Many people, when they are feeling miserable from a cold or the flu, get the urge to gorge on food. But picking the right foods can benefit and even speed healing.

"This is more or less a new area," said Kerry Neville, a Seattle dietitian and spokeswoman for the American Dietetic Association. "There has been some good research, and we'll be seeing more. But it remains to be seen how much of this can actually be helpful."

Teasing out how and where food can benefit is difficult because our immune systems -- a coordinated system of signals sent and received, feedback loops and multiple redundancies to ensure that foreign molecules are identified and destroyed if they are harmful -- are so complex. A breakdown in any part of the system leaves the whole body susceptible to infection and illness.

And lifestyle and environment can cause small breakdowns in the system all the time. Smoke, air quality, sunlight and poor diet can all contribute to a weakened immune system, particularly in the form of free radicals. These highly reactive molecules with unpaired electrons can break down cells, leaving them vulnerable to invading viruses and bacteria.

Antioxidants, a type of chemical found in plants, help neutralize free radicals and protect cells, thus bolstering the immune system. Antioxidants often give plants their color and can also include vitamins C, A, and E. Experts estimate that there are many more antioxidants that are as yet unidentified.

And studies have shown that some of the protective vitamins and minerals, when given alone, do not benefit people as much as getting those nutrients from their diets.

很多人在遭受傷風或流感的痛苦侵擾時,往往會采取大量進食的方式擺脫病害的困擾,選擇適當的食物不僅對健康有益,更能有效地促進身體的復原.

西雅圖營養學家兼美國飲食協會女代言人Kerry Neville發言說:"這是個嶄新的領域,對此已經進行了一些很好的研究,我們還將看到更多的新研究產生,但是對于食物能有效促進身體康復的實際程度還有待進一步的深入研究."

要弄清食物是如何對身體哪部分有益并非易事,因為人體免疫系統結構復雜,主要是由信號收發,反饋回路以及復合備份共同配合協作,及時辨析并破壞外界有害分子確保身體機能的正常運行,該系統任何部分的損傷都會導致整體免疫力下降,易受感染,遭受疾病侵害.

生活方式,外界環境都能導致免疫系統的微弱損傷,吸煙,空氣質量,陽光以及不良飲食習慣均會以自由基的形式削弱系統免疫力.這些帶未配對電子的高活性分子能損傷細胞,使之更易受病毒細菌的侵襲.

植物體內有種化學物質---抗氧化劑,能抑制自由基保護細胞免受損害,從而維持免疫能力.不同的抗氧化劑有各自不同的顏色,可分為維他命C,A和E.專家推測還有更多的未經確認的抗氧化劑存在植物體內.

研究表明,飲食中吸取的一些維他命和礦物質所起的功效遠大于單獨服用時所起的功效.