BODY AND BRAIN
Healthy Hearts and Minds
New research shows that the pitter-patter of the heart could determine how quickly the brain ages. In a study of more than 1,500 men and women ages 34 to 84, scientists found that people with weakly pumping hearts had decreased brain volume--a marker of brain aging--compared with those with more vigorous hearts. In magnetic-resonance-imaging scans, the brains of volunteers with the lowest cardiac index--a measure of how much blood is pumped from the heart relative to body size--appeared two years older than those of participants in the highest-cardiac-index group.
What surprised the scientists further was that even people whose cardiac index fell within the normal range had diminished brain size compared with people with the healthiest hearts. That means that even small reductions in blood flow to the brain may speed aging and potentially compromise cognitive function. More research is needed to confirm the findings and to determine whether the threshold for a healthy cardiac index should be shifted when considering brain age. "This [range] may be appropriate for cardiac health, but it may be different for brain health," notes the study's lead author, Angela Jefferson, a neurologist at Boston University.
The Legacy of Pregnancy Pounds
Your risk of obesity may develop well b efore birth--in the womb. Mothers who gain more weight during pregnancy tend to give birth to heavier babies, and high birth weight is associated with later obesity and diseases like cancer. But until now, it hasn't been clear why extra maternal weight leads to big babies. Is it the added pounds themselves, or are there genetic or lifestyle factors common to mom and baby that contribute to the trend?
For the answer, scientists at Children's Hospital Boston and Columbia University looked at women who had two or more singleton births between 1989 and 2003. By comparing pregnancies in the same women over time, researchers could better isolate the effect of their weight. When women put on more than 53 lb. (24 kg) during pregnancy, they were more than twice as likely to deliver a high-birth-weight baby than when they gained 18 to 22 lb. (about 8 to 10 kg).The more women gained, the heavier their babies were. (Doctors recommend that normal-weight moms-to-be add 25 to 35 lb., or about 11 to 16 kg, during their nine months.)
Animal studies suggest that excess gestational weight can cause hormonal changes in the fetus that affect fat development. Experts believe the same mechanisms may be at work in humans and that the new study highlights an earlier chance to combat obesity--during pregnancy.
FROM THE LABS
Harbinger of Cancer
a common mineral could predict how aggressive a breast tumor will be and how likely it is to recur after treatment. Researchers found that the most active tumors have low levels of a protein that regulates iron, leading them to speculate that in the future, women might be tested for the protein, and those with higher levels could be spared such invasive treatments as chemotherapy and radiation.
Preparing for H1N1