Kale is a good natural source of folic acid, which is important in the early stages of pregnancy. It is also a good source of lutein, a carotenoid with powerful antioxidant properties, important for maintaining healthy vision.
"The rise in popularity of 'super-foods' such as curly kale are coming about as people are on the look-out for high quality fresh foods that fulfill their healthy eating requirements, whilst at the same time being quick and simple to prepare. It seems that health is really high on people's shopping lists," said Moira Howie, Waitrose nutrition manager.
Consumers are increasingly heading for healthy options, especially those in the 'super-foods' bracket. Waitrose has seen increased sales in a number of fruits and vegetables classed as 'super-foods' such as kale or strawberries.
Strawberry sales in the UK are reported to have increased by 34 per cent during the last two years.
Growing public understanding of several fruits and vegetables has also seen demand increase across the UK for other berries. Sales of blueberries are reported to have rocketed by 130 per cent, while reaspberry sales grew by 62 per cent in the last two years.
Analysts from Innova Market Insights said recently that the increasing popularity of berries and berry flavours in recent years is now extending to other less well known super fruits, such as pomegranate, mangosteen, acai and noni, which are all being marketed on their antioxidant content and associated with health benefits.
Kale, a dark green leafy relative of the cabbage, acts as a good source of fiber, antioxidants vitamins A and C, and the energy releasing B vitamins. The vegetable also contains large amounts of phytonutrients that are thought to help in the fight against some cancers and have earnt kale's status as a 'super-food'.
"With health and nutrition so high on the national agenda, we are really seeing this translated into nutritious choices in our shops," said Moira Howie, Waitrose nutrition manager.
Kale is a brassica and is part of the cabbage family. It is grown in the UK from June until March and is at its most plentiful in October. Unlike other cabbage varieties it can be grown in harsher climates where other crops fail. Production in the UK is usually by farmers in the Lincolnshire area, but sales of the vegetable are greatest in the south.