Yearly Archives: 2015

130 grams of fiber, 2400 calories

How do I eat ~100 grams of fiber, on average, every day? Here’s my full dietary breakdown from December 30, 2015:

my diet 12-30.png

Green tea is associated with reduced all-cause mortality risk (, so I start every day with  green tea + lemon.

Then, I ate a giant salad (, consisting of pickles, lettuce, tomato, purple cabbage and corn, and topped with a blended dressing of fresh lemon, sesame seeds, cumin, jalapeño, and raw garlic.

Also on the list were sardines, which I eat every day. Snacks in between bigger meals were carrots, 1 whole red pepper, mushrooms, and a Brazil nut.

Then I ate a big bowl of broccoli topped with cherry tomatoes. I added mustard powder after the broccoli and tomatoes were done cooking (~10 minutes), because broccoli’s sulfurophane content decreases with cooking time (

At some point after that I had cod liver oil, to get my daily dose of Vitamin D and the fish oil fatty acids, EPA and DHA. I just (last week) sent my blood for analysis of my circulating Vitamin D, so I may need to increase my vitamin D intake based on what the result shows.

Next I had my beet-berry smoothie (

For dinner I had my barley-veggie mix (, including barley, cauliflower, celery, tomato, corn, collards, onions and olive oil. Also, with an orange for dessert!

In sum, 2400 calories, 130 grams of dietary fiber, and maximal nutrition!

fiber 130

7/2017 Update: When considering the link between linoleic acid and all-cause mortality (, Ive increased my intake of omega-6 fats, almost exclusively from walnuts, while cutting my carbohydrate intake to try to stay calorie neutral. In doing so, this change increased my HDL from 28 to ~50, while keeping my total cholesterol < 150, and LDL < 70.

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

Calorie Restriction Pioneer Roy Walford: Where Did He Go Wrong?

With the goal of improving health and extending lifespan, Roy Walford was a pioneer in terms of  studying (and implementing) a diet that is calorie restricted but that also contains optimal nutrition (CRON). Unfortunately, Walford died at age 80 from complications related to Amyotrophic Lateral Sclerosis (ALS). Were there any factors in his nutritional approach that increased his risk for developing ALS?

On Walford’s website,, he listed 2 sample days of both food intake and his resulting macro- and micronutrient composition:

day 1.png

Although several micronutrients (calcium, sodium, zinc) are below the RDA on day 1, Walford’s 2-day average bring these values close to the RDA. However, his Vitamin E intake on day 1 and day 2 (shown below) are glaringly deficient. On day 1, his Vitamin E intake was only 2.8 mg. On day 2, it was 6.1 mg, for a 2-day average value of 4.5 mg. The RDA for Vitamin E was updated in 2000 (Food and Nutrition Board, 2000) from 8 mg to the current 15 mg-he wasn’t close to either value!

day 2

Dietary Vitamin E has been reported to be decreased in patients with ALS, when compared with ALS-free controls, as shown below (Veldink et al. 2007). Although the subjects of Veldink et al. had an increased calorie intake when compared with Walford (2842 and 2938 calories in controls and in ALS patients, respectively), when scaled down to Roy’s 1500 calorie intake, a dietary Vitamin E intake of 9 mg would be found in ALS patients, with 10.8 mg found in the controls. For comparison, Walford’s 2-day Vitamin E intake was only 6.1 mg! Interestingly, the only other dietary nutrient category that was significantly different between ALS patients and controls was polyunsaturated fat (PUFA) intake, which was also low (8.8g) in Walford’s 2-day diet.

als e pufa

I’m not at all saying that Walford’s dietary deficiencies in Vitamin E and PUFA caused his ALS. It’s also unknown whether the 2 days that he posted on his website are representative of his overall CRON approach. But it’s an interesting observation, isn’t it?

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


Food and Nutrition Board, Institute of Medicine. Vitamin E. Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. Washington, D.C.: National Academy Press; 2000:186-283.

Freedman MD, Kuncl RW, Weinstein SJ, Malila N, Virtamo J, Albanes D. Vitamin E serum levels and controlled supplementation and risk of amyotrophic lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener. 2013 May;14(4):246-51

Veldink JH, Kalmijn S, Groeneveld GJ, Wunderink W, Koster A, de Vries JH, van der Luyt J, Wokke JH, Van den Berg LH. Intake of polyunsaturated fatty acids and vitamin E reduces the risk of developing amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry. 2007 Apr;78(4):367-71.

The Essential Fatty Acid, Linoleic Acid: Dietary Intake And Circulating Values, What’s Optimal For Health?

Linoleic acid (C18:2, n-6) is an essential fatty acid that must be obtained from the diet, because  our body can’t make it. How much linoleic acid should we eat every day for optimal health? To answer this question, I’ll investigate the association between circulating levels of linoleic acid with all-cause mortality risk, followed by identification of a corresponding dietary intake. Let’s have a look!

First, are circulating levels of linoleic acid associated with all-cause mortality risk? 4 studies have investigated this issue:

  • In a 15-year study of 1,551 middle-aged men (average age, 52y), increased circulating linoleic acid was associated with significantly reduced all-cause mortality risk in 3 of the 4 multivariable-adjusted models (Laaksonen et al. 2005).
  • In a 15-year study of 4,232 older adults (60y) elevated circulating linoleic acid was associated with significantly reduced all-cause mortality risk in men, but not women (Marklund et al. 2015).
  • In a 34-year study of 2,009 middle-aged men (average age, 50y) increased circulating linoleic acid was associated with significantly decreased risk of all-cause mortality (Warensjö et al. 2008). For example, shown below is the association between the risk of death from cardiovascular-related disease with the circulating linoleic acid concentration. At both 20 and 30 years after study onset, subjects that had circulating linoleic values above the median had approximately half of the mortality risk from CVD, when compared with below-median values for linoleic acid.

LA CVD mortality

  • In a 13-year study that included both older men and women (average age, 74y), and, more subjects (2,792) than the studies of Laaksonen and Warensjöet combined, plasma phospholipid percentages of linoleic acid greater than ~21-24% were associated with significantly reduced all-cause mortality risk:

LA total mort

Colectively, these 4 studies show that increased circulating levels of linoleic acid are associated with reduced all-cause mortality risk. How much linoleic acid should we eat to achieve optimal circulating values? In other words, what dietary intake of linoleic acid corresponds to 21%+ of plasma phospholipid linoleic acid? Based on the data below, dietary intakes of linoleic acid that are greater than 14% of total calories are associated with circulating linoleic acid values of 21% (Wu et al. 2014).

LA dietary in PL

On my ~2300 calorie diet, that translates into 322 calories (36g) from linoleic acid. I get a significant amount of dietary linoleic acid from one of the best linoleic acid food sources, walnuts, which contain 5.8 grams of linoleic acid per 100 calories (see Lipids, C18:2,

Just using walnuts alone, I’d need ~700 calories per day to reach 14% dietary linoleic acid! Although I’m always interested in dietary strategies that may reduce all-cause mortality risk, allocating ~30% of my daily calories to only walnuts is not ideal for my high-fiber approach to health (, nor would it satiate me, as high-volume vegetable meals are best for that. A more reasonable dietary linoleic acid target (for now) is ~8%, the point at which plasma linoleic acid mostly plateaus (see the plot above). 8% on my 2300 calorie diet translates into 20 grams of linoleic acid per day. I should note that I also get a good amount of linoleic acid (6.4 grams) from the 30 grams of sesame seeds that goes into my giant salad’s dressing, which I eat 2-3x per week. When combined with ~300 calories from walnuts/day, that gets me to at least 8% of my daily calories from linoleic acid.

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



Laaksonen DE, Nyyssönen K, Niskanen L, Rissanen TH, Salonen JT. Prediction of cardiovascular mortality in middle-aged men by dietary and serum linoleic and polyunsaturated fatty acids. Arch Intern Med. 2005 Jan 24;165(2):193-9.

Marklund M, Leander K, Vikström M, Laguzzi F, Gigante B, Sjögren P, Cederholm T, de Faire U, Hellénius ML, Risérus U. Polyunsaturated Fat Intake Estimated by Circulating Biomarkers and Risk of Cardiovascular Disease and All-Cause Mortality in a Population-Based Cohort of 60-Year-Old Men and Women. Circulationz 2015 Aug 18;132(7):586-94.

Warensjö E, Sundström J, Vessby B, Cederholm T, Risérus U. Markers of dietary fat quality and fatty acid desaturation as predictors of total and cardiovascular mortality: a population-based prospective study. Am J Clin Nutr. 2008 Jul;88(1):203-9.

Wu JH, Lemaitre RN, King IB, Song X, Psaty BM, Siscovick DS, Mozaffarian D. Circulating omega-6 polyunsaturated fatty acids and total and cause-specific mortality: the CardiovascularHealth StudyCirculation. 2014 Oct 7;130(15):1245-53

Vitamin C: Dietary Intake And Plasma Values, What’s Optimal For Health?

How much Vitamin C (ascorbic acid) is optimal for health? To answer this question, I’ll examine the association between circulating levels of Vitamin C with all-cause mortality risk. Then, which dietary Vitamin C intake corresponds to optimal plasma levels? Let’s have a look!

A variety of studies have investigated associations between plasma (or serum) Vitamin C with all-cause mortality risk:

  • In a 4-year study of 1,115 older adults (average age ~79y), plasma vitamin C values greater than 66 uM (micromolar) were associated with significantly decreased all-cause mortality risk, when compared with values less than 17 uM (Fletcher et al. 2003).
  • In a 12-year study of 725 older adults (average age, 73y), plasma vitamin C values greater than 52 uM were associated with significantly reduced all-cause mortality risk (Sahyoun et al. 1996). Interestingly, the most reduced mortality risk was found in those with plasma Vitamin C values greater than 89 uM, a value that can only be attained with dietary Vitamin C intakes greater than 1000 mg/day (more on this below!).
  • In a 16-year study of 8,453 middle-aged adults (average age ~49y), serum Vitamin C values greater than 45 uM were associated with significantly reduced all-cause mortality risk, when compared with values less than 17 uM (Simon et al. 2001).
  • In a 13-year study of 1,054 older adults (average age ~76y), elevated plasma levels of Vitamin C (risk ratios were reported without the actual Vitamin C concentration) were associated with significantly decreased all-cause mortality risk (Bates et al. 2011).
  • In a 4-year study of 19,496 older adults (average age ~59y), plasma Vitamin C values greater than 48 uM in men and 59 uM in women (both in quintile 3, shown below) were associated with significantly reduced all-cause mortality risk (Khaw et al. 2001). The most reduced all-cause mortality risk included average Vitamin C values of 73 uM for men and 85 uM for women (shown below in quintile 5), values which require greater than 500 mg of dietary Vitamin C/day (more on this also below!).

C risk

Studies that show weaker or no association between the plasma Vitamin C concentration with all-cause mortality risk include Loria et al. (2000) and Jia et al. (2007). In Loria et al. (2000), 9,450 middle aged adults (~48y) were followed for 12-16 years. Men in the highest Vitamin C quartile (> 74 uM) had significantly reduced all-cause mortality risk, when compared with men in the low plasma Vitamin C group (< 28 uM). Although a similar association was identified for women, significance was lost after multivariable adjustment. In Jia et al. (2007), although plasma Vitamin C values less than 61 uM were associated with increased all-cause mortality risk in older adults (median age, ~80y) that were studied for ~7.5 years, these data were not statistically significant (p-value = 0.18). However, the study sample size (398 subjects) may have been too small to detect significant effects.

Collectively these studies show that low circulating levels of Vitamin C may be related to increased mortality risk, whereas plasma values greater than ~50 uM are consistently associated with reduced all-cause mortality risk. How much dietary vitamin C is required to attain 50 uM+?

As shown below, the RDA for dietary Vitamin C is 90 mg for males and 75 mg for females older than 19 years (Institute of Medicine 2000).


If you consume the RDA for Vitamin C, what plasma Vitamin C concentration will that yield? Shown below is how the plasma Vitamin C concentration varies according to ingested dose (Levine et al. 1996). Consuming the RDA value for Vitamin C  yields a plasma Vitamin C value of 20-30 uM. From the studies listed above, that would put you in the increased all-cause mortality risk group! How much dietary Vitamin C would be needed to achieve plasma values greater than 50 uM? From the plot, we see that a dietary Vitamin C intake at double the RDA would be necessary. Furthermore, because 2 studies have reported decreased all-cause mortality risk at plasma Vitamin C values greater than 66 uM, dietary intakes intake between 500-1000+ mg/day may be necessary:

C dose

Which foods are  Vitamin C-rich? As shown below, sweet peppers (yellow, red, and green) are the All-Stars for Vitamin C content per 100 calories:

C foods

What’s my average daily Vitamin C intake? Shown below is my average daily Vitamin C intake, 875 mg/day, separated by month. Based on that value, my plasma Vitamin C concentration should be ~ 70 uM, which may be associated with maximally reduced all-cause mortality risk.

C intake

With the goal of optimizing plasma Vitamin C, it is also important to monitor dietary sodium intake. Intestinal absorption of Vitamin C requires dietary sodium (Friedman and Zeidel 1999). As shown below, 1 ascorbate ion (asc-) is absorbed from the intestinal lumen into intestinal epithelial cells in the presence of 2 sodium (Na+) ions. Vitamin C can then diffuse into the blood as Asc- or as dehydroascorbate (DHA):

na asc transport

Accordingly, based on my average dietary Vitamin C intake of 875 mg/day, to maximize absorption, a corresponding dietary sodium intake of 1750 mg would also be necessary.

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


Bates CJ, Hamer M, Mishra GD. Redox-modulatory vitamins and minerals that prospectively predict mortality in older British people:the National Diet and Nutrition Survey of people aged 65 years and overBr J Nutr. 2011 Jan;105(1):123-32.

Fletcher AE, Breeze E, Shetty PS. Antioxidant vitamins and mortality in older persons: findings from the nutrition add-on study to the Medical Research Council Trial of Assessment and Management of Older People in the Community. Am J Clin Nutr. 2003 Nov;78(5):999-1010.

Friedman PA, Zeidel ML. Victory at C. Nat Med. 1999 Jun;5(6):620-1.

Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000.

Jia X, Aucott LS, McNeill G. Nutritional status and subsequent all-cause mortality in men and women aged 75 years or over living in the community. Br J Nutr. 2007 Sep;98(3):593-9.

Khaw KT, Bingham S, Welch A, Luben R, Wareham N, Oakes S, Day N. Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. European Prospective Investigation into Cancer and Nutrition. Lancet. 2001 Mar 3;357(9257):657-63.

Levine M, Conry-Cantilena C, Wang Y, Welch RW, Washko PW, Dhariwal KR, Park JB, Lazarev A, Graumlich JF, King J, Cantilena LR. Vitamin C pharmacokinetics in healthy volunteersevidence for a recommended dietary allowance. Proc Natl Acad Sci U S A. 1996 Apr 16;93(8):3704-9.

Loria CM, Klag MJ, Caulfield LE, Whelton PK. Vitamin C status and mortality in US adults. Am J Clin Nutr. 2000 Jul;72(1):139-45.

Sahyoun NR, Jacques PF, Russell RM. Carotenoids, vitamins C and E, and mortality in an elderly population. Am J Epidemiol. 1996 Sep 1;144(5):501-11.

Simon JA, Hudes ES, Tice JA. Relation of serum ascorbic acid to mortality among US adults. J Am Coll Nutr. 2001 Jun;20(3):255-63.

An evidence-based approach for minimizing tooth decay risk

I’d like to keep my teeth healthy for as long as possible. I brush my teeth in the morning and at night, and floss every night, because daily flossing is associated with reduced mortality risk ( Is there anything else that I can do to optimize my oral health? To answer that question, it’s important to know how tooth decay (also known as caries) occurs. As shown below, bacteria located on our teeth (in plaque) use dietary sugars to make acid, which demineralizes tooth enamel, thereby resulting in caries (Limeback et al. 2012).

caries overview

Not all dietary sugars are equal in their ability to produce tooth decay. In the picture below, sugars with red boxes are the most cariogenic. For example, the worst offenders in terms of tooth decay are sucrose and glucose. Also note that starch is cariogenic, but less when compared with sucrose and glucose. The least cariogenic sugars are sorbitol and mannitol, and, the sugar xylitol has been shown to be protective against tooth decay (Limeback et al. 2012).

sugars cario

After eating a high sugar meal, there is an oral bacteria-induced increase in acidity that can lead to tooth demineralization. At an oral plaque pH of 5.5, tooth enamel demineralization occurs (Stephan and Miller 1943). Shown below is a graph of plaque pH vs. time for the 60 minutes following an oral glucose rinse. The green line is indicative of someone who is caries resistant: their plaque pH decreases from ~6.8 to ~5.8, followed by a relatively quick return to the starting pH value after 60 minutes. Note that at no point does the green line drop below the 5.5 threshold for enamel demineralization to occurr. The yellow line is indicative of someone at moderate tooth decay risk: their plaque pH drops from 6.8 to below 5.5, where it remains for ~ 10 minutes, and then slowly returns to baseline pH values after 60 minutes. The red line is indcative of someone that is at high risk for tooth decay: after the glucose rinse at time 0, their plaque pH rapidly drops below 5.5 and remains there for ~50 minutes, where significant teeth demineralization may occur. Note that their plaque pH doesn’t return to the baseline pH value after 60 minutes, either.

plaque ph

With these data in mind and my goal to reduce tooth decay risk I bought pH strips to test my daily oral pH. Shown below is what the pH strip looks like, without having been dipped in my saliva. Adjacent to that is the pH color scale, and to the right, my average daily fasted oral pH, ~6.5:

no samp20151015_110200pH4hr 20151015_130558

The good news is that I’ve yet to see an oral pH value below 6.5, which puts me at low risk for tooth decay. To further minimize that risk, in addition to brushing and flossing, after meals and throughout the day I gargle with a homemade 1% sodium bicarbonate (physiological saline is ~0.9%) and 10% xylitol solution. I use sodium bicarbonate to temporarily neutralize any potential oral acids. Xylitol can protect against tooth decay by reducing plaque and the level of tooth decay-causing bacteria (i.e. Streptococci mutans) in saliva and plaque (Söderling 2009). For example, fluoride-containing toothpaste in the presence of 10% xylitol reduces tooth decay more than fluoride toothpaste alone (Sintes et al. 1995; Sintes et al. 2002). However, it’s important to note that some xylitol-based studies have not been shown to reduce tooth decay risk (Riley et al. 2015). At worst, including xylitol may have no effect, whereas at best it may reduce oral Streptococci mutans, thereby decreasing tooth decay risk. 

After gargling, my normal oral ph (~6.5) changes to alkaline (~8.5), as shown in the pH strip below:


Couldn’t I use a store-bought mouthwash instead?  The measured pH of several commercially available mouthwashes is shown in the table below (Sun et al. 2014). Note that some are below the critical pH for tooth demineralization, 5.5! Others aren’t too far away from 5.5, either. In contrast, the pH of my homemade mouthwash pH is ~8.0.

mwash pH

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


Limeback H et alComprehensive Preventive Dentistry, Chapter 1: “A brief introduction to oral diseases: caries, periodontal disease, and oral cancer”. page 1-24. July 2012. ISBN: 978-0-8138-2168-9.

Riley P, Moore D, Ahmed F, Sharif MO, Worthington HV. Xylitol-containing products for preventing dental caries in children and adultsCochrane Database Syst Rev. 2015 Mar 26;3:CD010743.

Sintes JL, Escalante C, Stewart B, McCool JJ, Garcia L, Volpe AR, Triol C. (1995). Enhanced anticaries efficacy of a 0.243% sodium fluoride/10% xylitol/silica dentifrice: 3-year clinical results. American Journal of Dentistry, 8, 231–235.

Sintes JL, Elías-Boneta A, Stewart B, Volpe AR, Lovett J. (2002). Anticaries efficacy of a sodium monofluorophosphate dentifrice containing xylitol in a dicalcium phosphate dihydrate base. A 30-month caries clinical study in Costa Rica. American Journal of Dentistry, 15, 215–219.

Söderling EM. (2009) Xylitol, mutans streptococci, and dental plaque. Advances in Dental Research, 21, 74–78.

Stephan RM and Miller BF. (1943) A Quantitative Method for Evaluating Physical and Chemical Agents which Modify Production of Acid in Bacterial Plaques on Human Teeth. Journal of Dental Research, 22, 45–51.

Sun FC, Engelman EE, McGuire JA, Kosmoski G, Carratello L, Ricci-Nittel D, Zhang JZ, Schemehorn BR, Gambogi RJ. Impact of an anticaries mouthrinse on in vitro remineralization and microbial control. Int J Dent. 2014;2014:982071.

Drink Green Tea, Reduce All-Cause Mortality Risk?

Is green tea consumption associated with reduced risk of death risk from all causes? To investigate this question, Tang et al. (2015) performed a meta-analysis of 5 studies, including 200,884 subjects. As shown below, drinking 5 cups (40 oz.) or less per day is associated with reduced all-cause mortality risk. Drinking 2-3 cups (16-24 oz.) of green tea per day was associated with maximally decreased all-cause mortality risk, ~10%.

green tea

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


Tang J, Zheng JS, Fang L, Jin Y, Cai W, Li D. Tea consumption and mortality of all cancers, CVD and all causes: a meta-analysis of eighteen prospective cohort studies. Br J Nutr. 2015 Jul 23:1-11.

What I eat: Giant Salad!

Another meal that I eat 1-2x per week is a giant (delicious!) salad.


What’s in it? Approximately 1 pound of romaine lettuce, 1 pint of cherry tomates, 6-8 ounces of purple cabbage, ~3 ounces of pickles, and occasionally, 2-4 ounces of corn.  To top it off, I make a spicy-sesame dressing that includes 1 jalapeno, ~1 ounce of lemon juice, ~1 ounce of sesame seeds, 2-4 grams of ground cumin seed, ~10 grams of raw garlic, and 4-6 oz. of water. I then blend the dressing ingredients and add it to the salad!

salad ingred

How about nutrition? For 528 calories, it’s a nutritional All-Star for many things, including protein, fiber, calcium, magnesium, zinc, and many other nutritents.

salad nutrition

7/2017 Update: To increase my folate intake from my usual 1200 mcg to ~1500 mcg/day, I’ve increased the romaine lettuce component of the salad to ~20 oz. Also, I’ve added a small habanero in addition to the jalapeno/fresno pepper for more spice. Still yum!

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

What I eat: Barley-Cauliflower-Collard-Tomato-Celery-Onion-Corn-Mix!

What do I eat? Here’s a picture of one of my delicious “mixes” that I eat a couple of times per week.


What’s in it? As shown below, barley, collards, celery, cauliflower, olive oil, corn, onion, and tomatoes. The barley is boiled for 20-30 minutes before I add all the veggies, which I then boil for less than 10 minutes. When it’s finished cooking, I add the olive oil.

barl cals

Besides the taste, this mix is a nutritional All-Star! Within its 622 calories, it provides 29g protein, 37g fiber, 1545 ug of Vitamin K, and much more!

barl cals vitmin

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

Vitamin D: What’s an optimal daily intake and blood value?

How much Vitamin D is optimal for health? To answer this question, today I’ll examine the association between a circulating marker of Vitamin D, 25-hydroxyvitamin D, with all-cause mortality risk. Then, I’ll examine the literature to estimate a dietary intake that can achieve an optimal circulating 25-hydroxyvitamin D concentration.

Circulating 25-hydroxyvitamin D is the most commonly measured vitamin D metabolite because of its greater half life (~3 weeks) and up to 1000-fold higher serum levels compared with the physiologically active metabolite of vitamin D, 1,25-dihydroxyvitamin D (Zerwekh 2008). So what’s the evidence for the association between circulating 25-hydroxyvitamin D with all-cause mortality risk?

In a meta-analysis of 95 studies including 880,201 subjects, circulating 25-hydroxyvitamin D levels greater than 30 ng/mL (75 nmol/L) are associated with significantly reduced risk of death from all causes when compared with values less than 30 (<10, 20-29; Chowdhury et al. 2014):

d mort

Does the meta-analysis data for 25-hydroxyvitamin D mean that any values higher than 30 ng/mL are optimal for health? Maybe not. As shown below, although data from 11,315 subjects in the NHANES III study suggests that values between 30-40 ng/mL (75-99 nmol/L) may be optimal for decreased all-cause mortality risk (Sempos et al. 2013), 25-hydroxyvitamin D values greater than 48 ng/mL (120+ nmol/L) were associated with an increased all-cause mortality risk. Interestingly, in agreement with the Chowdhury meta-analysis data, this graph shows also increased mortality risk at values less than 30-40 ng/mL (75-99 nmol/L):

d mortality

However, whether increased circulating 25-hydroxyvitamin D is associated with increased all-cause mortality risk is debatable. In another meta-analysis (Garland et al. 2014), although circulating 25-hydroxyvitamin D values less than 30 ng/mL were again associated with increased risk, in contrast,  values greater than 48 ng/mL were not. Interestingly, values as high as 70 ng/mL (175 nmoL) were not associated with increased risk, either:


Aside from our skin making Vitamin D from sunlight during the summer months, what dietary intake can achieve the seemingly optimal 30-40 ng/mL (75-99 nmol/L) concentration for 25-hydroxyvitamin D in the winter? The RDA for Vitamin D is 600 IU for everyone older than 1 but younger than 70 (Institute of Medicine, 2010). If you’re over 70, the RDA is 800 IU. My average dietary intake is only ~170 IU-how can I increase this to at least the RDA, to achieve circulating values between 75-99 nmol/L?

Decent dietary sources of vitamin D include fish: salmon, sardines, mackerel, and tuna. Based on the table below (Holick 2007), eating ~3.5 ounces of wild salmon every day would achieve the RDA for vitamin D intake. In contrast, my daily tin of sardines puts me ~300 IU away from the RDA value! I could double my fish intake to ~8 oz./day, but I’d like to limit my animal protein intake, and, the extra ~200 calories would limit other nutrients that I’d like to enrich in my diet, like fiber.


Are there other, less calorie dense dietary sources of vitamin D? It’s important to note that dietary vitamin D can be found in 2 forms, D3, which is shown above, and D2. Which foods are rich in vitamin D2? Shown below is a picture of the best plant-based source of vitamin D2, maitake mushrooms:


The Vitamin D2 content of maitake mushrooms is 36 IU/calorie, whereas wild salmon only has 3.2 IU of vitamin D per calorie! Other “exotic” mushrooms (anything other than white button mushrooms is exotic to me!) like Chanterelle and Morel contain decent amounts of vitamin D2:


Before adding maitake and other “exotic” mushrooms into my nutritional plan for their vitamin D content, it’s important to ask, “does D2 increase circulating 25-hydroxyvitamin D to an equal extent as D3”? Unfortunately, the answer is no: although D2 and D3 both increase circulating 25-hydroxyvitamin D levels, D2-based sources increase 25-hydroxyvitamin D level about half as effectively as D3 (Trang et al. 1998). So, instead of consuming ~35g of maitake mushrooms to add 400 IU of vitamin D into my diet (to achieve the RDA of 600 IU), I’ve added ~70g/day.

12/29/2015 Update: Because of Maitake’s relatively high cost, $5 for only 100g, and the burden of having to eat it every day, for the past ~3 months I switched to Vitamin D supplements to achieve a D intake of ~1100 IU/day. Blood testing showed that this intake yielded a circulating 25-hydroxyvitamin D winter concentration of 31 ng/mL, putting me at low risk for all cause mortality, based on the meta-analysis D data.

8/23/2016 Update: I stopped supplementing with 1000 IU of Vitamin D in June 2016, to explore the effect of 3-4 hours of weekly sun exposure on my circulating Vitamin D levels. My unsupplemented, circulating 25-hydroxyvitamin D level was 41 ng/mL in my 8/2016 blood test. Accordingly, I intend on increasing my  Vitamin D intake to 1600 IU (1400 supplemental, ~200 dietary)/day to achieve a circulating winter 25-hydroxyvitamin D level that is similar my  the summer value.

11/12/2017 Update: I’ve been supplementing with 2000 IU of D3/day, bringing my average daily total to ~2200 IU/day. Based on that, my latest circulating 25-hydroxyvitamin D level (tested in October, 2017) was 39 ng/mL .

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


Chowdhury R, Kunutsor S, Vitezova A, Oliver-Williams C, Chowdhury S, Kiefte-de-Jong JC, Khan H, Baena CP, Prabhakaran D, Hoshen MB, Feldman BS, Pan A, Johnson L, Crowe F, Hu FB, Franco OH. Vitamin D and risk of cause specific death: systematic review and meta-analysis of observational cohort and randomised intervention studies. BMJ. 2014 Apr 1;348:g1903.

Garland CF, Kim JJ, Mohr SB, Gorham ED, Grant WB, Giovannucci EL, Baggerly L, Hofflich H, Ramsdell JW, Zeng K, Heaney RP. Meta-analysis of all-cause mortality according to serum 25-hydroxyvitamin D. Am J Public Health. 2014 Aug;104(8):e43-50.

Holick MF. Vitamin D deficiency. N Engl J Med. 2007 Jul 19;357(3):266-81.

Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.

Sempos CT, Durazo-Arvizu RA, Dawson-Hughes B, Yetley EA, Looker AC, Schleicher RL, Cao G, Burt V, Kramer H, Bailey RL, Dwyer JT, Zhang X, Gahche J, Coates PM, Picciano MF. Is there a reverse J-shaped association between 25-hydroxyvitamin D and all-cause mortality? Results from the U.S. nationally representative NHANES. J Clin Endocrinol Metab. 2013 Jul;98(7):3001-9.

Trang HM, Cole DE, Rubin LA, Pierratos A, Siu S, Vieth R. Evidence that vitamin D3 increases serum 25-hydroxyvitamin D more efficiently than does vitamin D2Am J Clin Nutr. 1998 Oct;68(4):854-8.

Zerwekh JE. Blood biomarkers of vitamin D status. Am J Clin Nutr 2008;87:1087S-91S.

Boiling drinking water for improved health?

I recently heard centenarian Bernando Lapallo say that he boils his drinking water ( Whether this is a contributor to or is merely associated with his longevity is debatable. What will boiling your water do, prior to drinking it, and is it worth the effort?

The ability of our immune system to combat infectious agents decreases with age (Ginaldi et al. 2001). Can we counteract this? Reducing intake of infectious agents would reduce the burden that our immune systems would have to deal with. Is it possible to reduce intake of infectious agents, including bacteria, viruses, and protozoa?

Boiling water can inactivate a variety of bacteria, viruses, and protozoa (WHO, 2015) that are increased in older adults. For example, as shown below, a water temperature greater than 60C (water boils at 100C) for 5 minutes will inactivate Escherichia Coli (E. coli). Why are E. coli important? E. Coli are elevated in older adults (70­-90y), when compared with young (20­-50y; Enck et al. 2009), and are associated with insulin resistance (Vrieze et al. 2012) and frailty (Claesson et al. 2012). Below we see that boiling water for 5 minutes would thermally inactivate E. Coli, potentially resulting in decreased work for our immune system.

water bacteria

Every morning I boil ~40 oz of water for my green tea. Later in the day in drink 10-20 oz of water, but not boiled. So, ~2/3 of my water intake is boiled, potentially reducing the infectious burden that my immune system has to battle. Whether boiling water reduces this burden by 1%, 10%, or more is unknown. However, based on the ability of water boiling to inactivate pathogens that are increased during aging, it may be a low risk (only the time used!), high reward strategy for improving health during aging. I’m actively considering boiling my 10-20 oz. of water at night, too.

7/2017 Update: In addition to boiling my water for green tea, I also use a high-powered water filter, the Big Berkey. I’m not paid to say that, but that’s what I do!

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


Claesson MJ, Jeffery IB, Conde S, Power SE, O’Connor EM, Cusack S, Harris HM, Coakley M, Lakshminarayanan B, O’Sullivan O, Fitzgerald GF, Deane J, O’Connor M, Harnedy N, O’Connor K, O’Mahony D, van Sinderen D, Wallace M, Brennan L, Stanton C, Marchesi JR, Fitzgerald AP, Shanahan F, Hill C, Ross RP, O’Toole PW. Gut microbiota composition correlates with diet and health in the elderly. Nature, 2012. 488(7410): p. 178‐84.

Ginaldi L, Loreto MF, Corsi MP, Modesti M, De Martinis M. Immunosenescence and infectious diseases. Microbes Infect. 2001 Aug;3(10):851-7.

Enck P, Zimmermann K, Rusch K, Schwiertz A, Klosterhalfen S, Frick JS. The effects of ageing on the colonic bacterial microflora in adults. Z Gastroenterol, 2009. 47(7): p. 653‐8.

Vrieze A, Van Nood E, Holleman F, Salojärvi J, Kootte RS, Bartelsman JF, Dallinga-Thie GM, Ackermans MT, Serlie MJ, Oozeer R, Derrien M, Druesne A, Van Hylckama Vlieg JE, Bloks VW, Groen AK, Heilig HG, Zoetendal EG, Stroes ES, de Vos WM, Hoekstra JB, Nieuwdorp M. Transfer of intestinal microbiota from lean donors increases insulin sensitivity in individuals with metabolic syndrome. Gastroenterology, 2012. 143(4): p. 913‐6 e7.

World Health Organization. Boil Water. January 2015.