Inflammation is a normal - and much needed - bodily function. It's the response of your immune system working to heal wounds and fight infection.
But sometimes the process can go into overdrive, churning out excessive inflammatory compounds causing diseases such as rheumatoid arthritis, asthma, chronic obstructive pulmonary (lung) disease and inflammatory bowel disease (Crohn's disease, ulcerative colitis).
It's long been thought that diet plays a role in easing symptoms of inflammation. Now, study findings published this month suggest that certain foods and nutrients can lower the risk of dying from inflammatory diseases.
Compounds in foods that help fight inflammation include antioxidants, omega-3 fatty acids, monounsaturated fat and phytochemicals.
In the study, published online in the American Journal of Clinical Nutrition, Australian researchers sought to determine if omega-3 fatty acids, fish and nuts were associated with the risk of dying from inflammation-related disease in 2,514 healthy older adults.
There are three omega-3 fatty acids: DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) found in fish oil and ALA (alpha-linolenic acid) found in flaxseed, chia seeds, walnuts, and canola oil.
After 15 years of follow-up there were 214 deaths caused by inflammatory disease. The findings revealed that women with the highest - versus lowest - intake of total omega-3 fats were 44 per cent less likely to die from non-cancer, non-cardiovascular inflammatory disease than those with the lowest levels.
Women with the highest intake consumed 1.1 to 4.7 grams of total omega-3 fats a day. (One tablespoon of ground flaxseed provides 1.2 grams of ALA, 14 walnut halves contain 2.5 grams ALA, and eight ounces of Atlantic salmon supplies roughly 4.8 grams of EPA and DHA combined.) Evidence suggests that older women are more sensitive than men to the anti-inflammatory effects of omega-3's. As well, about half of the inflammatory disease deaths in men were due to respiratory diseases upon which omega-3 fatty acids don't have a strong effect.
Omega-3 seemed to have a mixed effect on men. While intake of total omega-3's didn't seem to provide protection, alpha-linolenic acid did help them.
The study found that for both men and women, increasing daily intake of ALA lowered the risk of dying from inflammatory disease over the 15-year study.
Nuts, too, were protective. Compared to folks who rarely or never ate nuts, those who consumed up to 4.5 grams daily (e.g. two walnut halves, four almonds or three cashews) had half the risk of inflammatory disease mortality.
Surprisingly, fish intake was not related to inflammatory disease death. A protective effect of fish might have been missed if it was mainly low in omega-3 fats (e.g. sole, tilapia) or fried; previous research has tied fried fish intake to higher levels of inflammatory compounds in the blood.
Chronic, low-grade inflammation - the ongoing release of inflammatory immune compounds - is now recognized as a major determinant of many age-related diseases including heart disease, stroke, Alzheimer's, diabetes and metabolic syndrome.
It's caused by many factors including cigarette smoking, lack of sleep, high blood pressure, high blood sugar, abdominal obesity and a diet high in refined sugar and saturated fat.
The following foods can help subdue inflammation in the body by promoting the production of anti-inflammatory immune compounds.
Eat oily fish
To increase your intake of DHA and EPA, aim to eat six to 12 ounces of oily fish a week. The best sources of these omega-3 fatty acids include salmon, herring, anchovy, mackerel and sablefish (black cod). (These fish are also low in mercury.) If you don't like fish, consider taking a fish oil supplement. Most capsules provide 300, 500 or 600 milligrams of DHA and EPA (combined). Liquid fish oils often contain 1,300 milligrams of DHA and EPA a teaspoon.
Get your ALA
Alpha-linolenic acid also regulates inflammation in the body. Women require 1.1 grams of ALA a day and men need 1.6 grams.
The best sources include flax oil (1 teaspoon equals 2.4 grams ALA), ground flaxseed (1 tablespoon equals 1.6 grams), salba seeds (2 tablespoons equals 2.5 grams), walnuts (14 halves equals 2.5 grams) and canola oil (1 tablespoon equals 1.3 grams).
Snack on nuts
The anti-inflammatory properties of nuts are attributed to their polyunsaturated fat, magnesium and antioxidant content.
Include one ounce of nuts in your daily diet. Substitute nuts for less healthy snacks like cookies, candy, soft drinks, and refined starchy foods.
One ounce of nuts isn't that large - you'll need to count out 8 Brazil nuts, 18 cashews, 14 walnut halves, 24 almonds or 28 peanuts.
Switch to monounsaturated fat
This type of fat, found in olive oil, peanut oil, safflower oil and canola oil, helps shield the body from inflammation. Other sources of monounsaturated fat include avocado, almonds, hazelnuts, pistachios and peanuts.
Natural compounds in fruit, vegetables, soybeans and tea, called flavonoids, also dampen inflammation.
Flavonoid-rich fruit and vegetables include berries, cherries, red grapes, apples, citrus fruit, broccoli, kale and onions. Other good sources include green and black tea, dark chocolate, soybeans, edamame and tofu.
Take vitamin D
Among its many roles, vitamin D has anti-inflammatory effects in the body. In fact, research has shown that vitamin D deficiency is associated with higher levels of inflammation in adults.
Current vitamin D recommendations range from 600 to 2000 IU a day. In the fall and winter, when the sun isn't strong enough to produce vitamin D in the skin, Canadians are advised to supplement with 1,000 to 2,000 IU vitamin D a day.
The safe upper daily limit is 4000 IU a day. Speak to your health care provider about the right vitamin D intake for you.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Her website is lesliebeck.com.