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From John Ray's shorter notes
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4 September, 2024
Harvard researchers pinpoint TWO ultra-processed foods that surge heart attack risk - as well as 8 that surprisingly don't
I have had a look at the underlying academic journal article behind this report and am most amused. It is very much what I expected from previous studies of diet: Basically an attempt to find things that are not there
It's a general rule in academic reports that the fancier the statistics, the weaker are the effects being analysed. And this report has statistics of blinding complexity. And that foretells what this study has to report. They relied on extreme quintiles to detect what was going on in their data. That throws away the majority of your data before you analyse it. Not very reassuring! It suggests that there was nothing to report in the data as a whole.
And when they did squeeze something out of such tortured data, all they found were hazard ratios close to 1.0, indicating negligible effects
Given their tricks with the analysis, we have to conclude that there was nothing really going on in the data. Eating UPFs had NO effect on health
And, at the risk of beating a dead horse, I note that among the plethora of confounders that they allowed for, one they left out was the big one: income. But they did find that big eaters of UPFs were fatter and smoked more, so that could suggest that income was in fact an important confounder that they missed.
There are NO negative policy implications of this study. Eat what you like. You will be no worse off doing so.
I am 81 and have always eaten what I liked regardless of the vagaries of official diet recommendations so take heart if you too just eat what you like
The journal article:
https://www.thelancet.com/journals/lanam/article/PIIS2667-193X(24)00186-8/fulltext
Sugary drinks and processed meats are the only two ultra processed foods associated with a higher risk of heart attacks and strokes, Harvard researchers have discovered.
The scientists used data collected from nurses and health professionals to test the risk of cardiovascular disease, heart disease and strokes from eating a range of different ultra-processed foods.
But although they have long been vilified not all ultra-processed food (UPF) is made equal.
In fact, yoghurt, wholegrain bread and savoury snacks were shown to slightly reduce the risk of the diseases.
UPFs make up 57 per cent of the average UK diet — and the category includes fizzy drinks, processed meats like ham and bacon, as well as breakfast cereal.
One sign of a UPF food is that it contains ingredients you wouldn't find in your kitchen cupboard, such as unrecognisable colourings, sweeteners and preservatives.
Another clue, some experts say, is the unusually high amount of fat, salt and sugar in each item.
But supermarket staples such as breakfast cereals and pre-packaged bread can be mass-produced and are also considered to be ultra-processed.
That's because they often contain extra ingredients such as emulsifiers, artificial flavours and sweeteners, instead of just flour, salt, yeast and water.
However, the study published in the Lancet this week suggests we should 'deconstruct' the ultra-processed food classification as many of the UPFs have a 'diverse nutritional composition' and therefore have cardiovascular benefits.
UPF intake was assessed through food frequency questionnaires in three studies.
Researchers looked at data from The NHS Nurses' Health Study of 75,735 female nurses aged 30 to 55 years, a second nurses health study of 90,813 women aged 25 to 42 years and a follow-up study of 40,409 men aged 40 to 75 years.
Those who had prior cardiovascular disease, cancer or who had a high BMI were excluded from the study.
A selection of UPFs were divided into ten groups: bread and cereals; sauces, spreads, and condiments; packaged sweet snacks and desserts; packaged savoury snacks; sugar-sweetened beverages; processed red meat, poultry, and fish; ready-to-eat/heat dishes; yoghurt/dairy-based desserts; hard liquors; artificially-sweetened beverages.
The scientists found there was an associated risk of consuming a diet heavy in sugary and artificially sweetened drinks and cardiovascular disease risk.
This risk was also found in diets high in processed meats, such as sausages, bacon and hotdogs.
However, there were inverse associations observed for bread, breakfast cereal, yoghurt, dairy desserts and savoury snacks.
Processed meats and soft drinks should be particularly discouraged due to their consistent adverse association with cardiovascular disease, coronary heart disease, and stroke, study authors said.
But they stress some of the UPFs they studied had potential 'cardioprotective benefits', due to the vitamins, minerals and fibre found in them.
This included wholegrain breads as well as yoghurt, especially fermented types.
Study authors noted the benefit remained despite the usually high saturated fat and added sugar content of the dairy products. They added that yoghurts that contain probiotic bacteria or fatty acids may contribute to lower cardiovascular risk.
Professor Gunter Kuhnle, a food scientist and nutritionist based at the University of Reading, posted a graph from the study on X explaining that the data showed most UPF food groups ‘actually protect and reduce disease risk’.
‘The big problem is so many foods are classed as UPF,’ he told MailOnline.
‘Most studies show people who consume a lot of soft drinks, especially sugar and sweetened drinks, are more likely to be obese and suffer diabetes, as well as other diseases.
‘The data show a huge impact of sugar sweetened beverages and processed meat, while everything else is very neutral.'
For example, bread sold in supermarkets is often classed as a UPF but Professor Kuhnle explains it can still be healthy.
He said: ‘Wholegrain bread is probably a healthy form of bread, whether it is manufactured in a big factory or made at home, the difference between the two will be tiny.’
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