#Hormones #Nutrition #Endocrinology #SHBG
Sex hormones, such as
testosterone,
estradiol,
and
SHBG (
Sex Hormone-Binding Globulin), are steroid compounds derived from
cholesterol, primarily produced by the gonads. While they are historically
associated with
reproduction, sexual development, and
secondary sexual
characteristics, their function goes far beyond these roles. These hormones are
involved in
immune regulation,
muscle mass maintenance,
body temperature
control, glucose-lipid metabolism, and the
prevention of cardiovascular
diseases.
Recent data suggest that
dietary fat intake may
influence circulating levels of these hormones. Many studies have explored the
relationship between
dietary fat composition and
hormone concentrations. Some
of them reported that a
low-fat diet could decrease
testosterone,
estradiol, or
SHBG levels—especially in men and premenopausal women. Other studies, however,
found
no significant changes, fueling an ongoing debate in the scientific
literature.
In this context, the present study was designed
to
evaluate the effects of a
low-fat diet compared to a high-fat diet on
circulating sex hormone concentrations in adults.
Less fat, fewer hormones?
Eleven randomized clinical trials, including a
total of
888 participants aged 33 to 65, were selected. The subjects—both men
and women—had varied profiles, ranging from healthy individuals to patients
with
polycystic ovary syndrome (PCOS) or
breast cancer.
The duration of the
interventions ranged from
4 weeks to over a year. The studied sex hormones
included
testosterone, estradiol, estrone, SHBG, DHEAS, progesterone, and
androstenedione.
The results showed
no significant changes in
hormone concentrations between low-fat diets (≤30% of total energy intake) and
high-fat diets. For instance, estradiol levels did not differ significantly
between the two groups. Similarly, testosterone levels remained stable, with no
significant variation, and the same was true for SHBG.
Sensitivity and subgroup analyses—taking into
account factors such as
sex,
menopausal status, intervention duration, and
possible
co-interventions—confirmed the
consistency and robustness of the
results. However,
moderate heterogeneity was observed for some hormones,
suggesting that contextual or individual factors might modulate dietary effects
in specific subgroups.
Read next: Fats and Hormones: A Link to Clarify?
Fats under the spotlight, but no effect?
Sex hormones play a central role in the
development of many chronic conditions, including metabolic and cardiovascular
diseases, as well as certain cancers. Among the factors likely to influence
their regulation,
diet—and particularly fat consumption—has been considered a
potential contributor. Yet, current knowledge about the link between diet and
hormonal balance remains
mixed and controversial.
Against this backdrop,
the goal of this study
was to compare the effects of low-fat versus high-fat diets on sex hormone
levels in adults. The findings indicate that reducing fat intake
does not lead
to significant hormonal changes, challenging the commonly held notion that a
low-fat diet alone can have a preventive or therapeutic effect on hormonal
balance.
Although these results provide valuable
insights, further research is needed. The variability of the diets tested, the
differing intervention durations, and the lack of precise dietary adherence
tracking may affect conclusions. To better understand the link between diet and
hormonal balance, longer and more rigorous studies are necessary. These should
include precise tracking of dietary intake, detailed analysis of fat quality,
and consideration of participants' metabolic and physiological profiles. Future
studies may help identify
individualized nutritional profiles that could
influence hormonal regulation in a targeted and scientifically grounded way.
Read next: PCOS: Is homocysteine the hidden fertility marker?
