BBC – Ultra-processed foods ‘linked to cancer’
The Guardian – Ultra-processed foods may be linked to cancer, says study
Even the UK’s National Health Service has published guidance – Ultra-processed foods linked to cancer
Some go a bit further and suggest that ready-meals give you cancer, others claimed that pizza and cornflakes will increase your risk of cancer by 25%. That’s not strictly true at all.
To find out what is correct let’s turn to the actual study.
The Alpha Source
If we turn the the British Medical Journal then we can in fact find the original paper …
Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort
How exactly do they define the term “Ultra Processed”?
They basically categorised what we eat into 1 of 4 groupings. These are as follows:
- “unprocessed or minimally processed foods” – fresh, dried, ground, chilled, frozen, pasteurised, or fermented staple foods such as fruits, vegetables, pulses, rice, pasta, eggs, meat, fish, or milk
- “processed culinary ingredients” – salt, vegetable oils, butter, sugar, and other substances extracted from foods and used in kitchens to transform unprocessed or minimally processed foods into culinary preparations
- “processed foods” – canned vegetables with added salt, sugar coated dried fruits, meat products preserved only by salting, cheeses, freshly made unpackaged breads, and other products manufactured with the addition of salt, sugar, or other substances of the “processed culinary ingredients” group.
- “ultra-processed foods” – mass produced packaged breads and buns; sweet or savoury packaged snacks; industrialised confectionery and desserts; sodas and sweetened drinks; meat balls, poultry and fish nuggets, and other reconstituted meat products transformed with addition of preservatives other than salt (for example, nitrites); instant noodles and soups; frozen or shelf stable ready meals; and other food products made mostly or entirely from sugar, oils and fats, and other substances not commonly used in culinary preparations such as hydrogenated oils, modified starches, and protein isolates. Industrial processes notably include hydrogenation, hydrolysis, extruding, moulding, reshaping, and pre-processing by frying. Flavouring agents, colours, emulsifiers, humectants, non-sugar sweeteners, and other cosmetic additives are often added to these products to imitate sensorial properties of unprocessed or minimally processed foods and their culinary preparations or to disguise undesirable qualities of the final product.
The study specifically focused upon the consumption of that fourth category, the Ultra processed.
So what exactly did they do?
The study was run in France and they had 104,980 participants.
Since about 2009 adults with internet access have been recruited via various multimedia campaigns. They start them off with a detailed questionnaire and then proceed to track what they eat by getting them to fill in 24 hour dietary records. That’s not every single day for years, but rather by getting participants to do this about three times every six months. They also validate the quality of this data via an interview with a trained dietitian and against blood and urinary biomarkers.
What they track is very detailed and not only included everything consumed in the 24 hours, but also measures portion sizes as well.
They also recorded the health of the participants by getting them to complete a health questionnaire once a year. Where something specific such as cancer popped up, they were contacted by a doctor associated with the study and asked for permission to access their medical records. This yielded medical records from about 90% of the cancer patients in the study.
Their baseline of 104,980 patients started out with no cancer.
They could then track what happened over the years right up to 2017.
What did they discover?
Ultra-processed food intake was associated with higher overall cancer risk …
a 10% increase in the proportion of ultra-processed foods in the diet was associated with a significant increase of greater than 10% in risks of overall and breast cancer.
The precise details they collected are in fact quite extensive and so they do actually understand the proportions that sit within the ultra processed category that were being consumed.
This study does not tell you that you will get cancer if you eat ultra processed food. Instead it simply tells you that those that do so have an apparent increased risk.
So what exactly exists within the ultra processed grouping is causal, if anything?
OK, so let me toss out a few more questions.
- Does eating increased amounts of ultra processed food make you overweight, and that’s the problem?
- Is it perhaps the observation that those that eat ultra processed food also tend to be those that are more probably smokers, and that’s the problem?
- Could it be as simple as the observation that people who lean towards ultra processed food tend to make a lot of unhealthy choices in general, and that’s the problem?
- While consumed in isolation, the various food additives are safe. Could a high-intake combination of them be leading to an unexpected chemical reaction?
- Is overloading your sugar, salt and fat intake the problem?
All we actually know is that there is a correlation here, and that something associated the ultra processed consumption increases the risk, but it need not imply that everything or even anything in the category actually does, instead it might simply be associated with the other choices that high-intake ultra-processed consumers make.
The recommendation is the rather obvious one – further studies are needed to understand this.
They have a massive and continuously growing database that contains a vast amount of detail. Perhaps if they mined that data in a different way then they might find other correlations.
So how can I reduce my cancer risk?
The answer to that question is well-established, these are the big ticket items …
- Don’t smoke – if you do, it’s time to quit.
- Get plenty of exercise – you don’t need to join a gym, take a walk at lunchtime, go for a hike, get out more.
- Eat a well-balanced diet that includes fruit and vegetables
- Cut back on alcohol