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Nutrient Density

March 9, 2010 Written by JP    [Font too small?]

Several weeks ago I posted a link on Twitter about the benefits of drinking water on weight loss. One response I received essentially asked, “Doesn’t everyone know that drinking water helps you lose weight?”. Well, I suppose many people do. But this reader’s question may reflect similar thoughts you’ve had while reading my daily blogs. You may detect familiar ground in some of the issues I cover. In fact, at times I even point out that I’m updating a particular health issue. The reason I do this may not be entirely clear. Scientists generally like to re-test widely held beliefs in order to clarify and verify them. Even the most widely accepted concepts in medicine benefit from further investigation. The result of such inquiries often add to the knowledge base and allow for a more accurate application of the information in question.

Just about everyone knows that nuts and seeds are among the healthiest foods we can eat. They’re rich in fiber, healthy fats, nutrients and protein. Provided there are no allergy issues, most people should probably eat more of them. That’s the prevalent opinion in the field of nutritional science at the moment. But are all nuts and seeds equal? You might get that impression because these snack foods are often lumped together into one seemingly indistinguishable category. After all, when’s the last time a doctor or nutritionist prescribed a specific nut or seed to you? “Take 2 ounces of almonds, but not cashews or macadamia nuts, and call me in the morning”.

The term “tree nuts” typically refers to nine common nuts: almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts. An analysis of the 5 year National Health and Nutrition Examination Survey (NHANES) specifically looked at the impact of eating these nuts in a population of 13,292 US men and women. Of that group, a subset of study volunteers was classified as “tree nut consumers”. On average, these participants ate more than a 1/4 ounce of nuts per day. The adults who consumed tree nuts regularly demonstrated a higher intake of several protective dietary components: calcium (+73 mg/day), fiber (+5 g/day), magnesium (+95 mg/day), potassium (+260 mg/day) and Vitamin E (+3.7 mg/day). On average, sodium intake was also lower in these study volunteers (-157 mg/day). The authors of the examination concluded that, “Tree nut consumption was associated with a higher overall diet quality score and improved nutrient intakes”. They went on advise that, “Specific dietary recommendations for nut consumption should be provided for consumers”. (1)

Fiber, minerals and vitamins aren’t the only reasons to consider eating more tree nuts. A new report published by the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University describes the importance of non-nutrient antioxidants that are also present in this valuable food commodity. The USDA researchers note that substances such as hydrolyzable tannins, lignans, napththoquinones, phenolic acids, phytosterols, polyphenols and tocopherols are perhaps as noteworthy or even more so than the more commonly cited minerals and vitamins in tree nuts. They go on to explain that these potent phytochemicals exhibit antioxidant, antiproliferative (cancer fighting), anti-inflammatory, antiviral and cholesterol lowering activity. (2)

The most recent example of how one could apply nuts to a daily wellness routine can be found in the April 2010 issue of the journal Nutrition. Turkish scientists enrolled “32 healthy young men” (aged 21 to 24) with normal cholesterol levels in an 8 week trial that examined the effects of dietary pistachios (Pistacia vera L.). The study began by administering a Mediterranean style diet to all the volunteers for 4 weeks. After which, 20% of the added (monounsaturated) fat in the diet was replaced with pistachio nuts. Several measures of cardiovascular health were tallied at all stages of the trial. Testing included: cholesterol panels, fasting blood glucose, C-reactive protein (CRP), interleukin-6 and tumor necrosis factor-alpha (inflammatory markers) and a measure of circulation referred to as “brachial endothelial function”.

  • The addition of pistachios decreased fasting glucose by almost 9%.
  • LDL (“bad”) cholesterol dropped by 11.9%, total cholesterol by 9.9% and triglycerides by 33.8%.
  • Circulation or “endothelium-dependent vasodilation” improved (a 30% relative increase) as well.
  • Of the inflammatory markers, only interleukin-6 levels significantly declined.

There was also evidence of a positive antioxidant shift in the pistachio study group. Lower levels of lipid hydroperoxide and malondialdehyde and an elevation of superoxide dismutase indicate a health promoting alteration in oxidative stress in the test subjects. The researchers remarked that, “These findings are in accordance with the idea that nuts, in particular pistachio nuts, have favorable effects beyond lipid lowering that deserve to be evaluated with prospective follow-up studies”. (3)

Eating Almonds Combats Oxidative Stress in Diabetics
Source: J Nutr. 2008 Sep; 138(9):1752S-1756S (link)

Lignans are a class of polyphenols commonly found in seeds. The body converts these phytochemicals into bioactive substances such as enterolignans, enterodiol and enterolactone which exert modest estrogenic effects in the body. In addition, or perhaps because of this, they appear to play a role in supporting cardiovascular health and protecting against certain hormonally-dependent cancers. (4)

Flaxseeds and sesame seeds are two of the most abundant sources of lignans in the modern diet. A few recent studies have examined the effects of these two lignan donors in varied populations. The first was a double-blind, placebo-controlled experiment which involved 38 postmenopausal women. Half of the participants consumed two slices of bread that were supplemented with 25 grams of flaxseeds (providing 46 mg of ligans/day). The remainder was provided with wheat bran enriched bread, containing <1 mg of lignans/day. After 12 weeks, various indicators of cardiovascular and hormonal status were compared to baseline measures. No significant differences were exhibited between the two groups. However, it is interesting to note that all the women reported reductions in hot flashes and an overall improvement in menopausal symptoms as assessed by Kupperman Menopausal Index scores. (5)

The inclusion of 25 grams of sesame seeds daily, providing 50 mg of lignans, also failed to alter the health status of a group of “overweight or obese men and women”. This particular sesame investigation employed an even more accurate testing model than the previously mentioned flax study. The participants were administered sesame seeds or a placebo for 5 weeks. Following the initial 5 week intervention, there was a 4 week break or “washout period”. Finally, the study volunteers were given the opposite intervention for an additional 5 weeks (referred to as a crossover study). The researchers detected a dramatic 8-fold increase in the “urinary excretion of mammalian lignans, enterolactone and enterodiol” as a consequence of sesame intake. However, no relevant changes were documented in terms of blood pressure, inflammatory markers, lipid levels or oxidative stress. (6)

The point of today’s column isn’t necessarily to say that tree nuts are a better choice than flaxseeds or sesame seeds. My objective is simply to point out that not all nuts and seeds are created equal. In future studies, scientists may very well discover that higher levels of flaxseeds or sesame seeds are needed to evoke meaningful health benefits. Pistachios may continue to gain a heart healthy reputation or they could possibly be eclipsed by some other nutty contender. The real take home message here is that there is value in knowing the scientific track record of what you eat, especially if you plan to use food therapeutically.

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

Be well!


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Posted in Diabetes, Heart Health, Nutrition

7 Comments & Updates to “Nutrient Density”

  1. Nina K. Says:

    Morning JP 🙂

    from where do you always get those funny pics 🙂 ? I made a for me problematic detection: when i eat more sesame seeds and flax seeds it seems that they push estrogen very much. This is a problem for every women with estrogen dominance (PMS-symptoms). To reduce that fiber intake must be increased. But overall nuts and seeds are the best 🙂

    Greetings from the far side….
    Nina K.

  2. JP Says:

    Good day, Nina!

    We search high and low for the photos we use! 🙂

    That’s an interesting observation about the flax and sesame seeds. It just goes to show you that we need to be aware of how natural foods affect us an individuals. Even generally healthy foods can be inappropriate under certain circumstances. Thank you for this valuable reminder.

    Be well!


  3. JP Says:

    Update 06/05/15:


    Eur J Nutr. 2015 Jan 8.

    Effects of Brazil nut consumption on selenium status and cognitive performance in older adults with mild cognitive impairment: a randomized controlled pilot trial.

    PURPOSE: Oxidative stress is closely related to cognitive impairment, and the antioxidant system may be a potential therapeutic target to preserve cognitive function in older adults. Selenium plays an important antioxidant role through selenoproteins. This controlled trial aimed to investigate the antioxidant and cognitive effects of the consumption of Brazil nuts, the best selenium food source.

    METHODS: We enrolled 31 older adults with mild cognitive impairment (MCI) who were randomly assigned to ingestion of Brazil nuts or to the control group. Participants of the treatment group consumed one Brazil nut daily (estimated 288.75 µg/day) for 6 months. Blood selenium concentrations, erythrocyte glutathione peroxidase (GPx) activity, oxygen radical absorbance capacity, and malondialdehyde were evaluated. Cognitive functions were assessed with the CERAD neuropsychological battery.

    RESULTS: Eleven participants of the treated group and nine of the control group completed the trial. The mean age of the participants was 77.7 (±5.3) years, 70 % of whom were female. We observed increased selenium levels after the intervention, whereas the control group presented no change. Among the parameters related to the antioxidant system, only erythrocyte GPx activity change was significantly different between the groups (p = 0.006). After 6 months, improvements in verbal fluency (p = 0.007) and constructional praxis (p = 0.031) were significantly greater on the supplemented group when compared with the control group.

    CONCLUSION: Our results suggest that the intake of Brazil nut restores selenium deficiency and provides preliminary evidence that Brazil nut consumption can have positive effects on some cognitive functions of older adults with MCI.

    Be well!


  4. JP Says:

    Update 06/05/15:


    Nutrition Journal 2015, 14:54

    Improvement of antioxidant status after Brazil nut intake in hypertensive and dyslipidemic subjects

    Objectives: To investigate the effect of partially defatted Granulated Brazil nut (GBN) on biomarkers of oxidative stress and antioxidant status of hypertensive and dyslipidemic patients on nutrition and drug approaches.

    Methods: Ninety one hypertensive and dyslipidemic subjects of both genders (51.6 % men), mean age 62.1 ± 9.3 years, performed a randomized crossover trial, double-blind, placebo controlled. Subjects received a diet and partially defatted GBN 13 g per day (≈227.5 μg/day of selenium) or placebo for twelve weeks with four-week washout interval. Anthropometric, laboratory and clinic characteristics were investigated at baseline. Plasma selenium (Se), plasma glutathione peroxidase (GPx3) activity, total antioxidant capacity (TAC), 8-epi PGF2α and oxidized LDL were evaluated at the beginning and in the end of each intervention.

    Results: GBN intake significantly increased plasma Se from 87.0 ± 16.8 to 180.6 ± 67.1 μg/L, increased GPx3 activity in 24,8 % (from 112.66 ± 40.09 to 128.32 ± 38.31 nmol/min/mL, p < 0,05), and reduced 3.25 % of oxidized-LDL levels (from 66.31 ± 23.59 to 60.68 ± 20.88 U/L, p < 0.05). An inverse association between GPx3 and oxidized LDL levels was observed after supplementation with GBN by simple model (β -0.232, p = 0.032) and after adjustment for gender, age, diabetes and BMI (β -0.298, p = 0.008). There wasn’t association between GPx3 and 8-epi PGF2α (β -0.209, p = 0.052) by simple model. Conclusion: The partially defatted GBN intake has a potential benefit to increase plasma selenium, increase enzymatic antioxidant activity of GPx3 and to reduction oxidation in LDL in hypertensive and dyslipidemic patients. Be well! JP

  5. JP Says:

    Update 07/09/15:


    Br J Nutr. 2015 Apr;113(S2):S79-S93.

    Nutrition attributes and health effects of pistachio nuts.

    Epidemiological and/or clinical trials have suggested that nut consumption has a beneficial impact on health outcomes such as hypertension, diabetes, CVD, cancer, other inflammatory conditions and total mortality. Nuts are nutrient-dense foods with a healthy fatty acid profile, as well as provide other bioactive compounds with recognised health benefits. Among nuts, pistachios have a lower fat and energy content and the highest levels of K, γ-tocopherol, vitamin K, phytosterols, xanthophyll carotenoids, certain minerals (Cu, Fe and Mg), vitamin B6 and thiamin. Pistachios have a high antioxidant and anti-inflammatory potential. The aforementioned characteristics and nutrient mix probably contribute to the growing body of evidence that consumption of pistachios improves health. The present review examines the potential health effects of nutrients and phytochemicals in pistachios, as well as epidemiological and clinical evidence supporting these health benefits.

    Be well!


  6. JP Says:

    Updated 1/17/16:


    Nutr Res. 2016 Jan;36(1):80-89.

    Diet quality improves for parents and children when almonds are incorporated into their daily diet: a randomized, crossover study.

    The health benefits of nuts may, in part, be due to the fiber that provides substrate for the maintenance of a healthy and diverse microbiota. We hypothesized that consuming almonds would benefit immune status through improving diet quality and modulation of microbiota composition in parents and their children, while improving gastrointestinal function. In a crossover trial, 29 parents (35 ± 0.6 years) and their children (n = 29; 4 ± 0.2 years; pairs) consumed 1.5 and 0.5 oz, respectively, of almonds and/or almond butter or control (no almonds) for 3 weeks followed by 4-week washouts. Parents completed daily questionnaires of stool frequency and compliance with nut intake. The Gastrointestinal Symptom Response Scale was administered weekly. Participants provided stools for microbiota analysis and saliva for secretory immunoglobulin A. Serum antioxidant/proinflammatory balance was determined in parents. From weekly dietary recalls (Automated Self-Administered 24-Hour Dietary Recall), nutrient and energy intake were assessed and Healthy Eating Index-2010 scores were calculated. Consuming almonds increased total Healthy Eating Index score from 53.7 ± 1.8 to 61.4 ± 1.4 (parents) and 53.7 ± 2.6 to 61.4 ± 2.2 (children; P < .001). Minimal changes in gastrointestinal symptoms and no change in stool frequency were noted with the almond intervention. Microbiota was stable at the phylum and family level, but genus-level changes occurred with nut intake, especially in children. No differences were observed for immune markers. Although higher intakes of almonds or longer interventions may be needed to demonstrate effects on immune status, a moderate intake of almonds improves diet quality in adults and their young children and modulates microbiota composition. Be well! JP

  7. JP Says:

    Updated 06/29/16:


    Nutr Today. 2016 May;51(3):133-138.

    Compared with other nuts (Table ​(Table1),1), dry roasted pistachios have a lower fat content (43.4 g/100 g), which is composed mainly of saturated fatty acid (5.6 g), polyunsaturated fatty acid (13.3 g), and monounsaturated fatty acid (24.5 g)3 (Figure ​(Figure1A).1A). Of the fatty acids, oleic and linoleic acids represent more than half of the total fat content in pistachios. Pistachios are also a good source of vegetable protein (about 21% of total weight), with an essential amino acid ratio higher than most other commonly consumed nuts (ie, almonds, walnuts, pecans, and hazelnuts), and they have a high percentage of branched chain amino acids.4 The amount of total carbohydrates is low to moderate (about 29% by weight), but they are richer in fiber than other nuts with a 10% by weight of insoluble forms and 0.3% of soluble forms (Table ​(Table1).1). Pistachios also contain significant amounts of minerals (ie, potassium, phosphorus, magnesium, calcium; Figure ​Figure1B)1B) and vitamins such as vitamin A, vitamin E (especially γ-tocopherol), vitamin C, vitamin B (except B12), vitamin K, and folate (Table ​(Table2),2), with relatively high amounts of these compounds compared with other nuts.5 Moreover, pistachios are also a rich source of lutein and zeaxanthin (xanthophyll carotenoids) and phenolic compounds, including anthocyanins, flavonoids, and proanthocyanidins, and their antioxidant capacity is considerable. Pistachios are the nuts that have the highest content of phytosterols, including stigmasterol, campesterol, and β-sitosterol.6 This complete and diverse set of micronutrients and macronutrients means that pistachio nuts are potentially one of the more health-promoting foods.

    Be well!


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