Serving a Hot Dish of Anti-Inflammatory Food
The American College of Cardiology is serving up anti-inflammatory food. Dig in! In a press release earlier this month, the College told us that an anti-inflammatory diet can lower heart disease and stroke risk. It sounds great, but if you read the press release, you’ll find that these studies are all about modest correlations. Not evidence for the effectiveness of this anti-inflammatory magic.
Good, Healthful Eating
We should be clear. Healthful eating is a good thing. We have a pretty good evidence to tell us that eating a variety of minimally processed and whole foods is an important part of a healthy pattern for life. So, too, is getting plenty of sleep, healthy physical activity, and keeping stress at bay.
However, it’s also safe to say that dietary patterns are complex and the options for a healthful pattern of eating are many. You might even say that the possibilities are infinite.
The folks at Harvard have an index, the EDIP, that correlates pretty well with a person’s risk for systemic inflammation. This is important because systemic inflammation does indeed play an important role in many chronic diseases. It plays an important role in obesity, diabetes, heart disease, stroke, and many cancers. That much is clear.
It is also clear that healthy dietary patterns, as interventions, can lead to a reduction in markers of inflammation – for example, C-reactive protein. Good examples would be the Mediterranean diet and the DASH diet .
Anti-Inflammatory Efficacy
However, what is less clear is that the food making up these diets has some a direct and meaningful anti-inflammatory effect. People like to talk about foods as if they were medicinal, but they’re not. They are much more than that. They are nourishment. Good nourishment promotes good health. It’s not pharmacology, it’s nutrition.
For instance, the College makes reference in its press release to a study of walnuts for reducing inflammation. That study is a research letter that describes an analysis of inflammation markers that were neither primary nor secondary outcomes targets for the study that produced these data. In fact, that study was not a study of inflammation. It was a study of cognitive function and macular degeneration.
Researchers found no effect on cognitive function, so they dug through data on ten different markers of inflammation and found that six out of ten of them were improved in folks randomized to add walnuts to their diets. The other markers – C-reactive protein, for example – were not improved. These results might be grist for walnut marketing claims, but they are not evidence for a robust anti-inflammatory benefit.
In a recent controlled study to directly assess the effect of an anti-inflammatory diet on inflammation in rheumatoid arthritis, researchers found some glimmers of hope, but no effect in their primary analysis.
Let Food Be Food
This desire to pretend that food can be like an anti-inflammatory drug leaves us shaking our heads. Food is food. It is not medicine, it’s nourishment. A healthful pattern of eating can prevent and control chronic diseases. Not because food is medicinal. But because good food is good for you. Let’s just leave it at that.
Click here for the correlation study of inflammation markers and dietary patterns and here for an editorial comment in the JACC.
Boost Your Immunity, photograph © Ted Kyle / flickr
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November 12, 2020