How much red meat is good for us
This post is a little different from my normal in which I address the effect of nourishment and lifestyle on the human host and its microbiome. I want to bring your attention to an academic presentation that I think is important for two reasons. Firstly, the speaker highlights how eating meat and dairy provide healthy outcomes, especially to poorer people, infants and the elderly. Secondly, she highlights what appear to be sub-standard publishing practice by an academic journal that has historically influenced policy makers in the field of human nutrition. Given that we now know about the large differences between individuals’ needs for nutrition, I think we should aware of the topics covered in this talk.
In October 2022, Alice Stanton, Professor, Royal College of Surgeons in Ireland and Director Human Health, Devenish Nutrition made a presentation at “The Societal Role of Meat – What the SCIENCE Says”, a summit hosted by Teagasc, the Irish Agriculture and Food Development Authority. Her presentation is subtitled “The Importance of Transparent Evidence-Based Health Metrics”, the significance of which becomes glaringly clear.
Professor Stanton refers extensively to the published scientific literature to describe:
The benefits of animal-based nutrition for human health
Many people around the world suffering from a lack of nutrition
Recent dietary recommendations published in the Lancet do not accurately represent the benefit of animal-sourced nutrition and do not follow best-practices for assessing nutritional benefit
The most recent peer-reviewed scientific literature does not support the Lancet
The full 27-minute presentation can be watched here. I provide below a series of time-stamped bullet point summaries of the presentation for you to dip in and out of as you please.
A quick summary
Here are Professor Stanton’s summary points. If you want to hear those, skip to 25:27 in the video.
Animal-source foods (dairy, meat, fish and eggs) are nutrient rich foods
The relationship between red meat and disease burden is mirror J-shaped
When eaten as part of a balanced diet, red meat provides considerable protection against nutritional deficiencies
Low certainty evidence that relatively small deleterious effects possibly occur with consumption in excess of 500g weekly
The majority of the world’s population are not eating enough dairy nor omega-3 PUFA rich foods
Replacing animal sourced foods with plant-based ultra-processed foods, so as to solve greenhouse gas emissions, is very likely to harm human health – women, children, the elderly and those of low income will be particularly adversely impacted
Policy makers should be extremely wary of global health estimates that
Are not rigorously and transparently evidence-based
Ignore the protection against nutritional deficiencies afforded by animal-source foods
Professor Alice Stanton presenting at “The Societal Role of Meat – What the SCIENCE Says”, a summit hosted by Teagasc, the Irish Agriculture and Food Development Authority
What is a healthy diet?
The World Health Organisation defines a healthy diet as one which helps to protect against malnutrition of all forms plus non-communicable diseases such as diabetes, heart disease, stroke, and cancer (0:39)
Unfortunately, humankind currently suffers from a triple burden of malnutrition
1.9 billion people are overweight or obese
850 million people are chronically undernourished
2 billion people suffer from hidden hunger
a. Adequate calories
b. Inadequate amino acids, proteins, vitamins, and minerals
The value of animal-sourced nutrition and a sad lack of access
The most commonly lacking nutrients are iron, zinc, Vitamin D, and calcium (2:15)
Eighteen of the 20 best bioavailable sources of those vitamins come from animal-sourced food
Vitamin and mineral deficiencies are more likely in countries in which the percentage of calories from animal sourced foods is low
Childhood stunting is highest in those countries where meat, milk, and seafood consumption is low (2:57)
Poor maternal and childhood nutrition leads to childhood stunting
Small stature
Less well-developed brains
Less able to engage in education
Less academic achievement
Less career success
Fewer opportunities in life
Less able to support families
Leads to a vicious cyle of poor nutrition in the next generation
In sub-Saharan Africa and SE Asia, more than 30% of children are stunted
Too little animal-sourced food is also not good for the elderly and leads to shorter lives (4:15)
EAT Lancet
The EAT Lancet Commission is comprised of academics working to solve what they perceive as the challenge of feeding a growing population of 10 billion people by 2050. In January 2019 the Commission published its reference diet recommendations.
EAT-Lancet Commission Reference Diet recommendations (5:23)
Double intake of fruits, vegetables, legumes, nuts and seeds
Halve meat and dairy intakes
Observations by Professor Stanton
Predicts 11 million fewer non-communicable deaths due to changed calorie intake, not reduced red meat intake
Halving dairy likely to increase heart attack and cancer deaths
Nutritional deficiencies caused by halving meat and dairy not considered
Impact of ultra-processed plant-based alternatives not considered
Commenting on the ultra-processed plant-based alternatives proposed by EAT Lancet (7:07)
Currently available plant-based meat and dairy alternatives are ultra-processed, high in added sugars, salt, and cosmetic additives
“The mimicking of animal foods using isolated plant protein, fats, vitamins and minerals likely underestimates the true nutritional complexity of whole foods”
“Novel plant-based meat (and dairy) alternatives should arguably be treated as alternatives in terms of sensory experience, but not as true replacements in terms of nutrition”
Since the publication of the EAT Lancet reference diet recommendations, more authors recommended dramatic reductions and even elimination of animal-sourced food from the human diet (7:54).
The general theme is that excluding red meat and processed meats from the Western diet increases life expectancy
Some some of the claims made are specific to the point of stretching credibility
“Each single serving of Frankfurter sandwich results in 35 minutes of life lost”
“Changes from a typical Western diet to a diet which totally excludes those foods increases life expectancy by 3 years for women and by 4 years for men”
The Global Burden of Disease (GBD) 2019 report
The Global Burden of Disease (GBD) 2019 study in particular is important because it is very influential and many institutions use either its data or methods of analysis (8:46).
GBD studies are led by the Institute for Health Metrics and Evaluation, University of Washington, Seattle (9:22).
The GBD has been described as “The de-facto source for global health accounting”. GBD data and analyses are quoted by and influence the policies of:
Food and Agriculture Organization of the United Nations
World Health Organization
European Commission
The National Food Strategy (UK)
GBD 2019 contains significant changes to meat recommendations
Comparing GBD 2019 with 2017, three issues believed to cause unnecessary deaths arise with meat and dairy (10:27).
Milk consumption is considered to be too low
Seafood omega-3 fatty acid consumption is considered too low
Red meat consumption is considered to be too high
Milk consumption
It is believed that the GBD consistently under-estimates the number of unnecessary deaths caused by consuming too little milk (11:17)
GBD examines only the risk of colorectal cancer associated with too little milk consumption (11:32)
The majority of the world’s population drinks less than one helping/day of dairy
At least three helpings/day is considered protective against colorectal cancer
The GBD does not contain any data on the beneficial impact of dairy against heart attacks and strokes (12:05)
At least two full-fat dairy servings/day are associated with 32% less cardiovascular events and 25% fewer deaths
Seafood omega-3 fatty acids
The GBD considers only the risk associated with cardiovascular disease and ignores brain protective effects when considering the number of unnecessary deaths associated with not consuming enough seafood omega-3 fatty acids (13:19)
The risk in 2019 appears to have decreased. The number of deaths associated with omega-3 deficiencies has decreased from 1.5MM/year to just 0.3MM/year
No explanation for this large decrease in risk was provided in the 2019 report
Only 20% of the world’s population gets enough omega-3s (14:14)
The world’s oceans suffer from over-fishing
Farmed salmon and trout contain less
In assessing the risks of too little omega-3 fatty acids, the GBD ignores their importance earlier and later in life
During infancy and childhood, they are important for brain development, vision and muscle and joint health
Later in life they protect against mental illness, heart attacks, strokes, and cancer
Red meat
The number of deaths projected by GBD to be associated with consuming too much red meat increased from 25,000 in 2017 to 900,000 in 2019 (14:24)
No evidence was provided in the 2019 report for this 36-fold increase
The 2019 GBD report claims to have assessed the risks from heart attacks, strokes, breast cancer, colorectal cancer and type 2 diabetes (15:00)
The 2019 GBD report makes the claim that no level of unprocessed meat consumption is safe (16:00)
GBD recommendations not supported by peer-reviewed literature
The 2019 GBD claim that no level of unprocessed meat consumption is safe is not supported by the 10 largest studies reported between 2012 and 2021 comparing red meat consumption with mortality and death (17:19)
No studies reported increased risk when red meat consumption is less than 25g/day
Two N American studies show some increased risk between 25g/day and 75g/day red meat consumption
All other studies show either no increased risk or some increased risk at more than 75g/day of red meat consumption
Investigation of GBD admitted reporting errors but questions remain
Seeking to understand the significant changes in risk associated with red meat consumption, six professors from six universities in UK, Ireland, Belgium and Australia wrote to Lancet (18:30)
Where are the peer-reviewed publications of their updated or new systematic reviews?
Have the additional risks from iron deficiency, elderly fragility, child and maternal malnutrition associated with a finding that no level of meat consumption is safe been included in the report?
LANCET took nine months to publish the letter
Admission of errors from author in reply to letter (20:14)
“No evidence supporting a relationship between red meat consumption & sub-arachnoid haemorrhage”
“Setting of the red meat TMREL to zero in the GBD 2019 analysis is not correct”
GBD 2019 is not compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines
Key questions remain unanswered
Authors do not intend to include the totality of nutritional effects of red meat in their analyses
No effort has been made to correct the errors in the GBD report despite Lancet’s guidelines stating that correction of all errors of fact is mandatory
Scientific community criticism of and media interest in GBD 2019
Criticism of the GBD 2019 recommendations published in Lancet (21:08)
“We support Stanton and colleagues’ call for further clarification, justification, or reconsideration of the theoretical minimum risk exposure level of zero for unprocessed red meat selected by GBD in their latest estimates”
“The increase in the estimated burden appears implausible, and the lack of transparency undermines the authority of the GBD estimates”
“Neither WCRF nor other international organisations recommend complete avoidance of meat”
The absence of an explicit rationale for the assumptions is troublesome, unsupported by the evidence, and unrealistic”
The concerns raised have received considerable media and scientific interest (21:47)
Peer-reviewed studies do not support recommendations of GBD 2019
A 2022 Nature Medicine publication provides the results of a re-evaluation of the risks of unprocessed red meats associated with six non-communicable diseases (22:28)
Evidence that eating unprocessed red meat is associated with increased risk of disease is weak – insufficient to make stronger or more conclusive recommendations
More rigorous, well-powered research is needed to better understand and quantify the relationship between consumption of unprocessed red meat and chronic disease
From another 2022 study looking at cardiovascular disease, heart attacks, strokes, and cancers (24:50)
“A relatively high meat-dietary pattern is associated with somewhat higher chronic disease risks. These elevations appear to be largely attributable to the dietary pattern, rather than to consumption of red or processed meat per se.”
Summary (again)
Animal-source foods (dairy, meat, fish and eggs) are nutrient rich foods (25:27
The relationship between red meat and disease burden is mirror J-shaped
When eaten as part of a balanced diet, red meat provides considerable protection against nutritional deficiencies
Low certainty evidence that relatively small deleterious effects possibly occur with consumption in excess of 500g weekly
The majority of the world’s population are not eating enough dairy nor omega-3 PUFA rich foods
Replacing animal sourced foods with plant-based ultra-processed foods, so as to solve greenhouse gas emissions, is very likely to harm human health – women, children, the elderly and those of low income will be particularly adversely impacted
Policy makers should be extremely wary of global health estimates that
Are not rigorously and transparently evidence-based
Ignore the protection against nutritional deficiencies afforded by animal-source foods