Are Carrots for the Chop?
Can the Way We Prepare Vegetables Affect Their Nutritional Value?
Cooking carrots is back on the curriculum after academics at the University of Newcastle’s School of Agriculture (UK) spent time sweating over a hot stove recently (1).
Dr Kirsten Brandt, along with colleagues from the University of Denmark discovered what most of us already knew regarding the effect of chopping up vegetables. They cook faster and lose more nutrients - from an increased surface area exposed to the boiling water. Think about it - which defrosts faster, a spoonful of frozen peas or a large sprig of broccoli?
In fairness, the focus of their research had a sharper edge than this. Carrots store useful colourful fat-soluble compounds called carotenoids, which produce the pigmentation of many fruits and vegetables. Our bodies convert beta-carotene to vitamin A (or retinol), but it does not end there. Carotenoids are also powerful antioxidants, mopping up harmful free radicals from every cell in the body. The irony of aerobic respiration is that oxygen gas, which is essential to life, can also be toxic, encouraging the production of dangerous "exhaust fumes" ( free radicals) from inside our cells. The occurrence of chronic disease and the inevitability of ageing are both linked to the progressive failure of antioxidant systems (2).
New Findings
Another interesting compound in carrots is falcarinol, closely related to fatty acids and found to have potent anti-tumour properties when tested on rats (3). The way we cook our vegetables may destroy up to 70% of this compound - which is heat sensitive. By keeping our carrots whole during boiling, more of the falcarinol is conserved, making more of it available as a possible anti-cancer agent. There are two problems here. Firstly, plants such as Ivy (Hedera helix) contain large concentrations of falcarinol and are known to cause allergic reactions, so the isolated compound may have potency in other directions. Secondly, you will need a bigger saucepan...unless you enjoy eating raw carrots.
A Colourful History
The wild carrot (Daucus carota) was known to the Greeks and Romans, but it was valued more for its herbal qualities than anything else (4). Mention of the root vegetable as such does not appear until the 12th century, when the Arabs brought red, purple, yellow and green carrots westwards to Europe. These were the ancestors of the modern vegetable, selectively cultivated by the Dutch and brought to England in the 16th century. Normal (orange) carrots appeared around the 17th century according to paintings of the time, and have been with us ever since, although the occasional white mutation is not unknown. Nowadays, we tend to be preoccupied with more cosmetic matters of shape and texture, with a wide range of varieties to suit the palate, plate or possibly the tin.
Sweet or Savoury?
Surprisingly, carrots contain a lot of sugar (7.4g/100g portion), which compares favourably with beetroot at 8.8g/100g and sweetcorn at 9.6g/100g. Carrots and parsnips have been exploited as a source of refined sugar in the past, and their use in puddings and desserts was well known in the 18th century when sugar was scarce. Likewise during the years of the Second World War. Sugar beet on the other hand has a massive 20g/100g of extractable sugar but is otherwise considered inedible by humans. Nevertheless, we are more familiar with the use of root vegetables as savoury items, in stew, soups or raw in salads. In Asian and Iranian cuisine, shredded carrots are used as a garnish for pilaf dishes.
To enjoy the best of both worlds, try the modern-day version of traditional carrot cake, with generous proportions of cream cheese and sugar icing energetically compromising the more frugal version of the past. However, there is a "healthy" angle - it includes wholemeal flour and a few chopped nuts to go, so who says you can't have your cake and eat it?
References
- Cancer Boost from Whole Carrots. 16/06/2009. BBC News.
- The Process of Ageing (2009). Optimal Health of Harley Street, London.
- Kobaek-Larson M et al (2005). Inhibitory effects of feeding carrots or falcarinol on the development of lesions in the rat colon. J Agric Food Chem 9;53(5) 1823-7.
- Davidson A. (2002) The Penguin Companion to Food. Penguin Books.
Cutting up the Carotene
|
What do you think about this article?
More in Health & Wellness
Latest Articles