Animal-sourced foods, meat, fish, dairy and eggs, are nutrient-rich foods. In addition to being sources of high-biological value protein, many essential health promoting micro-nutrients are either most efficiently, or only, included in the human diet, through moderate consumption of animal-sourced foods.

Red meat is particularly rich in high-quality protein and is an excellent source of bio-available iron selenium, zinc and vitamins B6 and B12 which are important for optimal muscle, bone and brain growth, development and maintenance.

Recent analyses have concluded, that excessive red meat consumption may be linked to a very small number of deaths from cancer, diabetes, heart attacks and strokes. However, this evidence against excessive red meat consumption is not seen in all studies and is very likely to be confounded. It is therefore unreliable.

These same studies highlight the likely protective effects of moderate intakes of red meat, 250g to 500g/week (two to five portions/week), against iron deficiency anaemia, hip fractures, atrial fibrillation and dementia. Hence, it appears that regular, moderate, intakes of beef, pork and lamb are beneficial to young and old.

Substituting beef

Therefore, I read with considerable interest a paper from February’s edition of the Journal of Cleaner Production: “Substitution of beef with pea protein reduces the environmental footprint of meat balls whilst supporting health and climate stabilisation goals.”

The authors suggest a recently developed, yet to be commercialised, plant-based meat analogue, pea protein balls, is of higher nutritional value than Swedish-style beef meatballs from IKEA. The authors suggest that since these meat alternatives are more nutritious, substitution of beef with pea protein would improve human health.

Are these claims valid? Would the human race have better health if we ate considerable quantities of pea protein in place of beef?

The statement of superiority of the pea protein balls within the article is based on an assessment of nutritional value, using the nutrient density unit (NDU) of van Dooren. This is a very limited and simplistic assessment of nutritional quality, only including three parameters – total protein, essential fatty acids and fibre. Content of micro-nutrients has no impact on this measure.

The concept of nutrient density was devised to discourage the consumption of empty calories, junk food and ultra-processed foods.

The Nutrient Rich Food (NRF) indices, devised by Drewnowski, provide considerably more comprehensive and informative measures than that of van Dooren.

It is a family of nutrient-profiling models that balance nutrients to encourage against saturated fats, sugars, and sodium, using 100 kcal as the basis of calculation.

Various iterations of the score exist that vary in the number of positive nutrients included, ranging from 6 (NRF 6.3) to 15 (NRF 15.3). The 15 positive nutrients in NRF 15.3 are essential amino acids, essential mono and polyunsaturated fatty acids, fibre, vitamins A, B12, C, D2, D3, E, olate, minerals, calcium, iron, potassium and magnesium.

Unfortunately, the article does not provide sufficient information to calculate the NRF 15.3. However, it is highly unlikely that the ultra-processed pea protein balls would score very well on this more comprehensive assessment, particularly if covered in an ultra-processed creamy calorie, salt and sugar rich sauce, as is usual for the IKEA Swedish-style beef meatballs.

Plant protein not true replacement of nutrition from meat

These foods have been designed to mimic the sensory experience (taste and texture) of meat. Most are calorie-, sugar- and salt-rich, and as reported in the March 2021 Safefood report, many only contain a fraction of the protein content of animal-sourced foods.

Currently, available plant-based meat alternatives are all ultra-processed foods, and are very likely to contribute to the worldwide obesity crisis, with knock-on deleterious effects on cancer, heart attacks and strokes.

Finally, the mimicking of animal foods using isolated plant proteins, fats, vitamins, and minerals likely underestimates the true nutritional complexity of whole foods in their natural state, which contain hundreds to thousands of nutrients that affect human health.

Hence, the current consensus is that novel plant-based products, such as these pea protein balls, should only be treated as meat alternatives in terms of sensory experience, but not as true replacements in terms of nutrition.

Non–meat burgers are becoming more popular due to a perception that they are healthier for you and the planet. But what are these burgers made from, where is that coming from and what is the nutritional value? These questions will be answered in next week’s Irish Country Living.

Alice Stanton is a professor of cardiovascular pharmacology at the Royal College of Surgeons in Ireland and director of human health at Devenish Nutrition.