Photo: Thinkstock

2 of 10
2. Serenity

When mice were fed a strain of probiotics found in some yogurt, they became calmer under stress, Irish and Canadian scientists observed. The were less likely to panic like their broth-fed brethren, and they produced fewer stress hormones—effects similar to those brought on by antidepressants. Look for yogurt that has active probiotic cultures, and say, "Mmmm."