At this year’s Cardiometabolic Health Congress, a cardiologist I will call “Dr. Q” began his nutrition presentation with a factoid: 90% of cardiologists reported zero or minimal nutrition education, yet 95% of them felt it was their personal responsibility to discuss it. Meanwhile, 61% of the public thinks that doctors are “very credible” sources of nutrition information.

In other words, we have doctors who do not know what they are talking about talking about it anyway, and patients are listening and trusting them because they are doctors.

He called blueberries “the natural purple pill” and cited research showing that 93,600 women who were studied over 18 years and who consumed three servings of blueberries per week throughout the study had a 34% reduced risk of a myocardial infarction. He then flashed a slide listing the dozens of known chemical compounds in blueberries, asked how we know which nutrient or combination of nutrients is responsible for the benefits, and answered his own question with, “I don’t think any of that really matters,” intimating that the bottom line is that blueberries offer health benefits.

But the underlying mechanism absolutely does matter. He assumed a causal relationship between at least one of the chemical compounds and reduced risk of heart attack, but the relationship between blueberry intake and heart attack risk could also be correlation. For example, the real factor at play might not be some minute compound, but rather money.

Relative to other fruits, blueberries are incredibly expensive. According to data I obtained from Peapod.com, blueberries cost $0.44-$0.64/oz. (depending on the size of the container purchased), which exceeds apples, grapes, melons, strawberries, and all other fruits I examined except for pomegranate seeds ($0.63/oz.) and raspberries ($0.56/oz.)

Could it be that the women in the study who could afford to eat blueberries three times a week also had other financial advantages that enabled them to take better care of themselves, such as the ability to absorb higher insurance costs for office visits and testing, health club memberships, time off from work or no work at all, massages, and psychotherapy?

On the flip side, you know who is probably not splurging on blueberries or able to engage so extensively in taking care of their health? Those working multiple jobs just to get by, those living paycheck to paycheck, those suffering from food scarcity, those relying upon the Thrifty Food Plan, and those who need to make $3.33 stretch enough to buy multiple items to feed their entire family instead of blowing it on a small container of “purple pills.”

“Whether measured by income, formal education, or job status, there is a socioeconomic gradient to health,” Bacon and Aphramor write in Body Respect. “And the greater the inequality in society, the steeper the gradient. The United States has the greatest inequality of all wealthy nations – and the greatest health disparities.”

This is what I was getting at last year when I wrote about nutrition and politics. We talk about the concept of intersectionality and how various layers of oppression aggregate. The further one’s identity lies from that of the pinnacle of privilege – a thin, white, heterosexual, educated, wealthy, American-born, Christian male – the more the individual is subject to oppression.

It might not just be that one’s economic situation makes regularly consuming blueberries unrealistic and limits their access to health care, but that in addition to fretting about cash flow, that person might also have to worry about suffering a hate crime or having their rights stripped away. Even if someone does not fall victim to such misfortune, remember that stress itself is associated with cardiovascular disease, so the very threat itself is problematic.

Assuming that the reduced risk of heart attack was due to a few weekly handfuls of berries without considering the greater context is ridiculous and exemplifies the problems inherent in viewing nutrition solely as a hard science. Anybody who has extensively studied the field should know to consider social, cultural, and other factors, which makes me wonder: When Dr. Q told us that 90% of cardiologists reported zero or minimal nutrition education and yet 95% of them felt it was their personal responsibility to discuss it, was he describing himself?