Soy vs Dairy: Which Affects Testosterone More in Men Over 60?

by Goldman Labs Team

Soy vs dairy testosterone: dairy milk allergy affects up to 17% of people worldwide, and lactose intolerance affects two-thirds of the global population1. Many men now question the relationship between soy, dairy, and testosterone levels. This growing interest comes as dairy consumption continues to decline throughout Europe and the United States.

Recent human studies have shown that soy foods don't substantially affect men's testosterone levels26. The connection between dairy consumption and testosterone in older adults needs careful thought, especially since modern milk production has changed drastically to boost commercial output1. Men over 60 need to learn about how milk hormones and phytoestrogens interact with testosterone to maintain their best health.

This piece dives into the science behind how soy milk and dairy affect testosterone levels. You'll learn what research really says about these everyday food choices and how they might affect hormone levels in aging men, moving past common myths and misconceptions.

Understanding Testosterone in Men Over 60

Chart showing average male testosterone levels rising at puberty, peaking around 20, then gradually declining with age.

_{Image Source: Maximus Tribe}

Testosterone peaks during adolescence and early adulthood. Men's bodies start producing less of it around age 3527. This hormonal change affects men's health in many ways, especially after they turn 60. Men need to understand these changes to make better choices between soy and dairy testosterone effects.

Why testosterone matters for aging men

Testosterone is the main male hormone that develops and maintains masculine physical traits. This powerful hormone does more than just control sexual function. It affects mood, thinking, metabolism, immune function, and heart health27. Testosterone plays a vital role in bone strength, fat distribution, muscle mass, and red blood cell production28.

Men over 60 need proper testosterone levels more than ever. Low levels can harm aging men's health. They face higher risks of diabetes, dementia, heart disease, and even death27. Low testosterone also hurts male fertility. Some researchers think testosterone decline kickstarts the overall aging process in men27.

Research shows low testosterone links to several age-related conditions:

Weak bones and lower bone density
Alzheimer's disease and mental decline
Obesity and metabolic problems
High cholesterol and heart issues
Muscle weakness and poor physical function29

These problems are systemic, and many men now look for natural remedies for low testosterone to boost their hormone health as they age.

Natural decline and its effects on health

Testosterone drops in a predictable way. Men between 40-70 lose about 0.4% of total testosterone yearly. Free testosterone drops even faster at 1.3% per year27. By 70, men produce 30% less testosterone than their peak levels30.

The numbers paint a clear picture. One in five men over 60 have below-normal testosterone levels. This number jumps to half of all men over 8029. Notwithstanding that, 75% of older men maintain normal testosterone levels30.

Several things in the body cause this hormone change. Aging hits testicular function through:

Breakdown of the hypothalamic-pituitary-gonadal axis
Fewer working Leydig cells
Failing mitochondria in testosterone-producing cells
More oxidative stress in testicular tissue
Higher long-term inflammation
Reduced Sertoli cell count and function27

Low testosterone shows up in physical, sexual, and mental ways. Men often report less sex drive, trouble with erections, weaker muscles, more body fat, brittle bones, and higher heart risks31. They might feel tired, depressed, unfocused, and sleep poorly. Doctors call this "late-onset hypogonadism" when these symptoms come with low testosterone31.

How diet may influence hormone levels

Age and body weight affect testosterone more than food choices. Yet what you eat still makes a difference in hormone balance32. This matters when looking at the [andropause diet](https://goldmanlaboratories.com/blogs/blog/andropause-diet) and comparing how soy milk and dairy affect testosterone.

Food choices can affect estrogen dominance in men with age-related testosterone decline33. Here's how different nutrients affect hormone production:

Fat consumption - Your body needs cholesterol to make sex hormones. Very low-fat diets can hurt hormone health. Healthy fats help your body make testosterone34.
Carbohydrate quality - Too many refined carbs and sugars can lead to insulin resistance and mess with hormones34. The Mediterranean diet, full of whole foods and good fats, helps keep insulin and hormone production healthy.
Protein sources - Studies comparing different diets show vegans have slightly higher sex-hormone-binding globulin and testosterone than meat-eaters32. This matters when weighing plant estrogens against milk hormones in dairy.
Fiber intake - Good fiber helps gut health and removes extra hormones, especially estrogen. This helps keep hormones balanced in both men and women34.

Men worried about their hormones often ask if certain foods lower testosterone. Your body naturally balances small changes in androgen metabolism32. Still, older men should know which foods might throw off this balance.

Specialized supplements can help support hormone health alongside good nutrition when used correctly.

Soy Phytoestrogens: What the Science Says

Chemical structure diagrams of soy isoflavones including daidzein and genistein molecules.

_{Image Source: ResearchGate}

Soybeans contain unique plant compounds that have stirred up quite a debate in men's health circles, especially among those who worry about their hormone balance. These natural substances, called phytoestrogens, sit at the center of discussions about how soy and dairy products affect testosterone in aging men. The scientific evidence tells a different story from what many people believe.

What are phytoestrogens and isoflavones?

Phytoestrogens are natural plant compounds that look similar to estradiol, one of the body's natural estrogens8. Their structure lets them interact with estrogen receptors, though their effects are much weaker than the body's own estrogens. Scientists have studied isoflavones, a type of phytoestrogen, more than any other group35.

Soy stands out because it has so many isoflavones10. The three main types are:

Genistein - The most abundant isoflavone in soybeans
Daidzein - Second major isoflavone found in soy products
Glycitein - Present in smaller amounts compared to the others36

These compounds exist in soybeans as glycosides (bound to sugar molecules) - specifically genistin, daidzin, and glycitin. The body's digestion or fermentation turns them into their aglycone forms: genistein, daidzein, and glycitein36. This change shapes how these compounds work in the human body.

People eat different amounts of isoflavones depending on where they live. Asian countries see daily consumption between 25 to 50 mg/day. The numbers look quite different in Western nations - Europe, North America, and Australia/New Zealand - where non-Asian women eat less than 2 mg/day36. Men who want to choose between foods that lower testosterone and foods that support hormone health can use these numbers as a reference point.

Do they mimic estrogen in the body?

The name "phytoestrogens" comes from their similarity to 17-β-estradiol, which lets them interact with estrogen receptors inside cells36. The body has estrogen receptors in many places beyond reproductive tissues - bones, liver, heart, and brain all have them36.

Soy isoflavones work differently with different estrogen receptors. They prefer to bind with and activate estrogen receptor-beta (ER-β) over estrogen receptor-alpha (ER-α), which creates different effects in different tissues36. This means they can copy estrogen's effects in some places while blocking them in others36.

Scientists call isoflavones selective estrogen receptor modulators because of this selective behavior37. They differ from pure estrogen in several key ways:

Their bond with estrogen receptors is much weaker than natural estrogen8. They can both promote and block estrogen effects based on the tissue type and existing estrogen levels38. They also have biological effects that have nothing to do with estrogen receptors36.

These compounds might change hormone metabolism by stopping certain enzymes involved in estrogen and androgen processing, which could change how the body's natural hormones work36. This makes many aging men wonder if soy milk affects their testosterone levels differently than dairy.

Meta-analysis findings on soy testosterone men

Science keeps showing that soy doesn't feminize men, yet concerns persist. Several large studies have looked at this question head-on.

A detailed meta-analysis in Fertility and Sterility looked at 15 placebo-controlled groups and found no real effects from soy protein or isoflavones on testosterone, sex hormone-binding globulin (SHBG), free testosterone, or free androgen index (FAI) in men13. Different statistical approaches all showed the same result13.

A bigger meta-analysis later looked at 41 studies measuring testosterone in 1,753 men, free testosterone in 752 men, estradiol in 1,000 men, and estrone in 239 men3. The results backed up earlier findings - soy protein and isoflavones didn't change total testosterone, free testosterone, estradiol, or estrone levels in men3. Even when they looked at different isoflavone doses and study lengths, nothing changed3.

A newer study, published in 2021, analyzed 38 clinical studies and found the same thing - soy and isoflavones don't affect men's testosterone or estrogen levels10. These consistent results from multiple big studies show that claims about soy making men feminine don't hold up.

Men who ate much more isoflavones than usual didn't show any feminine traits14. This goes against stories about gynecomastia or other feminine changes supposedly caused by eating too much soy14. Scientists agree that eating normal or even high amounts of soy won't change men's hormones in any meaningful way.

These findings help older men choose between foods with phytoestrogens and dairy products that might contain milk hormones. The evidence clearly shows that many popular beliefs about how soy affects male hormones are just myths.

Dairy Milk and Hormonal Content

Assorted dairy products including milk, cheese, yogurt, and cream arranged around a blank clipboard.

The dairy industry looks quite different today compared to a few decades ago. Cows now produce milk through most of their pregnancy. This change in farming methods raises questions about milk's hormone content—something you might want to think over when comparing soy vs dairy testosterone effects.

Presence of estrogen and progesterone in milk

Plant-based alternatives differ from dairy milk because dairy naturally contains mammalian sex hormones. This happens because most commercial milk comes from pregnant cows. Today's genetically improved dairy cows keep producing milk during pregnancy, which leads to substantially higher hormone levels15.

Dairy products serve as the main source of animal-derived estrogens in human diets. They make up 60-80% of the female sex steroids we consume1. Milk and dairy products actually provide about 60-70% of estrogens in Western diets16.

These hormone levels change based on the cow's reproductive state:

Estrone (E1) rises from 7.9 ng/L in non-pregnant cows to 1,266 ng/L during the third trimester1
17β-estradiol goes up from 18.6 to 51.2 ng/L during pregnancy1
Progesterone increases from 5.42 ng/ml during estrus to 11.75 ng/ml during pregnancy6

Hormone distribution varies with milk's fat content. Estrogens dissolve in fat, so whole milk contains more hormones than skim milk5. Measurements show progesterone levels of 1.4 ng/ml in skim milk compared to 300 ng/g in butter6.

Effect of dairy testosterone elderly levels

Research shows mixed results about dairy's hormonal effects for men over 60 who worry about foods that lower testosterone. Scientists have looked at how milk consumption affects human sex hormone levels.

One study revealed that men who drank milk saw their serum estrone and progesterone levels rise quickly. Their testosterone, luteinizing hormone, and follicle-stimulating hormone dropped within an hour of drinking milk7. The research team found that milk's estrogens entered the bloodstream and reduced gonadotropin secretion, which led to lower testosterone production7.

A different picture emerged from a Taiwanese study. Men who ate more dairy products showed higher testosterone levels. Milk consumption explained over 25% of testosterone differences between participants17. Another study of men over 50 showed that high-protein dairy milk combined with exercise boosted muscle power without changing testosterone levels17.

These different results suggest that dairy affects hormones based on several factors:

Each person's metabolic differences
Overall eating patterns
Age and starting hormone levels
Exercise and lifestyle choices
How much and how often someone drinks milk

These factors matter to elderly men following an andropause diet. They need to weigh the effects of milk hormones against phytoestrogens testosterone interactions from plant alternatives.

Differences between organic and conventional dairy

People often ask if organic milk offers better hormone levels than conventional dairy. Organic dairy farms can't use recombinant bovine somatotropin (rBST)—a synthetic version of natural growth hormone that some farmers give cows to boost milk production18.

Both types of milk contain natural hormones. Let's clear up a common myth: organic milk isn't "hormone-free." Natural hormones exist in all animal-derived foods18.

Studies comparing hormone content between organic and conventional milk show different results. Some research finds more progesterone and estrogen in organic milk19, possibly because of different feeding practices. Other studies see no real difference in estrogen levels between organic and conventional products2.

Organic milk's proven benefits include:

No antibiotic residues
Better nutrition, especially omega-3 fatty acids
Less exposure to synthetic pesticides4

The choice between organic and conventional milk might not matter as much as overall dairy consumption patterns for men worried about dairy testosterone elderly interactions.

The bottom line? Men over 60 comparing soy milk vs dairy testosterone effects should know that all dairy naturally contains mammalian hormones. These hormones stay present after processing and show up in commercial milk products at levels that could affect hormone balance, especially if you keep taking them.

Comparing Soy Milk vs Dairy Testosterone Effects

Man in gray t-shirt flexing arm while holding a glass of milk against beige background.

Recent clinical research that directly compares soy and dairy milk shows surprising results. These findings challenge what many people believe about phytoestrogens testosterone interactions. Men need to make smart dietary choices as they age to keep their hormone levels optimal.

Clinical trial results in resistance-trained men

Scientists conducted a groundbreaking randomized crossover study to look at how both milk types affect male hormone levels right after consumption. The study included six male participants between 18-28 years who went through resistance exercise training (RET) sessions. They drank either dairy or soy milk afterward1. Each participant acted as his own control, which removed many issues that usually affect nutrition research.

The participants cut out all dairy and soy products from their diets two days before each test session20. Blood samples were taken at seven different points up to two hours after exercise1. This gave researchers a complete picture of how hormones responded.

The results were clear. Scientists found no major differences in immediate blood serum levels for:

Free testosterone (p=0.95)1
Percentage of free testosterone (p=0.56)1
Total testosterone (p=0.88)1
Progesterone (p=0.67)1
Estrogen (p=0.21)1

These results go against popular beliefs about soy milk making men more feminine or dairy milk lowering testosterone. One researcher stated, "soy milk consumption did not decrease circulating testosterone or increase circulating total estrogen more than dairy milk"20.

Short-term vs long-term hormonal changes

Area under curve (AUC) measurements show the bigger picture of hormone responses over time. These measurements revealed no significant differences between soy and dairy consumption1. Both types of milk seem to affect hormones the same way in the short term.

Scientists have done larger meta-analyzes on soy consumption's long-term effects. These studies consistently show no statistically significant effects on male hormone levels. A complete review of more than 50 treatment groups from peer-reviewed articles concluded that "neither soy foods nor isoflavone supplements from soy affect testosterone levels in men"21.

Research supports these findings for both short and long-term studies. Scientists found no meaningful hormone changes even after analyzing different isoflavone doses and study lengths1.

Men over 60 who worry about dairy testosterone elderly interactions can rest easy. Research shows neither type of milk changes hormone profiles much in the short term. Long-term studies continue to back this up for soy consumption.

SHBG, estrogen, and testosterone comparisons

Sex hormone-binding globulin (SHBG) controls hormone availability in the body. The crossover study found no major differences in SHBG levels between milk types1. This matters especially for older men since SHBG levels naturally go up with age and might reduce free testosterone.

The research found some group-by-time interaction effects for total estrogen. However, detailed analysis couldn't find any time-specific differences between milk types1. Small variations might exist in estrogen response patterns, but they don't make any real clinical difference.

Men who use resistance training as part of their natural remedies for low testosterone plan can benefit from these findings. Both milk types work equally well as post-workout drinks without hurting hormone health20.

The research gives men a practical takeaway about soy vs dairy testosterone choices in their diet. They can choose between these milk types based on taste, digestion, nutrients, or environmental impact without worrying about hormone effects.

Protein Quality and Muscle Health in Older Men

Muscle maintenance becomes harder but more vital for men's health and independence as they age. The way protein works in the body and its quality play significant roles in keeping lean tissue while testosterone levels drop naturally.

Leucine threshold and muscle protein synthesis

Muscle mass preservation relies on muscle protein synthesis (MPS). Essential amino acids (EAAs) regulate this process, and leucine acts as the main trigger. This branched-chain amino acid kicks off the mTORC1 signaling pathway that activates protein synthesis machinery12.

Men over 60 develop "anabolic resistance" in their muscles. Their bodies need more protein than younger men to build the same amount of muscle9. Research shows older people might need double the protein to achieve the same muscle protein synthesis as younger individuals9.

The "leucine threshold" matters a lot to elderly men. Scientific studies reveal:

Older adults need 3-4g of leucine per meal to get the most muscle protein synthesis11
Most seniors eat enough protein only at dinner and not enough at other meals11
The best MPS response happens with 35-40g of protein after exercise compared to 20g at rest12

Protein sources have different amounts of leucine per 100g:

Whey: 8.6g
Casein: 5.8g
Soy: 5.0g
Pea: 5.7g
Egg: 3.6g12

A 12-week study showed that soy protein helped elderly adults gain soft lean mass (1.43kg) and skeletal muscle mass (1.20kg), and they walked better too22. A mix of soy and dairy proteins helped muscle protein synthesis through steady amino acid delivery23.

Adding 4-5g leucine to regular meals boosts muscle protein synthesis in older people11. The right mix of protein sources can optimize muscle health, which matters if you have an andropause diet.

Experts suggest older adults should eat 1.0-1.2g of protein per kilogram of body weight each day24. This protein should be spread evenly across meals. Eating protein and doing resistance exercise together creates better results for keeping muscle mass and strength25.

Both dairy and soy proteins help maintain muscle health. They work best as part of a well-laid-out nutrition plan that includes enough leucine to overcome age-related anabolic resistance.

Key Takeaways

For men over 60 weighing dietary choices between soy and dairy, scientific evidence reveals surprising truths that contradict common misconceptions about hormonal impacts.

• Neither soy nor dairy significantly affects testosterone levels - Meta-analyzes of 41 studies found no meaningful changes in testosterone, free testosterone, or estrogen from either milk type

• Dairy contains actual mammalian hormones while soy contains weaker plant compounds - Milk from pregnant cows has measurable estrogen and progesterone, yet clinical trials show no greater hormonal impact than soy

• Both milk types support muscle health equally when leucine needs are met - Older men require 3-4g leucine per meal to maximize muscle protein synthesis, achievable with either protein source

• Age-related testosterone decline stems from physiological changes, not dietary choices - 20% of men over 60 have low testosterone due to natural aging processes, not food selection

• Focus on overall protein quality rather than hormone fears - Both soy and dairy provide complete proteins that support healthy aging when consumed as part of a balanced diet

The evidence suggests men can choose between soy and dairy based on personal preferences, digestibility, and nutritional goals rather than unfounded concerns about testosterone suppression.

FAQs

Q1. Does soy milk affect testosterone levels in older men? Recent studies have found no significant effect of soy milk consumption on testosterone levels in men, including those over 60. Soy isoflavones do not appear to meaningfully impact male hormone profiles when consumed as part of a balanced diet.

Q2. Is dairy milk better than soy milk for maintaining muscle mass in aging men? Both dairy and soy milk can support muscle health in older men when consumed as part of a protein-rich diet. The key is meeting the leucine threshold (3-4g per meal) to stimulate muscle protein synthesis, which can be achieved with either milk type.

Q3. Can drinking milk from cows increase estrogen levels in men? While cow's milk does contain mammalian hormones, including estrogen, clinical studies have not shown significant increases in men's estrogen levels from typical dairy consumption. The hormonal impact appears to be minimal in the context of a balanced diet.

Q4. How much protein should men over 60 consume to maintain muscle mass? Experts recommend that older adults consume 1.0-1.2g of protein per kilogram of body weight daily, ideally distributed evenly across meals. This higher protein intake helps overcome age-related anabolic resistance and supports muscle maintenance.

Q5. Are there any benefits to choosing soy milk over dairy milk for men's health? Soy milk may offer certain health benefits for men, such as potentially lowering the risk of prostate cancer and supporting cardiovascular health. However, both soy and dairy can be part of a healthy diet for men, and the choice often comes down to individual dietary needs, preferences, and tolerances.

References

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Soy vs Dairy: Which Affects Testosterone More in Men Over 60?