Expert gives verdict healthiest milk: Dairy vs plant-based
Nutritionist Rob Hobson says dairy milk provides protein, calcium, vitamin B12, riboflavin and iodine, while plant-based alternatives can contain less protein…
Registered nutritionist Rob Hobson says dairy milk offers a broad mix of nutrients that some plant-based alternatives contain in lower amounts. His comments follow a study warning that replacing dairy, even partially, could leave people short of nutrients such as iodine.
The concern matters for people choosing oat or almond drinks as substitutes, since the products differ in protein and fortification. Hobson says consumers should check labels rather than assume plant-based milk provides the same nutrients as dairy.
A 200ml glass of dairy milk contains about 7g of high-quality protein, along with calcium, vitamin B12, riboflavin and iodine. The study, published in Lancet Planetary Health, raised the possibility that swapping dairy for plant-based alternatives could contribute to micronutrient deficiencies.
“The recent Lancet study raises a valid concern because people may swap dairy for plant-based alternatives without realising they're losing some of the nutrients they were previously getting,” Hobson said.
Iodine is one of the nutrients at issue. Hobson said it supports normal thyroid function and described dairy as one of the main sources of iodine in the UK diet.
For protein, the source gives recommended daily amounts of 45g for women and 55.5g for men. It says those amounts are equivalent to about two and a half pints of milk.
What changes between dairy and plant-based milk?
Plant-based drinks vary. Some are fortified with calcium, iodine and B vitamins, but fortification does not make every product nutritionally identical to dairy.
Hobson said whole, semi-skimmed and skimmed dairy milk have fairly similar protein and calcium content. Their main differences are fat and calories, with whole milk containing more saturated fat.
Almond milk may suit people watching calorie intake because unsweetened varieties are usually very low in calories and saturated fat. But it can also provide very little protein, often less than 1g per 100ml.
That difference can be easy to miss. Hobson cautioned that almond milk should not be treated as nutritionally equivalent to whole almonds, which contain protein, fibre and healthy fats. Most almond drinks contain relatively few nuts.
“There's nothing wrong with choosing almond milk, especially if you enjoy the taste, but I'd look for one fortified with calcium and vitamins,” he said. For people replacing cow’s milk completely, he also advised checking that protein and iodine come from elsewhere in the diet.
Why does the study raise concern about switching?
The issue is not simply whether a drink is plant-based or dairy. Its nutrient profile, whether it is fortified and what else a person eats all affect what the switch means nutritionally.
Oat milk is often fortified and is popular for its creamy texture and use in coffee, but Hobson said its protein content is low compared with cow’s milk. He also noted that oat drinks generally contain more carbohydrate than almond or soya milk.
Oats themselves provide fibre, but Hobson said most oat milks do not contain enough beta-glucan to deliver the cholesterol-lowering benefits associated with eating oats. Processing can also produce sugars from oat starch, even when no sugar has been added.
His practical advice for regular oat-milk drinkers was to choose an unsweetened fortified version where possible. For almond milk, the label check should include calcium and vitamins, alongside attention to protein and iodine elsewhere in the diet.
The study’s warning centers on the possibility of losing nutrients during a switch, not on a claim that every plant-based drink has the same composition. A 200ml glass of dairy milk, Hobson said, provides about 7g of protein.
