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Stave off cognitive decline with seafood

Data from 915 older adults (mean age 81.4) participating in the very long-running Rush Memory and Aging Project, has found that those who reported eating seafood less than once a week showed greater cognitive decline compared to those who ate at least one seafood meal per week.

If you flush when you drink alcohol, drinking may increase your risk of Alzheimer’s

Research using human cell cultures and mice suggests that those with an uncommon variation of the aldehyde dehydrogenase 2 gene (ALDH2) may be more at risk of Alzheimer's if they consume alcohol. This gene variation is associated with facial redness following alcohol consumption, reflecting reduced activity of an enzyme that protects against a toxin produced by alcohol consumption (acetaldehyde). Flushing, and inflammation, is a response to the toxin.

Lower tau levels may obscure early Alzheimer’s in black patients

Data from 1,215 older adults, of whom 173 (14%) were African-American, has found that, although brain scans showed no significant differences between black and white participants, cerebrospinal fluid (CSF) showed significantly lower levels of the brain protein tau in African-Americans.

While both groups showed the same (expected) pattern of higher tau levels being associated with greater chance of cognitive impairment, the absolute amounts of tau protein were consistently lower in African-Americans.

More than half of Asian-Americans with diabetes are undiagnosed

Newly available 2011-2012 data from the very large National Health and Nutrition Examination Survey (NHANES) has revealed that Asian Americans have the highest proportion of undiagnosed diabetes among all ethnic and racial subgroups studied, at 51%. Diabetes was also common in Asian Americans, at 21%. The ethnic group with the highest prevalence of diabetes was Hispanic-Americans, at nearly 23%, with 49% of that undiagnosed.

One major reason for the high rate of undiagnosed diabetes among Asian-Americans may be that this group seem to develop type 2 diabetes at a lower body mass index than expected. The American Diabetes Association recommends Asian Americans get tested for diabetes at a BMI of 23 or higher, a lower threshold than the general population.

About 1 in 5 non-Hispanic black adults had diabetes, with 37% undiagnosed. Non-Hispanic whites had the lowest prevalence at 11%, and the lowest proportion of undiagnosed, at just over 32%.

However, overall the prevalence of diabetes has risen among American adults: from nearly 10% in 1988 to over 12% in 2012.

http://www.eurekalert.org/pub_releases/2015-09/niod-mth090315.php

Some people need more exercise to get the same benefits

Your risk of developing type 2 diabetes is about three times greater if someone in your immediate family (parent, sibling) has it. In a study looking at the effects of exercise on this group, it was found that men who have a family member with type 2 diabetes had to expend more energy than a control group, to achieve the same benefits.

The study involved 35 unfit, slightly overweight but completely healthy men aged 30-45 who, for seven months, exercised regularly at a fitness centre. Half of them had relatives with type 2 diabetes, and half did not. (It's perhaps worth noting that 50 men began the study, but didn't continue — these were roughly evenly divided between the two groups.) Three hour-long exercise sessions were available each week, and participants went to 39 sessions on average (the range was large though: 11-107).

Those with family members with diabetes tended to go to the gym more often (group average was 59% more sessions), and this may be due to their increased motivation.

It must be emphasized that both groups lost weight, reduced their waist size, increased their fitness, and showed similar improvements in gene expressions. So exercise was a good idea for both groups. However, statistical analysis indicates that the at-risk group had to do more exercise than the control group to achieve the same benefit. The findings support earlier findings that those with close relatives with type 2 diabetes show smaller physiological changes to exercise, compared to those without such familial links.

http://www.eurekalert.org/pub_releases/2015-10/lu-eig100215.php

Ekman, C., Elgzyri, T., Ström, K., Almgren, P., Parikh, H., Nitert, M. D., … Hansson, O. (2015). Less pronounced response to exercise in healthy relatives to type 2 diabetic subjects compared with controls. Journal of Applied Physiology, 119(9), 953–960. http://doi.org/10.1152/japplphysiol.01067.2014

Type 2 diabetes risk varies with magnesium intake, genes and ethnicity

Studies have found that low levels of magnesium increases the chance that you will develop type 2 diabetes, but a large study shows that this association is modified by genetic variations in magnesium-related ion channel genes. So, for example, among Hispanic American women with high magnesium intake, those with one particular variant had a 35% lower risk of developing type 2 diabetes.

The study involved 7,287 black women and 3,285 Hispanic women aged 50-79.

http://www.eurekalert.org/pub_releases/2015-01/bu-t2d010715.php

http://www.futurity.org/diabetes-magnesium-833412/

Chan, K. H. K., Chacko, S. A., Song, Y., Cho, M., Eaton, C. B., Wu, W.-C. H., & Liu, S. (2015). Genetic Variations in Magnesium-Related Ion Channels May Affect Diabetes Risk among African American and Hispanic American Women. The Journal of Nutrition, 145(3), 418–424. http://doi.org/10.3945/jn.114.203489

Genes involved in familial Alzheimer's disease

Submitted by Fiona McPherson on

Understanding a protein's role in familial Alzheimer's disease

Genetic engineering of human induced pluripotent stem cells has revealed very specifically how a key mutated protein is involved in familial Alzheimer's. Familial Alzheimer’s is a subset of early-onset Alzheimer's disease that is caused by inherited gene mutations.

Brains grow differently in babies with Alzheimer’s gene

Submitted by Fiona McPherson on

A brain imaging study of 162 healthy babies (2-25 months) has found that those who carried the ApoE4 gene (60 of the 162) tended to have increased brain growth in areas in the frontal lobe, and decreased growth in several areas in the middle and rear of the brain (precuneus, posterior/middle cingulate, lateral temporal, and medial occipitotemporal regions) — areas that tend to be affected in Alzheimer’s disease.

One Alzheimer's risk gene may begin to affect brains from childhood

Submitted by Fiona McPherson on

A gene linked to Alzheimer's has been linked to brain changes in childhood. This gene, SORL1, has two connections to Alzheimer’s: it carries the code for the sortilin-like receptor, which is involved in recycling some molecules before they develop into amyloid-beta; it is also involved in lipid metabolism, putting it at the heart of the vascular risk pathway.

Alzheimer's gene worse for women

Submitted by Fiona McPherson on

Analysis of data from more than 8,000 people, most of them older than 60, has revealed that, among the 5,000 people initially tested cognitively normal, carrying one copy of the “Alzheimer’s gene” (ApoE4) only slightly increased men’s risk of developing MCI or Alzheimer’s — but nearly doubled women’s risk (healthy men with APOE4 were 27% more likely to develop MCI or Alzheimer’s compared to those without the gene, while female carriers had an 81% greater risk).