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.

Walnuts are So Good for You (and Mice)

A diet high in walnuts may significantly decrease a person's risk of breast cancer, according to a study conducted by researchers from the Marshall University School of Medicine and presented at a conference of the American Association for Cancer Research.

A chemical analysis showed that omega-3 fatty acids, antioxidants and phytosterols contained in walnuts all contributed to the mice's tumor resistance.

"The omega-3 fatty acid, the phytosterols and antioxidants individually have been shown to prevent or delay cancers" Hardman said. "So if you add them all together, it looks like it may be really good."

In another study, Hardman found that feeding mice a diet enriched with the same omega-3 content as that contained in the walnut dose given in the current study was not as effective as eating the whole walnut.

"It did reduce cancer incidents," she said, "but not as dramatically as the walnut-containing diet did. So it's something else other than the omega-3 in the walnut that's contributing to the suppression of cancers."

Hardman noted that the effect of the whole food was probably greater than the sum of its parts.

With dietary interventions, you see multiple mechanisms when working with the whole food, she said.

For 20 years, I’ve been telling people to eat walnuts as a superfood; now we know it’s good for mice too.

Nuts and seeds contain plant sterols and other phytochemical compounds that we are just beginning to understand their benefits. Eating the whole food guarantees we are getting all of the known and unknown beneficial micronutrients contained in these superfoods.

 Sources for this story include: health.usnews.com www.voanews.com.

Higher Omega-3 Levels Linked to Lower Bodyweight

Omega-3 fatty acids, the good fats recently found to improve heart health and help prevent prostate cancer, are now being associated with lower bodyweight.

Published in the British Journal of Nutrition, scientists observed that overweight or obese people had blood levels of omega-3s roughly 1% lower than healthy people.

For the study, 124 people of varying bodyweights—21 were classified as healthy weight, 40 overweight and 63 obese—had blood samples taken, with results showing an inverse relationship between omega-3 levels and participants’ waist size and hip circumference.

Obese people had omega-3 levels of 4.53%, but healthy people had levels of 5.25%.

Sure, it’s only a small difference, but healthy bodyweight is just one perk of omega-3s. Other reports have shown omega-3 fatty acids offer protection from stroke, depression linked to pregnancy and help lower young children’s risk of type-1diabetes.

Good sources of omega-3 include flaxseed, walnuts and micro algae-derived supplements.

Via Food Navigator.

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What Vegans May Be Missing...

Certainly a plant-based diet which minimizes animal products is the best approach for losing weight, preventing and reversing disease, and optimizing health. However, those following a vegetarian or vegan diet, and those not consuming fatty fish like salmon each week, should be aware of recent studies that suggest they may be deficient in a critical and essential nutrient, especially EPA & DHA, the long-chain omega-3 fatty acids.

Alpha-linolenic acid (ALA) is an omega-3 fat and is the precursor of the longer chain omega 3 fats eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and to a lesser extent DHA can be made in the body from ALA. Primary sources of these fatty acids are certain fish and seafood.

As a result, vegetarian, and especially vegan, diets provide little EPA and DHA directly. A recent study reviewed the varying dietary fat intake across vegetarians, vegans, omnivores, and semi omnivores and its impact on essential omega-3 fatty acid availability in tissues. It concluded that vegetarians were left with reduced levels of omega-3 and recommended that they consume additional direct sources of EPA and DHA, regardless of age or gender, for physical, mental and neurological health benefits.1

In addition, ALA, EPA, and DHA are especially important for the prevention of certain cancers, particularly those of the breast and colon, and possibly of the uterus and the skin, and are likely to reduce the risk of postpartum depression, manic-depressive psychosis, dementias, Parkinson's, hypertension, toxemia, diabetes, and to a certain extent, age-related macular degeneration.2

Although vegetarian diets are generally lower in total fat, saturated fat, and cholesterol than are non-vegetarian diets and may appear to offer cardiovascular health benefits due to higher intakes of antioxidants and fiber, the lack of direct EPA or DHA dietary sources may cause an adverse effect.3,4

With all of this documented research, it is not surprising that when I draw blood for fatty acid analysis on many of my patients, I find that a large percentage of individuals who do not eat fish or seafood regularly do not have optimal levels of DHA, even those eating walnuts and flaxseeds on a regular basis. I often see patients eating otherwise excellent diets with itchy dry skin, seborrheac dermatitis and other signs of DHA deficiency.

Although, there are some vegans and vegetarians regularly consuming walnuts and flaxseeds (which supply adequate ALA) may produce enough DHA on their own and may not require supplementation. However, because this issue is so imperative to their health it should be confirmed with a blood test before assuming that the conversion level is adequate. In order to assure optimal production of DHA fat, without recommending that the consumption of fish or refined fish oils, I recommend taking a vegetable sourced DHA supplement. DHA alone can deliver the same benefits of fish oil, since the intake of DHA can cause a natural retro-conversion to EPA internally.

Laboratory cultivated DHA is made from microalgae and is a pure form of DHA without environmental contamination. It is grown in the laboratory, not collected in the wild. It has no mercury or other toxins, which is a concern even for non-vegans who are cautious about eating fish or seafood.

DHA has been shown to protect against dementia, depression, inflammatory diseases, attention deficit and hyperactivity disorder (ADHD), allergies, and to offer significant benefits for overall cardiovascular health.

There are other problems with consuming fish oils. The main problem is that the fat turns rancid as it sits on store shelves. As a result, many people complain of burping, indigestion, a foul taste, and long lasting fish-breath. I have also observed that rancidity of this fish fat can place a stress on the liver. Patients of mine have had blood tests showing abnormal liver function when consuming fish oil in significant amounts and then have had these tests return to normal when the fish oils were stopped.

Fortunately, vegetable derived DHA, from microalgae, is an alternative. However, even algae derived DHA can become rancid if not cared for properly. We go through great lengths to deliver the purest and freshest DHA product available on the market today. My DHA Purity is manufactured under strict conditions to ensure purity. Every step of the way, from production to packaging, transportation and storage, this product is kept refrigerated and handled to ensure optimal freshness.

In conjunction with a high nutrient, plant-based diet, I advise all people take a daily DHA supplement from a clean source. Early in life, DHA is supplied via the placenta and from breast milk. While adequate DHA is particularly important for pregnant and nursing women and young children, it is beneficial for all ages!

1. Kornsteiner M, Singer I, Elmadfa I. Very low n-3 long-chain polyunsaturated fatty acid status in Austrian vegetarians and vegans. Ann Nutr Metab. 2008; 52(1):37-47.

2. Bourre JM Dietary omega-3 fatty acids for women. Biomed Pharmacother. 2007; 61(2-3):105 12.

3. Davis BC; Kris-Etherton PM Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications. Am J Clin Nutr. 2003; 78(3 Suppl):640S-646S

4. Lee HY; Woo J; Chen ZY; Leung SF; Peng XH Serum fatty acid, lipid profile and dietary intake of Hong Kong Chinese omnivores and vegetarians. Eur J Clin Nutr. 2000; 54(10):768-73.

Image credit: CB Photography

Citrus Fruits Help Stave Off Vision Loss

Its not just citrus fruits, new findings in the journal Ophthalmology suggest older adults eating a lot of leafy greens, citrus fruits and fish are less likely to develop age-related macular degeneration (AMD), a major contributor to vision lose. Studying the diets of 4,000 adults, experts claim foods rich in omega-3s, vitamin C and E, zinc and antioxidants lower the risk of AMD. These low-sugar foods do not cause surges in blood pressure, which may harm retinas; Reuters reports.

Actually, last year researchers determined plant nutrients lutein and zeaxanthin, found in foods like spinach, kale and collard greens, promote eye health and prevent cataracts, while eating red meat 10 times week increases the likelihood of age-related macular degeneration by 47%.

In related news, a recent study showed vegetable-based diabetes offer superior diabetes control and omega-3 fatty acids, like those contained in walnuts, reduce inflammation linked to heart disease.

Image credit: Yannick .

Health-Points: Friday 5.1.09

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Eat Lignans for Healthier, Thinner Women

A new study in the British Journal of Nutrition claims a diet rich in lignans, phytochemicals found in flaxseed, whole grains, berries and other fruits and vegetables, lowers women’s body mass index and significantly reduces blood glucose levels. Participants, 115 women, tracked their lignan intake using a 3-day dietary record and blood tests revealed those women with the highest lignan levels had less body fat and a better metabolic profile, including higher insulin sensitivity; Nutraingredients reports.

Seeds are a great source of lignans! According to Dr. Fuhrman, lignans are a type of fiber and eating foods, like flaxseed, has been shown to protect against heart disease and cancer. Sesame seeds are cool too. They’re loaded with calcium, magnesium, copper, iron, manganese, zinc, fiber and vitamins.

Actually, my breakfast pudding is made with both sesame seeds and flaxseed. It’s also got sunflower seeds, walnuts and avocado, lots of healthy fats! Sometimes I throw blueberries in too.

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