Would you like regular milk with that? The question that accompanies every modern coffee shop order. Depending on how trendy the establishment is, whispering "cow's milk" can feel like an illicit act.
According to Starbucks, Britain is the 'alt-milk' capital of Europe, with non-dairy alternatives making up 16 percent of drinks sales by 2023.
Reasons such as taste, environmental concerns and animal welfare can all be part of your decision-making process. But what about health?
In the Northern Hemisphere, where we have a long history of cattle farming, it is an important part of our diet.
"It's not that we have to drink it or that we can't survive without it, but if you were to take it out of the diet of a typical British person you would have to think carefully about where else you would be getting the nutrients from milk. ," says nutritional scientist Bridget Benelam of the British Nutrition Foundation.
These are nutrients that are difficult to obtain elsewhere and are important for our development and health - "something you need to take into account when switching from dairy," says Benelam.
So what are the most important vitamins in your glass of cow's milk and how does it compare to the alternatives?
Egg white
Milk is a rich source of two types of proteins: casein and whey. Casein makes up 80 percent of the protein in milk and is known for its ability to increase the absorption of minerals, such as calcium and phosphorus. Whey, which makes up 20 percent, is known for its richness in amino acids such as leucine, isoleucine and valine.
"Compared to the alternatives, it is generally a better source of protein; there is about 3.4 grams more protein per 100ml," explains Duane Mellor, dietician at Aston University in Birmingham. "The only one that even comes close is soy milk. Oats are about 2 grams. Rice milk and almond milk are much lower."
Calcium
This nutrient is necessary for building and maintaining healthy bones, but also helps keep muscles, nerves and teeth healthy. According to the British Nutrition Foundation, adults need about 700 mg of calcium per day.
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"Dairy products are one of the main sources of calcium in the British diet. For example, a 200 ml glass of skimmed milk will provide 34 percent of an adult's daily calcium needs," says Benelam.
B12
B12, one of the eight B vitamins, is also called cobalamin and is the key to a healthy metabolism. A B12 deficiency can also cause megaloblastic anemia, a blood disorder that makes people tired and weak.
"This is also a vitamin that becomes more difficult to absorb as we age and can only be obtained from animal foods," says Mellor.
One glass (250 ml) of milk provides approximately 50 percent of the recommended daily amount.
Iodine
The body needs iodine to make thyroid hormones, which in turn regulate the body's metabolism and many other important functions.
"In Southeast Asia they get their iodine from their diet, mainly from seaweed," says Mellor. But traditionally in the Northern Hemisphere we find it in dairy products. "Other countries add iodine to their salt, but we in the UK don't," Mellor adds.
A 200 ml glass of milk provides 34 percent of the World Health Organization's recommended iodine intake per day for adults.
Riboflavin
Remember the days of untreated milk in glass bottles with a yellow, creamy top? "That color is riboflavin," says Mellor. Also known as B2, it has a number of roles. The most important link is metabolism and the release of energy.
"If you don't have enough, you can develop ariboflavinosis, a condition that leads to cracks in the corners of the mouth and can change the texture of the tongue. Riboflavin is the most abundant and bioavailable B vitamin present in milk.
However, it is very sensitive to degradation. Riboflavin content may vary depending on processing or type of milk; One study found that commercial milk in summer contained about 20 percent more riboflavin than milk in winter, due to a change in diet from grass silage to pasture.
How plant-based milk performs
Although calcium, B12, iodine, riboflavin and vitamin D are often added to plant-based milks, fortification varies widely by brand. And if it is organic, it is not allowed by law to fortify it. "That's a strange quirk," says Mellor.
He recommends always checking labels carefully to see what vitamin levels have been added.
"I would look for products that are fortified with calcium, riboflavin, iodine and ideally vitamin D. To get as close to cow's milk as possible when it comes to replacing those vitamins, look for at least 15-20 percent per 100 ml (of the amount in cow's milk)."
Dairy milk is generally not a good source of vitamin D, which is added in some plant-based milks.
A 2023 University of Minnesota study found that, compared to cow's milk, only 12 percent of alternative milk products contained similar or greater amounts of all three nutrients studied: calcium, vitamin D and protein.
Also pay attention to added sugars. Lactose is the sugar that occurs naturally in milk; it is the main carbohydrate in milk and provides the slightly sweet taste present in regular, unsweetened milk.
"In cow's milk, the sugar is only lactose, which is digested slowly, while plant-based milk alternatives can be sweetened with fruit juice or added sugar," says Mellor. "Added sugars are usually digested quickly and are therefore considered less healthy."
A common problem with vegan substitutes is that they are often functionally similar, but not nutritionally equivalent.
"Jackfruit is an example. Texturally it is a good meat substitute, but nutritionally it is not great at all. Likewise, with vegan cheese you get the functionality, but not the proteins or interesting fatty acids."
In milk terms, this means you may be able to achieve the same creaminess with oat or potato milk, but not the same nutritional value unless your milk is heavily fortified.
What if I am lactose intolerant?
Northern Europeans, by raising livestock and drinking milk for thousands of years, have adapted to retain the lactase enzyme that digests lactose. Yet in Britain it is still believed that around one in ten older children and adults are truly lactose intolerant.
However, a 2021 University of Bristol study found that thousands of babies are being wrongly diagnosed with cow's milk allergy. "There are a lot of things that can cause us to have uncomfortable symptoms," Benelam says of a misdiagnosis. "People may be avoiding dairy when they don't have to."
"It's a little tricky to specify the symptoms of lactose intolerance because the gastrointestinal symptoms will vary from person to person and occur in different amounts. It can be a subtle condition," says Benelam.
Dairy negatives
But dairy, including whole milk, is relatively high in fat - is that a problem? "Saturated fat is something we generally advise people to cut back on and replace with unsaturated fat, but there is some evidence that saturated fats in dairy products like milk and cheese may not raise cholesterol in the way you might expect."
The fat content of milk is not that worrying for Mellor: "Most people consume about a third of a pint of milk a day, in their tea or on their breakfast cereal. That's not a significant amount of fat. It is the other foods in their diet that contain more saturated fats that are worse."
But as with everything, moderation is key. Drinking three or more glasses of milk has been linked to an increased risk of bone fractures in women (the reason is not entirely clear, but d-galactose, a breakdown product of lactose, has been linked to oxidative stress and inflammation), while Excessive calcium from milk and other foods can increase the risk of prostate cancer, in addition to concerns about saturated fats.
"The overall health benefits of drinking milk are probably on the neutral side," says Mellor. "Where you will certainly benefit more is from fermented milk products, yogurt and some cheeses."
Which cow's milk is best?
Even the nutritional value of your cow's milk can vary greatly. "Data shows that the time of year can affect the nutritional value of your milk," says Mellor. "There are usually more fats if the cows are fed better; you get richer milk when there is more grass in early summer."
It also varies from cattle to cattle. "We know that Jersey milk contains more fat and is creamier than Holstein milk. Although the health benefits have not been proven."
Pasteurization is used in milk to extend its shelf life and reduce the risk of foodborne illness. "From a nutritional point of view, there is no difference between pasteurized and unpasteurized," says Benelam.
However, when you choose between full-fat, semi-skimmed milk and skimmed milk, there are small differences. "You get slightly less vitamin A with skimmed milk, because it is fat-soluble and therefore also in the fat part of the milk."
The other important vitamins are in the watery component of the milk: "So you don't lose any nutrients if you choose skimmed milk," says Benelam.
Whole cow's milk contains more calories and saturated fat compared to both semi-skimmed and plant-based alternatives.
By switching from whole milk to semi-skimmed milk in tea (up to five cups per day), the average person is likely to save less than 50 kcal per day. This means that even when considering calories and energy, the effect of reducing fat is minimal.
Quantity is the key. "Certainly if you drink milky drinks such as lattes and hot chocolate, there will be a difference in calories and fats. For most people, choosing reduced-fat milk is a good idea," says Benelam. Conversely, skim milk can spike your blood sugar levels due to faster absorption. "Like so many things around nutrition, it's about balance."
