Many people are confused by estrogen and its action on body fat. Does it store fat? Does it burn fat? Does it matter if you are taking birth control or HRT? What about its supposed effects on thyroid? Why do women suddenly gain belly fat at menopause? I heard estrogen makes female lower body fat more stubborn, is that true?
These are all great questions, and you are going to quickly find out that the answers are far more complicated than you may have thought. One of the main reasons for confusion is the simplistic view that hormones have one single action in the body. In fact, that is not true at all.
Hormones behave differently depending on which tissue they are acting in. For example, estrogen may have one impact in the brain, another in the uterus, and still another in your fat cells. Hormones also never work in isolation. Other hormones may accentuate or block estrogen’s actions. For example, a large amount of testosterone may decrease estrogen’s impact on female fat storage.
The story of estrogen can be a little confusing, but if you showed up here and are reading this blog, you are likely tired of the oversimplified explanations that dominate the web. So here are some of the major things to understand about estrogen, complication and all.
Estrogen & the Menstrual Cycle
- Estrogen rises steadily during the first 14 days of the menstrual cycle (called the follicular phase).
- Estrogen sensitizes progesterone receptors and progesterone sensitizes estrogen receptors. This means low estrogen or progesterone will have a negative impact on the other hormone as well.
- Estrogen and progesterone have opposite effects in many tissues. In the uterus, progesterone has a thinning effect on the uterine lining while estrogen has a thickening effect.
- Estrogen has a growth promoting effect on reproductive tissue and will cause the uterine lining to thicken.
- Estrogen peaks in the first half of the menstrual cycle and then dips before rising again.
- During the follicular phase of the menstrual cycle (day 1-14) estrogen is elevated without progesterone.
- During the luteal phase of the menstrual cycle both estrogen and progesterone are elevated together with progesterone more dominant.
- Before menses both estrogen and progesterone fall abruptly.
Estrogen & Female Fat Distribution
- Estrogen increases the number of alpha-adrenergic receptors in the lower body of women. These receptors slow fat release. This is one reason why many women have a gynoid or pear shape fat distribution.
- Some evidence hints that when estrogen levels are higher, the activity of the alpha-receptors are greater suggesting that training in low estrogen states may speed fat release from more stubborn estrogen impacted areas (like the lower body).
- Estrogen also makes women store fat more in the subcutaneous areas (fat just under the skin and in the arms and legs), versus the deep belly fat in the middle of the body.
- Estrogen may have a different impact on deep abdominal fat, either not impacting it at all or speeding its release. This may be one reason why menopausal women who have lost the influence of estrogen see their fat distribution switch to the belly.
- Women have about 9 times more alpha-adrenergic receptors in the lower body than do men.
- In animal studies, estrogen sensitizes the body to insulin and aids fat loss. These effects are not always seen in humans.
- Estrogen seems to have an anabolic effect (helps women build muscle) compared to progesterone. This may be related to its insulin sensitizing effects.
- Estrogen has an anti-cortisol effect, another mechanism by which it may control fat storage at the belly.
- Insulin and cortisol have far greater impacts on fat metabolism compared to estrogen and progesterone. This is important to understand and the reason why hormone replacement therapy does not suddenly result in weight loss. The stronger effects of insulin and cortisol wash out any positive effects from estrogen.
Estrogen & Thyroid
- Females have larger thyroids than men largely because estrogen has an anti-thyroid effect.
- Thyroid hormone and the adrenal catecholamines (aka adrenaline/epinephrine & noradrenaline/norepinephrine) are higher on the fat burning hierarchy than estrogen and progesterone. This is another reason why hormone replacement is not a recipe for fat loss and could even contribute to fat gain in some women.
Estrogen & Progesterone (estrogen dominance)
- Estrogen and progesterone need to be in balance as they both enhance the action of the other as well as offset the action of the other.
- Estrogen dominance is a term used in complementary & alternative medicine where estrogen action is greater than progesterone.
- Estrogen dominance refers to a relative deficiency of progesterone compared to estrogen. This can be the case whether both hormones are high, low, or normal.
- We live in an environment that is swimming in estrogens. Phytoestrogens (plant estrogens) and xenoestrogens (environmental estrogens) are now ubiquitous (i.e. found everywhere).
- Stress negatively impacts progesterone production.
- Animal foods, most notably dairy, can have significant amounts of estrogen and progesterone in it.
- Human fat cells, through an enzyme called aromatase, make and secrete estrogen. This is not true for progesterone.
- Common sources of environmental estrogens: fatty meats, milk products, caffeine containing foods, pesticides, plastic, cosmetics.
- Most common sources of plant estrogens include soy and flax, but there are many others with smaller amounts HERE.
- Estrogens can vary slightly in their chemistry with some being stronger in activity than others. Some believe that the 4 and 16 hydroxy estrogens have more negative effects while the 2-hydroxyestrogens are protective. Cruciferous vegetables (broccoli, cabbage, Brussels sprouts, etc) may increase the 2 and decrease the 4 and 16-hydroxy estrogens.
- Common conditions believed to be related to estrogen dominance are: fibroids, fibrocystic breast, ovarian cysts, endometriosis, breast cancer, PMS, and PCOS.
- A high fiber diet and regular bowel movements help decrease estrogen exposure since estrogen is removed through the body when the gallbladder releases its contents into the GI tract. However, improper elimination can cause estrogen to be reabsorbed.
Estrogen Contraceptives & Hormone Replacement
- OCPs (oral contraceptive pills), HRT (hormone replacement therapy), hormone releasing patches, and IUDS use estrogen compounds that are NOT identical to estrogen made in the body (unless you are specifically taking bioidentical hormones).
- These hormones can have weaker action in certain tissues compared with bioidentical hormones or stronger action.
- In general, the research is mixed as to whether these hormones cause weight loss or weight gain.
- The research hints that HRT has either no impact or has a slight weight gaining effect in women, although at the same time does reduce the belly fat distribution issue that occurs at menopause.
- HRT may have a fat gaining effect in those more susceptible to eating response to hunger since it does seem to increase the brain’s sensitivity to one of the major hunger hormones, ghrelin.
- Given estrogen and progesterone are further down on the fat burning totem poll compared with other hormones, a woman wanting to lose weight while using these will likely have little success unless controlling the other hormones first.
- Given the relationship between thyroid and estrogen compounds, females on hormone replacement may want to ask their doctors about possible anti-thyroid effects.
- Since these hormones are given in static doses across the menstrual cycle, women lose the natural rhythmic changes in estrogen and progesterone.
Estrogen, Mood & Cravings
- There are receptors for estrogen all over the body including in the brain.
- Lower estrogen, as it occurs at menopause and menses, can impact mood and cravings.
- Low estrogen states can especially impact dopamine (the brains number one motivating neurochemical) and serotonin (a major relaxing and well-being brain chemical).
- Estrogen also impacts GABA (the brains number one relaxing brain chemical).
- Using things like cocoa powder during low estrogen states (i.e. menses) can raise dopamine and serotonin. We have found this helps mood and cravings around the time of menses.
- Yogi brand bedtime tea is a favorite of ours to naturally raise GABA. We have also found this helps mood and cravings around the time of menses.
- For more on brain chemistry and cravings, see this BLOG.
Take Homes on Estrogen & Weight Loss
- Remember the hormonal hierarchy. Insulin and cortisol are the biggest issues here. This means a carb controlling and stress controlling approach especially if you are menopausal.
- Remember, if you are eating a high calorie diet on a regular basis this too will “wash out” any beneficial fat burning effects of any hormone.
- If you are menstruating normally and not on any hormones you may want to experiment with our phase training protocol by timing your eating and exercise with your cycle.
- Watch your consumption of animal based and plant based estrogen, but don’t stress too much. Stress and cortisol may matter more for weight loss.
- Watch your exposure to environmental estrogens through plastic, pesticides, cosmetics, and caffeine. But again, don’t stress too much as this may be worse.
- If you have symptoms of estrogen dominance, look into seeing an integrative physician who can help with this. You are welcome to contact our clinic as well. We consult with clients internationally via phone and Skype.
- Have a specific concern? Ask in the comments below and we will answer or update the blog to address it.
For more on female specific fat loss issues see our resource page on DIET PLANS FOR WOMEN.