Life sometimes foils the best of our intentions.
New research on women, stress and diet amply illustrates that sad fact. It shows that even when women greeted a new day with a "better-for-you" fast-food breakfast, that meal's expected health-promoting qualities were washed away by the carry-over effects of yesterday's stresses.
For women who reported experiencing no stress on the day before they showed up to participate in a study, eating a breakfast formulated with healthy fats paid handsome dividends: Compared with women who got a breakfast larded with saturated fat, after eating, these women saw no jump in several markers of inflammation — measures that are strongly linked to a wide range of diseases.
But suffering a day of stresses — serious financial worries, a child's health scare, the need to be in two places at one time — erased the difference between women who got healthy fats and those who got fats more commonly linked to heart disease.
Those findings, reported Tuesday in the journal Molecular Psychiatry, help illuminate the complex interactions between what we eat, how we live and whether we develop chronic diseases such as diabetes, heart disease or depression. At the core of this nexus is inflammation — a normal, healthy immune response when it's in check; a harbinger of trouble when it's chronically out of control.
By promoting clotting and the aggregation of other potential trouble-makers in the bloodstream, inflammation is widely seen as a risk factor for cardiovascular disease, metabolic dysfunctions, certain cancers and brain disorders ranging from depression to dementia. Though its exact role in such diseases is unclear, "it is not an innocent bystander," said Janice Kiecolt-Glaser, director of Ohio State University's Institute for Behavioral Medicine Research and the study's lead author.
So when markers of inflammation are driven up or down by what we eat and how we live, it offers scientists some insights into the mechanisms by which chronic inflammation does damage. And it offers those looking for better health some clear guidance about what to embrace and what to avoid.
In the current study, Kiecolt-Glaser and her team put 58 healthy women (with an average age of 53) through a battery of tests before and after they were assigned to one of two groups on two separate visits: After a day in which all participants got the same meals to eat at home, the women arrived to the study site and were assigned to get one of two meals, both of them a high-calorie (930 calories), high-fat (60 grams) breakfast of eggs, turkey sausage, biscuits and gravy. One group's breakfast was made the typical fast-food way, prepared in butter and very high in saturated fats. The second group of women got the same breakfast prepared with sunflower oil: Though still a dense, filling meal, the second group's breakfast leaned more heavily on the kinds of unsaturated fats that are a central component of what's called a "Mediterranean diet."
Before and after their meals, the women had their blood drawn to measure four different markers of inflammation. They were asked to detail the events of the previous day, including any stressors. Their blood pressure was measured, and all the women's current symptoms and past history of depression were measured and recorded.
Kiecolt-Glaser, a pioneer in the field of psychoneuroimmunology, said the kinds of stresses that erased the positive effects of the "healthier-for-you" breakfast were not life-changing. But neither, she said, did they amount to "a bad hair day." Women described having to scramble to ensure that work obligations didn't leave kids or spouses in the lurch. They described mid-sized household disasters and caring for recalcitrant older parents. In a group of 58 women, 31 reported at least one recent stressor at one visit, 21 at both visits. Six women reported no stressors at either visit.
The inflammation measures told an interesting story: Even when they got the breakfast formulated to be healthier, women who had weathered some real stresses the day before didn't show lower levels of inflammation than the women who got the less-healthy breakfast.
In the real world, the findings suggest, even a woman's smart dietary choices may not be enough to neutralize the harm done by a day of frantic juggling. Curiously, among women who got the fast-food breakfast high in saturated fat, prior-day stresses did not drive inflammation markers still higher: It seems, said Kiecolt-Glaser, that a mega-dose of Western diet "basically saturated the system at that point." Once your dietary choices push inflammation to those heights, the residual effects of a stressful day can't push it any higher.
The women's past history of depression also showed up in the before-and-after-meal measurements. Whether or not they got the classic fast-food breakfast or the reformulated one, women who had a past history of major depressive disorder were less likely to experience the expected drop in blood pressure that follows consumption of a meal than were women who had not experienced past depression. The expected result of such a pattern over the long-term: a steady accrual of wear and tear on the blood vessels and heart over a lifetime, which might help explain the long-observed link between depression and heart disease.
Kiecolt-Glaser warns that the take-away message of all this is decidedly not to give up on making good dietary choices if your life is stressful. "We all know that when we're stressed, we don't reach for broccoli unless it's covered in hollandaise sauce on it," she said. But it's important to recognize that what we eat and how we live can interact in ways strange and unforgiving, she said. So we need to make the best choices in managing stress and choosing our meals whenever we can.