Your adipose tissue also speaks in hormones

For years, fat was discussed as if it were only storage.

Calories in. Calories out. A number on a scale.

But adipose tissue is not a warehouse. It is an endocrine organ.

It produces signals. It responds to hormones. It becomes inflamed. It changes with sleep, food, stress, age and hormonal stage. And in perimenopause, that conversation becomes more important because the ovary starts producing estradiol less consistently.

That raises a question we almost never ask:

what happens when adipose tissue becomes a hormonal source exactly when the ovary starts turning the volume down?

Aromatase: the enzyme that converts androgens into estrogens

Aromatase, encoded by CYP19A1, converts androgens into estrogens.

In simple terms:

androstenedione -> aromatase -> estrone
testosterone -> aromatase -> estradiol

Before menopause, the ovary dominates much of cyclic estradiol production. After menopause, adipose tissue, skin, muscle and other peripheral tissues carry more weight in local and systemic estrogen production.

That does not mean adipose tissue "replaces" the ovary. It does not produce the same signal. It does not have the same rhythm. It does not deliver the same hormone proportions.

In postmenopause, adipose tissue tends to contribute more to an estrone-dominant signal, not an estradiol-dominant one. That distinction matters.

Estradiol is usually a more potent signal in many tissues. Estrone can behave as a reserve, a weaker signal, or a discordant signal depending on the tissue, receptor and inflammatory context.

Why "more fat = more estrogen" is a bad simplification

It is tempting to say: if adipose tissue produces estrogens, then more fat means more estrogen.

Biologically, that sentence is too flat.

The real question is not only how much fat is present. It is:

• where that fat is located;
• whether it is subcutaneous or visceral;
• whether it is inflamed;
• whether insulin resistance is present;
• which estrone-to-estradiol balance dominates;
• whether estrogen receptors still respond well;
• what cortisol, IL-6, TNFα and prostaglandin signals surround the tissue.

Visceral fat does not behave like gluteofemoral or subcutaneous fat. Visceral fat is more strongly associated with metabolic inflammation, insulin resistance and low-grade immune signaling.

So this is not an aesthetic issue. It is tissue endocrinology.

What recent research is showing

A 2025 review by Lee and den Hartigh in Frontiers in Endocrinology describes white adipose tissue as a relevant source of endogenous estrogens across the lifespan, with greater relative importance after menopause. The most interesting point is not that "fat produces estrogen", but that metabolic effects depend on estrogen type, fat depot and inflammatory state.

Ostinelli and colleagues, in Journal of Clinical Endocrinology & Metabolism, found increased adipose indices of androgen catabolism and aromatization in women with metabolic dysfunction, with higher CYP19A1 expression in visceral adipose tissue.

Iyengar and colleagues showed that, in postmenopausal women, aromatase in breast adipose tissue was associated with BMI, adipocyte size, local inflammation, IL-6, glucose, leptin, hsCRP and insulin resistance. Inflamed tissue also had more aromatase than non-inflamed tissue.

The reading is clear: this is not only fat mass. It is dysfunctional adipose tissue.

The epigenetic layer: histones, inflammation and hormonal signaling

The next layer is chromatin.

Histones help package DNA. When certain marks are acetylated, such as H3K9ac or H3K27ac, chromatin becomes more open and some genes can be expressed more easily. In a context of insulin resistance, that can favor inflammatory programs.

Vidal and colleagues reported that insulin resistance in women is associated with histone acetylation, chromatin opening at genes such as TNF and IL6, inflammatory signaling, senescence and accelerated epigenetic aging.

This matters because IL-6, TNFα, PGE2 and cortisol are not just noise around adipose tissue. They can become signals that push aromatase expression.

In parallel, another study by Wu and colleagues showed in an animal model that a high-fat diet can silence Esr1, the estrogen receptor alpha gene, in adipocytes. When that methylation was experimentally reduced, inflammation decreased and insulin sensitivity improved.

The emerging idea is uncomfortable but powerful:

a tissue can produce more local estrogenic signals and, at the same time, respond less to estradiol's protective signal.

The E1-high, ERα-low, inflammation-high state

At Lua Labs, this line of research points toward a model:

inflamed visceral fat
  -> IL-6, TNFα, PGE2, local cortisol
  -> more active CYP19A1 aromatase
  -> more local estrone signaling
  -> but weaker protection if ERα is repressed

This is not a new disease. It is not a diagnosis you can obtain from an app. It is a mechanistic hypothesis for understanding why some women experience the hormonal transition as a mix of vasomotor symptoms, metabolic fatigue, disrupted sleep, reactive hunger and changes in body composition.

Not everything is explained by "low estrogen".

Sometimes the issue may look more like this:

there is hormonal signal, but it comes from another tissue, in another rhythm, with another estrogen type and in an inflammatory environment that changes how the signal is heard.

Why this matters in perimenopause

Perimenopause is not a linear decline.

It is variability.

There can be cycles with higher estradiol, cycles with lower estradiol, less consistent progesterone, more fragile sleep, noisier cortisol, appetite shifts and more sensitivity to late food or alcohol.

If visceral fat or metabolic inflammation also increases, adipose tissue enters the hormonal conversation more strongly.

This may help explain why some women feel that "the same body no longer responds the same way":

• the same dinner feels heavier;
• the same bad sleep costs more;
• the same stress feels more physical;
• the same weight distributes differently;
• hot flashes and awakenings seem mixed with hunger, fatigue or brain fog.

Not because it is the woman's fault. Because the system changed.

What we can say honestly

We can say that adipose tissue is an endocrine organ.

We can say that aromatase in adipose tissue matters more after menopause.

We can say that visceral fat, inflammation, insulin, cortisol, estrone, estradiol and estrogen receptors form a network, not a simple line.

We also have to state the limits:

local aromatase cannot be inferred from symptoms. Estrone or estradiol cannot be known without measurements. A hot flash cannot be assigned to visceral fat. Epigenetics cannot be diagnosed with an app.

The responsible use of this science is to ask better questions.

For example:

Do my symptoms worsen after several nights of poor sleep?

Is there a relationship between late dinners, alcohol, nighttime heat and next-day energy?

Do appetite and central-weight changes appear together with more hot flashes or awakenings?

Is my body responding differently to the same food or routine depending on hormonal stage?

That is where longitudinal patterns matter.

The conversation ahead

For a long time, the conversation about women's hormones was reduced to ovaries.

Ovaries, estradiol, progesterone, FSH.

That still matters. But it is not enough.

The hormonal transition also involves the brain, adipose tissue, muscle, gut, liver, immune system, sleep and circadian rhythm.

Adipose tissue is one of the most underestimated pieces because we were taught to see it as weight. But in perimenopause it can become part of the signal.

This is not about demonizing fat.

It is about understanding that the body does not change in isolated compartments.

It changes as a system.

And when adipose tissue starts speaking more loudly in hormones, we need to learn how to listen with more precision.

Sources

• Lee A, den Hartigh LJ. Metabolic impact of endogenously produced estrogens by adipose tissue in females and males across the lifespan. Frontiers in Endocrinology. 2025. DOI: 10.3389/fendo.2025.1682231.
• Ostinelli G, Laforest S, Denham SG, Gauthier MF, Drolet-Labelle V, Scott E, et al. Increased Adipose Tissue Indices of Androgen Catabolism and Aromatization in Women With Metabolic Dysfunction. Journal of Clinical Endocrinology & Metabolism. 2022. DOI: 10.1210/clinem/dgac261.
• Iyengar NM, Zhou XK, Gucalp A, Giri DD, Harbus MD, Falcone DJ, et al. Menopause Is a Determinant of Breast Aromatase Expression and Its Associations With BMI, Inflammation, and Systemic Markers. Journal of Clinical Endocrinology & Metabolism. 2017. DOI: 10.1210/jc.2016-3606.
• Vidal CM, Alva-Ornelas JA, Chen NZ, Senapati P, Tomsic J, Robles VM, et al. Insulin Resistance in Women Correlates with Chromatin Histone Lysine Acetylation, Inflammatory Signaling, and Accelerated Aging. Cancers. 2024. DOI: 10.3390/cancers16152735.
• Wu R, Li F, Wang S, Jing J, Cui X, Huang Y, et al. Epigenetic programming of estrogen receptor in adipocytes by high-fat diet regulates obesity-induced inflammation. JCI Insight. 2025. DOI: 10.1172/jci.insight.173423.
• Zhao Y, Nichols JE, Valdez R, Mendelson CR, Simpson ER. Transcriptional regulation of CYP19 gene expression in adipose stromal cells in primary culture. Journal of Steroid Biochemistry and Molecular Biology. 1997. PMID: 9365191.