Soya's new health positioning, as opposed to its previous, narrower free-from positioning, has been one of the reasons for its turnaround in fortunes.

Manufacturers have been quick to capitalise on the fact soya is low in saturated fat, contains healthy polyunsaturated fats and Omega-3 and -6, is a source of fibre and protein and can actively lower cholesterol levels.

However, they have also had to contend with some negative PR. Over the past few years, there have been several scientific studies, pounced on by the national press, claiming soya can disrupt thyroid function, reduce fertility, or even "give you man-boobs".

These reports have made communicating a health message far from straightforward.

"There is a huge amount of misinformation and downright daftness about soya," says Dr Justine Butler, senior nutritionist at the Vegetarian and Vegan Foundation. "The result is confusion. People don't know what to believe."

The VVF is trying to restore soya's reputation with a website (www.safetyofsoya.com) that counters these claims and highlights the healthy aspects of soya.

But soya does fall down in some places. It lacks some of the nutrients that milk can provide, and most liquid soya products come fortified with calcium and vitamins.

"Soya does not have the complete nutritional profile of milk, so yes, we fortify with vitamins A and D and calcium. Our products have 20% more calcium than milk," says Daniel Derrick, So Good's managing director.

"Unfortified soya is not equivalent to dairy, but it still has cholesterol-lowering factors," adds John Allaway, commercial director at rival Alpro.

Emphasising the cholesterol-lowering benefits of soya could be a winning marketing strategy. Heart disease is the UK's biggest killer, claiming one in five male deaths and one in six female deaths, according to the British Heart Foundation.

There are plenty of other healthy attributes to shout about. Despite the odd bit of negative PR, household penetration, currently at 15%, is expected to rise 20% in the next five years.

Organic soya drinks may have an important role to play.

Of late, the price differential between organic milk and organic soya has diminished to almost nothing.

"That leaves shoppers with no reason not to try it," says Soya Health Foods marketing director Robin Gleave. And, although organic soya products are not allowed to be fortified, they are generating ever-stronger sales, says Gleave. Soya Health Foods' organic unsweetened soya generates 80% of its total sales.n