Category Archives: Mean Corpuscular Volume (MCV)

Biological Age = 31.3y, Chronological Age= 46y

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On June 10, 2019 (for the first time) I measured all of the blood test variables that are included in the biologic age calculator, Phenotypic Age, and ended up with a biological age = 35.39y (https://michaellustgarten.wordpress.com/2019/09/09/quantifying-biological-age/).

While that value is 23% younger than my chronological age (46y), I knew that I could do better! So I tried again on September 17, 2019. Basically, the same biological age, 35.58y:

pheno 8_2019.png

An 23% younger biological age on 2 separate dates, months apart might be good for most, but not for me. So, I tried again on October 29th, 2019, and voila, a biological age of 31.3y, which is 32% younger than my chronological age! How did I do it?

oct pheno.png

From my last blood test until my most recent blood test, I attempted a mild caloric restriction. To maintain my body weight, I require about 2800 calories per day, an amount which is based on daily body weight weighing in conjunction with daily dietary tracking. For the period of time that elapsed between my last 2 blood tests, I averaged 2657 calories/day, which is 3.2% less than the 2745 calories/day that I averaged for the dietary period that corresponded to my September blood test. That I was also in a very mild caloric restriction is confirmed by a reduction in my average body weight, which was (purposefully) down 0.7 lbs from September 17 to October 29th, when compared with the dietary period that corresponded to my September blood test (August 20 – September 17).

This is a superficial analysis of how I further reduced my biological age, but in future posts I’ll report the average dietary intake that corresponded to my relatively youthful biologic age!

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

Optimizing Biological Age: MCV

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Mean corpuscular volume (MCV) is one of the 10 variables included in the biological age calculator, PhenoAge (see https://michaellustgarten.wordpress.com/2019/09/09/quantifying-biological-age/). It’s calculated by dividing the fraction of the blood that contains RBCs (hematocrit) by RBCs (MCV = hematocrit/RBC), thereby identifying the average volume contained within red blood cells. Although the MCV reference range is 80 – 100 femtoliters (10^-15L), what’s optimal in terms of a youthful biological age, and minimized disease risk?

MCV increases during aging. In support of this, using a small subset of samples from the Baltimore Longitudinal Study on Aging (values not in parentheses), MCV increased from average values of 88.8 in young (18-39y), to 91.3 in middle-aged (40-59y), to 92.4 in old (>60y) subjects. Similarly, MCV also increased in the full sample size from the Baltimore Longitudinal Study on Aging (values in parentheses) from 89.2 to 91.1 to 92.9 in young, middle-aged and old, respectively (Araki and Rifkind, 1984):

Screen Shot 2019-10-12 at 3.32.31 PM

In a larger study that included 3,358 subjects, MCV increased from median values of 92.2 in women and 93.4 in men younger than 60y to 94.2 and 95.7 in women and men older than 60y, respectively (Lee et al. 2018):

mcv age

When considering that MCV increases during aging, one would predict that higher levels would be associated with an increased risk of death of all causes. In support of this, in the 36,260 subjects of Yoon et al. (2016), MCV levels > 94.2 in women and > 95.8 in men (Tertile 4) were associated with a 55% and 44% increased risk of death from all causes, respectively, when compared with MCV values between 89.2 – 91.6 in women and 90.5 – 93 in men (Tertile 2):

mcv acm

Collectively, these data suggest that a lower MCV may be better in terms of biologic youth,  and for a lower risk of death from all causes. What are my MCV values? I’ve measured MCV 25 times over the past 16 years. In my 30’s, I measured it 7 times, with an average MCV = 90. In my 40’s, I’ve measured it 18 times, for an average value = 91.1. Although these 2 groups of data are not significantly different (p=0.09), the red trendline for these data is slightly up (R2=0.02), which suggests that my MCV is slowly increasing with age:

mcv me

Although my MCV values are seemingly far from the increased mortality risk of Yoon et al. (> 95.8), it increases during aging, so I’ve definitely got my eye on it. Should it start to increase, I’ll intervene with dietary changes. Stay tuned!

 

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

 

References

Araki K, Rifkind JM. Age dependent changes in osmotic hemolysis of human erythrocytes. J Gerontol. 1980 Jul;35(4):499-505.

Lee Eun-jin, Kim Mi-young, Lee Eun-yeop, Jeon Beom, Lee Ji-won, Kim Han-sung, Kang Hee-jeong, Lee Young-kyung, Eun Jin Lee, Miyoung Kim, Eunyup Lee, Kibum Jeon, Jiwon Lee, Han-Sung Kim, Hee Jung Kang, Young Kyung Lee.vEstablishment of reference section for general blood test in healthy elderly. Establishing Reference Intervals for Complete Blood Cell Count in Healthy Korean Elderly Individuals. J Lab Med Qual Assur 2018; 40: 27-37. doi.org/10.15263/jlmqa.2018.40.1.27.

Yoon HJ, Kim K, Nam YS, Yun JM, Park M. Mean corpuscular volume levels and all-cause and liver cancer mortality. Clin Chem Lab Med. 2016 Jul 1;54(7):1247-57. doi: 10.1515/cclm-2015-0786.