ensure that they don’t contain traces of unsafe hormones or antibiotics before being sold.

However, these practices can have negative effects on a bigger scale. For example, chlorine washing chickens may encourage poor hygiene standards earlier in the production process. The use of rBST hormones can harm cows, and the widespread use of antibiotics in meat and dairy production can increase the development of antibiotic resistant bacteria; which is a serious problem worldwide.


Maeve has been consulting on The Food Medic Educational Hub for 12 months now and has been a huge asset to the team. Her ability to translate some very nuanced topics in nutrition into easy-to-follow, informative articles and infographics is really admirable.

Dr Hazel Wallace

Founder of The Food Medic

Maeve is incredibly talented at sharing scientific information in an easy to understand way. The content she shares with us is always really interesting, clear, and of very high quality. She’s one of our favourite writers to work with!

Aisling Moran

Senior UX Writer at Thriva Health

Maeve has written extensively for NHD magazine over the last few years, producing a wealth of dietetic and nutritional articles. Always evidence based and factual, Maeve creates material that is relevant and very readable. She provides high quality work with a professional and friendly approach. Maeve is a beacon of high quality knowledge and work within the nutrition writing community; and someone NHD magazine is proud to work with.

Emma Coates

Editor of Network Health Digest

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