Eating fish reduces risk of Alzheimer’s disease

People who eat baked or broiled fish on a weekly basis may be improving their brain health and reducing their risk of developing mild cognitive impairment (MCI) and Alzheimer’s disease, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

“This is the first study to establish a direct relationship between fish consumption, brain structure and Alzheimer’s risk,” said Cyrus Raji, M.D., Ph.D., from the University of Pittsburgh Medical Center and the University of Pittsburgh School of Medicine. “The results showed that people who consumed baked or broiled fish at least one time per week had better preservation of gray matter volume on MRI in brain areas at risk for Alzheimer’s disease.”

Alzheimer’s disease is an incurable, progressive brain disease that slowly destroys memory and cognitive skills. According to the National Institute on Aging, as many as 5.1 million Americans may have Alzheimer’s disease. In MCI, memory loss is present but to a lesser extent than in Alzheimer’s disease. People with MCI often go on to develop Alzheimer’s disease.

For the study, 260 cognitively normal individuals were selected from the Cardiovascular Health Study. Information on fish consumption was gathered using the National Cancer Institute Food Frequency Questionnaire. There were 163 patients who consumed fish on a weekly basis, and the majority ate fish one to four times per week. Each patient underwent 3-D volumetric MRI of the brain. Voxel-based morphometry, a brain mapping technique that measures gray matter volume, was used to model the relationship between weekly fish consumption at baseline and brain structure 10 years later. The data were then analyzed to determine if gray matter volume preservation associated with fish consumption reduced risk for Alzheimer’s disease. The study controlled for age, gender, education, race, obesity, physical activity, and the presence or absence of apolipoprotein E4 (ApoE4), a gene that increases the risk of developing Alzheimer’s.

Gray matter volume is crucial to brain health. When it remains higher, brain health is being maintained. Decreases in gray matter volume indicate that brain cells are shrinking.
The findings showed that consumption of baked or broiled fish on a weekly basis was positively associated with gray matter volumes in several areas of the brain. Greater hippocampal, posterior cingulate and orbital frontal cortex volumes in relation to fish consumption reduced the risk for five-year decline to MCI or Alzheimer’s by almost five-fold.

“Consuming baked or broiled fish promotes stronger neurons in the brain’s gray matter by making them larger and healthier,” Dr. Raji said. “This simple lifestyle choice increases the brain’s resistance to Alzheimer’s disease and lowers risk for the disorder.”
The results also demonstrated increased levels of cognition in people who ate baked or broiled fish.
“Working memory, which allows people to focus on tasks and commit information to short-term memory, is one of the most important cognitive domains,” Dr. Raji said. “Working memory is destroyed by Alzheimer’s disease. We found higher levels of working memory in people who ate baked or broiled fish on a weekly basis, even when accounting for other factors, such as education, age, gender and physical activity.”
Eating fried fish, on the other hand, was not shown to increase brain volume or protect against cognitive decline.

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New method of nerve stimulation developed

Better Electrical Stimulation Could Help Damaged Nerves

Functional electrical stimulation (FES) was developed to help return lost function to patients with upper and lower extremity injuries and spinal cord injuries, among other applications. However, the devices, which work by stimulating neuronal activity in nerve-damaged patients, have a potential shortcoming in that the electrical currents needed for the treatment to work can also send errant signals to surrounding nerves, resulting in painful side effects.

Earlier this fall, a plastic surgery research team at Beth Israel Deaconess Medical Center (BIDMC) and an engineering team from the Massachusetts Institute of Technology (MIT), described a new method of nerve stimulation that reduces the device’s electrical threshold by 40 percent, compared with traditional FES therapy. Reported in the October 23 Advance On-line issue of the journal Nature Materials, the findings could help researchers develop a safer, more efficient FES therapy with fewer side effects.

“This new device works by manipulating the concentration of charged ions surrounding the nerve,” explains co-senior author Samuel J. Lin, MD, a surgeon in BIDMC’s Divisions of Plastic Surgery and Otolaryngology and Assistant Professor of Surgery at Harvard Medical School. “This could potentially mean reduced risk to surrounding nerves because less electrical current is required to stimulate the affected nerve.” The researchers additionally discovered that they could use the device to block signals in nearby nerve fibers, which could help prevent unwanted muscle contractions.
The research team, led by Lin and MIT Associate Professor Jongyoon Han, PhD, determined that by altering calcium ion concentrations in the fluid surrounding the nerves they could adjust the electrical impulses.
“Nerve fibers fire their signals based on the message they receive from the interaction of ions, or charged particles,” explains coauthor Ahmed M.S. Ibrahim, MD, a Research Fellow in BIDMC’s Divisions of Plastic Surgery and Otolaryngology. “We wanted to achieve the lowest current possible that would still result in positive results.” After testing the manipulation of sodium and potassium ions, the researchers determined that consistent results could be achieved by removing positively charged calcium ions from the fluid surrounding the nerves.

The newly designed method not only prevents electrical impulses from traveling along a nerve but also uses significantly less current required by existing FES therapy. “This could be of particular benefit for the treatment of patients with various forms of paralysis,” explains Lin. “The nerves that control movements and the sensory nerves that carry pain signals are extremely close together, so existing FES therapy has had limitations.”
The researchers conducted their study of this new electrochemical-stimulation method in the nerves of frogs and plan to later test it in mammalian nerves.

“This is an important step towards the design of a device to help patients suffering from nerve paralysis and chronic neurological conditions,” say Lin. “By bringing together biomedical and engineering research teams we have been able to successfully develop this new technique. Going forward, these types of collaborations will be absolutely crucial to creating new clinical treatments and enhancing patient care.”
In addition to Lin, Han and Ibrahim, study coauthors include Rohat Melik of MIT, Amr N. Rabie of BIDMC and Ain Shams University, Cairo, Egypt; David Moses of Rice University, Houston, TX; and Ara Tan of the University of Minnesota.
This study was supported, in part, by a Harvard Catalyst grant from the Harvard Clinical and Translational Science Center (National Institutes of Health) and the Massachusetts Institute of Technology.

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Study connects religious service attendance to less depression

A new study published in the Journal of Religion and Health has connected the regular attendance of religious services with an increased level of optimism and a decreased risk of depression.

As a follow-up to a 2008 report from the Women’s Health Initiative that showed regular attendance of religious services increased life expectancy, this new study looked at 92,539 post-menopausal women over the age of 50. The religious affiliations of all the participants, as well as their social and economic statuses, were diverse.

Led by Eliezer Schnall from the Yeshiva University in Manhattan, the results showed that out of the participants that attended services regularly, 56 percent were more likely to be optimistic about their lives. It also showed that 27 percent of the participants were less likely to be depressed than those who did not attend services regularly.

Of those that were included in the research, 34 percent of the women said they had not attended services within the last month. Of those that attended, 21 percent were less than once a week, 30 percent were weekly and 14 percent attended activities more than once a week.

After the 2008 study showed that regular attendance of religious services by women reduced their risk of death by 20 percent, the researchers wanted to see what factors may contribute to that risk reduction and believe they could be related to psychological factors. The Women’s Health Initiative study began in 1991 and is funded by the U.S. National Institutes of Health in an effort to track women’s health and habits.

Schnall cautions that these results and their study apply only to women, and older women at that. The benefit of regular religious service attendance by younger women or men has not been looked at in this study. Past research has shown that older women tend to take more of a social role in religious activities and may gain the most from it.

Abstract

Measures of religiosity are linked to health outcomes, possibly indicating mediating effects of associated psychological and social factors. We examined cross-sectional data from 92,539 postmenopausal participants of the Women’s Health Initiative Observational Study who responded to questions on religious service attendance, psychological characteristics, and social support domains. 

We present odds ratios from multiple logistic regressions controlling for covariates. Women attending services weekly during the past month, compared with those not attending at all in the past month, were less likely to be depressed [OR = 0.78; CI = 0.74–0.83] or characterized by cynical hostility [OR = 0.94; CI = 0.90–0.98], and more likely to be optimistic [OR = 1.22; CI = 1.17–1.26]. 

They were also more likely to report overall positive social support [OR = 1.28; CI = 1.24–1.33], as well as social support of four subtypes (emotional/informational support, affection support, tangible support, and positive social interaction), and were less likely to report social strain [OR = 0.91; CI = 0.88–0.94]. However, those attending more or less than weekly were not less likely to be characterized by cynical hostility, nor were they less likely to report social strain, compared to those not attending during the past month.

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