As research on ultra-processed foods advances, so does the debate about it. These products usually contain a large amount of calories and are rich in added sugars, saturated fats and salt, making them unhealthy. Now, a new study has found that the mortality rate of people who include more ultra-processed foods in their usual diet is slightly higher than that of people who do not consume them.
The results of the work have been published in The BMJ and show that a higher intake of ultra-processed foods was associated with slightly higher all-cause mortality, driven by causes other than cancer and cardiovascular diseases. Associations varied among ultra-processed food subgroups, with ready-to-eat meat, poultry, and seafood products showing particularly strong associations with mortality.
Researchers evaluated the relationship between consumption of ultra-processed foods and mortality in two large cohort studies in the United States: the Nurses’ Health Study, which analyzed the long-term health of 74,563 registered nurses from 11 states, and the Health Professionals Follow -up Study that included 39,501 male healthcare workers from across the country, who had no history of cancer, cardiovascular disease or diabetes when they enrolled in the study.
They found a modest increase in the risk of total mortality with higher consumption of ultra-processed foods (7 servings per day on average), compared with lower consumption (3 servings per day on average). However, this association disappeared when overall diet quality was considered. Additionally, the association was stronger when distilled alcohol – which is considered a risk factor for premature mortality – was included and weaker with whole-grain packaged products.
The potential mechanisms that could explain the observed associations between ultra-processed foods and health outcomes are also varied, and include overnutrition due to energy density, fat, sugar and salt content, the potential harmful effects of certain additives and contaminants present in the packaging.
Not all non-ultraprocessed foods are healthy
In an editorial linked to the study and also published in The BMJ, researchers from New Zealand explain that most dietary guides already highlight the importance of consuming less processed foods, and in countries where packaged whole grain products such as breads are a staple recommended and an important source of fiber, adding a general statement in dietary guidelines about avoiding ultra-processed foods is not helpful.
And they add that recommendations to avoid ultra-processed foods can also give the false impression that foods that are not ultra-processed are healthy and can be consumed freely, which is problematic, since in addition to the effects on health they can have an impact about the environment. For example, extensive livestock farming produces methane, a greenhouse gas that influences climate change.
Therefore, they insist that the focus should be on advocating for broader global adoption of food policies that improve health, such as restrictions on the marketing of unhealthy foods to children, including warning labels on nutritionally poor food products, taxes on sugary drinks and bans on partially hydrogenated oils which are a source of industrial trans fats.
“Once again it is observed that the consumption of ultra-processed foods increases the risk of mortality from all causes, so we have more scientific evidence that supports the need to take urgent measures to discourage their consumption and promote the consumption of fresh and minimally processed foods. processed,” says Maira Bes-Rastrollo, professor of Preventive Medicine and Public Health at the University of Navarra and researcher at the Health Research Institute of Navarra (IdiSNA) and at CIBERobn, in statements to Science Media Center Spain.
“In public health messages we must remember the importance of consuming fresh and minimally processed foods to gain health and many years of life without disability”
“Unlike previous results, the authors did not find a risk association with cardiovascular mortality or cancer, so the observed risk relationship can be explained by an increase in neurodegenerative mortality and from other causes. According to the authors, these differences are due to the fact that the rest of the studies include distilled beverages in the calculation of ultra-processed foods and do not adequately take into account smoking habits throughout life. This statement is not correct, since at least one of the published studies did adjust the analyzes by pack-years of consumption and, when the effect of ultra-processed foods was evaluated in never-smoking people (restriction: there was no confusion due to tobacco), “An even greater risk was observed.”
“On the other hand, the authors, based on their results, conclude that the nutritional quality of ultra-processed foods has a more predominant influence on mortality than the consumption of these foods per se. However, there is much previous literature that affirms that the risk relationship of ultra-processed foods with health is due not only to their nutritional quality, but also to their processing. In fact, previous results from the SUN cohort showed that even with equal intake of saturated fatty acids, trans fatty acids, added sugars, sodium, or taking into account adherence to the Mediterranean diet, ultra-processed foods remained a risk factor for mortality.”
“In addition to nutritional quality, different reasons have been postulated that may explain this dangerous effect: the overconsumption of these foods because they are easily consumed and enjoy great palatability; the displacement of other more nutritious foods; the lack of intake of health-protective phytochemical substances present in fruits, vegetables and legumes; the presence of toxic contaminants created during processing or released from packaging materials; and the consumption of a ‘cocktail’ of additives potentially harmful to health if consumed together and in the long term.”
The expert has also pointed out that “the NOVA system for classifying foods according to their degree of processing has not been exempt from criticism for being a classification that includes a great diversity of food groups, as suggested by the authors of the article. Indeed, it is not perfect, but it is a clear, useful and easy-to-apply classification, which can be incorporated into public health messages remembering the importance of consuming fresh and minimally processed foods to gain health and many years of life without disability. .
