It's not clear who said that a pessimist sees the difficulty in every opportunity, while an optimist sees the opportunity in every difficulty.

But the difference between those two POVs may clearly explain why Finnish researchers discovered, after tracking 3,000 men and women ages 52 to 76 for 11 years, that the most pessimistic folks were twice as likely to die of heart disease as those who were least pessimistic.

And why other studies have found that pessimists are more likely to have high blood pressure, diabetes and shortened telomeres (shortened telomeres predict a shortened lifespan).

It seems that gloom and doom trigger chronically high levels of stress hormones associated with bodywide inflammation. Chronic inflammation ups your risk for peripheral artery disease, vascular dementia and some strokes.

So, if your glass is always half-empty, try these steps to raise your spirits and protect your heart.

1. Eat a handful of walnuts daily! A University of New Mexico study found that eating walnuts (baked into banana bread) daily for eight weeks boosted males' moods by a significant 28 percent (females, not so much)! Maybe the guys needed anti-inflammatory ALA omega-3 fatty acids and other nutrients (magnesium, potassium, vitamin B-6 and iron) that walnuts contain.

2. Eat smart and sleep well: You can reduce bodywide inflammation by eating 5-9 servings of fruits and veggies and walking 10,000 steps daily, plus getting 7-8 hours of restful sleep nightly.

3. Consider an online stress-management program and/or cognitive behavioral or other talk therapy to help reshape your take on the world.