Walnuts can reduce effects of fatty meals, say scientists

[Demi]

The Independent
London, UK
10 October, 2006


Walnuts may soon become the next great health food following a study showing that they can boost the body's ability to withstand the effects of a fatty diet.

Scientists have shown that raw walnuts can increase the flexibility of arteries, making heart attacks and coronary disease less likely.

Walnuts contain natural chemicals that help to prevent the hardening of the arteries, making them less prone to becoming blocked, said Emilio Ros, of the Hospital Clinico in Barcelona.

"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," Dr Ros said. "Over time this repeated damage is thought to contribute to hardening of the arteries and, in turn, to heart disease. Our research shows that eating walnuts helps to maintain the elasticity of the arteries."

The research, funded by the California Walnut Commission and published in the Journal of the American College of Cardiology, involved 24 adults. Volunteers were divided into two groups who for two weeks followed a Mediterranean diet designed to lower cholesterol levels, which was rich in fruit and vegetables and low in dairy products. Each group was given a high-fat meal of a salami-and-cheese sandwich followed by a full-fat yoghurt. One was also given five teaspoons of olive oil and the other was given about eight shelled walnuts.

The scientists found that the walnuts and the olive oil helped to decrease the sudden onset of inflammation and oxidation in the arteries - processes that contribute to the hardening of arteries. However, the walnuts also helped to preserve the elasticity and flexibility of the arteries, regardless of cholesterol levels, which enabled the blood vessels to expand when needed to increase the flow of blood.

Dr Ros said that walnuts are rich in an amino acid called arginine, which is important in the production of the body's natural sources of nitric oxide, a substance needed to keep arteries flexible. Walnuts also contain antioxidants and alpha-linolenic acid, a plant-based omega-3 fatty acid, which some scientists believe can help to stave off heart disease.

http://news.independent.co.uk/uk/health_medical/article1826305.ece

[kyrasdad]

"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," Dr Ros said. "Over time this repeated damage is thought to contribute to hardening of the arteries and, in turn, to heart disease.

Does anyone have a link to research on Dr. Ros's statement?

As to the rest of it, I like walnuts, and typically don't eat them because it's easier to get almonds. (And yeah, I realize that The California Walnut Commission isn't exactly an unbiased source).

[ceberezin]

The information about fat being inflammatory is doubtful. Even so, two points need to be made. The greatest source of lipids in the bloodstream is not dietary fat but de novo lipogenesis from carbohydrates, and glycation is a far more serious instigator of inflammation than whatever can be traced to fat.

[tom sawyer]

Their reasoning is crap, but at least they are recommending something good for a change! Yay Walnuts!

[betnich]

"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," Dr Ros said. "Over time this repeated damage is thought to contribute to hardening of the arteries and, in turn, to heart disease. Our research shows that eating walnuts helps to maintain the elasticity of the arteries."


Is this true? For all fats, or just saturated fat? Is the author making an exception for olive oil and other unsaturated fats? How about trans-fats?
And what about the effects of high sugar/carbs on insulin and blood glucose?

[mike_d]

Good I eat a lot of em :agree: They are high in Omega-3 other nuts are not.

Fat may indeed be inflamatory: if consumed with cake and a milkshake.

It should read: "Walnuts may soon become the next great health food following a study showing that they can boost the body's ability to withstand the effects of a fatty [and sugary] diet."

[ubizmo]

Does anyone have a link to research on Dr. Ros's statement?


I don't, but I'm pretty sure it's in reference to the study cited here: http://www.msnbc.msn.com/id/14229538/ --a study of meals consisting of carrot cakes and milkshakes! At least, given the publicity that this study got, that's my best guess.

Note that lean meats are also good sources of arginine. I say "lean" because obviously the arginine is an amino acid that is only found in the protein, so if you use a nutrient analysis tool, fatty meats will get a lower arginine score.

[Whoa182]

I suspect they should have a good mechanistic explanation of why 'fatty foods' would make the arteries stiffen. I haven't had walnuts in my diet for quite a long time, maybe its time to start buying them again :)

[kyrasdad]

I suspect they should have a good mechanistic explanation of why 'fatty foods' would make the arteries stiffen. I haven't had walnuts in my diet for quite a long time, maybe its time to start buying them again

Besides that, they are yummy. :)

If Ubizmo's link above is indeed their source, then it is shoddy research. Taking a menu like that and isolating on just the dietary fat is pretty much getting the results you want, not the results that are apparent. It's not much of a connection, which is what's been missing from the anti-fat argument. I am not open to the possibility that fat is just as unhealthy as they always told us it was, but we've eliminated it from the American diet for years and have gotten fatter, sicker, more diabetic, and have not reduced heart disease. Surely if fat were the sole factor, its reduction in our diet would have pushed the numbers in the right direction.

I know this...trying to eat low fat, I always felt lousy. Eating a diet 63% fat over three years has pointed all of my blood markers in the right direction and slashed 100 pounds off me. The jury is still out I suppose on the healthiness of high fat, but I will certainly continue to eat high-fat way until presented evidence to the contrary.

[kyrasdad]

Oh my that is an ignorant article...just read it over. Awful.

In the study, at The Heart Research Institute in Sydney, Australia, 14 people, ages 18-40, ate two meals of carrot cake and a milkshake one month apart. One meal was high in saturated fat — using coconut oil — and the other was high in polyunsaturated fat — using safflower oil.

I checked the nutritonal content...

One slice of carrot cake:

Total Fat 16.7g 26%
Saturated Fat 3.06g 15%
Polyunsaturated Fat 7.57g
Monounsaturated Fat 5.14g
Cholesterol 48.35mg 16%
Sodium 140.96mg 6%
Potassium 79.27mg 2%
Total Carbohydrate 42.46g 14%
Dietary Fiber 0.91g 4%
Protein 3.09g 6%
Alcohol 0.0764g

That particular slice, from FitDay is higher in polyunsaturated than it is saturated. Of course its carb count is much higher than its fat count. But that isn't even considered as a contributing factor.

A milkshake...(vanilla)

Total Fat 9.48g 15%
Saturated Fat 5.9g 30%
Polyunsaturated Fat 0.354g
Monounsaturated Fat 2.74g
Cholesterol 36.93mg 12%
Sodium 298.6mg 12%
Potassium 571.85mg 16%
Total Carbohydrate 55.56g 19%
Dietary Fiber 0g 0%
Protein 12.08g 24%
Alcohol 0g

Way more saturated than poly. But hugely carb-laden, 55.56 to just 9.48g fat.

They claim that saturated fat has long been linked to plaque buildup on the heart. Is that based on the dogmatic, correlary studies of the past, or is there some mechanism that actually shows causation, outside other factors like the overabundance of simple carbs?

[arc]

I think I will take my chances on the fatty meal. Walnuts are gross. http://bestsmileys.com/sick/9.gif

[Svetlana]

Don't think I've ever eaten a walnut... peanuts pistachios cashew macademia chestnuts yes... walnuts no... Are you supposed to cook with them, or snack on it like peanuts?

[Nancy LC]

They often put walnuts in baked goods, like brownies or christmas things. You can snack on them. I think I might be a little allergic to them myself, whenever I have them my mouth gets a bit sore.

[Whoa182]

There is only one nut that I have to stay away from... thats peanuts! I go near them, even smell them a tiny bit and it can make me gag or at least feel sick lol.

Now that is poison :lol:

[ubizmo]

Peanuts are not nuts anyway--but they are loaded with arginine!

I think walnuts are a pretty good snack, and they're not a nut that I'm tempted to eat a ton of.

[Katy131]

I think the researchers are seeing what they expect here, which of course is based on 50 years of flawed theorising and subsequent research on the same shaky basis.

First, they say that saturated fat causes just about any health problem you want to name, including hardening of the arteries and thus heart disease. They say this because cholesterol is found in dietary saturated fat (but 80% is produced in the body) and they have found that cholesterol forms part of the blockages in arteries. OK, they say, QED - high fat causes heart disease .... :lol:

Let me say here that old adage that you have probably all read many times: Blaming cholesterol for heart disease is like blaming the firemen for the fire! Cholesterol attaches to inflamed areas of the arteries in order to do its job which is to heal and repair.

50 years of research based on an unproved theory - a tough walnut to crack :D .... and all for the want of a horse shoe nail.

[GeorgeMead]

Blaming cholesterol for heart disease is like blaming the firemen for the fire! Cholesterol attaches to inflamed areas of the arteries in order to do its job which is to heal and repair.I not only love walnuts, but the wood of the tree is one of the most beautiful on earth.

[tom sawyer]

I used to be a little bit allergic to walnuts too, they would make my lips/mouth itch. Not so much anymore, since a lot of my allergic reactions are lessened after boing on LC for a few years.

They are great as a component in a nut crust for LC cheesecake. Or lightly sauteed in a little butter and added on top of butternut squash with a little Splenda and cinnamon/nutmeg, its like eating pumpkin pie.

[SunnyCarol]

The research, funded by the California Walnut Commission and published in the Journal of the American College of Cardiology, involved 24 adults. Volunteers were divided into two groups who for two weeks followed a Mediterranean diet designed to lower cholesterol levels, which was rich in fruit and vegetables and low in dairy products. Each group was given a high-fat meal of a salami-and-cheese sandwich followed by a full-fat yoghurt. One was also given five teaspoons of olive oil and the other was given about eight shelled walnuts.When will they ever do high fat research without the high carb/grain component? They never do the research with a true healthy high fat type meal. I know, they wouldn't get the results they are after if they didn't serve the high carbs along with high fat. Also, a group of 12 people per control group, coupled with only 14 days of the program will never give you good results.

I do believe that walnuts are healthy, but every time I eat them more than once or twice a week (1/8 cup at a time), I stop losing and start to gain.

Sunny!

[alisbabe]

Does anyone have a link to research on Dr. Ros's statement?

As to the rest of it, I like walnuts, and typically don't eat them because it's easier to get almonds. (And yeah, I realize that The California Walnut Commission isn't exactly an unbiased source).

the link between omega 6 fats (vegetable oils) and inflammation is supported (eg see http://www.omega3sealoil.com/Chapter3_1.html). First suggestion I've even read that other fats cause it though - omega 3's actually reduce inflammation, for a start.

I have no idea if said inflammation is in the right location etc to cause hardening of the arteries though

[alisbabe]

I think the researchers are seeing what they expect here, which of course is based on 50 years of flawed theorising and subsequent research on the same shaky basis.

Colpo thinks so too

http://www.theomnivore.com/One_High-Saturated_Fat_Meal%20.html