Walnuts keep your blood flowing

It’s no secret that nuts are good for your heart. We know that consuming nuts can dramatically reduce cardiovascular disease risk, but scientists are just beginning to figure out how this works.  We recently learned that almonds have a potent antioxidant effect, leading to decreases in circulating oxidized LDL, helping to keep the arteries clear of atherosclerotic plaque.

Like all nuts, walnuts are rich in fiber, minerals, micronutrients, phytosterols, antioxidants, and monounsaturated fats, but walnuts stand out because of their distinctively high levels of ALA, an omega-3 fatty acid and precursor to EPA and DHA.

Researchers at Yale University wondered whether walnuts would have beneficial effects on blood vessel function in individuals at risk for cardiovascular disease – those with type 2 diabetes.

Twenty-four subjects with type 2 diabetes were included in the study.  Half were assigned to supplement their diets with 2 ounces of walnuts per day for 8 weeks

The researchers tested flow-mediated dilatation (FMD), which is a measure of how well the endothelial cells, the cells that line all blood vessels, are working to keep blood pressure in a favorable range.  One of the endothelial cells’ most important jobs is to produce nitric oxide, which regulates blood pressure by relaxing the muscle in the walls of the arteries.

After 8 weeks of daily walnut consumption, flow-mediated dilatation was improved – the blood vessels were able to dilate more in the subjects who ate walnuts.1  This is good news for overall cardiovascular disease risk since loss of endothelial function is one of the initiating events in atherosclerotic plaque development.

Want another reason to eat some walnuts?  They may also protect against breast cancer and prostate cancer2, according to animal studies. Fascinatingly, nuts and seeds also promote weight loss.  Research on the issue shows when an equal number of carbohydrate calories are replaced with nuts and seeds weight loss increases. Scientists from Purdue University did a thorough review of all the research studies that looked at nut intake and weight loss. Not only did they find nuts were a rich source of nutrients and protect the heart and blood vessels, but they found a surprising inverse association between nut intake and Body Mass Index. Most studies explained this as being due to the appetite suppressing effect of nuts, but like beans all the calories may not be bio-accessible, meaning that not all of the calories in nuts are absorbed. Plus, they enhance the absorbtion of nutrients in vegetables when consumed in the same meal. 3

We can apply this information by following Dr. Fuhrman’s recommendations to include a variety of nuts and seeds in our diets. As time goes on, we can be sure that scientists will continue to reveal many more health-promoting properties of nuts and seeds. 


 

References:

1. Ma Y, Njike VY, Millet J, et al. Effects of walnut consumption on endothelial function in type 2 diabetic subjects: a randomized controlled crossover trial. Diabetes Care. 2010 Feb;33(2):227-32. Epub 2009 Oct 30.

 

Medscape Medical News: Walnuts Shown to Improve Endothelial Function in Diabetics

http://www.medscape.com/viewarticle/717343?sssdmh=dm1.597249&src=confwrap&uac=74561DY

2. Eurekalert! Walnuts slow prostate tumors in mice: UC Davis research shows walnuts affect genes related to tumor growth

http://www.eurekalert.org/pub_releases/2010-03/uoc--wsp032210.php

3. Mattes RD et al. Impact of peanuts and tree nuts on body weight and healthy weight loss in adults. J Nutr. 2008 Sep;138(9):1741S-1745S.

Antioxidants in almonds keep your arteries clean

Nuts are nutrient dense – they contain a spectrum of micronutrients including LDL-lowering phytosterols, circulation-promoting arginine, minerals - potassium, calcium, magnesium, selenium, and antioxidants including phenols, resveratrol, tocopherols (vitamin E), and carotenoids.

Almonds

Nuts, and almonds in particular, are some of the most beneficial foods for decreasing heart disease risk: 

  • A 2009 meta-analysis confirmed that almond consumption of at least 25 g per day (about 1 ounce) is associated with a 7 mg/dL decrease in total cholesterol.1 
  • Collectively, the data from the four most recent U.S. studies estimates that Americans who eat five or more servings of nuts per week have a 35% reduced risk of coronary heart disease.2 

There are many potential mechanisms by which nuts might exert these beneficial effects on heart health – the dramatic decrease in heart disease risk from nut consumption can’t be explained by cholesterol lowering alone. Scientists are now investigating the antioxidant and anti-inflammatory properties of nuts for their potential cardioprotective effects.

Almonds may have powerful antioxidant activity, in addition to their cholesterol-lowering activity. As well as their vitamin E, the skins of almonds contain a large and varied collection of phenol antioxidants. 

A study of hyperlipidemic individuals fed either almonds or a snack with a similar fatty acid profile each day for 4 weeks compared markers of oxidative stress in these two groups. The subjects fed almonds showed reductions in markers of oxidative stress.3 

This alleviation of oxidative stress was reflected in reduces serum levels of oxidized LDL.4 Since oxidation renders LDL more likely to be taken up by inflammatory cells, oxidized LDL is more dangerous in relation to atherosclerotic plaque formation. The synergistic effects of the healthy fats, antioxidants, and surely many other phytochemicals in almonds help to prevent this early and important step in the development of atherosclerosis. Though this study was reported on almonds, other nuts and seeds have similar marked effects that protect the heart.   

 

References:

1. Phung OJ, Makanji SS, White CM, Coleman CI. Almonds have a neutral effect on serum lipid profiles: a meta-analysis of randomized trials. J Am Diet Assoc. 2009 May;109(5):865-73.

2. Kris-Etherton PM et al. The Role of Tree Nuts and Peanuts in the Prevention of Coronary Heart Disease: Multiple Potential Mechanisms. J. Nutr. 138: 1746S–1751S, 2008.

3. Jenkins DJ, Kendall CW, Marchie A, et al. Almonds Reduce Biomarkers of Lipid Peroxidation in Older Hyperlipidemic Subjects. J. Nutr. 138: 908–913, 2008.

USDA/Agricultural Research Service (2008, November 4). Antioxidant Effects From Eating Almonds. ScienceDaily. Retrieved February 25, 2010, from http://www.sciencedaily.com /releases/2008/10/081031213057.htm

4. Jenkins DJ, Kendall CW, Marchie A, et al. Dose response of almonds on coronary heart disease risk factors: blood lipids, oxidized low-density lipoproteins, lipoprotein(a), homocysteine, and pulmonary nitric oxide: a randomized, controlled, crossover trial. Circulation. 2002;106:1327–32.

 

Pomegranates Fight Cell Inflammation

A new study in Journal of Inflammation claims polyphenols, plant nutrients that reduce the risk of cardiovascular disease and cancer, contained in pomegranate extract inhibit the production of inflammatory compounds, potentially preventing chronic inflammation associated with heart disease, Alzheimer's, osteoporosis, diabetes and arthritis. For the study, scientists stimulated cells to prompt an inflammatory response and then incubated the cells with pomegranate. Results showed pomegranate extract decreased pro-inflammatory reaction; Bakery and Snacks investigates.

Pomegranates are the real deal. Dr. Fuhrman calls them potent disease-fighters, especially for prostate cancer. In 2006, a study revealed men drinking pomegranate juice had better PSA scores. And pomegranates have also been found to help prevent atherosclerosis and diabetes.

In related news, the term “antioxidants” is resonating with consumers and increasing their willingness to try products including them. Maybe that’s the why the pomegranate phone is so darn cool.

Image credit: John-Morgan