Title: Fruit and ageing
Key words: Blueberries, antioxidants, memory, mobility, polyphenolics, Alzheimers
Date: April 2001
Category: Life changes
Fruit and Ageing
A daily serving of blueberries keeps you young, at least if you're a rat. Animals that ate the fruit recovered some of the coordination normally lost with old age.
James Joseph of Tufts University in Boston was studying antioxidant-rich foods like strawberries, spinach and blueberries. Antioxidants reverse some memory loss linked to old age, probably by mopping up free radicals in the brain.
For eight weeks, Joseph fed supplements of strawberries, spinach or blueberries to three groups of 19-month-old rats-the equivalent of 60 to 65 years old for humans. He then assessed their memories and mobility in standard tests.
All the rats showed improvements in memory compared with rats that were not given antioxidant-rich food to eat. Surprisingly, the rats fed with blueberries also had better balance and coordination in tasks such as running along a rod (The Journal of Neuroscience, vol 19, p 8114).
Joseph suspects that the extra coordination may be due to substances in blueberries called polyphenolics. There is evidence that some of these improve the way neurons signal to each other and also reduce inflammation in the brain linked to age.
Molly Wagster, from the National Institute on Aging near Washington DC, says: "It may have implications not only for normal cognitive motor function, but also for diseases like Alzheimer's."
A taste for naked fruit
Apple slices that taste like pears, and bananas that taste of pineapples can now be made with the help of a food coating developed by Food Science Australia (FSA). The peeled fruit will be coated with an edible film so that it stays fresh and does not turn brown. The first fruit with the coating, Snack Apple made by Westernport Coolstores, went on sale in Australia last week. Four varieties of apple are available, each flavoured with a hint of pineapple.
When fruit is cut open, it goes brown due to oxidation mediated by the enzyme polyphenoloxidase. The new coating, made from a combination of vegetable gums such as pectin and carragenans, and antioxidants such as vitamin C, prevents oxidation by binding to the enzyme and halting the browning reaction.
"What we set out to do was to increase the consumption of fresh fruits," says Vic Reyes from FSA in Melbourne. He says slices of the ready-peeled fruit will appeal to children because they often find a whole apple or orange too large to eat-or too hard to peel. But which fruit gets to taste like another will depend on consumer demand, says Reyes.
From New Scientist magazine, vol 160 issue 2154, 03/10/1998, page 7
© Copyright New Scientist, RBI Ltd 2000