To successfully lose weight, you must understand estrogen

Although the term estrogen has a strong gender orientation in the public's impression, in fact, estrogen exists in both men and women's bodies regardless of gender.

Estrogen mainly exists in three forms in the human body, namely estrone (E1), estradiol (E2), and estriol (E3). Among them, estradiol is the strongest form of estrogen, which is further metabolized to form 2, 16, and 4-hydroxyestrone. Among these three metabolites, in addition to the various health benefits of 2-hydroxyestrone, both 16 and 4-hydroxyestrone have adverse effects on health. For example, higher levels of 16 hydroxyestrone are associated with inflammation, obesity, hypothyroidism, and other problems, while 4-hydroxyestrone, although not produced in large quantities, may have a destructive effect on DNA and promote the occurrence of cancer [1].

In most cases, estriol only appears in women's bodies during pregnancy (16 hydroxyestrone is also slightly converted), and it is also the weakest form of estrogen; Estrone is mainly produced by adipocytes and can be further converted into the three types of hydroxyestrones mentioned above. Due to the fact that estradiol needs to be converted into estrone first before it can continue to produce subsequent products, estrone is the core link in regulating estrogen function.

The dominant hormone in the male body, testosterone, is catalyzed by aromatase to produce estradiol, which has a structure very similar to testosterone. Therefore, there is a close relationship between the amount of estrogen in the male body and aromatase. Aromatase is secreted by adipose tissue, so the more body fat a man has, the higher his estrogen levels may be.

Many people's first reaction is that women have higher body fat than men and have more estrogen in their bodies, which can lead to fat accumulation. This statement is also true or false. Saying it's right is because estrogen induces the distribution (accumulation) of body fat in specific parts of the body in women after puberty, which is matched with female reproductive function, such as the buttocks, inner thighs, and around the breasts. But normal estrogen does not cause an increase in visceral fat (which is a typical metabolic disorder).

In addition, significant centripetal obesity (i.e. a significant increase in subcutaneous fat in the abdomen) is observed in menopausal women, accompanied by an increase in visceral fat. After menopause, women's estrogen levels experience a cliff like decline, so the claim that estrogen causes obesity is clearly biased.

Molecular biology studies have shown that subcutaneous fat has a high concentration of estrogen receptors and almost no androgen receptors, while visceral fat has a higher concentration of androgen receptors. Therefore, the increase in visceral fat highly associated with metabolic disorders is clearly not mediated by estrogen. But this also precisely illustrates the correlation between subcutaneous fat and estrogen.

When it comes to obesity, we cannot ignore insulin resistance. Obesity is a chronic inflammation, and the inflammatory signals that appear in obesity are associated with insulin resistance. But interestingly, women exhibit much weaker levels of insulin resistance and inflammatory response induced by overeating and high-fat diets compared to men, suggesting that estrogen itself has anti-inflammatory properties (2-hydroxyestrone). In addition to reducing "bad" fats, normal estrogen levels (2-hydroxyestrone) also play a positive role in cardiovascular protection and combating neurological inflammation [3].

Estrogen can also reduce the ability of gastrointestinal hunger hormones to stimulate appetite, that is, weaken hunger. This holds true for both men and women. For women, the fluctuation of estrogen levels has the most significant impact on appetite before menstruation, and one of the main factors is the relationship between estrogen and gastrointestinal hunger hormones.

Of course, discussing the goodness or badness of something must not be separated from the category of "quantity". Anything that exceeds the normal limit has potential adverse effects, and estrogen is no exception. Excessive estrogen in the male body can lead to a decrease in the testosterone/estrogen ratio, which not only has adverse effects on some normal physiological processes, but also increases subcutaneous fat in men. Of course, having more subcutaneous fat does not necessarily result in negative health outcomes, but it should be noted that more body fat corresponds to more aromatase, which in turn leads to a higher proportion of testosterone being converted to estrogen. If this situation is allowed to occur (such as uncontrolled eating, prolonged sitting without exercise, etc.), it will lead to the occurrence of obesity in the long run.

For ordinary fitness enthusiasts, regardless of gender, it is necessary to control their estrogen levels within a reasonable range. In addition to not adding additional estrogen (such as avoiding excessive body fat and environmental estrogen), it is necessary to optimize the products of estrogen in the body. For example, we hope to have the highest possible level of 2-hydroxyestrone, while controlling the levels of 4 and 16 hydroxyestrone within the lowest possible range.

The method is actually very simple. In addition to physical exercise, it is necessary to increase the intake of isoflavone foods in the diet, such as beans and flaxseed, which will increase the conversion ratio of estrogen to 2-hydroxyestrone; Increase the intake of Omega-3 fatty acids, such as deep-sea fish oil, which contains lignans that competitively bind to estrogen receptors to weaken estrogen signaling, including reducing subcutaneous fat production; Eat more cruciferous vegetables, including broccoli, cabbage, cauliflower, Chinese cabbage, etc. Cruciferous vegetables are rich in 3,3-diindolylmethane [5], which can enhance the liver's clearance of excessive estrogen.

Ensure as much dietary fiber as possible in the diet. Because dietary fiber can prevent the intestinal reabsorption of estrogen, allowing more estrogen to be eliminated from the body. Adequate dietary fiber has a nourishing effect on beneficial gut microbiota, which in turn inhibits the absorption and reuse of estrogen in the gut, thereby reducing estrogen levels.

Reference material

1、Sepkovic DW, Bradlow HL. Estrogen hydroxylation—the good and the bad. Ann N Y Acad Sci. 2009;1155(1):57-67.

2、Lu SF, McKenna SE, Cologer-Clifford A, Nau EA, Simon NG. Androgen receptor in mouse brain: sex differences and similarities in autoregulation. Endocrinology. 1998;139(4):1594–1601.

3、Turgeon JL, Carr MC, Maki PM, Mendelsohn ME, Wise PM. Complex actions of sex steroids in adipose tissue, the cardiovascular system, and brain: Insights from basic science and clinical studies. Endocrine reviews. 2006;27(6):575–605.

4、Clegg DJ, Brown LM, Zigman JM, Kemp CJ, Strader AD, Benoit SC, Woods SC, Mangiaracina M, Geary N. Estradiol-dependent decrease in the orexigenic potency of ghrelin in female rats. Diabetes. 2007;56(4):1051–1058

5、J H Fowke 1, C Longcope, J R Hebert, Brassica vegetable consumption shifts estrogen metabolism in healthy postmenopausal women, Cancer Epidemiol Biomarkers Prev. 2000 Aug;9(8):773-9.