Tuesday, August 02, 2022

Is red meat bad for you

Below is the abstract of a journal article that has been bruited about in the popular press. The journal article appeared yesterday. It is one of a long series of attempts to discredit meat eating.

And the present article is no more conclusive than any of its many predecessors. I have been blogging on the subject for many years so I know where the skeletons are. I used to teach research methods and statistics at a major university so I know what to look for

And the present article follows a familiar methodology. I am going to put it bluntly: When there is no overall connection between the variables you are studying, you do comparisons of extremes -- as in tertiles, quartiles or quintiles. You can sometimes "save" your research that way if the extremes differ.

The present article resorts to extreme quintiles so they really had to stretch it to produce a reportable finding. The important thing to know, however, is that such anayses throw away the majority of your data so really tell you nothing. But the resort to extremes does of itself imply that there was NO overall relationship in the data. It's a common analysis but totally discreditable scientifically

The real result of the research therefore is that eating red meat had NO EFFECT on anything

Dietary Meat, Trimethylamine N-Oxide-Related Metabolites, and Incident Cardiovascular Disease Among Older Adults: The Cardiovascular Health Study

Meng Wang et al.


Effects of animal source foods (ASF) on atherosclerotic cardiovascular disease (ASCVD) and underlying mechanisms remain controversial. We investigated prospective associations of different ASF with incident ASCVD and potential mediation by gut microbiota-generated trimethylamine N-oxide, its L-carnitine-derived intermediates γ-butyrobetaine and crotonobetaine, and traditional ASCVD risk pathways.


Among 3931 participants from a community-based US cohort aged 65+ years, ASF intakes and trimethylamine N-oxide-related metabolites were measured serially over time. Incident ASCVD (myocardial infarction, fatal coronary heart disease, stroke, other atherosclerotic death) was adjudicated over 12.5 years median follow-up. Cox proportional hazards models with time-varying exposures and covariates examined ASF-ASCVD associations; and additive hazard models, mediation proportions by different risk pathways.


After multivariable-adjustment, higher intakes of unprocessed red meat, total meat, and total ASF associated with higher ASCVD risk, with hazard ratios (95% CI) per interquintile range of 1.15 (1.01–1.30), 1.22 (1.07–1.39), and 1.18 (1.03–1.34), respectively. Trimethylamine N-oxide-related metabolites together significantly mediated these associations, with mediation proportions (95% CI) of 10.6% (1.0–114.5), 7.8% (1.0–32.7), and 9.2% (2.2–44.5), respectively. Processed meat intake associated with a nonsignificant trend toward higher ASCVD (1.11 [0.98–1.25]); intakes of fish, poultry, and eggs were not significantly associated. Among other risk pathways, blood glucose, insulin, and C-reactive protein, but not blood pressure or blood cholesterol, each significantly mediated the total meat-ASCVD association.


In this large, community-based cohort, higher meat intake associated with incident ASCVD, partly mediated by microbiota-derived metabolites of L-carnitine, abundant in red meat. These novel findings support biochemical links between dietary meat, gut microbiome pathways, and ASCVD.


Living with COVID: how treating masks like umbrellas could help us weather future pandemic threats

Thankfully, the UK now looks to be past the peak of both the recent heatwave and the latest COVID wave. But there will be more of both – and in future, we might think about how we protect ourselves from COVID in the same way we protect ourselves from the weather.

An umbrella is a useful analogy. If we look out the window or check the weather forecast and see rain, we would probably take an umbrella out with us. Similarly, if COVID cases are starting to rise or if a new wave is forecast, we might consider grabbing a face mask, for example.

But just as there’s no need to carry an umbrella with us when it’s sunny, we needn’t be expected to wear masks all the time. Of course, some people may choose to wear masks more consistently in certain settings, while others may forgo wearing them altogether. This is the nature of the current phase of the pandemic we’re in, a big part of which is based on personal choice and responsibility.

Thanks largely to the impact of vaccines, we no longer need the kind of rules-based approach to risk management we saw earlier in the pandemic. But the umbrella analogy can guide our behaviour and choices in a variety of areas of our response moving forward. Beyond masks, these include testing, ventilation and social distancing.

The idea is that we can pick up or step up precautions when we most need them (when COVID cases are on the rise), before relaxing them, if we want to, when infection rates and risk are lower.

What might this look like in practice?

Let’s say we start to see COVID cases rising again come autumn. This is a distinct possibility.

It then becomes even more important to take a test if we have any symptoms that might be COVID-related. This will help inform our decision of whether, and to what extent, to minimise contact with others.

Isolation is no longer a legal requirement, and I think this should remain the case. However, if possible, staying at home while we’re unwell is a sensible and considerate thing to do, particularly when COVID rates are high.

Distancing should also remain a choice. But during a wave of infections, people might wish to maintain more distance between themselves and others in shops, or may choose to avoid crowded venues.

Back on masks, when cases begin to rise, the risk of contracting and transmitting COVID also rises, so masks become a more useful and reasonable precaution. They can be particularly valuable in certain circumstances – for example, if someone is unwell but can’t isolate, when visiting people who are vulnerable, or in crowded indoor spaces.

Opening windows even a little can increase fresh air indoors and also help reduce the likelihood of transmitting the virus.

Finally, the number of people in the UK who have had a COVID booster vaccine is considerably lower than the number who received their first and second doses. We know immunity from vaccines wanes, and boosters restore vaccine effectiveness. So if we start to see rising cases, or looking ahead to future waves, it would make good sense for people who are behind on their vaccines to get up-to-date.

It’s been a year since England’s “freedom day”, when most legal COVID measures were removed. But the pandemic is far from over. Along with high numbers of daily infections, long COVID is very common, and the pressure on the NHS is still unsustainable.

In a recent article in the British Medical Journal, Professor Susan Michie and I reflected on some of the lessons we’ve learned over the past year.

Among these, the pandemic has shown us that behaviour is not purely down to an individual’s choice or motivation. People’s actions are also shaped by the opportunities and supports they’re given – or not given. For example, while some people might want to stay home if they have symptoms, they may not if neither their employer or the government provides financial support.

People should be encouraged and supported as much as possible to stay home when they’re sick, particularly when cases are high. Amidst a winter COVID wave, Australia has re-instated its pandemic leave disaster payments to enable those with COVID and without proper sick pay to stay home and not lose out financially.

Further, governments could ensure that free at-home tests are available during times when infections are likely to, or starting to, rise.

And it’s important that, to mitigate the impacts of future waves, vaccination coverage is as high as possible. Public health campaigns should target both the unvaccinated and partially vaccinated, as well as encouraging people (particularly the most vulnerable) to take up booster offers.

We also need more action to ensure adequate ventilation. In the US, billions of dollars are being made available for improving air quality in schools and other public buildings.


Also see my other blogs. Main ones below:

http://edwatch.blogspot.com (EDUCATION WATCH)

http://antigreen.blogspot.com (GREENIE WATCH)

http://pcwatch.blogspot.com (POLITICAL CORRECTNESS WATCH)

http://australian-politics.blogspot.com/ (AUSTRALIAN POLITICS)

http://snorphty.blogspot.com/ (TONGUE-TIED)

https://immigwatch.blogspot.com/ (IMMIGRATION WATCH)

https://awesternheart.blogspot.com/ (THE PSYCHOLOGIST)


1 comment:

Justin_O_Guy said...

Tired of arguing? Go with what Nature provides. If a critter has nothing but ripping and tearing teeth, it's strictly a carnivore.
If it has nothing but teeth that look like the molars of a human? It eats plants.
If it has a combination of those types of teeth? It's a Flex Fuel model. It Can eat plants and it can eat meat, and it Needs some of each.