The volume of emails I receive from women who start having menstrual problems on a paleo diet is staggering.    It is not an enormous volume, no.  But it is enough to give a woman pause.  What gives?  Aren’t we supposed to be healthier on a paleo diet?

Yes, we are, and really, we are.  In the vast majority of women who eat a Standard American Diet, specifically those who are overweight, a paleo diet does wonders for balancing hormone levels.  It is usually only when a paleo/whole-foods diet is coupled with restrictive norms that women start running into problems.  Too little food, too much exercise, and too much stress are really what it all boils down to.   The whole foods are not to blame– not in the slightest.  What are to blame, instead, are the obsessive ways in which people interact with these foods.

There are several mechanisms that may be at play in the physiology, depending on each woman’s genetics and how each woman undertakes her paleo diet and lifestyle.

What happens in the body when it stops menstruating

The female reproductive system runs off of a sensitive fleet of circulating hormones.   When one or several of them is disrupted, many of the others fail at their jobs, too.

During the menstrual cycle, hormone levels in the blood signal to the hypothalamus to signal to the pituitary to release FSH and LH, two hormones that in turn tell the ovaries what to do.    FSH–follicle-stimulating hormone– is released in the first part of the menstrual cycle to incite egg development.  LH–luteinizing hormone–is released in the second part of the cycle and prepares the endometrium to be shed.  Without proper FSH and LH levels, the female body can never convince the ovaries to do their job.  FSH and LH are crucial, and they rely on proper functioning of the HPA axis.

This job of the ovaries is to produce the follicles and the eggs, but in doing so it also produces estrogen and progesterone.  This fact is important for signalling menstruation, because it is partly the rise and fall of estrogen and progesterone levels throughout the month that signal to the hypothalamus to release FSH and LH at different times.   This is, in essence, a circle of signalling.  LH and FSH from the hypothalamus to the ovaries, estrogen and progesterone back to the hypothalamus, and so forth.

Hormone malfunctions that cause amenorrhea

Decreasing estrogen levels stop the pituitary from being able to send out FSH and LH.

Decreasing leptin levels stop the pituitary from being able to send out FSH and LH.  This is because decreased leptin levels signal to the hypothalamus that the woman is lacking energy stores and is, in essence, starving.  When the hypothalamus thinks the woman is starving, it puts a halt to normal reproductive functioning.  Leptin levels decrease proportionally with fat mass decreases.   On the other hand, leptin can also go undetected when an individual is leptin insensitive.   Insensitivity is in general a larger problem for overweight women, and low absolute leptin levels are in general a greater problem for thin women.

Increased testosterone production interferes with estrogen levels.

Increased stress and cortisol levels put a halt to hypothalamic and pituitary function.

Cause 1: Weight loss

Both estrogen and leptin are produced in fat cells.  These are the two blood serum hormone levels necessary to signal to the hypothalamus that a woman is fed and happy, and that it should go ahead with normal reproduction.   Without these two hormones, reproduction ceases.  It is well known in the medical literature that the low body fat of anorexic women, models and athletes is what accounts for their amenorrhea.   Without fat, a woman simply cannot menstruate.

What is discussed less often in the literature, but is still true (see Wenda Trevathan’s Ancient Bodies Modern Lives) is the fact that a woman’s reproductive system is set up to run on the nutrient basis she has as a young girl.  Throughout puberty, if a girl has a higher-than-average or higher-than-healthy body fat percentage, her ovary to hypothalamus signalling may develop as ‘handicapped’ by these fat stores.    Because fat cell estrogen is so high, the ovaries do not have to produce as much.   For example: If the body’s estrogen set point is 100 units, and fat cells produce 80 units, then the ovaries only need to produce 20 units.  Then, if the woman loses weight, the set point remains around 100 or falls a bit to a healthier level (unique to each circumstance), and the fat cells production falls to around 30 units, such that estrogen from the ovaries is then expected to make up for the rest of the estrogen deficit.   Many women have no problem with this. Their ovaries jump into higher gear.   Many others, on the other hand, do struggle.  Their ovaries never end up rising to fill that gap.  The thing is– the set point is not stuck precisely at 100.  It will decrease to a healthy level.  But it might not decrease as far as a woman bent on meeting social expectations of body image is hoping.

The alignment of a woman’s sex hormone levels with the amount of nourishment she has during puberty accounts for why women who live their whole lives on the edge of starvation can still have babies, but women whose body fat percentage decrease from 28 to 21 cannot.

This is not to say that an overweight woman will stop menstruating when she loses weight.  Each body is capable of menstruating within the healthiest range of body fat percentages, from around 20 percent to 30 percent.  But a woman who has always erred on the side of heavier might  find that she cannot dip below 23 or 24 percent body fat without losing her period.  23 or 24 percent body fat is healthy, so this is fine.  It might not fly is the woman is trying to meet ridiculous standards of Western body image, but it is optimal for her to have the appropriate serum hormone levels.

Other factors that can hurt estrogen and leptin signalling may also play a role.  If a woman can correct those, then she may be able to decrease her body fat levels without hurting her reproductive system.  For example, chronic stress hurts hypothalamic signalling.  So a stressed out overweight woman is going to have a harder time with reproductive fitness while losing weight than a totally relaxed overweight woman.  This is a fact.  For menstruation to take place, estrogen and leptin levels must be high enough.   Body fat plays a significant role.  There are some other factors that can be addresssed and help as well.

Cause 2: Exercise

Weight loss can cause decreased leptin signalling, but exercise can, too.   Body fat is the major player in leptin levels, but energy deficiency in general hinders leptin.  When a woman is burning more calories than she is consuming–or when she is burning a high quantity of calories while under emotional and physical stress–her body calls it quits.  Instead of directing energy towards reproduction, it conserves it for other functions.

Cause 3: Low Calorie Diet

A low calorie diet performs the same function as both weight loss and exercise.  It stresses the body and puts the woman in a state of energy deficit.  The hypothalamus does not like being in energy deficit, so it tells the ovaries to stop working until it can get itself out of the energy deficit.

A low calorie diet is more of a problem for thin women than it is for women trying to lose weight.  Leptin levels first and foremost are reliant on fat stores.  The body can eat it’s own fat.  That is in fact how weight loss occurs.   So if a woman is eating her own fat, she is not starving.  Once her body fat levels dip too low, however, and if she is maintaining a low-calorie, starvation-type diet, then she may stop menstruating.

Cause 4: Low Carbohydrate Diet

Many, if not most, women have a real need for carbohydrates.  This cause is the most common cause of amenorrhea in the paleo world next to weight loss, in my experience.

Carbohydrates are necessary for the conversion of T4 into T3 (the active form of thyroid hormone) in the liver.  The liver is capable of producing its own glycogen when it’s not being fed sugar, but this process can become fatigued over time, especially if the woman is under any kind of stress, or restricting calories, too.

Hypothyroidism, or sub-clinical hypothyroidism, is one of the primary causes of ovarian malfunction.  Without sufficient levels of T3, organs shut down, and the reproductive organs are the first ones hit.  Without T3, estrogen cannot be produced, and follicles cannot develop.  Without T3, a woman cannot menstruate.

For this reason, many paleo women supplement their diets with iodine and find that their amenorrheic symptoms ease.  However, many others do not.  Instead, they have to add carbohydrates back in to their diets.

Another role that carbohydrates play is spiking leptin levels.  Whenever insulin spikes in response to blood glucose, leptin levels rise, too.  This means that carbohdyrates help signal to the hypothalamus that the woman is fed.  However, this is a short-term elevation.  It only spikes in bursts and with meals, so it cannot be used as a long-term solution to health.  It is important to note, however, that a high fat, low carbohydrate diet is consistently associated with the lowest leptin levels possible.

Cause 5: High-Dairy Diet (an influence, at least)

Dairy is full of hormones.  Even cows raised on pasture cannot help but produce certain hormones that influence a woman’s reproductive system.   Dairy is the most androgenic food.  It contains a protein that inhibits normal inhibition of testosterone in an individual’s body, such that when someone ingests dairy their testosterone levels can rise unchecked.  This is in fact why so many people experience acne when they eat dairy.  Even men.  It really can increase testosterone levels that much.

Moreover, much of the dairy consumed in today’s world is not organic and grass-fed but is instead choc-full of unnaturally injected hormones.  Farms and the US government are touchy about telling the public what goes into their animals, and they claim that these hormone profiles are insignificant.  However, anecdotally, myself and with some other women, it seems as though these hormones really can influence women who already have compromised reproductive function.  Conventionally raised animals can cause real problems.  This goes for dairy, and this goes for eggs and meat products as well.

Cause 6: Altered Phytoestrogen and Hormone-Ingestion Profile

This cause is related to the cause above.   We ingest hormones on a regular basis.  With a healthy reproductive system, this is not a problem.  Hormones from food are far less potent than hormones from the ovaries.  Please keep that fact in mind.   A healthy reproductive system has very little problem with phytoestrogens in foods.  But some women have struggling reproductive systems for one reason or another, and they need to be aware of what hormones they have been and what they are now consuming.

Phytoestrogens are plant estrogens.  They look a lot like estrogen, but are not identical.  This is why phytoestrogens should never be consumed as a replacement for estrogen.  Sometimes they relieve certain symptoms of estrogen-deficiency such as hot flashes, but they also fail to act exactly like estrogen does in the body.  This means that other signals and connections are not being made, potentially crucial ones.  Hot flashes may cease, but acne may continue to run on unchecked.   And other problems can ensue.  For example, breast cancer.

Phytoestrogens are primarily in legumes, nuts, and seeds.  Soy is the most potent phytoestrogen, and should be avoided at all costs.

There are other sneaky ways in which hormones can infiltrate a woman’s diet, especially if a woman undertakes a paleo diet with compromised reproductive function and inattention to the quality of her food.  For example, if a woman goes on an egg-heavy diet when starting paleo, but the chickens are fed a soy rich diet,  she is actually eating a soy-rich diet.  This is not normally a danger, but with a compromised reproductive system and a soy- or hormonal- influence from poorly treated animal products, it is worth taking into consideration.

These effects, I need to emphasize again, are not usually relevant for women with healthy reproductive systems, and should only be considered in severe cases. Only when hormone levels have dipped so low or have skyrocketed so high that the body becomes sensitive to these normally tolerable and easily managed fluctuations from food.  Certainly, conventionally-raised cows are not optimal, but I would not discourage anyone from eating them (in terms of their health) at all if they have no other options.  Sincerely.  Far, far more important is the quality of hormones being sent through leptin and estrogen signalling within the body.

Cause 7: Stress

The final cause should come as no surprise to anyone.  Stress halts reproduction: stress from toxic foods, stress from eating disorders, stress from social life, stress from exercise, stress from work, stress from existential despair… the list is vast.  The physiological result of all of the possible stressors is roughly the same, however.  Cortisol levels rise and these levels prevent the hypothalamus from sending the appropriate reproductive signals to the ovaries.   This may, in fact, be the most important of all the factors I’ve discussed.  There is no way to quantify it, and it burns ubiquitously throughout the Western world.  What if all of us calmed down?  What if we all lived in harmony, and peace, and did not fret?  Stress is significant, and stress is real.  Hundreds of thousands of American women do not menstruate because they are stressed.  How many more experience hindered reproductive function because of stress?  I suspect the number lies in tens of millions.

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