Dale Carnegie said, "When fate hands us a lemon, let's try to make a lemonade." That’s rule No. 6 in his book "How to Stop Worrying and Start Living."

But there are actually lots of other tasty ways to change your outlook from sour to sweet that don't call for added sugar.

A newly published SUN (Seguimiento Universidad de Navarra) study tracked 19,000 people for around 10 years and found that eating a diet with healthy amounts of fruits and vegetables (including legumes and nuts) reduces the risk of depression by 25 to 30 percent.

There are many reasons why unprocessed fresh fruits and vegetables help you achieve and keep a positive attitude.

First, they protect your overall health. Eating foods rich in polyphenols reduces inflammation and helps prevent some cancers, as well as cardiovascular and neurodegenerative diseases.

Fruits and vegetables also provide fuel for the brain.

Plus, when you're eating fruits and vegetables, chances are you're NOT eating foods that contain trans and saturated fats, added sugar and sugar syrups, and processed grains.

Unfortunately, Americans eat only one serving of fruit and two servings of veggies daily. And often those fruits and veggies are from sugar-added fruit drinks and French fries.

But good mental health is a pretty great reason to change your ways and eat five to nine servings of fruits and vegetables daily.

Then, as Eric Idle sings at the end of Monty Python's "Life of Brian," you'll be able to "look on the bright side of life.”