An antioxidant-rich diet could do your lungs a favor when exposed to air pollution, according to a small new study.

Researchers from Imperial College London found that asthma and chronic obstructive pulmonary disease (COPD) patients were more likely to be admitted to the hospital on days when there were high particulate matter levels outside, Environmental Health News reported. Particulate matter is a pollutant that causes oxidative stress in the body (raising the risk of health problems like heart attack).

However, the researchers found that people who had higher levels of vitamin C in their blood were less likely than those with low vitamin C levels to go to the hospital on these high-pollution days, MyHealthNewsDaily reported.

The findings add to "a small but growing body of evidence that the effects of air pollution might be modified by antioxidants," Michael Brauer, an environmental health scientist at the University of British Columbia who was not involved in the study, told MyHealthNewsDaily.

The study, published in the journal Epidemiology, included 209 people who were admitted to London hospitals. While researchers did find a link between vitamin C levels and hospital admission, they did not find as strong of a link for uric acid and vitamin E levels. They found no link between vitamin A levels and hospital admission, according to the study.

Previously, Cornell University researchers found that a diet rich in antioxidants could help to preserve lung function, the Cornell Chronicle reported. That study, presented at a meeting of the Federation of American Societies for Experimental Biology in 2008, showed protective benefits of selenium and vitamins C and E in particular.

Plus, in 2001, University of North Carolina at Chapel Hill researchers found that vitamin C supplements seemed to protect lungs against ozone, WebMD reported.

And humans aren't the only ones who can benefit from vitamin C. University of California, Riverside, researchers found that even plants can get some help defending against harmful effects of ozone when they are engineered to have increased vitamin C levels in their leaves.

For some surprising sources of vitamin C (that go beyond oranges) click through the slideshow:

Loading Slideshow...

  • Papaya

    One small papaya (about 157 grams) has <a href="http://ndb.nal.usda.gov/ndb/foods/show/2406" target="_hplink">95.6 milligrams</a> of vitamin C. A cup of mashed papaya has a whopping 140 milligrams. More bang for your buck? Papaya is also high in <a href="http://nutritiondata.self.com/facts/fruits-and-fruit-juices/1985/2" target="_hplink">vitamin A, folate and dietary fiber</a>, according to Self Nutrition Data.

  • Red Bell Peppers

    One cup of raw, chopped red bell pepper packs an impressive <a href="http://ndb.nal.usda.gov/ndb/foods/show/2406" target="_hplink">190.3 milligrams of vitamin C</a>. The same amount of a green pepper has <a href="http://ndb.nal.usda.gov/ndb/foods/show/3136" target="_hplink">119.8 milligrams</a>.

  • Broccoli

    Need <em><a href="http://www.huffingtonpost.com/2012/04/03/breast-cancer-vegetables_n_1400294.html" target="_hplink">yet another</a></em> healthy reason to eat your broccoli? Try this: One serving (148 grams) of chopped broccoli adds up to <a href="http://ndb.nal.usda.gov/ndb/foods/show/2939" target="_hplink">132 milligrams of vitamin C</a>.

  • Kale

    Hungry for a salad? Try kale. Just two cups of this veggie, chopped, offers 160.8 milligrams of vitamin C. This superfood is also rich in vitamins A, C and K, as well as phytonutrients and fiber, <a href="http://www.webmd.com/food-recipes/features/the-truth-about-kale" target="_hplink">according to WebMD</a>.

  • Strawberries

    Here's sweet news: one serving (147 grams) of strawberries has 86.5 milligrams of vitamin C. (And just this week, a study linked two servings of the red fruit a week to <a href="http://www.huffingtonpost.com/2012/04/26/cognitive-impairment-study-berries_n_1453557.html" target="_hplink">slowed cognitive degeneration</a>.)

  • Kiwi

    One serving of kiwi offers <a href="http://ndb.nal.usda.gov/ndb/foods/show/2353" target="_hplink">137.2 milligrams of vitamin C</a>.

  • Cauliflower

    One small head of cauliflower (with a four-inch diameter) has 127.7 milligrams of vitamin C (and just 66 calories).

  • Honorable Mention: Brussels Sprouts

    They may not beat an orange, but a cup of Brussels sprouts still has a solid 48.4 milligrams of vitamin C. And the <a href="http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2362/2" target="_hplink">veggie is also rich</a> in riboflavin, iron, magnesium, dietary fiber and vitamin A, among others.

  • Honorable Mention: Sweet Potatoes

    Another orange food to add to the list (even though it doesn't have more C than an actual orange) are sweet potatoes. One large sweet potato has <a href="http://ndb.nal.usda.gov/ndb/foods/show/3274?fg=&man=&lfacet=&format=Abridged&count=&max=25&offset=&sort=&qlookup=sweet+potatoe" target="_hplink">35.3 milligrams</a>.

  • Honorable Mention: Cantaloupe

    Again, this one doesn't have quite as much vitamin C as an orange, but one serving does offer <a href="http://ndb.nal.usda.gov/ndb/foods/show/2372" target="_hplink">49.2 milligrams</a>.

Also on HuffPost: