Corn: the good, the bad and the tasty
There is a range of corn varieties but the most common in your supermarket is sweet yellow. This type is higher in sugars, thus its name and delicious taste. Also seen occasionally is blue corn, an heirloom variety considerably higher in protein than its yellow cousin. This corn is still commonly eaten in its home country of Mexico.
It’s interesting to note that corn is, in fact, a kind of maize but this name is applied only when the plant is cultivated and left to fully mature with the grain then being milled and used as flour. The corn on the cob that you know is actually an immature version of this grain. It is picked before it has fully ripened as this is when its sugar content is highest.
Corn is thought to have originated in Mexico with 80,000-year-old fossils of the plant being found in Mexico City. It travelled through North and South America where it was used as a staple food by indigenous people. In fact, there is a significant record of its widespread use by the Incas, who thought it to be an energy food. Once Columbus arrived in the Americas, it wasn’t long before corn was cultivated and eaten throughout Europe.
Corn is an excellent source of fibre, so is a great addition to the diet as it can assist with healthy digestion and aid in reducing the risk for colorectal cancer. Plus corn is rich in a number of vitamins, in particular B3 and folate. Both of these nutrients are important for a healthy nervous system and B3 is essential for the metabolism of sugars along with a healthy digestive system and good skin.
There is a number of antioxidant nutrients found in corn that have been shown to have a huge range of health benefits. These antioxidants are from the carotenoid group and include beta-carotene, zeathanthin and lutein. These last two are best known for their importance in the macula area of the eye.
Lutein, in particular, has been found, as in its role in plants, to protect against UV light through its action as a blue light filter. This means it’s very important for the protection of both the macula in the eye and the skin. Recent studies have shown lutein can both protect the skin against basic sun damage or “sun ageing” as well as certain skin cancers. This is obviously a very important effect for Australians and New Zealanders with our high national skin cancer rates.
There is some disagreement in recent research as to lutein and zeathanthin’s efficacy as a treatment for eye diseases such as macular degeneration or cataracts. Most studies agree, though, that its use as a preventative of such conditions is clear. The prevalence of macular degeneration in Australians and New Zealanders over 55 is as much as 18.5 per cent, so adequate levels of these nutrients are clearly important.
Another very important effect of these two phytonutrients and therefore of corn is their antioxidant activity in preventing cholesterol oxidation. This results in a decreased rate of atheroma or plaque formation in the arteries, which means improved cardiovascular health as well as reduced risk of stroke and high blood pressure. These two flavonoids have also been linked to positive health outcomes for a range of chronic health conditions, from diabetes to arthritis.
Finally, the silk or “hair” you find when you peel your corn cob has fantastic properties as well. It is rich in the mineral silica, which strengthens connective tissue and is used by many for healthier hair, skin and nails. This can be brewed up as a tea and three cups or more a day can be drunk to achieve a therapeutic effect. Be warned, though, that it does have a flushing effect on the kidneys. In fact, it is also used to help soothe the discomfort of urinary tract infections due to its affinity with this organ and its cooling and calming nature.
Despite its many positive health properties, there are some not so healthy facets of this enjoyable vegie that you need to consider. First, it has a very high calorie content, so too much corn can mean too much tummy if you’re not careful. Many processed foods use corn syrup as a sweetener and this is where the serious trouble lies.
It is used by companies in their products to reduce the GI level of these foods as corn syrup has a lower GI than sugar because of its fructose content. As fructose tends to be sent straight to your liver for processing, it doesn’t cause a huge spike in blood sugar but is more likely to affect the health of your liver and be converted to fat. The use of this sweetener is becoming more and more common and has huge health implications for Australians. Your best bet is to read labels carefully and avoid corn syrup whenever possible.
So now you know the inside on this sweet vegie treat. Eat in moderation and you can harvest the health benefits.
Rowena York is a Melbourne naturopath, herbalist and nutritionist with a particular interest in food as medicine.
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