10 Surprising Facts About Walnuts

Here are 10 reasons why the walnut should be part of your daily diet:

1. They contain omega-3s and other "healthy fats."

Unique among nuts, walnuts contain the highest amount of alpha-linolenic acid, the plant-based omega-3 essential fatty acid. As one of the best plant food sources of omega-3s, a 1-oz serving of walnuts provides 2.5 grams of ALA. A growing body of scientific evidence indicates these omega-3s provide benefits to the brain and heart while tempering inflammation throughout the body.

2. They're a nutritional powerhouse.

An ounce of walnuts (about seven shelled or 14 halves) is brimming with nutrients that are essential for optimal health. In addition to essential ALA/omega-3 fatty acids, a serving provides a one-two punch of protein (4 grams) and fiber (2 grams), nutrients known to increase satiety or feelings of fullness. They're also a good source of magnesium and phosphorus that can benefit muscle function and bone mass, respectively.

3. They're delicious and versatile.

If you think of walnuts only when baking cookies or banana bread, you're missing out. They're a versatile ingredient for all types of dishes -- from appetizers and soups to main dishes and desserts. Try pumping up the nutrition of your oatmeal, salads, snacks, main dishes and even sweet treats with this nutty nutritional powerhouse. For a perfect "anytime" snack, try these Parmesan-Herbed Walnuts.

3. They're prehistoric.

Walnuts are the oldest tree food known to man, dating back to 7,000 B.C. The ancient Greeks and Romans were well aware that walnuts had special health benefits and wrote extensively of their medicinal uses.

[See: 6 Reasons You May Need to Eat More Salt.]

4. They help keep your mind sharp.

Preliminary studies suggest walnuts may play a role in helping maintain and improve brain health. An animal-model study published in the British Journal of Nutrition found that a diet containing as much as 6% walnuts (equivalent to one ounce per day in people) was able to reverse age-related motor and cognitive decline in animals. Results from another study suggested that adding walnuts to the diets of mice helped reduce their risk and slow the progression of Alzheimer's Disease.

5. They're California grown.

Although walnuts have only been commercially grown in the US since the 1860s, today California-grown walnuts account for 99 percent of the U.S. supply -- and three-quarters of world trade.

6. They're waistline-friendly.

According to recent studies, eating walnuts won't lead to weight gain, and they may help reduce belly fat when they're part of a calorie-controlled eating plan. Thanks to their protein, fiber and fat content, walnuts help keep you fuller longer.

[See: The 10 Best Diets for Fast Weight Loss.]

7. They're smart for your heart.

For decades, dozens of studies have confirmed that walnuts help reduce your risk for heart disease. In fact, there is so much evidence that walnuts provide heart-health benefits that they were one of the first foods to receive a qualified health claim about their heart-health benefits from the U.S. Food and Drug Administration. Here are some of their cardioprotective benefits:

-- Reducing total cholesterol

-- Lowering harmful LDL cholesterol

-- Raising beneficial HDL cholesterol

-- Decreasing blood pressure

-- Reducing inflammation

-- Improving blood vessel function

[See: The 12 Best Diets for Your Heart.]

8. They stay fresher longer when kept cold.

Walnuts will go rancid if they are stored in warm temperatures, but if kept in the fridge, they'll last for weeks. Fresh walnuts smell mildly nutty and taste sweet, but those that are bad will smell like paint thinner. Extend freshness by keeping walnuts in the refrigerator or, if you'll be storing them for a month or longer, keep them in your freezer.

9. You can make walnut "milk."

While you may have tried almond and cashew milk, you can easily make your own walnut milk with this recipe. It's delicious and is a great creamy and nutty base for smoothies.

10. They may help your bones.

While calcium-rich foods are essential for bone health, research suggests alpha-linolenic acid omega-3 provides bone-boosting benefits.

One study published in Nutrition Journal found that used ALA/omega-3s from walnuts and flaxseed reported a reduction in bone loss over a six-week period when these omega-3s were added to the diet.

Julie Upton, MS, RD, is a registered dietitian and communications expert specializing in food, nutrition and health. Ms. Upton is a nationally recognized journalist who has written thousands of articles for national newspapers, magazines and e-media including The New York Times, The Huffington Post, U.S. News and World Report, Prevention, Shape, Health, Good Housekeeping, Redbook and Men's Journal. She is co-author of "The Real Skinny: Appetite for Health's 101 Fat Habits and Slim Solutions" (Penguin 2013) and "Energy to Burn: The Ultimate Food and Nutrition Guide to Fuel Your Active Life" (Wiley 2009). Upton co-founded Appetite for Health, where she blogs daily about nutrition, fitness and health.