Category Archives: dietary fiber

Dietary fibre intake is associated with increased skeletal muscle mass and strength (Paper Review)

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Papers referenced in the video:

Higher dietary fibre intake is associated with increased skeletal muscle mass and strength in adults aged 40 years and older…

A defined, plant-based diet utilized in an outpatient cardiovascular clinic effectively treats hypercholesterolemia and hypertension and reduces medications…

The Impact Of The Microbiome On Lifespan

Germ-free mice (animals don’t have a microbiome) live longer than microbiome-containing mice, but it’s impractical for people to live in a bubble for their entire lifespan. As a more practical approach, which microbiome-derived factors impact lifespan, and can they be modified?

Dietary supplementation with acarbose increases lifespan, and one reason for that may involve reduced circulating levels of glucose, but the other side of that story involves increased gut bacterial production of short chain fatty acids (SCFAs). Whether acarbose will increase lifespan in people is unknown, and with the goal of increasing lifespan, are there other ways to increase SCFAs?

Biological Age Test #4 in 2020: Getting Better or Getting Worse?

My latest blood test results are in-how’s my biological age? In the video I discuss my dietary approach prior to my latest blood test, the blood test results, and my plan to improve them going forward.

Optimizing Blood Cholesterol Levels: What’s My Data?

In an earlier video, I presented data for total cholesterol (TC) levels in blood in terms of changes during aging and all-cause mortality risk. I’ve measured TC 25 times in the past 5 years, and in this video, I present that data, and my approach to optimize it.

Blood Test Analysis In A 100 Year Old Subject

What are the blood biomarkers of a centenarian, and is there room for improvement? Find out in the video below!

Dietary Fiber Improves Antiviral Defense

CD8+ T cells are a subset of lymphocytes that play a major role in antiviral defense (Kulinski et al. 2013). However, recently published evidence shows reduced levels of circulating CD8+ T cells in people infected with SARS-CoV-2 (Zheng et al. 2020, Wang et al.  2020; HC= healthy controls, NCP = patients with COVID-19 related pneumonia):


Immune enhancing treatments, including thymalfasin and immunoglobulin are being provided to SARS-COV-2 infected subjects with some success. For example, 37/55 (67%) subjects saw improvements for circulating CD8+ levels in Wang et al. 2020, but additionally, 18/55 subjects did not experience increased CD8+ counts:

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Accordingly, levels of CD8+ T cells were identified as an independent predictor for COVID-19 severity and treatment efficacy (Wang et al. 2020). When considering that CD8+ cells were not increased in all subjects in Wang et al., are there are other strategies that may be helpful? Interestingly, increased levels of CD8+ cells are found in the lungs of mice infected with the influenza A virus in response to a high soluble-fiber diet, when compared with control-fed mice (Trompette et al. 2018):

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As a result, lung viral load is more than 10-times reduced 8-days after infection in high soluble fiber-fed mice:

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Moreover, average survival in mice infected with influenza A is significantly better when fed the high soluble-fiber diet, when compared with control fed-mice:

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Is it possible that a high soluble fiber diet can increase CD8+ cells in people infected with SARS-CoV-2, thereby enhancing their recovery and survival? No studies have tested this hypothesis (yet). While conventional medical treatment is obviously helpful, based on the findings of Trompette et al. (2018), further optimization of immune defense against viral infections may occur when including soluble fiber-rich foods.


Kulinski JM, Tarakanova VL, Verbsky J. Regulation of antiviral CD8 T-cell responses. Crit Rev Immunol. 2013;33(6):477-88. Review.

Trompette A, Gollwitzer ES, Pattaroni C, Lopez-Mejia IC, Riva E, Pernot J, Ubags N, Fajas L, Nicod LP, Marsland BJ. Dietary Fiber Confers Protection against Flu by Shaping Ly6c Patrolling Monocyte Hematopoiesis and CD8+ T Cell Metabolism. Immunity. 2018 May 15;48(5):992-1005.e8. doi: 10.1016/j.immuni.2018.04.022.

Wang F, Nie J, Wang H, Zhao Q, Xiong Y, Deng L, Song S, Ma Z, Mo P, Zhang Y. Characteristics of peripheral lymphocyte subset alteration in COVID-19 pneumonia. J Infect Dis. 2020 Mar 30. pii: jiaa150. doi: 10.1093/infdis/jiaa150.

Zheng M, Gao Y, Wang G, Song G, Liu S, Sun D, Xu Y, Tian Z. Functional exhaustion of antiviral lymphocytes in COVID-19 patients. Cell Mol Immunol. 2020 Mar 19. doi: 10.1038/s41423-020-0402-2.

Coronavirus isn’t the only virus that negatively affects human health.

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Biological Age = 32.75y, Chronological Age = 47y: First 2020 measurement

Measurement of biological age with Levine’s Phenotypic Age calculator is strongly correlated with chronological age (r=0.94; see In 2019, I measured all 9 of its analytes 3 times, with biological age readings of 35.39y, 35.58y, and 31.3y, for an average 2019 biological age of 34.09y (see That’s 12 years younger than my chronological age in 2019, 46y!

On Feb 12, I had my first blood test measurement of 2020. I expected to see a worse biological age, as over the past week, I’d been hit with the flu, and since my last measurement in 2019, I made a few changes to my diet that I didn’t expect to favorably affect it. In contrast, I’ve been purposefully in a mild caloric restriction in an attempt to reduce my body fat from a relatively lean 10-12% to lower values. Since my last blood test 3+ months ago, my average calorie intake was 2553, which is 5-10% less than my maintenance intake, 2700-2800 calories/day. So how did these variables affect my biologic age? Let’s have a look at the data!

2020 BA

My biological age was 32.75y, which is less than my 2019 average value, and better than I expected considering the factors mentioned above! Note that there is room for improvement, including my creatinine and WBC levels, which both increased when compared with my average 2015-2019 values (which included 23 blood tests). My average daily fiber intake has been ~100g/day for a few years, and over the past 3 months, I purposefully reduced that to ~70g/day. Conversely, I increased my intake of meat, eggs, and cheese intake during that period, to see if eating less fiber and more animal products would negatively impact my blood test results. For me, eating more animal protein and less total fiber may not be optimal, as my creatinine levels also rose in 2019 when I performed a similar dietary experiment. Note that creatinine levels increase with age (see, so if I can avoid that by altering my diet, I will. For the next blood test, I’ll reduce, but not eliminate my intake of meat, eggs, and cheese, and I expect that my creatinine levels will decrease back towards my average 2015-2019 value of 0.94 mg/dL.

Also note my WBCs-although they’re not higher than the 3.5-6 optimal range (see, they’re increased when compared with my average 2015-2019 value of 4.5. This increase is more than likely a result of the flu/infection that I’m battling. Once it passes, I expect it to return to close to my average WBC value, ~4.5.

Going forward, I expect my creatinine and WBCs to come down to their average values, which would result in a biological age that is closer to 30y on my next blood test. Stay tuned for that data!

To quantify your biological age using Levine’s Phenotypic Age calculator, here’s the Excel link! DNAmPhenoAge_gen (1)

If you’re interested, please have a look at my book!

High-Fiber Diets Are Associated With Reduced All-Cause Mortality Risk

A meta-analysis of 10 studies, including 80,139 subjects was recently published that shows a significantly reduced risk of death for all causes in association with higher total dietary fiber intakes (35-39g/day), when compared with lower fiber (Reynolds et al. 2019):

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Should we supplement with fiber, or get it from whole food? Fiber from whole foods was significantly associated with lower levels of fasting glucose, body weight, whole body fat mass, LDL cholesterol, and triglycerides. Supplementation with fiber extracts or bran was not significantly associated with the reduction of any of these variables (NS, not significant; NM, not measured:




Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet. 2019 Feb 2;393(10170):434-445. doi: 10.1016/S0140-6736(18)31809-9.


If you’re interested, please have a look a my book!