Study: Measurable inflammation caused by highly processed foods

Study: Measurable inflammation caused by highly processed foods

The present study aims to investigate the association between consumption of highly processed foods and biomarkers of inflammation, particularly high-sensitivity C-reactive protein (hs-CRP). It is an observational study from the Melbourne Collaborative Cohort Study involving over 2,000 participants aged 40 to 69 years. The results showed that higher consumption of ultra-processed foods was associated with increased levels of hs-CRP, regardless of participants' body mass index (BMI) or gender. These results add to existing evidence showing a link between highly processed foods and chronic disease and increased mortality. The authors therefore recommend taking measures to limit consumption of highly processed foods and increase access to nutrient-dense foods to promote public health.

Details of the study:

reference

Lane MM, Lotfaliany M, Forbes M, et al. Higher consumption of ultra-processed foods is associated with higher levels of high-sensitivity C-reactive protein in adults: cross-sectional results from the Melbourne Collaborative Cohort Study.Nutrients. 2022;14(16):3309.

Study objective

To determine whether highly processed foods are associated with biomarkers of inflammation, particularly high-sensitivity C-reactive protein (hs-CRP).

Key to take away

Ultra-processed food intake was associated with a 4% increase in hs-CRP, and this association occurred regardless of body mass index (BMI) or gender.

design

Melbourne Collaborative Cohort Study (MCCS) Observational Study

Participant

Between 1990 and 1994, 41,500 people (24,500 women and 17,000 men) aged 40 to 69 years (mean age 57 years) were recruited to participate in the MCCS.¹

Participants were drawn from a sample of the MCCS for which valid baseline dietary data and plasma hs-CRP measurements were available.

The authors excluded participants who had missing hs-CRP data and whose total energy intake (kJ/day) was less than 1^stpercentile or above the 99th^Thpercentile or an hs-CRP concentration above 99^Thpercentile.

Ultimately, 2,018 participants remained for analysis, including both the cardiovascular disease deaths group (n=632) as cases and the random sample of all participants (n=1,386) from the original MCCS project as a subcohort.

Evaluated study parameters

Study parameters included a variety of sociodemographic characteristics such as age, gender, country of birth, marital status, highest level of education, and socioeconomic indices.

The researchers also assessed lifestyle and health-related behaviors such as smoking status, recreational physical activity in the past 6 months, and alcohol consumption as covariates. To determine BMI, anthropometric data such as height and weight were measured. They also collected dietary information using a food frequency questionnaire designed specifically for this multi-ethnic cohort.

Primary outcome measure

The researchers examined the association between hs-CRP concentration (mg/L) and intake of highly processed foods as classified by the NOVA food classification system.

Key findings

For every 100 g increase in ultra-processed food intake, there was a 4.0% increase in hs-CRP (95% CI: 2.1-5.9%).P<0.001) and this appeared to be independent of BMI. There was no difference between genders.

transparency

There was no external funding for this study.

Effects on practice

Significant public health concerns have arisen with the increasing prevalence of highly processed foods in the Australian diet, coupled with increasing prevalence of chronic disease and increased mortality.

While some previous studies with Brazilian subjects showed a direct cross-sectional association between consumption of highly processed foods and levels of inflammatory cytokines, the authors of the study examined here note that the sociodemographic characteristics of participants in these studies were associated with lower sociodemographic characteristics of consumption of highly processed foods. In the Brazilian sample of adolescents, ultra-processed foods contributed 26% of total daily energy intake, compared to 40% in the current study.²

In the current study, the authors found that hs-CRP increased with increased consumption of highly processed foods. Tests for effect modification by gender showed no evidence of an interaction. The authors note that “given the underrepresentation of women compared to men in our study (37.5% were women), it is possible that we did not have sufficient power to detect this interaction.”

In the Brazilian sample of adolescents, ultra-processed foods contributed 26% of total daily energy intake, compared to 40% in the current study.²

These results are consistent with recent systematic reviews and meta-analyses showing a direct association between ultra-processed food intake and the prevalence and incidence of common chronic noncommunicable diseases, morbidity and mortality, all of which include inflammation as part of their pathophysiology.^3-5

Conversely, dietary values ​​measuring adherence to a healthy or Mediterranean diet—rich in fruits, vegetables, fatty fish, poultry, extra virgin olive oil, and whole grains—appear to be inversely associated with inflammatory biomarkers in cross-sectional analyses.⁶Regarding experimental evidence, the current study results are also consistent with a previous meta-analysis of intervention studies showing that Mediterranean diets with higher proportions of unprocessed or minimally processed foods were anti-inflammatory.⁷

It is possible that policies that restrict the production, distribution and dietary intake of highly processed foods reduce their consumption.

Ultimately, these results, along with the results of several other studies, underscore the importance of access to both nutrient-dense foods and healthcare professionals who can provide advice on healthy dietary choices and behaviors, thus having a direct impact on reducing morbidity and mortality.

1. Krebsrat Victoria. Überblick über die Melbourne Collaborative Cohort Study (Gesundheit 2020). https://www.cancervic.org.au/research/epidemiology/health_2020/health2020-overview. Zugriff am 5. September 2022.
2. Martins GMdS, França AKTDC, Viola PCDAF, et al. Der Verzehr hochverarbeiteter Lebensmittel ist bei brasilianischen Jugendlichen mit Entzündungsmarkern verbunden. Public Health Nutr. 2021;25:591–599.
3. Lane MM, Davis JA, Beattie S, et al. Ultraverarbeitete Lebensmittel und chronische nichtübertragbare Krankheiten: eine systematische Überprüfung und Metaanalyse von 43 Beobachtungsstudien. Obes Rev. 2021;22:e13146.
4. Lane MM, Gamage E, Travica N, et al. Verzehr hochverarbeiteter Lebensmittel und psychische Gesundheit: eine systematische Überprüfung und Metaanalyse von Beobachtungsstudien. Nährstoffe. 2022;14:2568.
5. Moradi S., Ma HK, Bagheri R. et al. Verzehr hochverarbeiteter Lebensmittel und Diabetesrisiko bei Erwachsenen: eine systematische Überprüfung und Dosis-Wirkungs-Metaanalyse. Nährstoffe. 2021;13:4410.
6. Hart MJ, Torres SJ, McNaughton SA, Milte CM. Ernährungsmuster und Zusammenhänge mit Entzündungsbiomarkern bei Erwachsenen: eine systematische Überprüfung von Beobachtungsstudien. Nutr J. 2021;20:1-14.
7. Schwingshackl L, Hoffmann G. Mittelmeer-Ernährungsmuster, Entzündung und Endothelfunktion: eine systematische Überprüfung und Metaanalyse von Interventionsstudien. Nutr Metab Cardiovasc Dis. 2014;24:929-939.