You have probably noticed reports on yet another new study announced this week that seems to suggest that women eating higher amounts of red meat and poultry may be at a higher risk for breast cancer. Although the connection isn’t causative, this study has a twist that is even more confounding: The additional risk is only true for white women, not African-American women.
“Most breast cancer studies have been conducted in [white] women,” senior study author Dr. Elisa Bandera, an epidemiologist at the Cancer Institute of New Jersey, was quoted in an institute news release. “Our study provides new information on the role animal foods play on breast cancer development in women of European and African ancestry.”
Bandera and her fellow researchers used dietary questionnaires completed by 976 black women and 873 white women with breast cancer, and 1,165 black women and 865 white women without cancer. Eating meat raised the risk of breast cancer for white women, but didn’t impact African-American women.
What do we make of this report? Only what the investigators themselves stated in the news release.
Urmila Chandran, the study’s lead author and research teaching specialist, said that, “Being that this study may be one of the first to examine this association in [black] women, results from this group are not conclusive, and more investigation is needed to replicate these findings.”
Changing bad habits
There is another new study on lifestyle habits that is equally urgent and much more conclusive, however, and it is one that doesn’t require more investigation to reach a conclusion.
According to a report released this week at the annual meeting of the American Heart Association, the excessive hours people spend sitting in office chairs or loafing around on their couches tends to increase the deposition of a particularly unhealthy form of fat around the heart.
By itself, that isn’t exactly an earth-shattering revelation. But here’s the bad news: Once that unhealthy pericardial fat builds up, it stays in place even when people exercise regularly.
Using CT scans of more than 500 older Americans, the researchers found that excess time spent sitting was “significantly related to pericardial fat [development] around the heart,” study lead author Britta Larsen, a postdoctoral researcher in the department of cardiovascular epidemiology at the University of California, San Diego, stated in a news release from AHA.
Apparently, sitting is not just the absence of physical activity, according to Larsen and colleagues. It has effects on the body that go beyond lack of exercise.
“Even if you run every day but then you sit for eight hours a day, the sitting is still doing something bad for your health,” she said. The deleterious effect has been noted in other studies, as well—even after factoring out excess weight gain.
The study examined 504 Californian adults, average age 65, using CT scans that showed how much of certain types of body fat were deposited in each participant’s body.
“We looked at subcutaneous fat, [a “pot belly:], then visceral fat around the [internal] organs, intramuscular fat in muscles, chest cavity fat and pericardial fat around the heart,” Larsen said. The participants were also questioned about the amount of time each week they spent sitting and how much time they spent being physically active.
The conclusion: The more time spent sitting, the bigger the amount of fat deposited around a person’s heart, Larsen said, noting that pericardial fat is “strongly related to cardiovascular disease. It gets in the way of heart function, it clogs up the arteries—you don’t want it there.”
She added that people assume that they can exercise away all that pericardial fat, but the study data suggested that while regular exercise helps reduce visceral fat around the organs, which is strongly tied to diabetes and metabolic disease, it does not lessen the build-up of pericardial fat.
“The study emphasized that [sitting and exercise] are two distinct behaviors,” Larsen said. “In order to really be healthy you need to focus on both: get enough exercise but also not sit for 10 hours per day like most of us do.”
We can’t control our ancestry, and although the cancer in white women study is associative, not causative, it underlines the reality that certain genetic traits do pre-dispose people, not to the certainty of disease, but to a higher risk. That’s something we all have to accept.
But risk factors related to lifestyle, as the sitting on your butt study suggests, can be controlled.
Sedentary habits are merely that: habits, and they can be changed.
While we benefit from paying attention to what we eat, we can also benefit by remembering that the human body wasn’t designed to be plopped down on soft chairs and sofas for hours at a time.
I’m typing that sentence sitting in an office chair, but now that this column’s complete, I think I’ll get up and do something a little more active.
You ought to consider doing likewise.
The opinions expressed in this commentary are solely those of Dan Murphy, a veteran food-industry journalist and commentator.