Ask Doctor K: Prevent chronic inflammation with a healthy diet

DEAR DOCTOR K: You’ve written that chronic inflammation has been linked to diseases such as diabetes and heart disease. Is there anything I can do to fight inflammation without using medications?

DEAR READER: Inflammation in the body is a double-edged sword. Short-lived inflammation, directed by your immune system at invaders like bacteria or viruses, protects your health.

But sometimes inflammation persists, even when there is no health threat. That’s when it can become your enemy. Many major diseases have been linked to chronic (ongoing) inflammation, including cancer, heart disease, diabetes, arthritis, depression and Alzheimer’s.

The good news is that powerful tools to combat inflammation can be found in the grocery store. I spoke to my colleague Dr. Frank Hu, professor of nutrition and epidemiology in the Department of Nutrition at the Harvard School of Public Health. He explained that components of many common foods have anti-inflammatory effects.

By choosing the right foods, you may be able to reduce your risk of illness. Consistently pick the wrong foods, however, and you might speed up the inflammatory disease process.

The same foods that contribute to inflammation are already generally considered bad for our health, so it’s easier to remember them. They include sodas, refined carbohydrates, and red and processed meats. These foods affect inflammation directly.

They also contribute to weight gain, which is itself a risk factor for inflammation. How does that happen? When you put on weight, the fat cells in your body become more numerous and also grow larger.

We used to think that what fat did was provide a storehouse of energy for when we needed it, sort of like insulation that protected us against the cold. In the past 20 years we’ve learned that fat cells are little factories that make hormones and immune system chemicals. These substances influence our appetite, our metabolism — and inflammation.

To reduce inflammation, avoid or limit:

– Refined carbohydrates, such as white bread and pastries;

– Fried foods such as french fries;

– Soda and other sugar-sweetened beverages;

– Red meat (burgers, steaks);

– Processed meat (hot dogs, cold cuts);

– Margarine, shortening and lard.

On the flip side are foods and beverages that reduce the risk of inflammation and chronic disease. Fruits and vegetables are particularly effective. Good choices are blueberries, apples and leafy greens, which are high in natural antioxidants and polyphenols. These are protective compounds found in plants. Nuts and coffee may also be protective.

Include plenty of these anti-inflammatory foods in your diet:

– Tomatoes

– Olive oil

– Green leafy vegetables, such as spinach, kale and collards

– Nuts, such as almonds and walnuts

– Fatty fish like salmon, mackerel, tuna and sardines

– Fruits such as strawberries, blueberries, apples, cherries and oranges

– Spices, particularly ginger and turmeric

If you’re looking for a dietary plan that closely follows the tenets of anti-inflammatory eating, consider the Mediterranean diet. This diet is high in fruits, vegetables, nuts, whole grains, fish and healthy oils.

(This column ran originally in October 2014.)

(Dr. Komaroff is a physician and professor at Harvard Medical School.)