What Does Your Food Have To Do With Chronic Inflammation?3/13/2013
Most people think of inflammation as something that happens after you get injured. Or infected. It’s a normal part of your body’s immune system, after all. However, that immune response can go awry in many ways. Some of the most obvious examples are the autoimmune disorders, like rheumatoid arthritis, or lupus.
But more subtle chronic inflammatory states are being increasingly recognized as big contributors to major disease states, like heart disease, cancer, chronic kidney disease, Alzheimer’s disease, and more.
How does what you put in your mouth matter?
Much of what is known about dietary influence on specific health outcomes arises from observations of how well people who have specific dietary patterns do with respect to developing many of these diseases. And how poorly others do with different eating habits.
It has been known for many years, for example, that a Mediterranean style dietary pattern is protective for cardiovascular disease – a finding recently confirmed by a well-done randomized controlled trial that compared this to a standard Western diet (low-saturated fat, as recommended by the American heart Association)(1). Observations such as these have led investigators to try to figure out why.
With increasing knowledge about the inflammatory underpinnings to many of these conditions, it has also become apparent that eating certain foods drives chronic inflammatory states whereas eating others shuts chronic inflammation down when it is not needed.
What Foods are Pro-Inflammatory?
- Saturated fats. These include animal and dairy fats (including butter), palm oil, coconut oil, and cocoa butter.
- “Bad” polyunsaturated fats (including trans fats). These tend to be omega-6 fats, partially hydrogenated oils, and oils (corn, safflower, sunflower, cottonseed, soybean, and peanut). Our meats, poultry, and dairy products have high levels of omega-6 fats, too, since the animals are fed with grains instead of grasses. Omega-6 fats, like omega-3 fats are “essential” fatty acids, which means our bodies can’t make them but they are used in key roles. Omega-6 fats are made into hormones that tend to increase inflammation, blood clotting, and cell proliferation. Our diets are chock full of them, and most of us have a dietary ratio of 15-20:1 (omega-6 to omega-3), instead of the healthier 2:1 ratio. Trans fats are types of polyunsaturated fats found in processed foods (especially baked goods), chips, fried foods, and margarines; they are there to prolong an item’s shelf-life.
Refined Carbohydrates, and High-Glycemic Index Foods. The glycemic index of foods has been closely tied to markers of systemic inflammation, such as the serum CRP. Spikes in blood sugar are thought to trigger the release of pro-inflammatory cytokines, and can lead to insulin resistance. A 2004 study from Journal of American Medicine found that people who adopted a low glycemic index diet decreased their serum CRP by 48%(3). And, a higher dietary glycemic index has been associated with increased risk of cardiovascular events, such as heart attack(4). Examples of high glycemic index foods include: sugar, dried fruits, potatoes, and refined flour (white and wheat breads) – most people don’t know wheat breads don’t count as “whole grain” foods; they can produce as abrupt a rise in blood sugar as other refined carbohydrates. Avoid breads, bagels, instant rice, rice and corn cereals.
What Foods are Anti-Inflammatory?
- Monounsaturated fats. Found typically in foods that are also high in omega-3 fats.
- Fish oils and “good” polyunsaturated fats (omega-3 fats). Fish oils are high in omega-3 fats (especially salmon, sardines, herring, and bluefin tuna). Fish-n-chips won’t count. Oils with high omega-3 content include olive, canola, avocado, flaxseed, hempseed. Walnuts, almonds, flaxseed, and chia seed also have high omega-3 content. Omega-3 fats are made into hormones that tend to suppress inflammation, stabilize cell membranes, and weakly inhibit blood clotting.
Fruits and Vegetables. Fruits, especially apples, berries (blueberries, strawberries), cherries, and citrus fruits have high levels of anti-oxidant and anti-inflammatory compounds call flavenoids and carotenoids. Fruits can typically have a high sugar content, so you can overdo it. There’s no such thing as too many vegetables (you may have to choose carefully and follow your doctor’s advice if you are taking prescription blood-thinning medications like coumadin or warfarin).
Whole Grains. These are the whole or cracked grains that you can see. Brown, basmati, and wild rice, barley, quinoa, steel-cut oats, buckwheat (including soba noodles).
Healthy Herbs and Spices. Basil, thyme, turmeric, oregano, rosemary, and ginger all have natural anti-inflammatory properties. Peppers and spices from them (red pepper and cayenne, for example) have particularly potent anti-inflammatory compounds, such as capsaicin, a potent inhibitor of the pro-inflammatory neuropeptide “substance P.”
Beverages. Teas (especially green tea), and alcohol (especially red wine) – in moderation (1-2 glasses/day) – appear to have beneficial anti-inflammatory effects due to naturally occurring substances – catechins in tea help prevent cell proliferation and control inflammation. Alcohol itself, as well as the flavinoids found in high concentrations in red wine help to prevent cardiovascular disease, diabetes, and dementia. Multiple studies have shown reductions in inflammatory markers, such as the CRP and various cytokines, such as interleukin-1.
Where To Go For Additional Resources About Diet and Inflammation:
There are many “anti-inflammatory” diets promoted by various authors and entities, some more restrictive than others, many with specific claims of health benefits. Most are based upon variations of a standard Mediterranean diet. What matters most is a generalized pattern of eating, not necessarily a specific plan.
Dr. Andrew Weil has a long-standing interest in this topic.
A good single page guide to anti-inflammatory eating is available here through the University of Wisconsin School of Medicine and Public Health.
- Estruch, R, et al. Primary prevention of cardiovascular disease with a mediterranean diet. N Eng J Med; February 25, 2013DOI: 10.1056/NEJMoa1200303
- Viscolgliosi G, et al. Mediterranean dietary pattern adherence: associations with prediabetes, metabolic syndrome, and related microinflammation. Metab syndr Relat Disord. 2013, Mar 1.
- Seshadri,P, et al. A randomized study comparing the effects of a low-carbohydrate diet and a conventional diet on lipoprotein subfractions and c-reactive protein levels in patients with severe obesity. Am J Med;117(6):398-405.
- Mirrahimi A, et al. Associations of glycemic index and load with coronary heart disease events: a systematic review and meta-analysis of prospective cohorts. J Am Heart Assoc. 2012 Oct;1(5):e000752