© by Elizabeth Lee Vliet MD and Kathy Kresnik
Are you experiencing the beginning signs of low testosterone? Fewer morning and nocturnal erections, running out of energy later in the day, losing muscle, maybe not feeling as “sharp” at work as you used to? Saboteurs of your testicular testosterone production may be lurking in your kitchen and you don’t realize the subtle damage taking place every day. It’s somewhat like termites eating away at the inside of wood frames in your home, invisible until major damage hits! Slow gradual loss of testosterone robs men of energy, strength, libido, and vitality over time, and they don’t realize that there are simple fixes to stop the decline and begin restoring testosterone production.
That’s the focus of my Health Tip today: helping you recognize how the Standard American Diet (SAD) sabotages testosterone production, and the food and supplement allies you can choose instead to help boost testosterone production, improve energy, strength, libido and vitality.
In addition to today’s short, focused Health Tip, I presented a series of four seminars for our Faith Over Fear series addressing hypogonadism in men:
The Hidden Health Costs of Low T in Men. You can watch those programs here:
November 4: The Hidden Health Costs of Low T in Men
Dec. 9 The Hidden Health Costs of Low T in Men: PART II: Health Benefits of Testosterone, studies on Testosterone therapy after successfully treated prostate cancer.
Dec. 16 The Hidden Health Costs of Low T in Men: PART III: Androgen Deprivation Therapy – Risks and Benefits. PLUS Research Update on Testosterone Therapy After Prostate Cancer
Jan. 13, 2026: The Hidden Health Costs of Low T in Men: PART IV Lifestyle Changes to Boost Testosterone: Exercise, Diet, Nutritional Supplements/Nutraceuticals
I saw recently a partially correct post on X headlined with an exaggered claim that “Vitamin E nearly doubles testosterone!” The post was short, clearly had misinterpreted the medical study cited, and lacked details but it did make a valid point about how the American diet high in seed oils, and ultra-processed foods decreased testosterone levels in men. That part is correct, and a point I have been making in books, seminars and patient evaluations for several decades.
The post cited a 1982 study stating taking vitamin E boosted testosterone levels by improving the gonadal response to pituitary stimulation by HCG and suggesting taking vitamin E is the way to combat the oxidative damage to the gonads and decreased testosterone output from a high seed oil diet.
If you have been following my medical programs and articles, you already know that I would offer a more direct solution first: Stop eating seed oils and processed foods! Don’t think you can just pop a pill (even if the pill is vitamin E) to fix the damage while you continue more damage by eating seed oils and processed foods! That’s a band-aid approach I do not support. The best option is fix the cause of the damage. Then modify diet to focus on healthy real food and the right forms of supplements.
I have recommended the right type of vitamin E supplements for years for many of my patients and have included it in my Resilience formula. What is the right type? You need natural vitamin E (not synthetic) and full spectrum with mixed tocopherols and tocotrieneols, which is what we selected for our TruVitamin E™ Full Spectrum. I’ll explain that in more detail later in the Health Tip.
I am opposed to the American mindset in both allopathic and naturopathic medicine that has a narrow focus on popping pills (whether prescription medicines OR supplements) without evaluating properly these individual factors that help determine an appropriate approach tailored to your needs:
1) underlying causes of health problems
2) the big picture totality of what’s going on with your body and your individual familial risk factors
3) objective laboratory tests to confirm specific deficits and targets for treatment.
So today I take a deeper dive into that 1982 study and what it really showed, what this means for your choices now, and what deficiencies you need to test for that may also be causing low T levels. I’ll summarize for you the science-backed dietary and lifestyle changes that you control and can begin now.
What the Science Actually Shows:
Research confirms that vitamin E plays a key role in the pituitary-gonadal axis, and there are studies showing it can increase basal plasma testosterone and improve the responsiveness of testosterone to human chorionic gonadotropin (HCG) stimulation. Specifically, vitamin E supplementation helps protect against oxidative destruction of Leydig cells, reduces apoptosis (cell death), and improves LH receptor affinity in the the testes. All of these mechanisms together are ways Vitamin E can contribute to modest testosterone increases. We have known more more than 100 years, since Evans and colleagues study published in1922, that vitamin E has been considered as an antisterility factor, playing an important role in the hypo-thalamic-pituitary-gonadal axis regulating reproduction and the endocrine system.
What about the claim “Vitamin E nearly doubles testosterone?”
The quote refers to a 1982 human study where 483 mg of vitamin E daily modestly increased basal testosterone and made the acute HCG‑stimulated testosterone rise roughly twice as large as before supplementation. This 1982 study did not show vitamin E alone “nearly doubled” baseline testosterone in normal men.
Look at what the study actually found:
- The primary human data are from Umeda et al., 1982, evaluated the more common synthetic form of vitamin E to assess its effect on the pituitary–gonadal axis in rats and in normal male subjects.
- In the human arm, oral vitamin E modestly increased basal plasma testosterone and free testosterone index (not doubled rise in testosterone level). 11 healthy men given ~3–5 mg/d dietary vitamin E plus 483 mg/d vitamin E acetate for 8 weeks; mean total testosterone rose from about 416 ng/dL to about 545 ng/dL (~24% increase), not a doubling.
- Vitamin E supplementation also enhanced the responsiveness of plasma testosterone to HCG compared with pre‑supplementation values. When HCG was then administered to the same men in the study, the increase in testosterone was about twice as large as it had been with Vitamin E alone without HCG. That why the claim that vitamin E alone distorted the actual findings which showed that HCG stimulation lead to greater increase than vitamin E alone.
The most accurate conclusion for the 1982 study is that high‑dose vitamin E increased basal testosterone ~20–25% in small samples of healthy men and potentiated the acute HCG‑stimulated testosterone response, roughly doubling the response magnitude relative to pre‑vitamin E, not doubling total T from baseline.
I want you to also understand that this study was limited in other important ways:
- This study involved a young, healthy, group of men with normal testosterone levels (eugonadal), not men with low T (hypogonadal) or men with fertility problems (hypofertile).
- Results from healthy men with normal T levels cannot be extrapolated two hypogonadal men. It is unlikely that low T hypogonadal men would have the same amount of increase with Vitamin E alone, since other causes of low T would have to be addressed, and would not likely be overcome with just Vitamin E.
- The form of vitamin E used in 1982 was synthetic dl-α‑tocopherol acetate). This is a critical difference, since observational data in population samples actually show an inverse association between synthetic vitamin E serum levels and testosterone levels. That means higher serum (synthetic form) Vitamin E levels correlate with lower levels of serum testosterone. In these studies, long‑term supplementation of synthetic vitamin E resulted in lower testosterone levels. So, men watch out! Taking high doses of synthetic vitamin E can actually be a saboteur of optimal testosterone levels.
- The SELECT trial in which 400 IU/day synthetic vitamin E was associated with increased prostate cancer risk. Some meta‑analyses even found a higher all-cause mortality using 400 IU/day synthetic vitamin E.
- NHANES III in a controlled trial in smokers, higher serum α‑tocopherol was associated with lower testosterone and estradiol (E2), and Testo and E2 levels decreased further in some situations when vitamin E was supplemented. In this study, investigators did not control for synthetic vs natural vitamin E, which was a major flaw in study design. Participants were told to continue whatever they had been taking. At the time of the study, it was very unusual to find readily available reasonable cost commercial forms of natural vitamin E. The majority of commercial vitamin E products, then as well as today, contain the synthetic dl-alpha tocopherol.
Toxic effects, increased cancer risk and increase in all-cause mortality have been documented in a variety of studies with dl-alpha-tocopherol synthetic Vitamin E 400 IU and above doses over time. I suspect that we would see different result if these studies were redone with a natural full-spectrum form of vitamin E (as I always recommend), we would see a positive long-term benefits, including improvement in testosterone levels.
Seed Oils: A Saboteur of Healthy Testosterone Production
What is the impact of a diet high in polyunsaturated fatty acids (PUFA), primarily from processed seed oils vs fats such as olive and avocado oil, nut oils, and even the fat in dairy, meat and eggs? Does the oxidative damage from seed oils adversely affect the testicles and lead to decreases testosterone levels? Data from human studies leads to mixed results. There have been many problems with study designs and methods, so we don’t have clinically meaningful clear cut data to definitely claim that seed oils (i.e., high‑linoleic omega‑6 vegetable oils) lower testosterone.
A close look at the studies, however, does show trends that are in line with HHS Secretary RFK Jr’s 2026 dietary guidelines: EAT REAL FOOD! Here are some of the results of studies on type of dietary fat and effect on testosterone levels:
- A cohort of middle‑aged Finnish men found higher seed oil intake of poly-unsaturated fatty acids (PUFA) initially associated with slightly lower total and free testosterone, while higher intake of saturated fatty acids (meat, dairy, eggs) was associated with higher testosterone, but these associations disappeared after adjusting for other variables such as BMI, lifestyle, etc. From this study, we cannot conclude there is an independent effect of seed oils alone.
- A systematic review/meta‑analysis of low‑fat diets (higher‑carb and relatively higher in seed oil percentage) reported modestly lower testosterone in men on low‑fat diets versus higher‑fat diets, with total fat reduction appearing to be the main driver.
- An RCT (randomized controlled trial) in overweight adults comparing DHA‑rich fish oil vs similar calories from corn oil (similar to seed oils in being high in PUFA omega‑6) for 12 weeks found that the fish oil arm increased T in men, but no direct evidence that the corn‑oil (seed‑oil) control reduced T relative to baseline.
- A human observational study reported that omega‑3 PUFA intake showed a positive association with serum T in adult males, but higher seed oils (higher omega‑6 intake and a higher omega‑6/omega‑3 ratio) correlated with less favorable testicular function and sperm parameters.
- A 2020 RCT secondary analysis found increased T in men given DHA‑rich fish oil, with rise in T levels with EPA/DHA and reduced T levels with omega‑6 arachidonic acid.
Overall, these data suggest that intake of seed oils leading to high omega-6 levels OR a very high omega‑6/omega‑3 ratio both appear suboptimal for male reproductive health, but do not show that seed oils acutely “crash” testosterone in humans. But avoiding the worst effect (lower T levels) is NOT the whole story! Our goal is to help you achieve optimal levels of hormones and nutrients for overall optimal health!
What’s Healthier: Saturated Fats or Poly-unsaturated Fats?
Taken as a whole, and contrary to what the government guidelines have told us since the 1980s, my medical opinion is that saturated fat (SFA) is more favorable for gonadal function as well as overall health than are the seed oils with poly-unsaturated fatty acids (PUFA). But I think the effect size is small, data are inconsistent, and overall fat amount and health status matter more than just looking at one variable about type of fat. There are some small, inconsistent signals that mono-unsaturated fatty acids (MUFA)‑rich oils such as olive and avocado oil may support T levels in some contexts.
Key Human Data:
- A large Finnish cohort (KIHD, n=2546) found that higher saturated fat intake was associated with higher total and free T, and the opposite was true with high intake of seed oils (PUFA) that led to lower T in age‑ and energy‑adjusted models. Since these associations disappeared after taking into account BMI, lifestyle, and disease; the authors concluded fat type was not independently linked to T.
- In 12 strength‑trained men, higher intake of seed oils (PUFA) correlated with lower T, and higher saturated fat and mono-unsaturated fat intake correlated with higher testosterone.
- A meta-analysis review of the mechanisms of potential ways type of fat affects gonadal function showed that higher intake of seed oils (PUFA) in rodents altered testicular lipids, increased oxidative stress, reduced steroidogenic enzyme activity, and reduced testicular free cholesterol, leading to lower T production.
This same review did not show those effects in diets higher saturated fat and mono-unsaturated fats.
- A Moroccan RCT (healthy men, 3 weeks) replacing usual fat with argan or extra‑virgin olive oil (both MUFA‑rich) increased total T by ~19–20% and LH by ~19–21%, suggesting MUFA‑rich oils can support testicular steroidogenesis, possibly via improved testicular antioxidant status.
- Across better‑powered human data, fat quality (SFA vs MUFA) has, at most, a small effect on serum T once confounders are controlled; total fat, energy balance, adiposity, and health status dominate.
- Extreme or unbalanced omega 6 PUFA intakes with high oxidative stress appear to be less favorable for testicular function than diets with adequate SFA/MUFA and antioxidants.
BOTTOM LINE: The pragmatic end result of all these findings supports three dietary priorities to support healthy testicular function and testosterone production in men (which I extrapolate to healthy ovarian function in women!):
- Adequate total daily fat intake for absorption of fat-soluble vitamins (A, E, D, and K) and to provide cholesterol as the building-block for our hormones.
- Reduce or avoid seed oils (PUFA).
- Eat a mix of saturated fats (SFA) and mono-unsaturated fatty acids (MUFA) SFA are found in meat, eggs, and dairy (REAL food, remember?) and MUFA are found in olives, avocados, and nuts, such as in a balanced Mediterranean diet.
Synthetic Saboteur vs Natural Ally for Low T: Choosing the Best Vitamin E Supplement
In the last section of today’s Health Tip, I will hit some highlights from my four-part series on low testosterone symptoms, causes, how to get properly tested, other dietary deficiencies and medicines that lead to low testosterone, and lifestyle strategies to help boost testosterone levels in those men with functioning testicles.
But given that many people today are still eating highly processed foods and seed oils in the Standard American Diet, it does become important to take the right antioxidant vitamins, such as Vitamin E, to help combat oxidative damage to the testicles leading to lower testosterone levels. The right Vitamin E may also be a helpful additional strategy for men following recommended dietary guidelines but who have lower than optimal testosterone levels and/or symptoms of low testosterone until you can pursue more in-depth medical evaluation of other causes of low T.
If you are going to take Vitamin E, it is critical to look for a high quality product that contains FULL SPECTRUM natural Vitamin E (d-alpha tocopherol), WITH mixed tocopherols AND all the tocotrienols. A great option is our TruVitamin E™ Full Spectrum, and the profits from our store go back to support our public charity educational programs. A win-win!
So what’s the difference between synthetic and natural vitamin E?
Synthetic vitamin E (dl-alpha‑tocopherol) is made in the laboratory from petrochemicals like toluene, acetone, isobutylene and formaldehyde via multi‑step reactions. After the reaction, the mixture is worked up by neutralizing acids, washing with aqueous base, removing solvent, and then purifying the crude tocopherol by vacuum distillation and/or crystallization to yield purified synthetic vitamin E suitable for further formulation. To make dl‑alpha‑tocopherol acetate (the form used in many supplements and cosmetics), the purified dl‑alpha‑tocopherol is reacted with acetic anhydride. Does this sound like something you really want take in a concentrated pill or eat in all the “fortified foods” on grocery store shelves???
Natural vitamin E (d‑alpha‑tocopherol) is the form found in real foods like Sunflower Seeds, Almonds, Avocados, Hazelnuts, Spinach (or other leafy greens), Olive Oil (extra virgin), and Wheat Germ Oil.
Natural d-alpha tocopherol is the Vitamin E isomer that is absorbed and utilized more effectively by the body than is synthetic dl‑alpha‑tocopherol. Natural vitamin E is 1.3 to 2 times greater potency than the synthetic version, so you actually need to take less natural vitamin E is needed to achieve comparable tissue concentrations and antioxidant effects.
Natural vitamin E is a single stereoisomer that exactly matches the form to match what the body’s transport proteins are designed to recognize. Synthetic vitamin E (dl‑alpha‑tocopherol) is a mixture of eight stereo-isomers that don’t exactly fit the body’s transport protein receptors, so they have much lower biological activity and some are preferentially excreted.
A full spectrum supplement of natural vitamin E contains mixed tocopherols and the complete group of tocotrienols to better mimic dietary vitamin E components and support a broader antioxidant profile than isolated synthetic dl-alpha alone. This is why I take myself and only recommend a complete natural form of vitamin E as in our TruVitamin E™ Full Spectrum.
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