Nuts for your heart: Good for your arteries and for lowering cholesterol, walnuts are the way to go
National Post
Tue 13 Feb 2007
Page: A17
Section: Body & Health
Byline: Rosie Schwartz
Column: The Enlightened Eater
Source: National Post

As you contemplate affairs of the heart at this time of year, you might want to consider adding walnuts to the menu.

When you crack open one and see a heart-shaped nut inside, you may get a clue of some of the health benefits nature offers in these nuts. And while a steady pace of published studies over the past few years has revealed just how beneficial walnuts are to maintaining healthy arteries, science is demonstrating that there are many more reasons to consume them on a regular basis.

Walnuts may be an especially smart addition to the menu when festive eats are on the agenda. While it may seem to be counter-intuitive -- adding fat containing walnuts to an already fat-laden meal -- research shows that for those with existing artery disease, walnuts may offer protection against the damaging effects of consuming a glut of fat.

This protective action of walnuts is due to their impact on the endothelial function of the arteries. Endothelial function or dysfunction, in the case of diseased arteries, is emerging as a key in preventing heart attacks or strokes.

The endothelium is the inner lining of the walls of blood vessels, both arteries and veins. And it's how well the endothelium functions that can affect the risk of heart disease and stroke. One of the roles of a healthy endothelium is to influence the rate of blood flowing through the arteries, allowing them to dilate or relax in such situations as emotional stress or physical exercise. Think of endothelial dysfunction making arteries more like a rigid pipe in these conditions rather than a flexible tube. Therefore endothelial dysfunction significantly boosts the likelihood of having a heart attack or stroke.

In Spanish research, scientists assessed the impact of walnuts after subjects consumed a meal high in saturated fat. It's this type of meal, when a surplus of fat is put into the bloodstream, that can trigger a heart attack or stroke in those with endothelial dysfunction. But after the walnuts were included with the fatty food, the rate of blood flow was not slowed--a very healthy sign.

Scientists are not sure which of the nuts compounds may be responsible for this particular effect on endothelial function but one thing's for sure -- there's a wide array compounds contained in these nuts that may play a role in promoting heart health. Among them are arginine, an amino acid, the B vitamin folate, fibre and antioxidants.

And then there are the fats contained in walnuts. These nuts contain polyunsaturated fats -- both the type that significantly lowers levels of the artery -clogging LDL-cholesterol as well as omega-3 fats. Alpha-linolenic acid--ALA--is the kind of omega-3 fat in walnuts and other plant foods.

Over the past few decades, there has been an emerging consensus among many scientists that we consume too much in the way of such omega-6 fats as corn and soybean oil and not enough of omega-3 fats. And while coldwater fish with their omega-3 fats have certainly garnered much attention because of their assorted health perks, boosting the intake of plant-based omega-3 fats --ALA sources --at the same time may offer lesser-known health benefits. Italian researchers showed that with just four walnuts a day, blood levels of omega-3 fats in the blood rose substantially.
The risk of the bone-thinning disease, osteoporosis, is just one example of how ALA may provide other health benefits.

In research just published, Penn State scientists compared the rate of bone turnover in subjects fed various diets including a typical American diet, a pattern high in omega-6 fats or one high in ALA. The rate of bone turnover is thought to have an impact on the risk of osteoporosis. And it was the ALA diet that offered a defence against bone turnover.

But as good as walnuts are for you, some people simply don't like their taste. But after a recent walnut harvest tour in California, where I sampled the freshest of nuts, I realized that if you purchase walnuts with any bitter aftertaste, you might want to look for a new supplier. Properly stored walnuts should be nutty and sweet.

All too often, they're simply not stored properly. Walnuts should be kept in the refrigerator if they're going to be used right away or in the freezer, for longer term storage.

It's also recommended that while they can be stored in original sealed packaging, once the container is opened they should be transferred to an airtight container.

And though walnuts are an easy portable snack, they're also a delicious addition to meal time -- from appetizers right through to dessert. Pureed together with beans or chick peas, herbs, lemon juice and olive oil, they make for a tasty dip. Chopped, toasted or glazed, they can be added to side dishes such as a whole-grain pilaf or even to a main course such as fish or chicken.