Go back a few decades and it was only cartons of green, blue or red topped milk that you would find lining fridge doors in Britain. It was a simpler time. Now, even though we’re drinking half as much milk as we were 50 years ago, the variety on offer has grown.

The humble cow’s milk is passed over by one in three Britons who favour trendier soya, almond, oat or coconut options, presumably because of the belief that it is better for their health or the planet (with it costing double the price, it’s certainly not for the benefit of their wallet).

However, a new report from the Government’s nutrition advisers indicates that people who drink vegan milk alternatives could be consuming more added sugar, noting that these products are not “nutritionally equivalent” to cow’s. In particular, children under five who drink them could be at risk of an “inadequate” intake of some micronutrients, the scientists caution.

The health benefits of cow’s milk

1. It’s full of protein and calcium

Milk is a high-quality source of protein, says nutritionist Rob Hobson. Each 200ml glass contains around 7 grams of protein, contributing to the 45g and 56g that the average woman and man need per day.

Each glass also provides 130 milligrams of calcium (equating to around a third of your daily requirement). The mineral supports healthy bones, teeth and muscles.

2. It’s a great source of B12

A glass of milk contains almost all of our daily vitamin B12 needs (it offers up 1.3 micrograms (μg) and adults need 1.5μg per day). We need enough B12 for the body to make red blood cells, keep the nervous system healthy and release energy from food.

This nutrient support bone health, muscle function and energy production, making milk a beneficial addition to a balanced diet, says Hobson.

3. It boosts serotonin

Cow’s milk may protect against anxiety and depression, research suggests. A study, which monitored rates of mental illness among more than 350,000 people in the UK, found that those who drank semi-skimmed cow’s milk were 12 per cent less likely to be depressed and 10 per cent less likely to have anxiety, compared to people who drink plant-based milk.

The fatty acids in semi-skimmed milk may protect the brain, which could play a role in reducing the risk of depression and anxiety, Hobson notes. “Plant-based milks like oat milk often lack these nutrients unless fortified, which may partly explain the findings,” he says.

“It’s important to note that this study shows an association rather than proving causation,” Hobson notes. “For those opting for plant-based milks, choosing fortified versions and ensuring a diet rich in calcium, vitamin D and healthy fats from other sources is essential.”

4. It helps lower your bowel cancer risk

Drinking cow’s milk every day may reduce the risk of developing bowel cancer by 17 per cent, research suggests. Scientists found that getting an extra 300mg of calcium per day, equivalent to a large glass of milk, was needed to see the effect.

The protective effect of milk may be down to calcium binding to carcinogenic compounds in the gut, such as bile acids and free fatty acids, reducing their potential to damage the colon lining, Hobson explains.

Calcium can also support healthy cell division and reduce inflammation in the colon, which are both important factors in cancer prevention, he notes.

“Milk also provides other nutrients, like protein, that support overall gut health and cellular repair processes,” Hobson says.

While milk appears to protect against bowel cancer, it’s also essential to eat a fibre-rich diet, limit consumption of processed meat, reduce alcohol intake, exercise and avoid smoking to reduce the risk of cancer, Hobson explains. “Milk can be part of a healthy diet, but its benefits work best alongside these other preventative measures,” he adds.

What are the healthiest types of cow’s milk to buy?

“The choice between skimmed, semi-skimmed and whole milk largely depends on personal taste and health goals,” says Hobson. Some people prefer the creamier texture of whole milk, while others prefer the lighter feel of semi-skimmed or skimmed varieties, he notes.

Whole milk, unsurprisingly, is the most calorific and fattening milk, with 132 calories and 7.4g of fat per 200ml. However, it naturally has slightly higher levels of fat-soluble vitamins like A, though lower-fat milks are usually fortified to add these back in, Hobson explains.

Semi-skimmed milk is the most popular option in the UK, selected by around 80 per cent of people, according to Ian Givens, a professor of food chain nutrition at the University of Reading. It has 100 calories and 3.6g of fat per glass.

Skimmed is the lowest-calorie option (74) and fat (0.6g) option. However, “very little” skimmed milk is actually bought in Britain, Prof Givens says.

Semi-skimmed and skimmed milk may be a better choice if you’re aiming to manage your weight or watch your cholesterol levels, Hobson notes.

Though research shows full-fat dairy can increase levels of “good” high-density lipoprotein (HDL) cholesterol, potentially balancing out the higher saturated fat content, he adds.

What about filtered, branded, organic and local milk?

Filtered cow’s milk, such as Cravendale, offers no significant nutritional advantage over regular milk, though it may keep slightly longer in the fridge (around seven days once opened compared to the usual five days for normal milk), Hobson says.

Whether you fork out on pricer branded milk, rather than choosing a cheaper supermarket carton, won’t have a bearing on your health. “I think this is more of a focus on provenance, taste or production methods,” says Hobson. “The nutritional differences are minimal unless the milk is fortified.”

Organic milk, however, may be worth the extra pennies, according to Hobson. “It often contains higher levels of omega-3 fatty acids and antioxidants like vitamin E, thanks to cows being pasture-fed or eating a natural grass-based diet, which is a key part of organic farming practices,” he explains.

However, Prof Givens says that, while this is true, organic milk does not contain enough extra nutrients compared to standard milk for it to influence our overall health. “The impact that this has on whole diet intake is very small and unlikely to represent a health benefit,” he says.

There has also been an increase in people buying milk from local farms. While this is a great way to support a local farm and the milk may be fresher, “unless it’s organic or grass-fed, it offers similar nutritional content to supermarket milk”, Hobson notes.

Additionally, some farms sell non-pasteurised (raw) milk directly to the public, meaning that it goes straight from the cow to the bottle and it hasn’t been heat-treated to kill off harmful bacteria, Prof Givens notes.

The Food Standards Agency warns that this milk can contain bacteria that causes food poisoning and vulnerable groups, such as the over-65s, pregnant women and children, shouldn’t drink it.

Which are the healthiest alternatives to cow’s milk?

1. Soya

Soya is the healthiest dairy-free milk, says Hobson. “It’s closest to cow’s milk in protein and often fortified with calcium and vitamins – look for brands with no additives, like Plenish.”

Each glass of soya milk has 66 calories (34 fewer than semi-skimmed), a sixth of the fat (0.6g) and nearly as much protein (6.6g, compared to 7g in cow’s milk).

The protein content of milk is important, especially for children, who may not be getting enough if they drink plant-based milks, says Prof Givens. “The exception is soya products. So I would put them second after milk.”

2. Oat

Compared to soya and cow’s milk, oat milk contains much less protein (2.2g per 200ml) and more calories (120 per glass), though it does have a bit more fibre (1.2g).

It’s usually fortified with nutrients to match the calcium and vitamin B12 levels in cow’s milk, Hobson notes.

However, research shows the vitamins and minerals that are added into plant milk are not absorbed by the body in the same way as if they were naturally-occurring, Prof Givens notes.

3. Almond

“Almond milk is low in both calories and protein,” Hobson notes. Each glass has just 30 calories, a third of the amount in semi-skimmed, and just 2.2g of fat. However, it has less than 1g of protein per serving.

“As with other plant-based milks, opt for brands that are fortified to ensure you’re getting enough nutrients,” he recommends.

4. Coconut

Coconut milk is another low-calorie milk, with just 40 calories per cup, and has the lowest fat content of other milks, apart from skimmed. However, it also has the lowest amount of protein, at just 0.2g per serving, which makes it the least healthy option, Hobson says.

FAQs

Is it good to drink milk every day?

“There’s absolutely nothing wrong with drinking milk every day – lots of people already do, whether it’s in their cereal, porridge, or a splash in tea and coffee,” says Hobson.

There’s no strict rule on how much milk to drink but it’s a good idea to aim for three servings of calcium-rich foods per day. Milk can count for one of these, while yogurt and cheese can make up the other two.

Which milk is best for bones?

“All types of milk contain protein and calcium, which are essential for bone health,” says Hobson. If you buy plant-based milk, ensure it’s fortified with both calcium and vitamin D to support bone health, he adds.

“Theoretically, fat-reduced milk (like skimmed and semi-skimmed) should contain more calcium and magnesium,” which support bone health, says Prof Givens. “But the difference is so small that it doesn’t make a difference.”

Should adults stop drinking milk?

Milk is valuable for adults, as well as children, says Hobson. “It helps ensure they get enough calcium to support bone growth and maintenance,” he says.

Drinking 200ml per day is a good starting point for adults, as it provides essential vitamins and minerals, Prof Givens adds.

Does heating milk make a difference?

“Heating milk slightly reduces its vitamin content,” Hobson explains. This is particularly the case for heat-sensitive vitamins like B12, he says.

“However, the protein, calcium and most other nutrients remain intact, making it perfectly fine for lattes, porridge or cooking.”