Do hormone levels in postmenopausal women affect cognitive function? New research sheds light on the postmenopausal brain.

In a recently published study, researchers found that estrogen levels after menopause may have no impact on cognitive skills, but progesterone levels might. Progesterone had some association with global cognition and verbal memory among newly postmenopausal women.

643 healthy postmenopausal women were part of the study, ranging from 41 to 84 years old. Neuropsychological tests were done to assess cognition and memory, and hormone levels were determined including estradiol, estrone, progesterone, and testosterone. The findings showed no association between estrogen and cognitive skills. However, women with higher levels of progesterone had better outcomes on the verbal memory and global cognition tests, particularly in those who had started menopause less than six years prior. None of the hormones appeared to have any association with depression or mood either.

More research must be done to confirm the new findings regarding progesterone levels. Also, there is no way to directly measure hormone concentrations at the brain level, but this research implies that estrogen therapy may not have a significant effect on cognitive skills. To learn more about when hormone therapy is beneficial , visit Northwestern's menopause website here.

Source reference: Henderson VW, et al "Cognition, mood, and physiological concentrations of sex hormones in the early and late menopause" PNAS 2013; DOI: 10.1073/pnas.1312353110.

Eating fish at least once a week could help lower older patients' risk of developing dementia, according to Cyrus Raji, MD, PhD, from the University of Pittsburgh and colleagues reported at the Nov. 2011 Radiological Society of North America meeting.

Those who ate baked or broiled -- but not fried -- fish on a weekly basis had a greater volume of gray matter in areas of the brain associated with Alzheimer's disease than people who didn't eat fish as often.  Preserving brain volume was also associated with lower rates of developing cognitive impairment, he said.

"Fish consumption benefits gray matter volume, potentially reducing the risk of [Alzheimer's disease and dementia] long-term," Raji said during a press briefing.

Although a National Institutes of Health panel decided last year that nothing conclusively prevents Alzheimer's disease, researchers continue to investigate whether a healthy diet, or specific components thereof, can have any beneficial effects.

For their study, Raji and colleagues assessed 260 people, mean age 71, when they enrolled in the Cardiovascular Health Study between 1989 and 1990. At that time, they filled out questionnaires on dietary intake; 163 reported eating fish at least weekly, and some did so as often as four times a week.

All patients had an MRI 10 years later to assess brain volume, and then had follow-up cognitive testing between 2002 and 2003.

The researchers found that patients who ate fish at least once a week had greater volume in the frontal lobes and the temporal lobes, areas responsible for memory and learning, which are severely affected in Alzheimer's disease, Raji said.

Five years after the MRI, they found that 30.8% of patients who had low fish intake had developed mild cognitive impairment or dementia, compared with just 3.2% of those who had the highest fish intake and the greatest preservation of brain volume.

They also saw that 47% of patients with brain atrophy who didn't eat fish had abnormal cognition five years later compared with 28% of those who ate more fish and had more gray matter volume, Raji reported. "That's an impressive reduction in the risk of developing mild cognitive impairment of Alzheimer's," Raji said.

In further analyses, the researchers found that mean scores for working memory -- a function severely impaired in Alzheimer's disease -- were significantly higher among those who ate fish weekly and those findings persisted even after accounting for potential confounders.

This "simple lifestyle choice" of eating more fish increases the brain's "resistance" to Alzheimer's disease, Raji said, potentially via a few mechanisms: Fish are rich in omega-3 fatty acids, which can help increase blood flow to the brain and can also act as an antioxidant, thereby reducing inflammation, he said.

Omega-3s may also prevent the accumulation of amyloid plaques in the brain, he added.   He noted that fatty fish like salmon have more omega-3s, while smaller fish, such as cod, have less.

Although dietary intake of fish was measured only twice -- once at baseline and again in 1995 -- Raji said patients tended to maintain their levels of consumption, and he suspects that the observed benefits "are more likely to be observed if eating fish is a long-term habit as opposed to a short-term approach."

Mary Mahoney, MD, of the University of Cincinnati, who was not involved in the study, said that future studies should investigate whether omega-3s specifically are leading to benefits in brain volume.

"We're making the assumption" that fish is a marker for healthy lifestyle, she said. "If we could just cut to the chase and look at the protective mechanism, that would be better."

It's important to note  that the findings are preliminary and should be replicated in a larger sample and sex differences should be included since Altzeimer's is more prevalent in women.  In the meantime, it can't hurt to add fish to your diet...for many reasons!

Source reference:
Raji C, et al "Fish consumption, brain structure, and risk of Alzheimer's disease" RSNA 2011.

Scientists have discovered four new genes associated with an increased risk of late-onset Alzheimer’s disease. The findings will help researchers explore new therapies and allow doctors to better predict who will develop the disease.

The Alzheimer’s Disease Genetics Consortium conducted the research in collaboration with 44 different universities and research centers, including Northwestern University. The study, published in the current issue of Nature Genetics, is the largest of its kind.

The results of the study double the number of genes currently known to contribute to Alzheimer’s. Of the four genes previously confirmed, the gene for apolopoprotein E-e4, called APOE-e4, has the largest effect on risk. The genes discovered in this study are called MS4A, CD2AP, CD33 and EPHA1.

Alzheimer’s disease affects more than 13 percent of people age 65 and older and nearly half of those 85 and older. Women are more likely than men to have this common form of dementia, possibly because women have a higher life expectancy.

Although there are currently no effective treatments or preventative measures for Alzheimer’s, the ability to predict who will develop the disease will be important when preventative steps become available. The findings will also help researchers identify the disease’s earliest stages and understand the events leading to brain damage. Alzheimer’s is associated with the destruction of large parts of the brain and is characterized by the loss of cognitive abilities, including memory loss and intellectual decline.

Alzheimer's disease affects twice as many women as it does men, according to a new report that portrays women as being "under siege" by the dreaded condition.

Created in conjunction with California first lady Maria Shriver, "The Shriver Report: A Woman's Nation Takes on Alzheimer's" shows that two-thirds of the people living with Alzheimer's are women, and 60 percent of Alzheimer's caregivers are women.  Shriver became involved in the issue when her father, Sargent Shriver, 94, was diagnosed with the disease in 2003.

The report finds that primary caregivers to Alzheimer's patients are six times more likely to develop the disease, or other forms of dementia, themselves, in part because of the emotional stress and physical demands of providing care to relatives and loved ones.

The estimated societal impact of the disease on government and businesses is $300 billion a year, according to the report.

Scripps Howard News Service