We all know eating lots of red and processed meat isn’t good for your health – but it turns out regular consumption of any meat isn’t that great for you, either.
That’s according to a large study conducted by the University of Oxford, using data from almost 475,000 UK adults, which found regular meat consumption is linked with a range of diseases researchers hadn’t previously considered.
Previous research has shown excess consumption of red and processed meat, such as bacon and sausages, may be associated with an increased likelihood of developing colorectal cancer.
But the results of the new study, published in BMC Medicine, associated regular meat intake with a higher risk of various diseases, including heart disease, pneumonia and diabetes.
The study analysed the participants for 25 major causes of non-cancerous hospital admissions. At the start, participants completed a questionnaire which assessed their dietary habits including meat intake, after which they were followed-up for an average period of eight years.
Participants who consumed unprocessed red meat and processed meat regularly – meaning three or more times per week – were more likely than low meat-eaters to smoke, drink alcohol, have overweight or obesity, and eat less fruit and vegetables, fibre, and fish.
However, after taking these factors into account, the results indicated that higher consumption of unprocessed red meat and processed meat combined was associated with increased risks of ischaemic heart disease, pneumonia, diverticular disease, colon polyps, and diabetes.
For example, every 70g higher red meat and processed meat intake per day was associated with a 15% higher risk of ischaemic heart disease and a 30% higher risk of diabetes.
The study heralds bad news for chicken and turkey fans, too. Higher consumption of poultry meat was associated with higher risks of gastro-oesophageal reflux disease, gastritis and duodenitis, diverticular disease, gallbladder disease, and diabetes.
Every 30g higher poultry meat intake per day was associated with a 17% higher risk of gastro-oesophageal reflux disease and a 14% greater risk of diabetes.
Researchers said most of these positive associations were reduced if body mass index (BMI, a measure of body weight) was taken into account, which suggests that regular meat eaters with a higher average body weight could be partly causing these associations.
On a more positive note, the team found higher intakes of unprocessed red meat and poultry meat were associated with a lower risk of iron deficiency anaemia. The risk was 20% lower with every 50g higher per day intake of unprocessed red meat and 17% lower with every 30g higher per day intake of poultry meat.
A higher intake of processed meat was not associated with the risk of iron deficiency anaemia, however.
Why has meat shown to cause a higher risk of disease?
The research team suggest unprocessed red meat and processed meat may increase the risk of ischaemic heart disease because they’re major dietary sources of saturated fatty acids. These can increase low-density lipoprotein (LDL) cholesterol, an established risk factor for ischaemic heart disease.
Lead author Dr Keren Papier, from the Nuffield Department of Population Health at the University of Oxford, said: “We have long known that unprocessed red meat and processed meat consumption is likely to be carcinogenic and this research is the first to assess the risk of 25 non-cancerous health conditions in relation to meat intake in one study.”
Additional research is needed, she said. For example, they want to know whether these diseases could be prevented by decreasing meat consumption.
“The result that meat consumption is associated with a lower risk of iron-deficiency anaemia, however, indicates that people who do not eat meat need to be careful that they obtain enough iron, through dietary sources or supplements,” Dr Papier added.
Meat is a good source of protein, vitamins and minerals in your diet, but the NHS recommends people who eat more than 90g of red and processed meat per day should cut down to 70g, as this could help reduce the risk of bowel cancer.
In response to the study, Professor Robert Pickard, member of the Food Advisory Board, says it is important to think about the balance of foods that make up a varied and healthy diet – “plenty of wholegrains, fruit and vegetables, and limited amounts of foods high in saturated fat, salt and sugar” – rather than focusing on one particular food alone.
“Red meat can form part of a healthier dietary pattern, and is included in the government’s healthy eating model – the Eatwell Guide – and is an important contributor in the UK diet to nutrients like iron, zinc and vitamin B12,” he says.