Animal vs Vegetable Proteins: The Food Processing Debate

Different types of protein

While animal products are well-known as important sources of protein, there are also numerous non-animal sources. Not only are there significant differences between animal and vegetable proteins, proteins derived from different members of each group are themselves incredibly varied.

The Harvard School of Public Health (HSPH) points to complete, as opposed to incomplete proteins, as an example: “Animal protein has a balanced combination of all the amino acids, hence it is called complete protein, (while) plant protein is incomplete.”

Even soya protein, which is an exception to this rule, is deficient in methionine, an essential amino acid, meaning that within a vegetarian diet, “to achieve a balanced amino acids intake, a variety of plant protein sources need to complement each other.”

There are a variety of additional factors to consider when analysing the proteins in one’s diet. As the HSPH asserts: “Animal protein and vegetable protein probably have the same effects on health. It’s the protein package that’s likely to make a difference.”

The school’s research found that six-ounce servings of broiled porterhouse steak and salmon provide 38g and 34g of protein respectively. But while the steak also contains 44g of fat, including 16 saturated, the salmon only contains 18g of  which just 4 are saturated. A cup of cooked lentils, meanwhile, although offering less protein (18g), contains less than 1g of fat.

Processed animal proteins

The UN Food and Agriculture Organisation (FAO) senior nutrition officer Ellen Muehlhoff, of the nutrition and consumer protection division, says that especially in developing countries, fish and other meat, as well as eggs and milk, are a vital source of high-quality protein and micronutrients that are harder to obtain from plant sources alone.

Another high value animal protein is whey – the water-soluble byproduct of the cheese-making process. Rich in amino acids, whey protein isolate is 90% pure protein and free of both fat and lactose.

Muehlhoff does point out, however, that, “Contrary to popular belief, most proteins we take from animal foods are only slightly superior to those from plant food.”

Processed vegetable proteins

Soy products are among the best options available in terms of vegetable proteins. Naturally cholesterol-free, soy is rich in high-quality vegetable protein and unsaturated fats, as well as low in saturated fats.

“Vegetable sources of protein, such as beans, nuts, and whole grains, are excellent choices, and they offer healthy fibre, vitamins and minerals,” states the HSPA study, while a 2007 summary report on Dutch company Solanic’s production of a potato protein quoted Professor Rudy Rabbinge of Wageningen University as saying, “(This) new separation process not only reduces energy and water consumption dramatically, it also changes a waste product into a promising vegetable protein.”

The report states that scientists have concluded, “Animal or vegetable origin does not determine the value of proteins. Regardless of their origin, there are only high quality and low quality proteins for the human diet,” adding, “Potato proteins are generally ranked among the high quality proteins.”

Apart from dietary value, functionality and stability during food processing are also important.

Using mild separation technology, Solanic’s final dry food ingredient contains at least 27% of the protein Patatin.

Professor Gertjan Schaafsma states in the report that “potato protein scores even better than soy protein” in terms of amino acid content, the digestibility of these amino acids and the protein’s fortification of amino acid patterns of inferior proteins such as wheat.

Health issues and the green debate

Economic factors are also central to the animal / vegetable protein debate. “People in high-income countries typically have diets that are high in meat and saturated fat and low in fruits and vegetables and whole grains,” says Muehlhoff.

“There is overwhelming evidence to show that this dietary pattern increases the risk of heart disease, certain types of cancer, stroke and diabetes,” she adds, “so in high-income countries, there needs to be a reduction in total meat intake – including processed meat, salted animal-source foods and total saturated fat.”

“On the other hand, high intakes of fruits and vegetables, legumes, whole grains, and fish have been shown to lower the incidence of chronic diet-related disease and their risk factors, including obesity. The latter pattern of eating is a modern nutritional recommendation inspired by the traditional ‘Mediterranean’ diet of the 1960s, which was typically high in plant foods and low in red meat.”

According to the European Natural Soybean Association (ENSA), “The shift towards vegetable proteins closely follows the transition towards a more environmentally conscious, and therefore responsible, general attitude towards lifestyle choice.”

The ENSA also believes that “Greater reliance on plant-based foods, such as soya products, is part of the solution to the global food security concern.”

Consumer perspectives

The ENSA stresses that changing consumer perception is vital: “Raising awareness in consumers of the health and ecological advantages of plant-based products including soy, with particular emphasis on the GM-free status of ENSA members’ products and the sustainable nature of the land on which soy beans sourced by its members are grown, is a prerequisite to the acceleration of the gradual shift away from animal-based products that is already underway.”

The association feels that consumers are already realising that over reliance on animal-based products, whether meat or dairy, is no longer a viable option in the long-term, and that processing companies are beginning to act on this: “The growing trend can be seen, for example, by the introduction of ‘veggie days’ – designed to promote small changes in diet as a meaningful step towards more sustainable food consumption – in schools and the public administration.”

The ENSA strongly advocates this approach, stating: “Rebalancing our diets through incremental shifts, rather than fully changing our existing diets, is an easy way to mitigate the environmental impacts of food production and consumption.”

However, there is plenty of room for further education on potential protein sources. Last year, an International Food Information Council (IFIC) survey found that Americans are twice as likely to say that protein is found in animal sources than in vegetable sources.

“While we found that half of US consumers are trying to consume more protein, we were surprised to find that only a quarter of consumers realised plants were a good source of protein, as well as animal products,” says IFIC President and CEO, David Schmidt.

A balance in all things

While a move towards vegetable protein sources clearly has numerous benefits, experts warn against a ‘blanket’ approach to the issue.

It is highly unlikely that vegetable protein will ever fully replace animal protein sources. The ENSA supports variety and diversity of diet, saying, “A higher proportion of animal proteins can easily be replaced by vegetable proteins in food processing and this would clearly be desirable both on a health and an environmental level. Nevertheless, we are convinced that both sources of protein will continue to co-exist over time.”

Muehlhoff cites the various other benefits to be gleaned from animal-source foods: “We need a variety of food – from plants as well as animals – to provide the many different nutrients required for human health,” she says. “In general, livestock products are major sources of protein, fat and micronutrients such as iron, zinc, calcium, vitamins B12, A and riboflavin.”

Despite representing natural soyfoods manufacturers’ interests, the ENSA agrees: “We believe a complete move to vegetable-sourced proteins is utopist and unrealistic. Both animal and vegetable protein sources are there to co-exist, although we believe their respective proportions will change over time. This is not a matter of ‘or/or’ but rather [a matter of] ‘and/and’.”