By: Jean Johnson for Heart1“It’s good news, but it’s like preaching to the choir with us,” Denise Lewis, a recent transplant to Washington, DC from Portland, Oregon, said about the research published in the October 2006 issue of the Journal of the American College of Cardiology.
The study, undertaken at the University of Barcelona’s Hospital Clinico and sponsored by the California Walnut Commission, revealed that contrary to popular opinion, olive oil does not provide the vascular protection people have believed it to have. Rather, notes the American College of Cardiology (ACC), “Consuming a handful of raw walnuts along with meals high in saturated fat appears to limit the ability of the harmful fat to damage arteries.”
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Tips on Moving Toward a Mediterranean Diet
Set up a place to chop vegetables, nuts, and fruits in the kitchen. Have fun in the kitchen. If a chop of walnuts scattered over some roasted beets sounds good, go for it, remembering that Julia Child’s husband ate many a mistake on his wife’s way to chefdom. Julia always maintained that a dish with great ingredients that didn’t turn out quite right was still far superior to a meal based on inferior ingredients that has been mass produced.
Eat in season. Matching food to the changing rhythms of the seasons brings variety naturally and adds a compelling connection between the bounty of the table and the turning of the earth. That’s how they do it in the Mediterranean. |
“We eat all kinds of nuts – walnuts, hazelnuts, peanuts, almonds, cashews. Also pumpkin seeds which I roast, and sesame seeds,” said Lewis, a paragon of lean, youthful vivacity in her late thirties. “They help add the extra touch that makes salads and soups something we really look forward to and enjoy. I put walnuts in a gingery carrot salad I make in the fall after the new apples reach the stores. And toasted hazelnuts go great with a winter pear and romaine salad – I added that to my repertoire while we lived in Portland. Then there are peanuts or peanut butter, which shine in Thai food. And my husband eats almond butter on whole wheat just about every day for lunch.“We always did rely on nuts more than olive oil, although we do use that too in our cooking. So I’m glad to hear that we’re doing our arteries and hearts a favor with all the nuts,” said Lewis, who enjoys dancing salsa to the live music the couple has found in Washington, DC.
“Eating healthy food works for us because we’ve found we feel better when we do. That way we can stay out late and dance, and still have the energy we need for the next day. My husband’s parents are the same way as far as trying to eat well, and now that they are older they are really noticing the difference. They don’t salsa, but they travel and are enjoying their golden years by helping out in their community. Besides, once you develop a taste for fresh foods prepared nicely, going back to the standard American diet is just something you’re not interested in doing.”
The Research
Lead researcher in the study, Emilio Ros, MD, PhD, director of the Lipid Clinic at Hospital Clinico, explained that, “Each time we eat a high-fat meal, the fat molecules trigger an inflammatory reaction that, among other ill effects, reduces the elasticity of the arteries.
“Over time, this repeated damage is thought to contribute to hardening of the arteries and, in turn, to heart disease,” Ros told the ACC. “Our latest research shows that eating walnuts helps to maintain that elasticity of the arteries.”
When we eat a meal high in fat – like the salami and cheese sandwich and full fat yogurt that participants in the study ate for the purposes of the research – there is a sudden onset of inflammation and oxidation in the arteries. “These harmful processes,” states the ACC, “which typically follow consumption of high-fat meals, can lead to hardening of the arteries, or atherosclerosis, a precursor of heart disease.”
While both olive oil and walnuts helped to decrease the inflammation and oxidation, only the “walnuts helped preserve the elasticity and flexibility of the arteries, regardless of people’s cholesterol levels.”
“The inner lining of the arteries produces a substance called nitric oxide that is needed to keep the arteries flexible,” said Ros. “When we eat a high-fat meal, the fat molecules temporarily disrupt the production of nitric oxide, preventing the arteries from increasing blood flow in response to physical activity.”
The living tissue of the arteries enables blood to circulate, and at the level of the capillaries, lets the bright red oxygenated blood exchange its life-giving forces for waste products that the venous system then dispels.
More, arteries accommodate varying loads of blood, expanding when the heart is pumping harder during physical and emotional stress and then relaxing during normal circulation loads. It is precisely this aspect of arterial health that can be compromised by high saturated fat diets – and that can be assisted by walnuts.
Robert A. Vogel, MD, a professor of medicine at the University of Maryland, joins Ros in this more holistic assessment of eating patterns. Commenting on the walnut study, Vogel told the ACC that: “This demonstrates that the protective fat from walnuts actually undoes some of the detrimental effects of a high-saturated-fat diet, whereas a neutral fat, such as olive oil, does not have as much protective ability.”
Backgrounder
Saturated fats, along with their notorious pals trans-fats, are solid or semi-solid at room temperature like butter, ice cream, whole milk, and margarine. On the positive side of the scorecard are the mono- and polyunsaturated fats that are liquid at room temperature. Over on this side is where the nuts, olives, fish, and cooking oils appear.
That’s one of the reasons why Americans made fast tracks to their nearest bottle of olive oil in the same way they did a decade ago when news of how healthy the Mediterranean diet was reached our ears (See “A Closer Look at the Mediterranean Diet at http://www.reflux1.com/ news/Refluxmainstory.cfm/102?srchfrm=Body1. Another is that we Americans tend to want quick fixes.
Ros noted, “People would get the wrong message if they think that they can continue eating unhealthy fats provided they add walnuts to their meals. Instead they should consider making walnuts part of a healthy diet that limits saturated fats.
“This raises a very interesting issue because many people who eat a Mediterranean diet believe the olive oil is providing the benefits. But this research and other data indicate that’s not true,” said the University of Maryland’s Vogel. “There are probably other factors in the diet, including that it is a relatively rich source of nuts. This is not to say that olive oil is bad, but it’s not the key protective factor in the Mediterranean diet.”
In fact, according to the ACC, “research continues to indicate that all monounsaturated-rich foods, including olive oil, likely are relatively neutral in terms of their ability to protect vascular health.” On the other hand, stated Vogel, “omega-3 rich oils and fats – including walnuts, canola oil, and flaxseed oil – are probably quite protective.”
