New studies improves carotenoid-cancer understanding
partly responsible for the protective effects of fruits and
vegetables against colon cancer. But there is little known about
the antioxidant impact of carotenoid-rich foods in the
gastrointestinal tract, report German researchers who set out to
investigate the effect.
In a small study published in the May issue of the Journal of Nutrition (134:1081-1083) on 22 men, the scientists measured the antioxidant impact of tomato juice and carrot juice.
Antioxidant capacity was assessed by the "lag time" of ex vivo LDL oxidation induced by copper and lipid peroxidation as determined by measurements of malondialdehyde (MDA) in plasma and faeces using HPLC with fluorescence detection.
"Although consumption of both carotenoid-rich juices for two weeks increased the carotenoid level in plasma and faeces, the antioxidant capacity of LDL tended to be increased by only 4.5 per cent, and lipid peroxidation in the men's plasma and faeces was not affected," report the researchers at the Institute of Nutritional Physiology, Federal Research Centre for Nutrition and Food in Karlsruhe, Germany.
They conclude that processes, other than lipid peroxidation, could be responsible for the preventive effects of tomatoes and carrots against colon cancer. Lipid peroxidation is a well-established mechanism of cellular injury in both plants and animals, and is used as an indicator of oxidative stress in cells and tissues.
The growing consumer demand for fortified foods and functional foods has triggered an increase in use of carotenoids, still primarily used as colouring agents, by the food industry for their antioxidant properties. In addition to the preventative effect on heart disease and certain cancers, carotenoids have been shown in some studies to reduce the risk of degenerative diseases, such as age-related macular degeneration.
A report from market research firm Frost & Sullivan pitches the current carotenoid market in the region of $348.5 million (€291.4m), tipped to grow to $419.6 million in 2010. Revenue expansion is projected to be driven by an emphasis on personal health combined with the rising interest in preventative health measures by Europe's ageing population.
According to the report, the low level of public awareness about the health benefits of carotenoids is expected to stifle market growth in the short term and the challenge to educate consumers will be made more difficult by forthcoming European Union legislation designed to clamp down on misleading health claims. European carotenoid makers are also facing the rising threat from Chinese and Indian manufacturers.
