Olive oil brings out nutrients in salads

Charlyn Fargo, Contributor

The type of salad oil used in your salad dressing can actually affect how well your body utilises the nutrients in the leafy greens and other veggies in your salad, according to a study at Purdue University.

The study, published in Molecular Nutrition & Food Research, compared dressings made with higher percentages of saturated fat (butter), polyunsaturated fat (corn oil) and monounsaturated fat (canola) at three different levels of fats. Salads were fed to 29 volunteers, whose blood was subsequently tested for fat-soluble carotenoids, such as vitamin A.

Salads dressed with three grams of monounsaturated fat promoted as much carotenoid absorption as those with 20 grams of the other types of fat. The monounsaturated fats, like those in olive and canola oil, are most effective at liberating the fat-soluble nutrients in salads.

Here's what you need to know: The findings raise a caution about low-fat salad dressings, suggesting you may be losing out on nutrients when you cut the fat. The findings also give a strong recommendation to make that home-made vinegar and oil dressing with either olive or canola oil.

- Information courtesy of Molecular Nutrition & Food Research and Tufts University Health & Nutrition Letter

Water and losing weight

Q: Does drinking more water really help you lose weight?

A: In some small studies, drinking 16 ounces of water before meals has helped decrease calorie consumption and improved weight loss among middle-age and older adults participating in weight-loss programmes. It also seemed to help them maintain their weight loss after the programmes ended. We need more studies to know if this really works. If it does, it's not clear whether it would be because of reducing hunger or if it has direct effects on metabolism.

You may hear claims that drinking more water will rev up your metabolism, so you lose weight by burning more calories. However, I can find only a couple of controlled studies that tested this. These studies show a small increase in calorie burning after cold water was consumed. This involved a bit over 16 ounces of cold water in adults and proportionately smaller, but still substantial, amounts in overweight children. However, in one study, the increase in metabolic rate was minimal; in the other, although the effect was larger, it was shown only briefly.

Only a few pounds

Even if repeated several times a day, researchers estimate that it would result in weight loss of a couple of pounds over a whole year. Other claims that drinking water supports weight loss through washing out fat are not founded on research at all. It seems more likely that if drinking water works, it does so by helping you eat less.

Other studies suggest that consuming more water-rich foods may be even more effective at helping reduce calorie consumption. For example, in a study in which people consumed the same amount of water at a meal as a beverage or in soup, those who ate the water-rich soup consumed fewer calories.

- Information courtesy of the American Institute for Cancer Research

Charlyn Fargo is a registered dietitian at Creators Syndicate writers and cartoonists. Visit Creators Syndicate's website at www.creators.com.