The popular wisdom has held that obesity after menopause is associated with decline of mental abilities, including memory, language, and thought-processing speed.
But in a study of 300 post-menopausal women included in the Cardiovascular Prevention Program “Corazón Sano,” in Argentina, obese participants in the study performed better on three cognitive tests than participants of normal weight – leading researchers to speculate about the role of sex hormones and cognition.
According to the study’s lead investigator, Judith M. Zilberman, MD, of the Instituto Cardiovascular de Buenos Aires, these results may be attributable to estrogen stored and released by fat cells.
Dr. Zilberman discussed her team’s findings (“Association Between Menopause, Obesity, and Cognitive Impairment”*) Oct 13 at the Physiology of Cardiovascular Disease: Gender Disparities conference, held at the University of Mississippi in Jackson.
The researchers reviewed the records of 678 women participating in the CVD prevention program. Of this number, 300 (44.3%) were identified as having been post-menopausal for at least 1 year. Of this group, 158 women (52.6%) were also classified as obese either because of their waist circumference or body mass index (BMI). The average age of the women in the group was 59.8 years.
Each of the 300 post-menopausal women took three cognitive tests: The Mini-Mental Statement Examination, a common test for evaluating the global cognitive status, a clock-drawing test to determine the women’s executive function (planning, problem-solving, verbal reasoning, etc.); and the Boston Abbreviated Test to assess the women’s memory.
• The researchers found that BMI was positively correlated with higher levels of cognition.
• They also found an equal correlation between obesity-related waist circumference and global cognition.
But where does estrogen fit in?
“Where there is increased adipose tissue, there is increased estrogen,” said Dr. Zilberman. “My hypothesis is that estrogen may be protective of cognitive function in this case.”
According to Dr. Zilberman, the possibility that naturally occurring estrogen from a woman’s own fat cells may help preserve cognition flies in the face of current medical advice.
“Based on previous studies, many research institutions have decided against recommending estrogens as a preventive intervention in cognitive impairment or dementia,” she said. “That’s what makes our findings so important.”
* To receive a copy of Dr. Zilberman’s abstract, contact Donna Krupa at firstname.lastname@example.org or 301 634-7209
Source: American Physiological Society news release, Oct 13, 2011