Snoop around the contents of an “eat clean” aficionado’s grocery basket and chances are, among the organic cauliflower and mountain of avocados, you will come across a carton of almond milk. A few years ago, those avoiding cow’s milk because of lactose intolerance or for ethical reasons were drinking soya, but health scares have seen a rising demand for alternative plant “milks”, including rice, hemp and – most popular – almond. This week, Waitrose said almond milk had overtaken soya as its customers’ preferred dairy alternative.

Almonds are one of the healthiest foods you can eat. The nuts (or seeds, if you are a botanical pedant) are packed full of vitamins, minerals and beneficial plant chemicals, as well as protein, healthy fats and fibre, and eating almonds is associated with a lowered risk of heart disease and Alzheimer’s, among other conditions.

It makes sense, then, to assume almond milk is packed with healthy properties. On cartons of Alpro (“enjoy plant power”), one of the market leaders that uses almonds grown in the Mediterranean, there is a picture of an almond breaking open as if this elixir of good health is exploding out of it. But, like many other brands, Alpro’s almond content is just 2% – the biggest ingredient is water, followed by sugar. Like most others, it also contains additives such as stabilisers and emulsifiers. The amount of sugar is less than the natural sugars found in cow’s milk, so it has fewer calories, but there is also less protein – 0.5g to the 3.5g you’ll get in the same amount of cow’s milk. Protein, says Helen Bond, spokesperson for the British Dietetic Association, “gives a feeling of fullness, it helps you to feel fuller for longer, and a lot of people are trying to get their protein intake up”. Dairy, she adds, “is a really great source of a readily available form of calcium, so you need to look for plant-based milk that is fortified with calcium, essential for maintaining bones as we get older”.

Like quinoa, another staple of hip “health” obsessives before it, production of almond milk also appears to have a hefty environmental impact. More than 80% of the world’s almond crop is grown in California, which has been experiencing its worst drought on record. It takes 1.1 gallons (5 litres) of water to grow one almond, and thanks to the big profits they bring in, almond orchards continue to be planted (this isn’t to say cow’s milk, which takes about 100 litres of water to produce 100ml of milk, is more environmentally friendly – more that its production is not concentrated in one area of the globe).

Last year, an apocalyptic piece for Mother Jones by Tom Philpott, who has long detailed the environmental ravages of this crop in California, summed up the problems: almond farmers drilling thousands of feet down into aquifiers to pump out water has resulted, in some areas, in subsidence of around 11 inches a year, which “threatens vital infrastructure like bridges, roads, and irrigation canals” and could trigger earthquakes. Furthermore, insatiable demand for almonds is harming honeybees, already an embattled species. Almond trees need to be pollinated but bringing in 1.6m hives to California every year, “into an area dripping with insecticides is a recipe for disaster” writes Philpott (up to 25% of the hives were damaged in 2014), including whole colonies killed off; this spring they fared better after guidelines were issued about pesticide-use during the trees’ blooming season). It’s enough – or should be – to make anyone spit out their almond milk latte in alarm.