Soya-, cereal-, seed- or nut-based plant drinks are consumed increasingly frequently as milk substitutes. Agroscope researchers have studied the macro- and micronutrients in these drinks and have identified major differences between the plant drinks themselves as well as in comparison with milk.
Producing foods of animal origin is a resource-intensive process and the considerable emissions of greenhouse gases involved have a polluting effect. In particular, excessive consumption of meat with respect to dietary recommendations exacerbates environmental pollution. A predominantly plant-based diet can make a substantial contribution to the protection of human health and the environment. The food industry responds to this situation by regularly launching new products on the market that can, or are intended to, serve as substitutes for meat, fish, milk and eggs.
In Switzerland, traditionally a grassland country, milk production is one of the most important agricultural sectors. The consumption of milk and dairy products has always been very high. For a long time, (cow’s-)milk substitutes focused primarily on infant nutrition, in order to offer an alternative for (formula-fed) infants with a cow’s milk-protein allergy, lactose intolerance or galactosaemia. Only in the last ten years have plant-based drinks for other age groups been a focus on the market.
In-depth analysis of nutrient profile of commercially available plant drinks
Agroscope examined 27 plant-based drinks and two full-fat milk samples. Total energy as well as the macronutrients protein, fat and carbohydrate were determined for all samples. The amino acid spectrum, individual fatty acids and carbohydrates (lactose, saccharose, fructose, glucose and starches) were also analysed.
Micronutrients such as water-soluble vitamins (C, biotin, niacin, pantothenic acid, B1, B2, B6, B12 and folic acid) as well as the fat-soluble vitamins (A, D2, E, K1 and K2) were also determined. In addition, minerals and trace elements (P, Na, Mn, Mg, K, Fe, Cu, Ca and Zn) in the plant drinks were analysed.
Plant drinks provide less energy and nutrients than milk
All in all, most plant drinks had a lower energy density than milk and in general contained lower amounts of all macronutrients. This means that these products do not have the same nutritional value as milk, and are thus not an equivalent substitute for the latter. On the other hand, these products do have a potential for reducing calorie consumption. The use of drinks to lower calorie intake, however, only makes sense if the plant alternatives contain similar amounts of essential nutrients to milk.
Plant drinks are often enriched with vitamins and minerals
The vitamin profiles of the plant drinks differ significantly from milk. To ensure a sufficient intake of vitamins that are present in abundance in milk, enrichment of the plant drinks is necessary.
As with the vitamin profiles, there were considerable differences between the individual plant drinks in terms of mineral and trace element content. Rice, oat, spelt and coconut drinks were generally low in minerals, with the exception of sodium and chloride, which were at nearly the same levels as in milk due to the addition of table salt.
By contrast, soya-, almond- and cashew-based drinks were found to be good sources of certain minerals and trace elements. Soya drinks in particular were shown to be consistently rich sources of most minerals and trace elements.
How does the consumption of plant drinks affect nutritional status?
Since most plant drinks are less energy-dense than milk and generally contain lower amounts of all macronutrients, they are not an equivalent substitute for milk. If they are used as a complete dietary replacement for milk, additional measures such as supplementation with micronutrients are essential to balance out the nutritional differences.
Plant drinks are regarded by many as an alternative source of protein allowing them to reduce their animal-protein intake. However, the relatively low total protein content and lower protein quality of most of the plant drinks examined makes it clear that reducing one’s intake of or completely forgoing cow’s milk requires an adjustment of the overall diet, especially in the case of children or older adults with a higher protein requirement.
- The general nutritional composition of plant drinks cannot be considered equivalent to that of milk.
- The nutrient spectrum of plant-based drinks differs significantly from that of milk. This is particularly true for protein content and quality. Only soya-based plant drinks have a protein content comparable to that of milk.
- Enrichment is the only way to ensure that plant-based drinks contain equivalent levels of the major vitamins and minerals present in milk.