Readers respond to articles about exercise and dementia, a long-time prof and a royal visit
Don’t Discourage Exercise
We were dismayed to read “Don’t Overdo It!” (Spring 2011), which suggests that women who exercise strenuously may be at greater risk of developing dementia later in life. After reading the source research paper, by Prof. Mary Tierney, we are shocked that anyone would recommend reducing the intensity of activity on the basis of such uncertain results.
The study found weak to moderate correlations between reported physical activity and neuropsychological test scores among 90 women. A questionnaire asked the women to recall participation in strenuous activities (such as swimming laps or aerobics) and moderate activities (such as brisk walking or volleyball) from high school to menopause. This measure, however, has not been validated and reports an average of 2.5 hours of strenuous activity per week – well beyond the average amount of vigorous activity (less than 0.5 hours per week for women ages 20 to 60) reported in the Canadian Health Measures Survey.
Moreover, other research rejects increased risk with more activity. Middleton and colleagues studied more than 9,000 women and found lifetime activity actually reduced the risk of cognitive impairment. The amount of exercise had no effect. Another study of 1,880 people, by Scarmeas et al., found that the risk of Alzheimer’s decreased by 25 per cent with some activity and by 33 per cent with much activity.
While U of T alumni appreciate lively stories of interesting research, they also appreciate nuanced discussions of careful, well-developed research – not to mention a balanced exploration of both sides of an issue. Responsible research requires much more substantive evidence before we can make a public recommendation.
Prof. Scott Thomas and Dr. Doug Richards
Faculty of Physical Education and Health University of Toronto
A Questionable Link
I was surprised by the discussion in “Don’t Overdo It!” regarding the relationship between exercise and neuropsychological test scores, which identified estrogen deficiency as the possible mechanism. Data have demonstrated that exercise itself is not the primary cause of menstrual-cycle dysfunction; rather, it is exercise in the presence of an energy deficiency that can lead to menstrual-cycle abnormalities and estrogen deficiency. There is no supporting evidence that these women suffered from lower estrogen over their lifetime.
Sarah L. West
Prof. Mary Tierney responds:
Prof. Thomas and Dr. Richards express concern that we found “weak to moderate correlations” between reported physical activity and cognition. In fact, we found significant regression coefficients, which indicated that greater amounts of strenuous activity were significantly associated with poorer performance on five of our six neuropsychological tests.
Thomas and Richards refer to two studies that supposedly refute our findings. However, Middleton et al. acknowledge that their cognitive measure was a very insensitive tool and unable to detect a response to exercise dose. We, on the other hand, used highly sensitive measures of cognitive function that allowed us to detect this relationship. Scarmeas et al. studied only older men and women and their likelihood of developing dementia whereas our study examined lifetime exposure to physical activity in women before menopause. Therefore, the two studies are not comparable to ours.
While we recognize that our measure has not been validated and is a limitation, the measure we used was the same one used in a study of 110,599 California teachers (Dallal et al.). Consistent with this study, we reported 2.5 hours of strenuous activity per week. Although this is beyond the 0.5 hours per week reported in the Canadian Health Measures Survey, our sample included healthy, well-educated women, who are known to engage in more physical activity (for example, Lee et al.). The authors of the Canadian Health Measures Survey also caution that this tool is likely to underestimate vigorous activity.
On the issue of estrogen, lower estrogen was only one mechanism we used to explain the negative associations between lifelong strenuous activity and cognition. This is the same mechanism used to explain why strenuous activity reduces the risk of breast cancer. The other proposed mechanism was long-term elevations in circulating glucocorticoid levels, known to be toxic to the brain. We are not proposing that lower estrogen causes menstrual-cycle abnormalities as only 11 women in our sample reported amenorrhea for short durations.
I was delighted to pick up the spring issue and see the face of a man with whom I have had no contact for some 55 years: Prof. Michael Hare (“A Capital Achievement”).
It was my privilege to be acquainted with Mike from 1951 to 1955, while we were enrolled in commerce and finance at U of T. We spent much of our time in the bowels of what was formerly the economics building, on Bloor Street. We last spoke at a classmate’s wedding that we attended together shortly after our graduation.
My clearest memories of Mike are his attempts to explain economic theory to me in our graduating year. I must say that he was not entirely successful, but I did manage to graduate.
I ascertained from the article that he has refined his teaching skills over the years, imparting his vast knowledge to more than 32,000 students.
I can only hope that he and I will meet at least once more, with our remaining classmates, perhaps, at our 60th class reunion in 2015!
Morton (Morty) Eisen
Criticisms, or Curios?
Most government ministers are capable of earning brickbats, but it takes Foreign Affairs Minister John Baird to up the stakes to “bric-a-bracs,” as reported by Andrew Mitrovica in “True North” (Spring 2011).
Diminishing the Past
I was astonished to read in the spring issue that the visit of King George VI and Queen Elizabeth to the university in 1939 is to be considered a “more minor royal event” than the marriage of Prince William to Kate Middleton. Whether one is a monarchist or not, it should be obvious that a visit by the then-reigning monarch was a very major event – considerably more so than watching the marriage, via television, of a prince who is not even the heir to the throne. Maybe members of your staff should take a course in constitutional history.
BA 1952 Victoria
Group of Eight
I wish to correct an error that appeared in the article “Body Double” (Spring 2011). Although he worked closely with the seven artists during his lifetime, Tom Thomson was not a Group of Seven artist. The original members named themselves the Group of Seven in 1920, three years after Thomson died.
BA 1948 Victoria
The spring issue touts your new typefaces as “highly legible . . . for readers of all ages.” One of them has “subtle quirks.” These subtle quirks make it almost illegible for readers of old age. The print in the sidebars is microscopic, and the non-white background adds to the problem. We older graduates may have eye problems, but we like to read – if editors allow it.
BA 1950 Victoria