The European Society of Cardiology (ESC) have published a press release on an observational study looking at intake of red and processed meat and heart function.
Please note these comments are based on the press release alone. There was no study available:
Prof Gunter Kuhnle, Professor of Nutrition and Food Science, University of Reading, said:
“From the information available in the press release this appears to be a well conducted study, making use of the excellent outcome data of the UK Biobank. The results are not surprising, as previous studies have suggested an increased risk of heart diseases in people eating a lot of meat – but this study adds a lot of information which will help to understand the underlying mechanism better. While we have a reasonably good understanding of the link between meat and cancer, there are fewer data for the link with heart diseases. So this study is very welcome!
“It is important to have a holistic approach to diet and not consider individual foods in isolation. Meat can be an important source of protein and iron – and anaemia is a considerable problem. The focus on individual foods and food groups is unlikely to have an overall beneficial effect, but might result in an increase in eating disorders.”
Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, said:
“There’s really not much I can say about this – it’s just a press release of the research, and there’s nowhere near enough detail to assess it properly. Also, I think it hasn’t yet been peer reviewed. I will point out, though, that it’s an observational study and so can’t establish cause and effect. That’s because the people who eat different amounts of red meat (or oily fish) will differ in many other ways too, and those differences could be, in part or in whole, the actual cause of any differences in heart health. The press release does say that the researchers made statistical adjustments to try to take into account these other differences between people, but there isn’t enough detail given to understand how adequate these adjustment were. In any case, one can never be certain that adjustments like that have accounted for every aspect – you just can’t know enough about cause and effect from a single study like this. Other aspects of the research might be good, bad, or indifferent – we just can’t say on the basis of such very sparse information.”
Tracy Parker, Heart Health Dietician at the British Heart Foundation (BHF) said:
“This is an observational study which looked at meat consumption and imaging of heart health. It found that specifically, individuals with a higher meat intake in their diet had smaller ventricles, poorer heart function and stiffer arteries – all of which are markers of worse cardiovascular health.
While meat can be a nutritious part of the diet, offering a source of protein, vitamins and minerals, research has revealed time and time again that people who eat more red and processed meat are at a greater risk of heart and circulatory diseases.
When it comes to lowering our risk of heart and circulatory diseases, most of us could benefit from reducing our intake of red and processed meat – in the UK, it’s recommended that people should try and limit red and processed meat to no more than 70g a day. The BHF recommends following a traditional Mediterranean diet, which has been linked to a reduced risk of heart and circulatory diseases. This includes eating less meat and including more plant-based proteins in our diets such as lentils, nuts, seeds, fruit, vegetables, fish and wholegrains.”
Professor Ian Givens, Director, Institute for Food, Nutrition and Health, University of Reading, said:
“There is not enough information in the press release alone to be able to evaluate the claims made. For example, we need to know more about the meat involved in the study. For most health issues processed meat poses a substantially higher risk than red meat and I see that processed meat is mentioned but was its differential affect studied? There is also a very large range of products that fall into the processed meat category and they vary between countries. Indeed even red meat is variable as it includes pork which is not very red.”
Dr Duane Mellor, Registered Dietitian and Senior Teaching Fellow, Aston Medical School, Aston University, said:
“Studies like this can give useful insights into how lifestyle might impact on heart health, especially as it looked at a large number of individuals who are part of the UK Biobank study. This, study is only a snap shot, looking at what people report eating, in this case red meat and heart health, with this analysis looking at heart health using detailed imaging. It is important to note that this study has not been published in full and is only a conference abstract, so more details are needed.
“As well as looking at heart muscle function, it also considered the health of blood vessels which measures how stretchy arteries are, with more stretchy or bouncy blood vessels being healthier. Whereas oily fish intake were associated with healthier bouncy blood vessels, red meat intake was linked to less healthy heart muscle and less stretchy arteries.
“As this study was just a snapshot at one point in time it cannot suggest this effect is causal, and when making recommendations to improve heart health we look at the whole dietary patterns as a range of foods may help improve heart health including oily fish, vegetables, nuts, seeds and sources of fibre such as oats, often the foods considered to be the basis of the Mediterranean Diet.
“It should be remembered that people who eat more red meat, some of these individuals may not be eating as much fish or vegetables as those eating less red meat, so we need to think not just about the foods people eat in studies like this, we also need to consider what is not being eaten! After all, if you are eating pilchards on toast for lunch you might not be having a bacon sandwich!”
Dr Dipender Gill, NIHR Clinical Lecturer in Pharmacology at St. George’s, University of London, said:
“This is an observational study exploring the association between self-reported meat consumption and measures of cardiovascular health.
“The identified associations are interesting and generally support the results of previous studies. However, as the authors point out, these findings should be interpreted in light of their notable limitations. Firstly, the dietary traits were self-reported, and so may be subject to recall bias. Secondly, there may be unmeasured or unknown confounding that results in spurious associations between the dietary traits and cardiovascular parameters. Thirdly, cardiovascular parameters such as the size of the heart and the elasticity of the vessels are related to the size of the individual. Adjusting for potentially confounding variables such as body mass index may itself also induce spurious associations between dietary traits and the considered outcomes.
“To conclude, while the findings are of interest and contribute to the growing body of literature on this topic, they themselves should not be used to infer causal effects of dietary traits on parameters of cardiovascular health, nor their clinical significance.
“As is already suggested by doctors and health authorities, individuals should continue to follow a balanced diet and lifestyle to minimise their risk of cardiovascular disease.”
All our previous output on this subject can be seen at this weblink:
Prof Kevin McConway: “I am a Trustee of the SMC and a member of its Advisory Committee. My quote above is in my capacity as an independent professional statistician.”
Dr Duane Mellor: “No declarations of interest.”
Dr Dipender Gill: “I am employed part-time by Novo Nordisk.”
None others received.