What to Eat: Food that’s good for your health, pocket and plate. Joanna Blythman

and carbon dioxide, but they taste about as carroty and juicy as blotting paper.

      It is an interesting exercise to compare the flavours of organic and conventionally grown root vegetables. The difference is most noticeable with carrots. The organic ones often taste better, which is perhaps why carrots are the most commonly bought organic vegetable.

      Beetroot has a sweet, earthy flavour and a sumptuous colour. Unless you get a chance to buy small, tender summer varieties, go for larger beetroots because they keep better, and choose roots that are hard and not wrinkled. Don’t discard the leaves on beetroot if they are still fresh and green: use them as winter spinach or salad leaves.

      Celeriac is a big continental favourite which has become more popular in Britain in recent years. It has a mild celery flavour and tastes slightly nutty.

      Parsnips have a unique, unmistakable flavour. They taste sweetest and best in the depths of winter when frost has converted their carbohydrates into sugar.

      The fantastic, complex flavour of Jerusalem artichokes makes a spectacularly velvety, rather aristocratic soup.

      Sweet potatoes have luscious, melting flesh and a taste that is reminiscent of chestnuts.

      Swede is good in traditional winter broths but can be very fibrous, so chop it finely or grate it and cook long and slow. The smaller white-violet turnips that are in season in the spring, on the other hand, are tender and need only very light cooking.

      Things to do with root vegetables

      • Coarsely grated carrot and beetroot (along with kohlrabi, if you like) dressed with toasted nigella (kalonji) seeds, lemon or Seville orange juice and olive oil, make a striking-looking and unusual winter salad. Stunning with grated fresh turmeric root added, if you can find it.

      • Roast beetroots in their skins, then peel, slice and serve in a salad with watercress, creamy goat’s cheese and walnuts.

      • Juice carrots and beetroot with tart apples and celery for a winter breakfast drink.

      • Grated celeriac, dressed with equal amounts of natural yogurt and mayonnaise and a little horseradish or Dijon mustard, goes brilliantly with thin slices of cured or roast ham and sizzling hot bacon or pancetta.

      • Par-boil quartered parsnips, roll in flour, egg, then a mixture of breadcrumbs and grated Parmesan. Shallow-fry them, dust with smoked paprika and dip in soured cream.

      • Deep-fry ultra-thin slices of any root vegetable (cut on a mandolin, if you have one) for home-made vegetable crisps.

      • Par-boil sweet potato, celeriac or parsnip, slice thinly, brush with oil and chargrill on both sides on a ridged, cast-iron grill pan. When nicely marked with lines, remove and serve warm, drizzled with more oil, chopped fresh herbs and chilli flakes.

      • Par-boil and mash sweet potatoes, then fry with ground cumin, coriander and onions. Add canned tomatoes and chickpeas and simmer for five minutes, then stir in chopped or baby spinach at the last minute. Good with sausages or any grilled meat.

      • Finely sliced or chopped raw Jerusalem artichoke gives sweet crunch to winter salads.

      Are root vegetables good for me?

      Carrots and sweet potatoes are an exceptionally rich source of antioxidant vitamins C and E, which help neutralize the damage done by harmful free radicals that can predispose the body to disease, and a very good source of beta carotene, which converts to vitamin A. The deeper and more orange-coloured the carrot or sweet potato, the more beta carotene it has. Among other things, carrots may be protective against heart disease and certain cancers, and help safeguard vision against degenerative conditions such as cataracts. Much of the nutrients in carrots lie just below the skin, so they are most nutritious when eaten unpeeled. Some research suggests that organic carrots have higher levels of nutrients than their conventionally grown equivalents and higher nutrients generally means bigger flavour. Organic growers do not rely on nitrogen-based fertilizers to boost crop yield, so their carrots and other root vegetables grow more slowly and contain more dry matter, which may account for the higher nutrient levels.

      The purple pigment in beetroot, betacyanin, has been identified as having powerful anti-cancer properties. This vegetable is also a really rich source of folate, which helps protect against birth defects. Some research suggests that beetroot is anti-inflammatory and strengthens the immune system. It is used in traditional medicine in many countries as a treatment for anaemia and as a general tonic.

      Celeriac, parsnip, swede and other types of turnip are all good sources of soluble fibre and minerals. Parsnip and swede rapidly release sugar into the blood, which means that they are not foods to be eaten in large quantities by anyone who is trying to lose weight or make their blood sugar levels more stable.

      A light was shone on the environmental and human health impacts of pesticides on root crops in the 1990s when government tests found that carrots contained high levels of organophosphate residues. Since this problem was highlighted the situation has improved. Consumer concern about the toxicity of the chemicals used encouraged growers to find less malign alternatives, such as using protective fleece to act as a physical barrier to pest attack at a critical point in the growing year. Pesticide residue levels in carrots have diminished, but unless they are organic, they are still a crop routinely sprayed with insecticides, herbicides and fungicides. Government tests have shown that about half of all conventionally grown carrots contain residues. The government insists that any residues are so minute that they pose no risk. However, if you want to minimize your exposure, choose organic carrots.

      How are root vegetables grown?

      Root vegetables are mainly grown in open fields throughout Britain and Ireland. When the roots mature in autumn, the fields are often covered in straw, which makes it easier to harvest them when the ground is very cold in the depths of winter. Sometimes they are sowed in among crops like barley and mustard to give them cover and to stop the topsoil blowing away. Carrots, beetroots and white-violet turnips can also be grown for the early summer market in large, unheated polytunnels. Carrot production is most associated with the sandy soils of eastern England, Norfolk, the Fens, Cambridgeshire and Suffolk and the peaty land around Lancaster. Nowadays considerable quantities are also grown in Nottinghamshire and Scotland. All our sweet potatoes are imported, usually from Israel, because they only grow in hot countries.

      Are root vegetables a green choice?

      Root vegetables that are harvested in the autumn can be stored for months in a cool place as they are well nigh indestructible, giving us a constant supply of affordable and versatile vegetables. As such, they contribute greatly to our self-sufficiency, or food security. Why buy imported root vegetables, such as Dutch carrots or Australian parsnips, which will have been shipped and trucked to these shores and clock up unnecessary food miles? These imported root vegetables are marketed in spring as newer, fresher roots, at a time when the previous autumn’s UK crop is beginning to look a bit old. However, these stored UK-grown roots will still be fine to eat, and other home-grown new vegetables such as asparagus, broad beans and purple sprouting broccoli will be coming on stream.

      As supermarkets’ cosmetic specifications stipulate that root vegetables must have uniform dimensions, they routinely reject roots that do not fit that bill. It is thought that a typical supermarket ‘pack-out’ rate (rejection) might account for anywhere between 35 and 50 per cent of the crop, which is a profligate waste of perfectly sound food. Supermarkets also add to waste by refusing to sell carrots unless they have been washed and put through a ‘polishing’ machine. This leaves the carrots looking pretty but weakens them. They don’t keep as well and often rot in the bag. Root vegetables sold in farm shops or market stalls won’t have been graded as they are in supermarkets, so they will be different shapes and sizes, dirtier and perhaps not so visually perfect, but they should taste at least as good and make a more ecological choice. Supermarkets also generate unnecessary packaging with their insistence that roots like swede must be shrink-wrapped in plastic. Root vegetables are pretty robust so that packaging is redundant.

      Supermarket cosmetic standards for root vegetables have also encouraged growers to use more chemicals to meet the retailers’