"We should all eat more whole foods, including edamame," said Mark Messina, Director of Nutrition Science and Research for Soy Nutrition Institute (SNI) Global.
But putting soymilk and veggie burgers in the same category as soda and Twinkies is not helpful, said Messina, who has just co-authored an article published in the journal Advances in Nutrition arguing that the NOVA classification system - which categorizes foods according to the level of processing they undergo - is “simplistic and does not adequately evaluate the nutritional attributes of meat and dairy alternatives based on soy.”
Processing can impact nutrition, acknowledged Messina, noting that eating an apple is preferable to drinking apple juice (read Dr Robert Lustig's take on this HERE) while soy protein isolates and concentrates do not contain the same level of fiber and isoflavones as the whole bean, for example.
Using the apple vs apple juice example, Messina told FoodNavigator-USA: “Disrupting the food matrix can have an effect on blood glucose levels, for example, even if the fiber and nutrient content is the same, but our primary point [in this paper] is that it makes no sense from a nutritional standpoint to compare a plant-based burger to a sugary soda or snack food, but because of NOVA, they are classified in the same way.
“We looked at some of the common criticisms of ultra-processed foods and examined whether they applied more to soy milk and soy burgers than they do to their animal-based counterparts cow's milk and beef, and for the ones we looked at, that was just not the case.”
Soymilk, Impossible Burgers, and Twinkies are not the same
According to the NOVA system (see box below) developed by researchers at the University of Sao Paulo, Brazil, beef is classified as minimally processed (group 1).
However, as soy-based meat alternatives typically contain soy protein isolate or concentrate, and soymilk - even if made from whole soybeans - typically contains emulsifiers or other additives, they are both classified as ‘ultra-processed foods’ (group 4), which consumers are being advised to avoid, said Messina.
In many cases (again, think Twinkies and soda), this is with good reason, he said, citing studies associating highly-processed foods with an array of health issues from cardiovascular disease and obesity, while the physical and structural characteristics of some ultra-processed foods may spike blood sugar and encourage overeating thanks to their high energy density.
“However, evidence indicates that these concerns do not apply to soy-based meats or soymilk,” argued Messina, who said consumers are being told about the nutritional and environmental benefits of plant-based diets, while at the same time being told plant-based meat and dairy products are ‘ultra-processed’ and therefore unhealthy, “presenting a confusing picture.”
Good and bad plant-based diets?
While you can certainly make an argument that not all plant-based diets are equal, with some industry commentators distinguishing between ‘healthy’ plant-based diets rich in whole foods, unprocessed beans, fruits, vegetables and grains, and 'unhealthy' plant-based diets high in ‘ultra-processed’ meat and dairy substitutes, the devil is in the detail, said Messina, who said not all packaged plant-based foods are the same.
For example, some plant-based milks are low in protein and minerals, while some plant-based cheeses made from oils and starch may not be very nutritionally dense.
However, studies comparing plant-based burgers with beef burgers suggest plant-based versions from soy or pea compare favorably on pretty much every measure aside from sodium content, which is something manufacturers are beginning to address, he said.
The 2020 SWAP MEAT study in the American Journal of Clinical Nutrition, for example, showed beneficial effects on cardiovascular disease risk markers (LDL cholesterol and trimethylamine- N-oxide) after switching from beef burgers to Beyond Meat (pea-protein based) burgers over eight weeks, coupled with reductions in saturated fat and small increases in fiber intakes. Other studies meanwhile, have shown positive changes in the gut microbiome.
As for protein quality, he said, “Very recently, Fanelli et al. determined that the DIAAS [Digestible Indispensable Amino Acid Score] for the [soy-based] Impossible Burger was similar to the DIAAS for 80% ground beef when calculated using the indispensable amino acid pattern for older children, adolescents, and adults.”
Processing and energy density
As for energy density (calories/gram) – something frequently cited as an issue with ultra-processed foods (you can eat a donut in three bites and barely notice you’ve consumed hundreds of calories) - soy burgers are “similar to or lower than that of beef,” said Messina.
Soymilks, meanwhile, have a “lower energy density than both whole and 2% cowmilk and contain similar amounts of protein," he pointed out.
"The major difference between milk types is with respect to carbohydrate content: the soymilks contain fiber (2 g/serving) and sucrose, whereas cow milk has no fiber and contains lactose. However, the soymilks contain a lower percentage of calories from carbohydrate and are lower in sugar.”
He added: “It is also notable from an overall health perspective that, as a percentage of calories, the soymilks and soy burgers are lower in saturated fat than their animal-based counterparts."
From a sustainability perspective, meanwhile, the environmental footprint of soymilk and soy meats is lower than that of meat and milk from cows, he observed.
Adam Drewnowski: ‘The poorly defined ‘ultra-processed’ category catches many ‘good’ plant-based products’
As with any food classification system, said Messina, once you start applying NOVA to specific products, it throws up some odd results.
“Take a smoothie you’ve made with dairy milk and fruits in a blender. That’s classified as group one [unprocessed and minimally processed foods]. If you add some pea or soy protein powder, it’s suddenly in group four [ultra-processed foods]. But I’d hazard a guess that most nutritionists would argue that the fruit smoothie with the protein is actually a better choice.”
His comments were echoed by Dr Adam Drewnowski at The University of Washington, who was speaking to FoodNavigator-USA last year following the publication of a study noting that 90% of plant-based milks meet the NOVA criteria for ultra-processed foods.
“The poorly defined ‘ultra-processed’ category catches many ‘good’ plant-based products and stands in the way of innovation.”
Can you pronounce methyl cellulose?
The debate over how ‘processed’ plant-based meats are has generated arguments both within the industry (as some players such as Lightlife have attempted to position themselves as more ‘natural’ than others), and between traditional and plant-based players (the meat-industry backed Center for Consumer Freedom notably ran a series of ads in 2019 attacking 'ultra-processed' plant-based burgers hiding scary unpronounceable ingredients).
Impossible Foods came out with a witty riposte to one such ad (which implied there's something sinister about plant-based meats because they contain ingredients 10-year-olds can't spell), while Beyond Meat CEO Ethan Brown noted that focusing on processing per se isn’t hugely helpful when assessing the healthfulness or otherwise of plant- or animal-based meats.
“Our products are free of many other elements in animal protein that are subjects of medical study and debate for their role in inflammation and potential carcinogenic and cardiovascular risk. Nor do they contain what the USDA refers to as residual contaminants that can be present in certain but by no means all commercial meats."
Former chief communications officer at Impossible Foods Rachel Konrad, meanwhile, also noted that Impossible Foods adds a lot of micronutrients (zinc, vitamin B1, B2, B3, B6, B12) to its flagship burger, which "is as ‘processed’ as a freshly-baked apple pie," adding: “The plant-based Impossible Burger delivers as much protein, bioavailable iron and key micronutrients as animal-derived beef, without the many downsides associated with beef.”
As for ‘all-natural’ beef, she added: “Virtually all cows in America today are conceived by artificial insemination, treated with growth-promoting hormones and antibiotics, and housed in bleak and miserable conditions, ending in their death and processing in a slaughterhouse rife with fecal aerosol and other contaminants. Nothing could be further from nature.”
Source: Advances in Nutrition, March 23, 2022
Title: ‘Perspective: Soy-based meat and dairy alternatives, despite classification as ultra-processed foods, deliver high-quality nutrition on par with unprocessed or minimally processed animal-based counterparts’
*Authors: Mark Messina, John L Sievenpiper, Patricia Williamson, Jessica Kiel, and John W Erdman, Jr, some of whom have interests in the soy industry. Messina is executive director of the industry-funded Soy Nutrition Institute; Williamson works at Cargill, which processes soy; and Kiel works at Medifast (which uses soy protein in some products).
NOVA is a food classification system developed by researchers at the University of Sao Paulo, Brazil.
Group 1 - Unprocessed and minimally processed foods: Unprocessed foods are the edible parts of plants (fruit, leaves, stems, seeds, roots) or from animals (muscle, offal, eggs, milk), and fungi, algae and water, after separation from nature. Minimally processed foods are natural foods altered by methods that include removal of inedible or unwanted parts, and also processes that include drying, crushing, grinding, powdering, fractioning, filtering, roasting, boiling, non-alcoholic fermentation, pasteurization, chilling, freezing, placing in containers, and vacuum packaging.
Group 2 - Processed culinary ingredients: Includes oils, butter, lard, sugar and salt that are rarely if ever consumed by themselves.
Group 3 - Processed foods: Includes canned or bottled vegetables or legumes preserved in brine; whole fruit preserved in syrup; tinned fish preserved in oil; some types of processed animal foods such as ham, bacon, pastrami, and smoked fish; most freshly baked breads; and simple cheeses to which salt is added.
Group 4 - Ultra-processed foods: Formulations of ingredients, mostly of exclusive industrial use, typically created by a series of industrial techniques and processes. Includes carbonated soft drinks; sweet, fatty or salty packaged snacks; candies; mass produced packaged breads and buns, cookies, pastries, cakes and cake mixes; margarine and other spreads; sweetened breakfast cereals and fruit yogurt and energy drinks; pre-prepared meat, cheese, pasta and pizza dishes; poultry and fish nuggets and sticks; sausages, burgers, hot dogs and other reconstituted meat products; powdered and packaged instant soups, noodles and desserts; and baby formula.
Covers ingredients subject to processes such as fractionation, hydrolysis, hydrogenation, or other chemical modifications, extrusion, molding and pre-frying, includes colors, flavors, emulsifiers and other additives.