Carnivore Diet Year 4: Part 2

State of My Health 2024: Assessing My Lab Blood Work

In Part 1 of this series we looked at an overview of my blood work labs — total testosterone, Vitamin D, fasting insulin, cholesterol, inflammation, and body fat — all of which were very good. Here we’ll dig more into the details of free testosterone, HbA1c, and thyroid hormones as well as recommendations for myself going forward.

Photo by Cristiano Pinto on Unsplash

According to LabCorp’s reference ranges, none of these markers were abnormal or outside the expected reference range. However, the case for thyroid hormones was that I simply didn’t know a lot about them; and for free testosterone (FT) and HbA1c (A1c) they weren’t “bad”, but not what I expected, so I wanted to dig into that more.

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Thyroid Hormones:

TSH: 3.980 (ref. 0.450 - 4.500)
Thyroxine (T4): 6.2 (ref. 4.5 - 12.0)
T3 Uptake: 29% (ref. 24 - 39)
Free Thyroxine Index (FTI): 1.8 (ref. 1.2 - 4.9)

While all of these values were within the normal reference range, you can see that TSH is on the higher side, T4 is about in the middle (good), and T3 is a little on the low side as is FTI.

High TSH and low T4 may indicate hypothyroidism and pituitary gland problems (1, 2, 3). Low T3 and low FTI can also indicate hypothyroidism (4, 5). High TSH has a positive correlation with systolic blood pressure, diastolic blood pressure, and triglycerides and a negative correlation with blood glucose in men (6).

FT4 (in men) has a negative correlation with triglycerides and a positive correlation with waist circumference, systolic blood pressure, diastolic blood pressure, and HDL (6). Elevated T3:T4 ratio may indicate increased arterial stiffness and cardiovascular risk, with the mediator of other metabolic syndrome symptoms (7).

From a macro-nutrient perspective carbohydrate restriction (~2% calories) increased T3 uptake (8). As for micro-nutrients in the treatment of hypothyroidism, it’s advised to avoid heavy metals (cadmium, lead, nickel, tin, aluminum) and fluoride; while increasing chromium, manganese, inositol (a sugar found in citrus fruit), and fish oil / omega-3 (9). That same study notes meat, carbohydrates, and alcohol as inflammation hazards, but recalling my CRP score, that is not the case for me.

General recommendations for some of those minerals are as follows:

• Selenium (Se): > 200 mcg / day (10)

• Iodine (I): > 150 mcg / day (11)

• Zinc (Zn): > 30 mg / day (12, 13)

Fe, Zn, Se, and iodine definitely aren’t the issue for me with several multiples of the RDA being consumed daily. However, Me and omega-3s could use some work, coming in at around 33% RDA.

I’ll talk more about heavy metals below, but also note here that SHBG levels are correlated positively with free thyroid hormones (14) which is kind of a conundrum because given my low-ish thyroid levels, SHBG may not be as big of an issue as I make it out to be below; but let’s look anyway!

Possible Solutions:

• Eat grapefruit / cantaloupe (inositol).

• Eat fish (Omega-3).

• (Conversely) Eat fewer carbs (see below regarding A1c).

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Testosterone:

Total (TT): 1167 ng/dL (ref. 264 - 916)
Free (FT): 18.0 pg/mL (ref. 8.7 - 25.1)

While my TT is literally off-the-chart, my FT is in the high-moderate range. Again, this isn’t bad, but it’s peculiar to me. The culprit that jumps to my mind in sex-hormone binding globulin (SHBG) which would have been nice to include in this panel.

SHBG is a protein made in the liver that binds to sex hormones (like testosterone and estrogen) to control how much of those hormones your tissues can use (15). It’s interesting too that SHBG positively corresponds with total testosterone levels in men who are not receiving exogenous testosterone support (16). SHBG is also related to insulin and thyroid hormones (and their corresponding dysfunction) which makes it very relevant to our discussion here (17, 18, 19).

In a study of “over-training” in the military, the authors found that over-training increased blood levels of SHBG at both 4 and 7 week intervals (20). Similar results were found in a study of triathletes (21). Before my most recent labs, I specifically took a passive rest day, and then went for a moderate aerobic run the day before to try and dampen this effect.

Another study (22) looked at the relationship between macro-nutrients and SHBG concentrations and found the following:

• Carbohydrate (p, not significant)

• Total Fat (p, not significant)

• Vegetable Fat (p, not significant)

• Ethanol (p, not significant)

• Cigarette smoking (p, not significant)

• Protein (r = -0.05, p = 0.05)

• Animal Fat (r = -0.05, p = 0.05)

Even the statistically significant macro-nutrient variables (total protein and animal fat) had a very weak correlation (both negative) that’s dwarfed by a factor of 4-5 in variables like BMI, waist-to-hip-ratio, age, and weight.

Regarding dietary micro-nutrients there seems to be a positive relationship between the concentrations of magnesium (Mg), iron (Fe), and zinc (Zn) and the endocrine system in aging men, in contrast to manganese (Mn) and chromium (Cr). Toxic metals (cadmium/Cd, lead/Pb) seemed to negatively affect bio available testosterone (23).”

Another likely culprit I thought of was alcohol. However, it’s not quite accurate to compare myself to someone drinking 10 drinks per day (24), but consuming about 1.5 drinks / day was found to cause ~17% higher SHBG and ~18% lower FT in a female sample (25); however “Positive trends for liquor consumption and luteal estradiol, luteal estrone, and SHBG were no longer evident after adjusting for wine and beer intake.”

This means that the effect of alcohol consumption on SHBG was not the same for beer and wine as it was for liquor. This seems to be related to the ferments and filtration processes which reduce levels of arsenic in the beer brewing process, but may not have any effect on heavy metals like Cd (29, 30).

The relationship between caffeine and SHBG doesn’t appear clear as there are studies suggesting both a positive and null response (26, 27, 28). However, heavy metals are also a notable concern in some coffees though they’re generally below the “safe” legal limits (31, 32). In fact, herbs and spices may be a bigger risk factor for heavy metals than coffee (33). Nevertheless, sourcing appears to matter as well, as Columbia-sourced coffee had 10x as much Cd and 30% more Pb than Nicaragua-sourced coffee (34).

Possible Solutions:

• Rest more.

• Drink less alcohol, especially beer and wine (to reduce heavy metal intake).

• Drink light roast or non-Columbian coffee (to reduce heavy metal intake).

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Insulin / A1c:

Fasting Insulin: 4.9 (ref. 2.6 - 24.9)
HbA1c (A1c): 5.6 (ref. 4.8 - 5.6)
HOMA-IR: 1.4

This was a bit of a bugger to pin down because based on my recent glucose tolerance testing I’m not metabolically broken, nor am I a Type-1 Diabetic as far as I know, and regarding fatty liver disease it seems that insulin would also be elevated if I had fructose or alcohol induced liver damage (35). We should also note that fructose in fruit is not the same as HFCS (36, 37).

Alcohol can falsely lower fasting insulin (38) and falsely raise A1c (39); bingo! Additionally, poor sleep quality appears to also contribute to elevated A1c (40) as does stress (41, 42). If we’re really concerned about NAFLD, then Omega-3s may help reduce liver fat (44).

I will admit, that since I started drinking again last summer, I don’t like how — in the month or so leading up to these labs — alcohol became a go-to coping skill for some exuberant life stressors. I’m not saying I was a day drunk or putting anyone’s safety or quality of care at risk, but it was more than I like and I definitely recognized the slippery slope taking effect.

As I was writing this, I was listening to THRR and Robb Wolf made a reference to Dave Feldman referring to slightly elevated A1c being characteristic of lean-mass-hyper-responders. Robb also referred to the recent “Oreo Study” (43) to recommend 50 - 100g of carbs / day to “alleviate the stress of lipid mobilization” and “quasi-T1D symptoms.”

Possible Solutions:

• Decrease alcohol intake.

• Add 50g carbs / day (see fruit recommendations above)

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Summary & Recommendations:

To recap, things still looked pretty good overall, but the big kicker was:

• Alcohol is problematic.

• Alcohol is a drug of abuse.

• I’ve been drinking more (alcohol) than I like, or beyond social circumstances, partly because of the above.

Alcohol was a common potential culprit for all of the hangnails I explored here — A1c, TSH, T3, and FT. Coffee was not a huge concern, assuming modifications in roast and sourcing.

I’ve let myself slip and get lazy on the occasional fish / liver intake which seems like it would be helpful. Additionally, my training is going to lean heavily into endurance work over the summer — which was the original catalysts for me reintroducing carbohydrates. Notably, those sources can be benefactors to both my thyroid hormones (milk, grapefruit) and my blood sugar.

Another consideration is that acute boron supplementation reduced hsCRP and SHBG within 6 hours and within one week increased FT (45, 46). Effective dose ranges can be as little as 1 mg / day (47) and you get about 1.5 g in 1C of prune juice (48).

Lastly, oysters and clams are good animal sources of manganese (49). Pulling everything together then, here’s what I’ve come to conclude:

• Alcohol:

  • Reduce to < 1.5 drinks / day (1 “drink” is about 12oz of 5% beer; 14g ethanol). For good measure we can round this down to 1 drink / day.

• Carbs

  • grapefruit juice (inositol), prune juice (boron)

  • 8oz / day each would dive ~50g carbs. My preferred timing is naked (not with other food) and post-workout.

• Fish

  • sardines (omega-3), clams (manganese)

  • Given their respective potency, alternating sardines and clams throughout the week should be sufficient — sardines days 1 and 2, then clams on day 3, repeat.

• Coffee

  • Light roast, non-Columbian origin. It wouldn’t hurt to pull this back a bit either.

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Disclaimer: Nothing in this post should be considered medical advice. These are my results and information I’ve found and decisions I’m making; not recommendations to others.

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