Soy isoflavones in the elderly
 The benefits of isoflavone depend on converting soy foods and supplements to biologically active compounds such as equol, which occurs in the intestines and is altered by age-associated conditions.
Researchers from the University of Wisconsin in Madison studied the effects of soy in older nondemented men and women.
First, the details.
- A group of elderly men and women (62 to 89 years old) ingested 100 mg/day soy isoflavones or matching placebo tablets for 6 months.
- Neither the participants nor the researchers knew the treatment given — double-blind.
And, the results.
- Blood levels of genistein and daidzein (the major phytoestrogens in soy) increased significantly.
- Blood levels of equol (an isoflavone converted from daidzein by bacteria in the intestines) didn’t.
- While similar at the start, the groups differed over 6 months of treatment on 8 of 11 cognitive (reasoning) tests.
- Those taking isoflavone significantly improved on tests of visual-spatial memory (the ability to mentally manipulate 2- and 3-dimensional figures) and construction, verbal fluency, and speeded dexterity.
- But placebo-treated participants were faster in tests of executive function (carrying out, implementing, administering orders).
- The groups had similar side-effects.
The bottom line?
In addition to being well tolerated, the authors concluded that the “data support the potential cognitive effects of soy isoflavones in older adults.”
12/14/08 21:40 JR
