Most dairy-free milks do not contain adequate levels of iodine, according to a 2017 study by University of Surrey researchers. Iodine is a mineral which is needed to make thyroid hormones and is particularly important for pregnant women, as it’s essential for normal foetal brain development.
In the UK, cow’s milk and dairy products are the main sources of iodine. The recommended iodine intake for adults is 150 mcg per day, while in pregnant women it’s 200 mcg per day. But researchers said a glass of a milk-alternative would only provide around 2 mcg.
Last April, a leading health charity warned of the dangers of cutting out cow’s milk, saying young people may go on to develop osteoporosis, which causes bones to become brittle and break, later in life.
Typically people should consume 700ml of calcium a day, however with unfortified, plant-based milk products this can be difficult to achieve. In light of this, we spoke to nutritionists and dieticians about the nutritional value of cow’s milk and other plant-based alternatives on the menu.
Milk consumption rates in the UK have dropped by about 30% in the last 20 years. This is down to a number of reasons including disputing the ethics of cow farming, not enjoying the taste, allergies, or simply because there are more alternatives widely available. But dietician and British Dietetic Association (BDA) media spokesperson Rick Miller says “there’s no single replacement for cow’s milk in the diet”.
Cow’s milk is a well-known source of calcium and protein as well as other vitamins and minerals such as phosphorous, potassium, iodine and vitamin B12, explains AfN registered nutritionist Charlotte Stirling-Reed.
It contains roughly 47 calories per 100ml (semi-skimmed milk) and its calcium is “well absorbed by humans”, whereas from certain plant sources it often isn’t.
Experts agree that cow’s milk forms a crucial part of children’s diets due to the calcium content, which is needed to help them develop strong and healthy bones. In fact, Stirling-Reed hails it as “the most nutritious milk available”.
Vitamins and minerals that are found naturally in this type of milk have to be added into plant-based alternatives by manufacturers - a process called fortification.
“Soya milk is nutritionally the most similar to cow’s milk and therefore is probably the first port of call when it comes to an alternative to standard milk,” says Stirling-Reed. “It’s also readily available in the UK and is fairly low cost in comparison to some of the other milk alternatives.”
The variety is beneficial to people with an intolerance or allergy as it doesn’t contain cow’s protein or lactose.
Soya milk has a similar profile to cow’s milk in terms of macronutrients, protein, carbohydrates and fat, according to Miller. That said, it doesn’t contain large amounts of calcium, iodine or B vitamins, he adds.
Soya milk has a higher calorie content than almond, coconut and hemp milk, containing roughly 39 calories per 100ml.
Due to the milk being derived from a plant, it isn’t naturally sweet and therefore sugar is often added. As such, it should be consumed in moderation to keep teeth healthy or, alternatively, it’s worth purchasing unsweetened versions.
Experts advise buying soya milk that is calcium and vitamin B fortified. In some children’s soya milk products, for example Alpro ‘Growing Up’ milk, they also add iron and vitamin A.
Laura Thomas, an AfN registered nutritionist, says that while hemp seeds themselves might be a good source of omega 3 fatty acids, fibre and other nutrients, that doesn’t mean the milk version will be the same.
“It is the equivalent of juicing a fruit,” she explains. “By making them into milk you’re stripping away a lot of the essential nutrients.”
Hemp milk contains roughly 35 calories per 100ml. A relatively lesser-known kid on the block, it is also high in protein but, unlike soya milk, contains more plant-based essential fatty acids.
These ‘good’ fats, which make the milk taste quite creamy, “are ideal for boosting cardiovascular health, improving cholesterol levels and are also beneficial for skin integrity”, Miller claims.
“A little bit of hemp in the diet might go a long way,” he adds, before suggesting that it’s one of the better milk alternatives to choose from.
Oats contain beta-glucan, which can contribute towards the maintenance of normal blood cholesterol levels. Miller claims these benefits transfer to oat milk too, however to enjoy them consumers would need to have multiple servings of milk each day, for example in tea, coffee and cereal.
Oat milk naturally contains more B vitamins than soya and coconut milk, and has proven to be a great option for people who have multiple allergies - for example to nuts, soya and dairy products.
One downside to oat milk is that it’s naturally low in protein and other vitamins and minerals. Therefore opting for a fortified version is highly recommended.
Its calorie content is also higher than other milk alternatives - at around 45 calories per 100ml.
While almond nuts may be great for health - they’re rich in protein, healthy fats and flavonoids for starters - their milk counterpart doesn’t tend to boast the same benefits.
“Almond milk is usually made from around 2% almonds, so there is very little almond in the product,” explains Stirling-Reed. “Therefore many nutritional components found in whole almonds (such as protein, fibre and calcium) are not found naturally in almond milk.”
That said, almond milk is low in calories (it contains roughly 24 calories per 100ml) and, if fortified, can provide a substantial amount of calcium, vitamin D and B-vitamins to your diet.
Thomas adds that people should be wary when buying almond milk as “there are a lot of products out there that are basically made up of almonds, salt and water only, with no fortification”.
“One of the main benefits of coconut milk is that it’s got a low calorie content,” explains Miller. “It contains around 28 calories per 100ml.”
But aside from the attractive calorie content and its sweet and palatable taste (from added sugar), it doesn’t really have many health benefits.
Stirling-Reed explains that coconut milk contains “almost no protein” and “therefore doesn’t compare well with soya or cow’s milk”. It’s therefore essential to purchase fortified coconut milk if you’re using it as a milk replacement.
Coconut milk is also one of the more expensive alternative milks on the market.
While cow’s milk appears to come out on top in terms of nutritional value, Thomas notes that more studies are needed to look into the benefits of plant-based milks.
“We talk about dairy being crucial to a healthy balanced diet, however we don’t have the same amount of studies on plant-based alternatives,” she says.
The nutritionist acknowledges that, for a lot of people, it’s not possible to adopt a dairy diet and concludes that if you do choose to go dairy-free, the best type of milk is “the one you like and the one that’s fortified with nutrients”.
For example, she drinks almond milk which contains 120mg of calcium per 100ml. Conversely, cow’s milk contains approximately 140mg per 100ml - so not far off the mark.
That said, she warns against making your own milk at home. “There’s become a huge issue with people creating their own plant-based milks at home, spurred on by the likes of Instagram influencers and unqualified nutritionists,” she says.
“The problem that I see, and this is uniform across the board with plant-based milks, is that they’re not fortified with vitamins D, B and calcium, especially if you make them at home.
“So making your own milk could have potentially detrimental consequences.”
She adds that while plant-based alternatives may be lower in protein, you shouldn’t be too concerned about that as it’s quite easy to make up for this elsewhere in your diet. Foods such as eggs, fish and seafood, soya tofu, pistachio nuts, pork, chicken, beans and pulses all contain lots of protein.
Agreeing with other experts in her field, she concludes that the main concern with people going dairy-free is that they may become deficient in calcium. “Especially women who are prone to developing osteoporosis later in life,” she says. “This is why it’s crucial to choose fortified milk.”