ULTRA-PROCESSED FOODS AND CARDIOVASCULAR DISEASE RISK

Ultra-processed foods and their potential negative impact on health have gained increasing media attention over the past few years. However, ultra-processed foods, according to the NOVA classification, include a wide variety of foods which can vary significantly in their nutrient contents and there have been some questions raised about the functionality of NOVA in its current form.

In a recently published paper, researchers from the Harvard T.H. Chan School of Public Health and colleagues investigated the relationship between ultra-processed foods and cardiovascular disease in three large well known prospective studies, the Nurses’ Health Study (NHS), Nurses’ Health Study II (NHSII), and Health Professionals Follow-Up Study (HPFS). There were more than 200,000 participants in the three studies.

After adjusting for multiple confounding factors which can influence cardiovascular disease risk, the researchers found a small but statistically significant increase in risk of cardiovascular disease (CVD) and coronary heart disease (CHD) for the highest versus the lowest intakes of ultra-processed foods, overall. Those eating the highest amounts of UPF were 11% more likely to develop CVD and 16% more likely to develop CHD.

In addition, they performed a meta-analysis of 22 prospective studies and found that individuals who consumed the highest amounts of ultra-processed foods had a 17% increased risk of CVD, 23% higher risk of CHD, and 9% higher risk of stroke compared to those with the lowest intakes. They rated the quality of evidence as being high for CHD, moderate for CVD and low for stroke.

However, they also looked at the association between different ultra-processed food groups and the findings were not as straightforward. Sugar and intensely (“artificial”) sweetened beverages and processed meats (e.g., bacon, sausages, salami, etc…) were associated with higher cardiovascular disease risk. But other foods classified ultra-processed according to NOVA, including breads, cold breakfast cereals, yoghurt and dairy desserts and savoury snacks (e.g., popcorn, crackers, etc…), were associated with a reduced risk.

The authors point out the diverse nutritional composition found in so-called ultra-processed foods, emphasising the need to look more closely at the classification of these foods in order to fully understand their impact on cardiovascular health, including understanding the role of both food processing and nutritional quality. In the meantime, they recommend discouraging consumption of soft drinks and processed meats given their consistent adverse association with cardiovascular disease.

These findings mirror those of another paper published last year looking at the association between ultra-processed food consumption and risk of type 2 diabetes (T2D) in the same study cohorts. The authors of this paper found a significant increase in the risk of T2D in those consuming higher intakes of ultra-processed foods overall. Compared to those eating the lowest amount, those with the highest intakes had an almost 50% increased risk of developing T2D.

However, like the first study, differences were seen amongst subgroups of ultra-processed foods. In this study UPFs like refined breads; sauces, spreads and condiments; intensely (“artificial”) and sugar sweetened beverages; animal-based products; and ready-to-eat mixed dishes were associated with a higher risk of T2D; whereas UPFs like cereals; dark and wholegrain breads; fruit-based products; and yoghurt and dairy-based desserts were associated with a lower risk.

More high-quality research is needed to determine the usefulness of the NOVA system and in particular the UPF classification with respect to making healthy food choices.

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