Food for Thought

Potato Lovers Look Back to a Healthy Future
There’s a ‘modest positive association between the consumption of potatoes and the risk of type 2 diabetes in women’ write the authors in a prospective study reported in the February 2006 issue of the American Journal of Clinical Nutrition. ‘This association was more pronounced when potatoes were substituted for whole grains.’ The Harvard investigators conducted a prospective study of 84,555 women, aged 34 to 59 years with no history of chronic disease, who were enrolled in the Nurses’ Health Study. The women completed a validated food frequency questionnaire and they were followed up for 20 years with repeated dietary assessments. During the study, 4,496 participants were diagnosed as having type 2 diabetes. After adjustment for age and dietary and non-dietary factors the researchers found that those with the highest potato intake (around one serving a day) had a modestly elevated risk of developing type 2 diabetes (about 20% higher). The link was strongest among obese women, who are already at increased risk of the disease, suggesting that heavy potato consumption may pose a particular problem for them, the researchers point out. ‘These data support a potential benefit from limiting the consumption of these foods in reducing the risk of type 2 diabetes,’ conclude the authors. ‘Substitution of these sources of carbohydrate with lower glycemic, high-fibre forms of carbohydrates such as whole grains should be encouraged.’

Cutting back on potatoes is something many people on a low GI diet find hard to do. So what’s the answer?
First of all, there’s no need to say ‘no’ to potatoes altogether just because they may have a high GI. They are fat free (when you don’t fry them), nutrient rich and filling. Not every food you eat has to have a low GI. So enjoy them but in moderation.

Secondly, look for the lower GI varieties of potato or serve them in a way that reduces the glycemic response. University of Toronto researchers found that the GI of potatoes ranged from 56 to 89 depending on variety and cooking method (Journal of the American Dietetic Association). Precooking and reheating potatoes or consuming cold cooked potatoes (such as potato salad) reduced the glycemic response. The highest GI values were found in potatoes that were freshly cooked and in instant mashed potatoes. Margareta Leeman and her colleagues at the University of Lund in Sweden found that preparing potatoes the day before and serving them cold as potato salad with a vinegary vinaigrette dressing can lower the GI (European Journal of Clinical Nutrition). In Low GI Eating Made Easy, dietitian Kaye Foster-Powell suggests steaming small new potatoes (with their skin for added nutrients), or bake a jacket potato and add a tasty topping based on low GI beans, chickpeas or corn kernels.

Third, remember that potatoes are a relative newcomer to the Western dinner plate. Athough the Spanish brought them back to Europe from South America in the mid-sixteenth century, people tended to regard them with suspicion and fit only for animals. They didn’t become a regular part of the European diet until the late eighteenth century. And it wasn’t until the nineteenth century that we really developed a taste for them replacing traditional wholegrain staples such as wheat, barley, rye and oats, which have much lower GI. So look back to a healthy future and add variety to your meals by enjoying wholegrains, legumes, pasta, noodles, basmati rice on a regular basis and potatoes occasionally. You’ll reduce the overall GI and GL of your diet and your risk of chronic disease.