This piece was written by one of our contributors; dietitian Maeve Hanan.
Eating red meat has become a more controversial topic in recent years. It’s not surprising that many people feel confused about the health impact of eating red meat, considering the amount of conflicting messages about this topic in the media and online. This article will primarily focus on the nutritional benefits and risks related to consuming red meat.
Types of Red Meat
Red meat is defined as fresh meat which is red when it is raw. This includes: beef, lamb, pork, venison, goat and horse meat. Red meat which has been minced or frozen is still considered to be unprocessed, fresh meat (1).
Whereas processed red meat has been preserved or enhanced using food processing techniques, such as: smoking, curing, salting, fermentation or the addition of preservatives (1). Examples of processed red meat include: bacon, sausages, ham, salami, pâté and corned beef.
The Food and Agriculture Organization of the United Nations (FAO) categorise the different types of processed meat as (2):
- Cured meat pieces (treating the meat with a small amount of salt, with or without the addition of potassium chloride, nitrate or nitrite salts) e.g. bacon and cooked ham.
- Fresh industrial processed meat products (mixtures of meat, animal fat and other flavourings which are salted only, not cured or pre-cooked) e.g. sausage and kebab meat.
- Precooked ready-to-eat products e.g. frankfurters, canned corned beef and liver pâté.
- Fermented sausages e.g. pepperoni, salami and chorizo.
- Dried meat e.g. beef jerky.
The third type of red meat is offal. This is the internal organs and entrails of an animal, for example: liver, kidneys, tripe or small intestine.
Nutritional Characteristics of Red Meat
Protein
Red meat is a good source of ‘high quality’ protein – which means that it contains all nine essential amino acids in good quantities. Essential amino acids can’t be produced by our body alone, so we need to consume them in our diet.
To put this in context, most people require about 15 – 40g of protein per meal (depending on their weight and activity levels), and a 4 ounce steak or quarter pound of beef mince (112g) provides about 25g of protein.
Iron
Red meat is also a good source of iron, which plays a vital role in the transport of oxygen around our body. Therefore a lack of iron leads to symptoms such as tiredness, weakness and shortness of breath (i.e. iron-deficiency anemia). Offal is especially high in iron, 2 slices of beef liver provides about 12mg of iron (men require 8.7mg of iron per day, and menstruating women require 14.8mg). The type of iron found in red meat is called haem iron, whereas plant-based iron is non-haem iron. Haem iron is easier for the body to absorb and use. However, we can boost the absorption of non-haem iron by consuming foods high in vitamin C along with it (such as berries, orange juice, broccoli or red pepper).
Minerals: Zinc, Phosphorus and Selenium
Other important minerals found in red meat include: zinc, phosphorus and selenium. Zinc is vital for wound healing, a healthy immune system and DNA synthesis. Phosphorus plays an important role in bone health, dental health, DNA production and releasing energy from food. Selenium acts as an antioxidant in our body, and is also important for DNA production, reproductive health and thyroid health.
Vitamin b12
Red meat is a great source of B vitamins, especially vitamin B12 which plays an essential role in our brain function, nerve function, creating red blood cells and releasing energy from food. A 4 ounce (112g) portion of red meat provides 2.3 mcg of vitamin B12, and we are advised to have at least 1.5 mcg per day.
Choline
Another vital nutrient found in red meat is choline. This is an amino acid-like nutrient which is essential for our brain and nervous system, as well as muscle contraction and gene expression.
Vitamins
Offal contains a moderate amount of vitamin C, whereas other types of red meat generally don’t contain any vitamin C. Offal is also extremely high in vitamin A – as excess vitamin A can harm a developing foetus, pregnant women are advised to avoid offal such as liver.
Dietary fat
Red meat can be high in saturated fat, and a high intake of saturated fat is bad for heart health. However, the amount of saturated fat varies between different cuts of meat with lower amounts present in lean mince and leaner cuts such as flank and loin.
Red meat also contains a moderate amount of monounsaturated fat. Although grass-fed beef has been found to contain almost twice as much omega-3 fat as grain-fed beef, this is still a low amount of omega-3 overall compared with rich sources such as oily fish (3).
Salt
Processed meats like bacon and sausages are high in salt. One sausage or slice of bacon usually contains 0.5 – 1g of salt, and we are advised to consume no more than 3-6g of salt per day. For more information about salt and health check out this article.
Red Meat & Cancer Risk
In 2015, the International Agency for Research on Cancer (IARC) classified processed meat as a group 1 ‘definite’ cause of bowel cancer, and red meat as group 2a ‘probable’ cause of bowel cancer (4). This generated a media buzz, as processed meat was placed in the same category as tobacco. However, this doesn’t mean that tobacco and processed meat pose the same level of cancer risk – as tobacco poses a much higher cancer risk. Rather, it means there is strong evidence that both processed meat and tobacco are linked with increasing cancer risk.
Certain chemicals associated with red and processed meat have been found to damage cells in the bowel and increase the risk of cancer:
- Nitrates and nitrites – which are added to processed meat such as bacon as part of the curing process.
- Haem – a red pigment found naturally in red meat.
- Heterocyclic amines and polycyclic amines – these are formed when meat is cooked at high temperatures, particularly when it becomes charred or burnt.
Cancer Research UK state that “more expensive or organic processed and red meat are not necessarily any healthier, so it’s better to cut down altogether rather than to switch to these” (5). This is because they still contain haem, and heterocyclic amines and polycyclic amines can still be formed during cooking.
It’s important to remember that red and processed meat consumption is just one part of the puzzle. For example, there is also strong evidence that consuming plenty of fruit, vegetables and wholegrains reduces the risk of bowel cancer (6, 7, 8, 9).
Red Meat & Heart Health
Plant-based diets are associated with a lower risk of heart disease (10). However, we don’t have strong evidence to say that we need to avoid red meat altogether within a heart healthy diet. Furthermore, the type of meat matters, as a higher intake of processed red meat (rather than lean red meat) is seen to increase heart disease risk (11, 12).
It is also important to highlight that consuming a lot of meat often displaces other heart healthy foods in the diet, such as: fruit, vegetables, wholegrains, nuts, seeds and fish. For example, eating 5-10 portions of fruit and vegetables per day is also associated with a lower risk of heart disease, regardless of whether animal products are included in the diet (8).
As discussed above, a high intake of red and processed meat leads to a high intake of saturated fat and salt. Consuming a lot of saturated fat is associated with higher levels of LDL cholesterol in the body, which is a risk factor for heart disease (13). Similarly, excessive salt intake can lead to raised blood pressure, which is also a risk factor for heart disease (14).
Overall, consuming too much meat is usually bad for heart health. But of course the development of heart disease depends on a variety of factors including: genetics, age, the balance of the overall diet, physical activity levels, sleep and stress levels.
How Much Red Meat is Healthy to Consume?
The World Cancer Research Fund recommends that we limit our intake to roughly three portions per week (350 – 500g cooked weight), and to eat little to no processed meat (15). The UK government recommends that those who consume more than 90g (cooked weight) of red and processed meat per day should reduce this to 70g per day (16).
However, some cancer experts suggest that this amount should be lowered, as a large UK study from 2019 found that consuming 76g of red and processed meat per day was associated with an increased risk of bowel cancer. This was a 20% increase in the relative risk of bowel cancer – which means an increase from 40 to 48 people developing bowel cancer for every 10,000 people consuming 76g of red and processed meat per day (as compared with 21g per day) (9).
Here are some examples of the typical cooked weights of red meat:
- 3 thin slices of roast lamb, beef or pork – 90g
- 1 sausage – 57g
- 1 rasher – 25g
- 1 slice of black pudding – 30g
- 1 slice of ham – 20g (thin slice of ham – 11g)
- Grilled 4oz beef steak – 85g
- 5oz rump steak – 100g
- Quarter-pound beef burger – 80g
Other Considerations
A big part of the debate around red meat is related to ethical considerations such as animal welfare and the environment.
When it comes to animal welfare, deciding whether to consume animal-based products is a very individual decision. Some people focus on reducing their intake of meat, or buying from farms with a good reputation. Whereas others feel most comfortable avoiding animal-based products. This also needs to be weighed up in the context of each individual’s circumstances. For example, if somebody is recovering from an eating disorder it might not be in the best interest of their health to cut out a food group. Other individual considerations include health status, food availability and cooking skills, knowledge and equipment.
In terms of the environment, red meat production (particularly beef) is the biggest contributor to greenhouse gas emissions in our food supply (17, 18). However, sustainable eating is a complex topic, so there is no one sustainable diet which applies to all countries. The current consensus from sustainability experts is that we need to reduce our intake of animal-based products and increase our intake of plant-based products on a global scale (18, 19). However, this doesn’t mean that following a vegan diet is the only way to eat sustainably. For example, the EAT-Lancet report from 2019 advised that upto 196g of red meat per week could be included within a ‘planetary healthy diet’ (i.e. up to 2 portions of red meat per week) (19). Similarly, a study from the Carbon Trust found that if the UK population followed The Eatwell Guide (healthy eating guidelines), this would reduce the environmental impact of the food supply by 32% (20).
Take-home Messages
Meat is a very nutritious food, which provides high quality protein, iron, B vitamins, choline, zinc, phosphorus and selenium. However, for the sake of our own health and the health of the planet we should limit our intake of red meat to 2-3 portions per week, and consume very little processed red meat.
It is also important to remember the bigger picture of health: having a balanced diet which includes plenty of fruit, vegetables and wholegrains; not smoking, not drinking too much alcohol, regular physical activity, managing stress and getting enough sleep.
For those who want to reduce their intake of red meat, here are my top tips:
- Try to limit your intake of red meat to 3 days, and processed red meat to one day maximum per week.
- Reduce your red meat portions e.g. a standard burger instead of a quarter-pounder, a 4 ounce instead of an 8 ounce steak.
- Aim for at least one meat-free day per week – vegetarian sources of protein include beans, lentils, chickpeas, tofu and mycoprotein.
- Have fish at least twice per week, one of which being oily fish (like salmon, trout, mackerel or sardines).
- If having a cooked breakfast reduced the amount of bacon and sausages and add more vegetables (e.g. mushrooms, tomatoes, beans, spinach, onions).
- In casseroles, stews, curries, and lasagnas bulk up with extra vegetables and use half the amount of meat, or use half beans half pulses (e.g. half mince half tinned lentils in a lasagna).
References:
(1) IARC (2018) “IARC Monographs: Red Meat and Processed”
(2) Heinz & Hautzinger P (2007) “Meat processing technology for small – to medium – scale producers. Rome, Italy: Food and Agriculture Organization of the United Nations” [accessed February 2020 via: http://www.fao.org/documents/card/fr/c/fb92d00f-7ff3-593a-a77c-7b19003b2554/]
(3) Średnicka-Tober et al. (2016) “Composition differences between organic and conventional meat: a systematic literature review and meta-analysis” Br J Nutr; 115(6):994-1011
(4) WHO (2015) “IARC Monographs evaluate consumption of red meat and processed meat” [accessed February 2020 via: https://www.iarc.fr/wp-content/uploads/2018/07/pr240_E.pdf]
(5) CRUK (2019) “Does eating processed and red meat cause cancer?” [accessed February 2020 via: https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/diet-and-cancer/does-eating-processed-and-red-meat-cause-cancer]
(6) SACN (2015) “Carbohydrates and Health” [accessed February 2020 via: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/445503/SACN_Carbohydrates_and_Health.pdf]
(7) Aune et al. (2011) “Dietary fibre, whole grains, and risk of colorectal cancer: systematic review and dose-response meta-analysis of prospective studies” [accessed February 2020 via: http://www.bmj.com/content/343/bmj.d6617]
(8) Aune et al. (2017) “Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-a systematic review and dose-response meta-analysis of prospective studies.” [accessed February 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/28338764]
(9) Bradbury et al. (2019) “Diet and colorectal cancer in UK Biobank: a prospective study” [accessed February 2020 via: https://academic.oup.com/ije/advance-article/doi/10.1093/ije/dyz064/5470096]
(10) Kim et al. (2019) “Plant‐Based Diets Are Associated With a Lower Risk of Incident Cardiovascular Disease, Cardiovascular Disease Mortality, and All‐Cause Mortality in a General Population of Middle‐Aged Adults” [accessed February 2020 via: https://www.ahajournals.org/doi/10.1161/JAHA.119.012865]
(11) Micha et al. (2010) “Red and processed meat consumption and risk of incident coronary heart disease, stroke, and diabetes mellitus: a systematic review and meta-analysis.” [accessed February 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/20479151]
(12) Rohrmann et al. (2013) “Meat consumption and mortality–results from the European Prospective Investigation into Cancer and Nutrition.” [accessed February 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/23497300]
(13) Hooper (2015) “Reduction in Saturated Fat Intake For Cardiovascular Disease” [accessed February 2020 via: https://www.ncbi.nlm.nih.gov/pubmed/26068959]
(14) He et al. (2013) “Effect of longer term modest salt reduction on blood pressure: Cochrane systematic review and meta-analysis of randomised trials” [accessed February 2020 via: https://www.bmj.com/content/346/bmj.f1325]
(15) WCRF Website “Limit red and processed meat” [accessed February 2020 via: https://www.wcrf.org/dietandcancer/recommendations/limit-red-processed-meat
(16) NHS Website “Meat in your diet” [accessed February 2020 via: https://www.nhs.uk/live-well/eat-well/meat-nutrition/
(17) FAO (2013) “Tackling Climate Change Through Livestock” [accessed September 2018 via: http://www.fao.org/3/a-i3437e.pdf]
(18) BDA (2018) “One Blue Dot” [accessed February 2020 via: https://www.bda.uk.com/uploads/assets/539e2268-7991-4d24-b9ee867c1b2808fc/421de049-2c41-4d85-934f0a2f6362cc4a/one%20blue%20dot%20reference%20guide.pdf]
(19) Summary Report of the EAT-Lancet Commission (2019) [accessed February 2020 via: https://eatforum.org/eat-lancet-commission/eat-lancet-commission-summary-report/]
(20) The Carbon Trust (2016) “The Eatwell Guide: a More Sustainable Diet”
