There is a new study out that is getting a lot of media attention. The conclusion of this study:
High vegetable but not fruit consumption may beassociated with slower rate of cognitive decline with older age.
One should never get too excited about the results of any one study. Still, this is a serious piece of work done by the Rush Institute for Healthy Aging in Chicago.
There is some concern since, as far as I can see, the study did not attempt to control for other “healthy lifestyle” indicators. In other words, people who eat more vegetables may be focused on health and so might exercise frequently or drink red wine or do crossword puzzles to keep the mind active — and this might be the cause of slower cognitive decline, not vegetables.
This is why the study conclusion identifies only association, not causality, between vegetable consumption and slower mental decline.
The spinach industry gets a much needed boost from the study, as Fox News reports:
Green leafy vegetables, including spinach, kale and collards, appeared to be the most beneficial. The researchers said that may be because they contain healthy amounts of vitamin E, an antioxidant that is believed to help fight chemicals produced by the body that can damage cells.
Although this particular study focused on older people, the study may have implications for our efforts to help children to eat more produce. In an exchange with Bryan Silberman in PRODUCE BUSINESS last year, the Pundit pointed out that we need to focus on getting children to eat vegetables, but many of the efforts to increase produce consumption focus on snack fruit.
Another interesting thought derived from this study is that various efforts to reduce obesity, which include things such as fat-free dressings and not using dressing but just a little lemon juice, may deprive consumers of healthy fats important to realize the benefits this study associates with vegetable consumption:
Vegetables generally contain more vitamin E than fruits, which were not linked with slowed mental decline in the study. Vegetables also are often eaten with healthy fats such as salad oils, which help the body absorb vitamin E and other antioxidants, said lead author Martha Clare Morris, a researcher at the Rush Institute for Healthy Aging at Chicago’s Rush University Medical Center.
All this really goes to show the limits of association studies. People who eat lots of salad, in general, eat lots of salad dressing. Which means that, for all we know, the beneficial effects observed to be associated with salads may really be associated with salad dressing!
