Consider this recent headline “Vegan fake meats are linked to increase in heart deaths: Experts say plant-based diets can boost heart health – but NOT if they are ultra-processed.” Upon reading it, you may think it is referring to a study that examined the relationship between the intake of plant-based meat alternatives (i.e., fake meats) and risk of cardiovascular disease (CVD). In the view of this author, the study has less to do with processing and plant-based meat alternatives and more to do with overall diet quality.
The study in question found that every 10 percentage points increase in the intake of plant foods that were Nova-classified as ultra-processed, was associated with a 5% increased risk of CVD and a 12% increase in CVD mortality.1 Conversely, every 10 percentage points increase in the intake of non-ultra-processed plant foods was associated with a 7% lower risk of CVD and a 13% lower risk of CVD mortality. These findings come from an analysis of data from the UK Biobank participants (40–69 y) who completed at least two 24-h dietary recalls between 2009 and 2012 (n = 126,842; median follow-up: 9 y), with subsequent data linkage to hospital and mortality records.
There exists a wide array of products within the category of “plant foods” that offer varying nutritional attributes – some of which are healthy and some unhealthy. For example, the nutritional differences between tofu and Oreos, both of which are plant foods (vegan), are notable.
These nutritional variances should also be top of mind for those familiar with the scientific literature. In 2017, Harvard University researchers noted that “… in studies of vegetarian diets all plant foods are treated equally, even though certain plant foods, such as refined grains and sugar-sweetened beverages (SSBs) are associated with higher cardio-metabolic risk.” As a result, the Harvard researchers created healthy and unhealthy plant-based dietary indices. The former and latter have been shown to be associated with a lower and higher risk respectively of heart disease,2 type 2 diabetes,3 breast cancer,4 dyslipidemia,5 and cancer and overall mortality.6
Now, back to the UK Biobank study.1 The table below lists the foods categorized as non-ultra-processed plant foods and ultra-processed plant foods. As noted at onset, despite the headline calling out “fake meats,” this study wasn’t about “fake meats” at all because this category of foods accounted for only 0.2% of total caloric intake (the lowest intake category listed). Aside from that, is it any wonder that CVD risk was decreased in response to a higher intake of non-ultra-processed plant foods– a category that includes fruit and vegetables– but was increased in response to the consumption of ultra-processed plant foods– a category that includes pastries and soft drinks?
Contribution of different types of plant foods to total caloric intake1
Plant-sourced foods | Percent calories | SD2 | Plant-sourced foods | Percent calories | SD |
Non-ultra-processed | 30.5 | 11.8 | Ultra-processed | 39.4 | 13.2 |
Fruit | 8.9 | 5.7 | Industrialized packaged goods | 9.9 | 5.8 |
Beer and wine | 5.8 | 6.9 | Pastries, buns and cakes | 6.9 | 6.8 |
Cereals | 3.7 | 4.5 | Biscuits | 3.9 | 4.6 |
Vegetables | 2.5 | 1.9 | Margarine and other spreads | 3.3 | 3.0 |
Pasta | 2.2 | 2.8 | Industrial chips (French fries) | 2.8 | 3.9 |
Roots and tubers | 1.7 | 2.1 | Confectionary | 2.7 | 3.7 |
Processed bread | 1.7 | 3.3 | Breakfast cereals | 2.7 | 3.2 |
Nuts and seeds | 1.2 | 2.5 | Soft drinks, fruit drinks and fruit juices | 2.0 | 3.3 |
Table sugar | 0.8 | 2.1 | Packaged salty snacks | 1.7 | 2.6 |
Vegetables/fruit preserved | 0.7 | 0.9 | Industrial pizza | 1.3 | 4.8 |
Legumes | 0.6 | 1.5 | Packaged pre-prepared meals | 0.9 | 1.6 |
Others | 0.5 | 1.2 | Distilled alcohol drink | 0.8 | 2.3 |
Sauces, dressings and gravies | 0.3 | 0.5 | |||
Meat alternatives | 0.2 | 1.0 |
The authors of this study concluded that their results support the notion that when shifting to plant-sourced foods to improve CVD health outcomes, food choices should consider the degree of processing. However, in my view, the findings of this study have more to do with nutrient content than with processing. As intake of non-ultra-processed plant foods increased, the intake of calories, sodium, free sugars, and saturated fat decreased whereas the intake of fiber increased. The results of this study are consistent with the findings of previous studies that consider nutrient content, not processing.2-6
Additional points to consider:
- Dietary data were collected between 2009 and 2012, long before the new generation of plant-based meat alternatives reached the marketplace.
- Plant milks were included in the category of soft drinks, fruit drinks, and fruit juices.
- Tofu and tempeh were classified as ultra-processed because although plain tofu is not considered ultra-processed, according to the authors, most options of industrially produced tofu and tempeh in the marketplace at the time of data collection included natural flavorings and thickeners such as guar gum.
References:
1. Rauber F, Laura da Costa Louzada M, Chang K, et al. Implications of food ultra-processing on cardiovascular risk considering plant origin foods: an analysis of the UK Biobank cohort. Lancet Regional Healt – Europe.2024:10098. https://https://doi.org/10. 1016/j.lanepe.2024.100948
2. Satija A, Bhupathiraju SN, Spiegelman D, et al. Healthful and Unhealthful Plant-Based Diets and the Risk of Coronary Heart Disease in U.S. Adults. J Am Coll Cardiol.2017;70(4):411-22. https://10.1016/j.jacc.2017.05.047
3. Satija A, Bhupathiraju SN, Rimm EB, et al. Plant-based dietary patterns and incidence of type 2 diabetes in US men and women: Results from three prospective cohort studies. PLoS Med.2016;13(6):e1002039. https://10.1371/journal.pmed.1002039
4. Rigi S, Mousavi SM, Benisi-Kohansal S, Azadbakht L, Esmaillzadeh A. The association between plant-based dietary patterns and risk of breast cancer: a case-control study. Scientific reports.2021;11(1):3391. https://10.1038/s41598-021-82659-6
5. Lee K, Kim H, Rebholz CM, Kim J. Association between different types of plant-based diets and risk of dyslipidemia: A prospective cohort study. Nutrients.2021;13(1). https://10.3390/nu13010220
6. Thompson AS, Tresserra-Rimbau A, Karavasiloglou N, et al. Association of healthful plant-based diet adherence with risk of mortality and major chronic diseases among adults in the UK. JAMA Netw Open.2023;6(3):e234714. https://10.1001/jamanetworkopen.2023.4714
This blog is supported by SNI Global and U.S. Soy.