Recent studies on carotenoids, used extensively in the food industry as a colouring agent, show that these antioxidants may reduce the risk of degenerative diseases, such as age-related macular degeneration. They are also linked to a preventative effect on heart disease and certain cancers.
But Europe's health food industry has 'under-utilised' the nutraceutical properties of carotenoids and consumers are still unaware of their health benefits, showed a recent report from market analysts Frost & Sullivan on the $348.5 million (€291.4m) carotenoid market.
But findings from this latest study on carotenoids, published in the August 2004 issue of the American Journal of Clinical Nutrition, could offer more opportunities for food manufacturers in the sauce and dressing sectors looking to slice into the burgeoning health market.
For the study seven participants each consumed three salads consisting of equivalent amounts of spinach, romaine lettuce, cherry tomatoes and carrots, with salad dressings containing 0g, 6g or 28g of canola oil.
The salads were consumed in random order separated by washout periods of two weeks and blood samples were collected hourly from midnight to midday.
Chylomicrons were isolated by ultracentrifugation, and carotenoid absorption was analyzed by HPLC with coulometric array detection.
The scientists - from the Department of Food Science and Human Nutrition at Iowa State University, Ohio State University, Columbus, and The Procter & Gamble Nutrition Science Institute in Cincinnati - found a marked difference in carotenoid (carotene, ß-carotene, and lycopene) absorption when participants ate the fat-free, reduced-fat or full fat dressings.
"Essentially no absorption of carotenoids was observed when salads with fat-free salad dressing were consumed. A substantially greater absorption of carotenoids was observed when salads were consumed with full-fat rather than reduced-fat salad dressing," they reported.
This latest research (American Journal of Clinical Nutrition, Vol. 80, No. 2, 396-403, August 2004) links up with additional findings, not yet published but presented at the Institute of Food Technologists (IFT) annual meeting last month, that suggested avocados act as a "nutrient booster", allowing the body to absorb significantly more nutrients like alpha-carotene, beta-carotene and lycopene found in fruits and vegetables.
Dr. Steven Schwartz from Ohio State University who participated in research for both studies commented: "Many fruits and vegetables are rich in beneficial carotenoids, but most fruits and vegetables are virtually fat free, which may limit the body's ability to absorb some of these nutrients. Our latest research shows that the natural fat content in avocados increases carotenoid absorption, which offers nutritional advantages over other sources of fat like salad dressings."
In the Ohio State Study, adult men and women consumed salads and salsa with and without fresh avocado. The subjects, report the scientists, who consumed a lettuce, carrot and spinach salad containing 75g of avocado (equivalent to 2.5 tablespoons) absorbed 8.3 times more alpha-carotene and 13.6 times more beta-carotene, both of which help protect against cancer and heart disease. The subjects also absorbed 4.3 times more lutein, believed to contribute to eye health and protect against macular degeneration, the leading cause of blindness in the elderly.
Subjects, claim the Ohio researchers, who consumed salsa with 150g of avocado absorbed 4.4 times more lycopene, which has been linked to prostate cancer protection, while absorption of beta-carotene doubled.