Arterial Fat Buildup: Another Difference Between Men and Women

As if there were not enough differences between men and women, Science News reports on research that appears to demonstrate that before menopause, one of the avenues for clearing meal-derived fats
from the blood operates better in women than in men of the same age.  The story reports that the new finding emerged from a small feeding trial done at the University of Michigan and involving 10 lean
and healthy volunteers—half men, half women. At 6 p.m. on the first
day, each participant was admitted for an overnight stay at the
university’s metabolic-research center. Dieticians carefully tailored a
dinner and a late-evening snack to maintain each recruit’s body weight. Upon rising the following morning, each volunteer received
baseline blood tests followed by an unusual breakfast—liquid whipping
cream sweetened with a sugar substitute. The goal, Science News explains, was to provide a meal with enough fat to
be easily tracked as it moved through biochemical processes in the
body. To facilitate that tracking, the researchers added a tracer
isotope—carbon-13—to the cream so that the triglycerides it passed on
to the volunteers’ bodies could be distinguished from other fats
circulating in their blood. Among the women, triglycerides peaked in blood 2 hours after
the creamy breakfast, and the fat’s blood concentration was back to
prebreakfast readings within 6 hours of eating. In men, however, the
triglyceride rise took roughly twice as long to peak and didn’t return
to each man’s baseline concentration until 9 hours after the meal. Science News reports that the tests showed that this
difference wasn’t because the women broke down the fat more efficiently
or just packaged more of it into other lipoproteins. Instead, for
reasons that remain unknown, the men simply hung on to their
chylomicron triglycerides longer than the women did. Read the whole article.