Study sheds light on men’s vs. women’s response to food

Maybe it really is a guy thing.

Men appear to be better than women at controlling their brain’s response to their favorite foods, a unique brain-imaging study has found. The results were published online this month in the Proceedings of the National Academy of Sciences journal.

The researchers who led the study believe the findings might help explain why women have higher rates of obesity and eating disorders than men do, and why women often have a harder time losing weight.

The study was conducted at the U.S. Department of Energy’s Brookhaven National Laboratory and involved 23 volunteer subjects – 13 women and 10 men who underwent positron emission tomography scanning of the brain.

During one set of scans, they were presented with their favorite foods, such as pizza, warm cinnamon rolls or barbecued ribs, and asked to smell, taste, observe and react to the food but not eat it. During another set of scans on a separate day, they were told to inhibit their desire for food before being tempted with the same foods. Control scans also were conducted with no food.

The volunteers were also asked to rate the food and describe their feelings of hunger and desire to eat during the scans when food was present.

Among both men and women, several brain areas associated with emotional regulation, conditioning and motivation lit up in response to tempting foods, indicating increased brain activity. When asked to inhibit their response to food, both men and women described themselves as less hungry – but only the men showed a corresponding decrease in food-activated brain activity. Among the women, activity could still be seen in regions of the brain that control the drive to eat.

The study did not explore possible reasons for this gender difference, although the researchers speculated that differences in sex hormones, such as estrogen, might play a role.

The authors said their findings are consistent with behavioral studies showing women are more likely than men to overeat when they’re presented with tempting food or are under emotional stress.

Weighing in on the Hib vaccine

Last week’s news story about a resurgence of Haemophilus influenzae B in Minnesota is reverberating around the medical blogosphere.

Should parents be held accountable for not vaccinating their children against Hib (or other vaccine-preventable diseases, for that matter)?

Dr. Rob Lamberts, a pediatrician who blogs at Musings of a Distractible Mind, thinks so:

These parents probably thought “what’s the harm? Why can’t we just wait to do the immunizations until the risk is less?” A 7-month-old infant died from this logic.

WhiteCoat, an emergency room physician who blogs, puts the question to his readers, who respond with some choice comments about parents who refuse to vaccinate. "This issue is one that makes me almost homicidal with rage," one person writes.

And here’s Sandy Szwarc at Junkfood Science:

Today, most younger doctors and nurses have never even seen a case of Hib and few parents have watched babies get sick or die from Hib. So, Hib might not seem a big deal. We can only hope that we can reach young parents and help them understand why it is a big deal and why it is important to get their babies vaccinated.

 

To be sure, the underlying shortage of Hib vaccine remains an issue. Even when parents are willing to have their child vaccinated, they can be stymied by a lack of vaccine.

And it’s somewhat alarming to note that because of the cost associated with buying and administering vaccines, some primary care doctors are giving serious thought to not offering children’s vaccines anymore. The study, reported last month in the Pediatrics journal, notes, "Although large-scale withdrawal of immunization providers does not seem to be imminent, efforts to address root causes of financial pressures should be undertaken."