An increasing number of studies have shown that moderate nut consumption - as little as two servings per week, may ward off heart disease and lower the risk of heart attack. (Vahid Salemi/Associated Press)

In Depth: Food: [http://www.cbc.ca/news/background/food/nuts.html]

Last Updated October 5, 2007

by Michelle Gelok

There is an increasing amount of research to suggest that nuts should not only be part of a healthy diet, but moderate consumption is also being linked to heart health.

If you're curious about the best way to enjoy nuts as part of a healthy diet, read on to find out all you need to know to make the most of these nutrient powerhouses.

While nuts have received a bad rap in the past for being high in fat, it's actually their fat content that is thought to be responsible for their health benefits - specifically their link to heart health.

The type of fat found in nuts is unsaturated fat - specifically monounsaturated and polyunsaturated fat. Both of these unsaturated fats are known for their ability to reduce low-density lipoprotein (LDL), also called "bad" cholesterol, when consumed in moderation.

An increasing number of studies have shown that moderate nut consumption - as little as two servings per week, may ward off heart disease and lower the risk of heart attack.

One of these reports, part of the Nurses' Health Study published in the British Medical Journal in 1998, looked at the health of more than 86,000 women. It found that those who ate 142 grams (five ounces) of nuts per week were 35 per cent less likely to develop heart disease than women who ate less than one ounce per week.

Likewise, after examining findings from the U.S Physicians Health Study, Harvard researchers found that men who ate nuts two or more times per week were 47 per cent less likely to die of a heart attack and 30 per cent less likely to die of heart disease than men who rarely ate nuts. These findings were published in the Archives of Internal Medicine in 2002.

The Adventist Health Study, which examined the diets of more than 31,000 Seventh Day Adventists, found that participants who consumed nuts more than four times per week experienced 51 per cent fewer heart attacks compared to those who consumed nuts less than once per week. These findings were published in the Archives of Internal Medicine in 1992.

Omega-3 fat, a type of polyunsaturated fat that is found in walnuts, has also been linked to a variety of health benefits, from protecting against Alzheimer's disease to lowering the risk of stroke. A study published in the September 2007 issue of the Journal of the American Medical Association even found that children with an increased risk of developing Type 1 diabetes could lower their risk by consuming a diet high in omega-3 fatty acids.

Aside from providing a healthy dose of unsaturated fats, nuts are also a source of fibre, protein, vitamin E, vitamin B6, as well as niacin and folic acid.

Nuts in general contain as much as 80 per cent fat. Despite the fact that most of the fat found in nuts is the heart-healthy unsaturated kind, it can still add up to a lot of calories.

While most nuts appear to be healthy when enjoyed in moderation, some seem to be healthier than others. An increasing amount of research suggests almonds, walnuts, pecans and macadamia nuts are leading the pack in terms of heart health.

The following chart provides a nutritional overview of some of the more popular types of nuts.

When eating nuts, a little goes a long way in terms of nutrition. In fact, as many studies have shown, just a handful of nuts a few times a week is enough to reap their heart healthy benefits.

When adding nuts to your diet, there are a few things to keep in mind, though.

First of all, as mentioned above, nuts are nutrient-dense and are a source of calories in the diet despite their healthy profile. Instead of adding nuts to your diet on top of everything else you eat in a day, eat them to replace other less-healthy foods, such as foods high in saturated or trans fat. According to Canada's Food Guide, nuts are considered a meat alternative - that means they are a rich source of protein in the diet.

Secondly, be mindful of portion size. A serving of nuts is 60 ml, 1/4 cup or about 30 grams. For nut butters, the appropriate portion size is 30 ml, or about two tablespoons (be sure to choose nut butters that don't contain added sugar or fat).

Finally, to maximize the health benefits that nuts have to offer, you're better off enjoying them on their own instead of drenched in salt or smothered in chocolate or added fat. Added salt, sugar and fat can offset any benefits that nuts have to offer.

Want to add more nuts to your diet, but not sure where to begin? The following tips will get you started.

Remember, nuts have a lot to offer, and the best way to reap their benefits is by adding them to your diet in moderation to replace other high-fat foods.