Yet another salvo in the endless battle over what rich western societies should eat has been fired in the press today here and here. The responses from this community about food and diet under topics like labelling, sugar etc suggest that there will be some interest.
In a nutshell the idea is that it isn’t just the poor dietary composition of highly processed food (high in fat, sugar, salt; low in fibre) that is unhealthy, nor is it just the propensity to gain weight on high fat/sugar diets that cause health problems but that there is something inherently harmful about highly processed food beyond those factors.
Do you think that it’s true and that it matters? Why?
Some nutrients are lost (folate, thiamine, vitamin C.) through the processing (including heating/cooking to prolong shelf life) . Nutrients which are unstable, such as folate, thiamine and vitamin C.are lost first, with others disappearing over time.
Effects of processing
There are a number processes used in the manufacture of ultra-processed foods processes, which can affect the nutritional value of foods. These include:
grinding, milling or sifting of cereals, nuts, seeds and pulses - this can remove some of the most nutritional parts of the raw food such as phytochemicals and other essential nutrients. It also lowers the fibre content of the product undergoing these processes making it more difficult for an average person to meet their recommended daily fibre intake. This process also exposes the final product to air which can result in the oxidisation of the nutrients which are left and also allow microbes to also enter the food causing spoiling and degradation.
blanching - typically used or tinned and frozen foods to kill any microbes which may result in premature spoiling of the foods. Blanching results in the water soluble nutrients being washed or leached from the food or the heat in itself destroys the nutrients.
cooking - while this may occur in the home kitchen, typically processed foods are cooked more than one would usually do. This is to ensure that the food is safe to eat as processed foods have a high risk of microbe contamination and also the food is essentially double or triple cooked (blanched, cooked at the food processing plant and then heated/cooked again in the home kitchen). Each heating cycle destroys the nutritional value of the food even more.
canning/pasteurisation - high prolonged temperature is applied to foods to ensure that they are sterile after the cooking or before/immediately after packaging (e.g. canning process where filled cans are subject to high temperature water bath), This high temperature have a significant impact on the nutritional values of the food. It impacts on heat and water soluble nutrients. One advantage of canned foods is preservatives are not needed as the contents remain sterile until the outer metal can is opened or ruptured. This means that the nutritional value of the can is unlikely to change much over time (unlike fresh foods which nutritional value can deteriorate through prolonged storage.
freezing - while freezing has the potential to retain and maintain the food when processed, the frozen food is usually subject to bleaching (see above).
high pressure processing - this is becoming more mainstream for fresh fruit juices and there has been some reports that it is also suitable for fresh milk. It is also used for cooked food processing where an industrial sized pressure cooker may be used to speed the cooking process. While for juices and milk it can reduce nutritional losses which would otherwise occur through heating, often processed foods are also subject to high cooking temperatures which affect the food as outlined above.
desiccation/dehydrating - this can result in the loss of some unstable nutrients, but may also concentrate other nutrients, sugars and salts. It also can allow one to eat more of the food as more food is needed to feel full compared to the undesiccated product (e.g. dried fruits compared to fresh fruits…one can consume dozens of sultanas but would struggle to eat the same number of grapes).
food additives - a wide range of food additives are added to processed food for a range of different reasons. Some of these additives may be beneficial (such as replacing nutrients lost through processing or addition of preservatives for food safety), many consumed in excess can be detrimental (such as salts, fats, sugar, artificial flavours and colours etc) and are added to improve the taste of the food or make it more attractive for one to consume…
What can be done?
Unless processed foods are banned, the only thing to do is to ensure that there is education on the disadvantages of consuming processed (inc. ultra-processed foods). Good and accurate labelling also has an important role such as that being championed for Choice for sugar, but there is is also room for warning labels like that used on other countries (Chile is a good example) to warn the consumer on purchase packaged and processed foods which are high in salt/sodium, fats (inc. saturated), sugars and calories.
In the past all government have been reluctant to add warning labels to processed foods, potentially due to lobbying from the (multinational) food manufacturing industry and also because the science has not been fully resolved. As the science has been resolved and there is overwhelming proof of the negative health consequences of highly or ultra-processed foods containing additives, it is long and truly overdue for some more serious action to be taken (such as highly conspicuous warning labels on all products which are unhealthy).
The government has also believed that its role has been in advertising…but its success has been limited otherwise conditions like type 2 diabetes and obesity would have become less prevalent.
While the 5-Star health rating system has its merits and is endorsed by the food manufacturing industry (which they would as it hides or makes it difficult for the average consumer to determine why a product is unhealthy), what is is needed is more confronting change to labelling to ensure the customer fully aware when making purchase choices…
I agree with general direction that you are going that many processes reduce nutrients in food to some degree. But I don’t think that is what the article is about. My reasons are:
The authors make a distinction between processed food (that has been around for millenia) and ultra processed food. We have been drying, salting, pickling, grinding, cooking etc since Adam was in nappies.
If the problem was just due to destruction of nutrients the various panel quoted would say so, instead they speak of added complexities that are not yet understood. In particular nutrient loss is dismissed by at least one:
[quote]
Mark Lawrence, a professor of Public Health Nutrition at Deakin University’s Institute for Physical Activity and Nutrition, agreed.
“There is a message in there that I think is new,” he said. “We need to stop focusing excessively on nutrients and thinking [that] so long as we take care of the nutrients in our diets, it’ll be healthier. These [studies] challenge that as too simplistic. It’s more than just how much saturated fat or whatever in the diet; it’s also about the extent of processing.”
[unquote]
The linked article covers much of the same ground as the two that I quoted including the definition of ‘ultra processed’ food. It then jumps to talking about additives. These are not defined and how the rest of the blog about ultra processing relates to additives is not stated. We are then told to read their material so we can go additive free. Unless there is something elsewhere tying all this together the leap from ultra processing to additives is a huge non sequitur.
That piece did not go into the main questions of why some studies have found people eat more of processed food or why ultra-processed food is not as good for you as minimally processed even if the two are matched nutritionally.
This one however gives us a little more. It is early days yet but I found the observation that a possible mechanism for causing overeating of processed foods is that they do not make us feel as satisfied,
“When fed minimally processed foods, people in the clinical trial produced more of a hormone that suppresses appetite, and less of a hormone that causes hunger. The reason for the biological reaction isn’t clear. Another finding: People ate processed foods faster.”
One anomaly about how much subjects eat is to do with taste. We have reports, and possibly personal experience, that processed food is tastier but then in the controlled study the subjects rated the minimally processed and highly processed foods similarly for taste but ate more processed.
Much more work is required on all this I think. At least somebody is actively looking for data and not just being judgemental about those who can’t resist industrial comfort food. ‘Just say no’ works about as well for limiting ice cream consumption as avoiding teenage pregnancy.
Occasionally I like to have a hamburger. I’ve been known to go to Hungry Jacks for these. They used to have decent hamburgers when they introduced the grillmaster range (thick meat patties and salad stuff) but then, they took out most of the salad and replaced it with things like chips and battered onion rings., WHAT THE…?
A good hamburger is tasty and nutritious, by ‘good’ I mean with a good range of tastes and textures, plenty of fresh salad, not too much fat in the meat or sauce and easy on the salt. There are and have been a number of individual shops that produce such a thing but I don’t know of any chain that does. As for sweet buns - yuk. Well done a burger is not highly processed at all.
Another fast food that is very similar is Subway. They have fresh bread of fair quality, lots of fresh salad, etc. This is not your low calorie diet food but you have the option to buy a half serve (plenty for me) and for those who want (in many cases need) a big lunch, like manual workers you can do a lot worse. There may be some who reckon processed meat (eg ham, corn beef, salami) and and marinated meats and sauces that have some fat are not acceptable but if you look at the alternatives that feature fries, sweet buns and low veg, low fibre meals Subway is much better.
Isn’t it strange how in this modern world we spend so much time worrying, even obsessing, over what we eat. Every day the news is filled with stories about good food, bad food, super food, new food, old food rebadged. Diets telling you that you should/shouldn’t, must/must not eat all manner of things. You would think by now if we were as sophisticated as we imagine that we are we would have worked out what to eat by now.
A major problem that is not even being mentioned in the mainstream is that the processed, soft foods (even so-called healthy foods) including those we feed our infants, are causing serious mouth and breathing issues. The lack of chewing hard and a lot daily has meant/means that our faces, jaws and airways have been getting much smaller during the last few hundred years. Results: small mouths with crowded, crooked teeth and many breathing issues resulting in many people mouth-breathing (dry mouths leading to tooth decay, more infections due to breathing unfiltered air etc), snoring, sleep apnoea and more. This is just a tiny part of that problem.
Two places to start: Katy Bowman, MSc, biomechanist, Nutritious Movement; “Breath: The New Science if a Lost Art”, James Nestor, ch 7 particularly pps 133-134 and check his references to various studies, including Sandra Kahn & Paul R Ehrlich, “Jaws: The Story of a Hidden Epidemic”, Stanford, CA: Stanford University Press.
Thanks for that. I don’t have either of those books and I am a long way from a good library. Is there anything I can read on line, or could you give us a rundown of the major points?
Isn’t evolutionary change much slower than suggested, and due to natural selection?
I can’t see how over a few generations changes in human food preparation can cause those with a smaller mouth and jaw to be more successful at reproducing, while those with larger through genetics and eating less refined food fail to be successful or reproduce.
We are on average getting taller and larger over the centuries, are we not?
How much longer before our heads are so small we look like cartoon characters, might be a great question to consider? It’s such a complex subject.
We are still reproducing but the smaller mouth/jaws is not an evolutionary change: it’s a mechanical change, much the same as most of us being soft, fleshy, weak, overweight and unhealthy. We are not using our bodies (jaws, muscles etc) so they get smaller and weaker but that can be changed by actions that an individual takes. That is not an evolutionary change. Note that relatively short-term changes (over decades or a few hundred years) caused by lifestyle changes are not the same as evolutionary changes in whole populations such as skin and hair pigmentation (climatic adaptation due to living in places where there is strong sunshine - darker- or very fair - where there is very little/weak sunshine: things that the individual cannot change in themselves).
