The popularity of plant-based “milks” is on the rise for many reasons, some people choosing them as an alternative to cow’s milk. If you’re one of them, the chances are you’re wondering how their nutrient content compares with cow’s milk – especially if you’re buying for your family.
This is exactly the question the experts are asking too. This review reveals that plant-based alternatives shouldn’t be seen as a total replacement for cow’s milk. Indeed, it’s hard to beat dairy products such as milk and yogurt when it comes to good nutrition.
The findings raise concerns that if people completely replace their dairy milk with plant “milks”, they may miss out on some important nutrients in their diet. This is particularly relevant for children, for whom cow’s milk provides a great package of nutrients to support healthy growth and development.
Why do people switch to plant-based “milk” alternatives?
You may opt for a plant-based alternative to cow’s milk (plant “milks”) if you’re a vegan or if you suffer from lactose intolerance or milk protein allergies. Supermarket shelves now offer a great choice of options if you’re looking for plant “milks” – you can choose “milk” made from soy, coconut, rice, nuts, oats, even hemp.
But finding products that match the nutrient-dense content offered by diary is a tall order. In addition to providing energy, protein and fat, cow’s milk and dairy products supply more than half our daily requirement of calcium – and contribute a raft of other minerals and vitamins.
Plant-based “milks” may be a useful alternative – but what do we know about their nutrient profile?
The objective of this review was to compare the nutrient composition of milk and plant-based milk alternatives, as well as highlight dietary issues that consumers should consider when choosing plant-based milks.
The authors compared the nutrient contents of cow’s milk (skimmed, 1% fat, 2% fat and whole milk) and 17 plant milk alternatives including five brands of soy, five almond “milks”, three coconut “milks”, two made from cashews, one from rice and one from hemp.
Among plant milks, soy-based products have the most protein
Results showed that the plant-based milk alternatives varied widely in their nutrient content, even among brands made from the same plant base. For example, the protein content of plant milks ranged from as little as 5% up to 100% of the protein content of whole cow’s milk.
Among the plant “milks”, soy “milk” had the highest average protein content – twice as much as the next highest, cashew-based “milks”. Almond “milks” had the lowest average protein content, along with the rice-based “milk” included in the study.
The quality of protein can be seen from its content of essential amino acids – those that we can’t make in our body and so have to get from our diet. Studies show that cow’s milk proteins are a better source of these essential amino acids than are plant-based “milks”. Among the plant “milks” in this review, the soy “milks” scored the highest on this measure of protein quality, the authors report.
‘…..differences in beverage formulations between brands results in a high degree of variability in the nutrient composition of plant-based milk alternatives, even between beverages made with the same plant base.’ – Chalupa-Krebzdak et al, 2018.
Plant “milks” may be good for your cholesterol levels
Fats in our diet are important for energy intake, essential fatty acids, and fat-soluble vitamins. Although cow’s milk might be expected to have potentially harmful levels of saturated fatty acids, the WHO reported no link between drinking cow’s milk and heart disease – perhaps because the many nutrients in dairy products offset the effects of its saturated fats content, say the authors.
With the exception of coconut “milk”, soy- and other plant-based “milks” tended to contain less saturated fat and more unsaturated fats than cow’s milk. This could be beneficial in terms of blood levels of ‘bad’ cholesterol (LDL-cholesterol), which is a risk factor for heart disease.
Plant-based “milks” may benefit our health in other ways, too. Oat “milk” contains soluble fibre that also reduces LDL-cholesterol, while almond “milk” is rich in vitamin E, a fat-soluble vitamin that’s important in protecting cells from the harmful effects of free radicals that can promote cancer and heart disease.
Plant “milks” tend to have higher energy content than cow’s milk
Carbohydrates contribute to dietary energy, excess of which can lead to obesity. In their review, the authors found the carbohydrate content of plant-based “milks” varied widely. Overall, the energy content of plant “milks” was higher than that of cow’s milk. In most plant “milks”, more of the energy content is provided by carbohydrates and sugars – which means they may not be as good a choice as cow’s milk if you’re trying to keep your blood sugar levels down.
Cow’s milk may be a better source of calcium than plant “milks”
We need calcium for normal working of our blood vessels, muscles, and nerves as well as for healthy bones and teeth.
The authors found that plant milks fortified with calcium often contained similar amounts, or even more calcium than cow’s milk. But we may not be able to absorb calcium from plant “milks” as readily as the calcium found naturally in cow’s milk. Calcium added to plant “milks” tends to collect as a sediment and even when these products are shaken, the calcium may not be soluble enough to be of best use.
On the other hand, cow’s milk contains lactose which has been shown to boost the bioavailability of calcium, say the authors.
Plant “milks” may contain anti-nutrients
As well as helpful nutrients, plants contain bioactive compounds that can interfere with how well our gut absorbs nutrients when we drink plant-based “milks”. These are known as an anti-nutrients and include phytic acid and oxalate, which inhibit the absorption of calcium, while lectins inhibit glucose absorption and saponins interfere with protein digestion.
If you’re switching to plant “milks”, check out what else you eat
The authors conclude that plant “milks” may offer some health benefits – for example, in helping to control blood cholesterol levels. However, from a nutritional point of view, it’s important to avoid thinking of plant “milks” as complete alternatives to cow’s milk, the authors advise.
So if you’re choosing to drink plant-based “milks” instead of cow’s milk, don’t forget to adjust other parts of your diet so that you’re not missing out on key nutrients you’d otherwise get from dairy products. This is especially important if you’re buying plant “milks” for your child, the authors advise, as many children eat a smaller range of foods than adults.
