Is plant-based milk good for you? What about for the planet?

Doctors, too, say plant-based milk alternatives are not always the healthiest choice, especially for children.

The FDA guidance comes as grocers offer dairy alternatives made from an ever-expanding assortment of nuts, cereals and other plants, including coconuts, hemp, oats, peas, quinoa and rice.

Worldwide sales of alt-milks are growing steadily, driven both by the needs of consumers who have an intolerance to cow’s milk and the desire of some to reduce the environmental impact.

WHAT ARE ALT-MILKS?

They are beverages made, generally, by soaking a base ingredient in water, often after roasting it, then sometimes blanching or steaming it.

In a process called wet milling, water is added and the material is ground up, then filtered. Extras such as stabilisers, thickeners, sweeteners, flavourings, vitamins and minerals may be added, and the liquid may be heat-treated to sterilise it.

Finally, the fluid is homogenised so that it approximates the appearance and mouthfeel of cow’s milk. Based on the widely used classification system known as NOVA, developed by researchers at the University of São Paulo, alt-milks fall into category 3 for processed foods or category 4 for those that are ultra-processed, whereas cow’s milk is in category 1 - unprocessed or minimally processed food.

The European Union prohibits alt-milk makers from using the word “milk” to market their products, a common practice in the US. The US dairy industry has pushed for enforcement of the FDA’s “standards of identity”, which define milk as a bovine product.

US courts, however, have ruled that alt-milks are not misbranded because they are not sold as actual milk. Judges have said consumers understand that almond milk, for example, is not really milk.

HOW ARE ALT-MILKS SELLING?

The market for plant-based milk globally may reach nearly US$20 billion this year, according to a projection by consulting company Future Market Insights.

The growth rate for sales in the previous five years was nearly 8 per cent, according to the company, which expects a rate of almost 10 per cent for the next 10 years.

In the US, while the volume of plant-based products has grown, that of dairy milk has shrunk. Alternative milk’s share of pints sold there increased from 5.9 per cent in 2017 to 9.4 per cent in 2022, based on data from the market research company IRI. As a share of revenue, the figures went from 9 per cent of US$16 billion to 13 per cent of US$18 billion.

HOW MANY PEOPLE ARE INTOLERANT TO MILK?

In a study published in the Lancet in 2017, researchers estimated that about two-thirds of people worldwide are unable to digest or fully digest lactose, a sugar found in milk and products made from it.

This is usually because of insufficient levels of lactase, an enzyme produced by the small intestine. For those with the condition, consuming milk may result in cramps, nausea, diarrhoea, gas or bloating.

Lactose intolerance is especially common in Asia, the Middle East and Africa, less so in Western Europe and the US. Plant-based milks contain no lactose, though those made from nuts and soy are not suitable for people with allergies to those foods. Milk producers have introduced no-lactose and reduced-lactose versions of their product.

They accounted for 7 per cent of milk sales by volume in the US in 2022. Alt-milk sales, however, were almost 1.6 times higher.

HOW DO ENVIRONMENTAL CONCERNS FACTOR IN?

In recent years, many consumers have said they are trying to have a positive impact on the environment, including through their purchases, and modern dairy farming is relatively rough on the planet.

The main issue is that, as part of their digestive process, cows emit the greenhouse gas methane, mostly through belching. It has been estimated that dairy cattle account for about 3 per cent of all greenhouse gas emissions connected to human activity.

In addition, decomposing manure on dairy farms can pollute water sources. Some consumers are also motivated by concerns about the welfare of farm animals, including dairy cows.

Producers of almond and rice milk have been criticised for the amount of water required to grow the main ingredients for their products.

However, according to research by the Food Sustainability Analytics program at Oxford University, producing dairy milk is significantly more water-intensive.

HOW WELL DO ALT-MILKS APPROXIMATE MILK?

It varies with the product and the brand. Some reviewers say that almond and oat varieties are the closest match to dairy milk. Some of the base ingredients can produce a flavour that is slightly off.

That matters less when, rather than being imbibed as a beverage, alt-milks are poured over cereal or added to tea or coffee, as milk is about half the time when consumed by adults in the US.

HOW DO ALT-MILKS COMPARE NUTRITIONALLY TO MILK?

Again, it varies, but generally, they are less nutrient-rich. That alt-milks typically contain fewer calories can make them attractive for those concerned about weight.

Soy options have been found to have similar levels of protein to milk, whereas almond, oat and rice have much lower levels.

Cow’s milk also contains a wide assortment of minerals and vitamins that its imitators do not always match. For this reason, the American Academy of Pediatrics encourages families to mostly avoid plant-based milks other than fortified soy options, unless there is a medical necessity.

Cases of severe nutritional deficiencies have resulted from infants being fed plant-based milk exclusively.