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Seed cycling is an alternative medicine practice believed to help regulate reproductive hormones.
Evidence on seed cycling is non-existent, but the practice has been around for a long time.
There’s probably not much risk to trying seed cycling.
I first heard of seed cycling from a friend of mine who works as a healthy-living chef. According to her, seed cycling could regulate any “hormonal imbalance.” Intrigued, I set out to find some science behind seed cycling and potentially try it out for myself.
Plenty of people have been talking about seed cycling, and some pretty notable bloggers were publishing their own recipes using the seeds. Instagram seemed to be ground zero for “health experts” promoting seed cycling to fix whatever hormonal ailment was afflicting you.
Hormonal variations in estrogen and progesterone, as well as androgens, can influence the menstrual cycle and cause symptoms ranging from hair growth, acne, weight changes, infertility, and irregular cycles (1).
Some people look to hormonal birth control to regulate these symptoms. But if you’re trying to become pregnant or just looking to avoid taking hormonal birth control, your options can feel limited (2).
Perhaps that’s why seed cycling has been on the tip of everyone’s lips over the past year or so. It’s certainly not a new method—alternative medicine practitioners from herbalists to acupuncturists and naturopaths have long recommended it for a list of hormonal woes including infertility and menopause.
So I gave it a go. But first I dug a little deeper.
What is seed cycling?
According to all the chatter online, seed cycling is diet supplementation with four different seeds: pumpkin, flax, sesame, and sunflower. The seeds are eaten every day, raw and ground. Whole seeds won't break down completely in your gut, so grinding them enables your body to extract more nutrients from the seeds. They can be eaten alone or added to other foods like smoothies and salads.
The recommended regimen has two phases.
Phase 1 of seed cycling is one tablespoon of raw, ground pumpkin seeds and one tablespoon of raw, ground flax seeds from day one of your period until the day before you ovulate. Phase 1 should be about two weeks for most people.
Phase 2 of seed cycling involves eating one tablespoon of raw, ground sunflower seeds and one tablespoon of raw, ground sesame seeds per day from the day of ovulation until the day before the first day of your period. Phase 2 should also last about two weeks for most people.
Why supplement with seeds? These seeds contain specific vitamins, nutrients, and fatty acids that are believed to support hormonal function.
Pumpkin and flax in Phase 1 are thought to support the estrogen-dominant follicular phase when the ovaries increase estrogen levels in the body (1). Likewise, sunflower and sesame seed supplementation in Phase 2 are thought to support increases of progesterone in the luteal phase (1).
Is there any science to support seed cycling?
“Believed” and “thought” are both key words when talking about seed cycling and its benefits.
Seed cycling is generally considered alternative medicine, and there isn’t much science on its risks, benefits, or efficacy. Most reports of seed cycling are anecdotal. However, there’s probably little risk to ingesting seeds daily. In fact, there may be other health benefits to eating seeds including increased dietary fiber and protein (3, 4).
Since there haven’t been any published studies on seed cycling specifically, I looked for data about the seeds individually and their impacts on hormones. Even data on the seeds themselves was sparse. Here’s what I found.
Each of the seed types utilized in seed cycling contains lignans, plant compounds that are believed to weakly mimic some of the effects of human estrogen (5). This is important because estrogen influences the menstrual cycle, which can in turn impact ovulation, fertility, and menopause.
Flaxseed and the cycle
One small study of 18 people published in 1993 found that when people with cycles ate a traditional western, low-fiber, omnivorous diet supplemented with flax, there were some interesting results. There were fewer anovulatory cycles, and the average luteal phase was longer, but cycle length was unchanged. No changes in estrogen levels were noted (6).
This means that flax could possibly have an impact on fertility. Anovulatory cycles seem like normal cycles with normal periods, but ovulation doesn’t actually occur. Ovulation occurring each month means more opportunities for the person to become pregnant, while a longer luteal may be more supportive of early pregnancy (7).
Another small study found that when people in menopause added flaxseed to their diets, the concentration of estrogen in their blood decreased (8). This is an interesting finding, since estrogen might be linked with the incidence of breast cancer in postmenopausal women (8).
Pumpkin seeds and the cycle
In addition to containing lignans, pumpkin seeds are high in zinc, providing 15% of the Recommended Dietary Allowance (RDA) per ounce (9). Some case reports associate zinc with decreases in menstrual cramps (10). It’s believed that menstrual cramps are caused by excess prostaglandins, and zinc is thought to decrease the metabolism of prostaglandins (11).
Sunflower seeds and the cycle
Sunflower seeds are high in vitamin E (12). The findings of one study supported the idea that vitamin E supplementation might increase progesterone, the hormone that helps maintain early pregnancy, in women who were unable to conceive (13). This results of this study can’t be isolated to just vitamin E, though, because there were other ingredients in the supplement. And while there was a small difference in progesterone levels, it wasn’t considered statistically significant. A review of the role of vitamin E in female reproductive health suggested vitamin E is an antioxidant critical to promoting fertility (14).
In 1972, a study was published on vitamin E and its similarity to estrogen and progesterone (the hormones that impact the menstrual cycle) in rats. This paper cited references that corroborated the hormone-like effects of Vitamin E, dating back to as far as 1929 (15).
Sesame seeds and the cycle
One small study of postmenopausal women who consumed sesame seed powder found that eating the seeds increased levels of one form of vitamin E circulating throughout the body (16). Seed consumption didn’t increase estrogen, but it decreased a type of androgen and increased sex hormone binding globulin (SHBG). It's worth noting that the increase was minor and not statistically significant (16). Theoretically, this might reduce health risks for some people during menopause including cardiovascular disease and cancer risk, but the research findings are mixed (even contradictory) and not well understood (17).
How to seed cycle
To put it bluntly, these studies are small and far from conclusive. Without any convincing evidence, I didn’t feel especially compelled to try seed cycling, but in the interest of research, I ordered four bags of seeds and decided to try it for one month.
Overall, I spent about $40 for what seemed to be about four months of seeds in their organic, raw form. Most of the health and wellness gurus online say it takes three to four months to see the real benefits of seed cycling. I followed these steps:
Grind one week’s worth of pumpkin and flax seeds.
Store sealed in the fridge to maintain freshness.
Consume two tablespoons of seeds each day. I put mine in smoothies, on top of salads, pasta and just about everything I ate.
Repeat after one week.
Switch seeds the first day of menstruation.
Switch seeds the day of ovulation.
How can you tell when you ovulate?
I’ve had a few friends try seed cycling as well, and the biggest hiccup seems to be that not everyone can tell when they’re ovulating. There are a few ways to determine when you’re ovulating, but if you’re using hormonal contraception, these won’t apply (and seed cycling really won’t do much for you since you are already taking hormones).
You can monitor your cervical mucus using the Billings Ovulation Method. This method works by observing the wetness of your vulva each day. When you ovulate, your cervical mucus will be wet, slippery and similar to raw egg whites.
You can use Clue to track your cycle and pinpoint when you’re likely to ovulate. You can enable a notification to let you know when it’s ovulation day.
An over-the-counter test
You can buy an over-the-counter ovulation test that measures luteinizing hormone (LH), the hormone that surges before you ovulate.
Does seed cycling work?
I did notice a few changes during my 28 days of seed cycling. I usually experience both painful ovulation (called mittelschmerz) and painful menstrual cramps. The month I tried seed cycling, my ovulation pain was basically eliminated and I did notice some reduction in period cramping. I didn’t notice any changes in mood or bleeding volume or length. The reduction in pain was a tangible benefit, but at the end of the month, I didn’t continue with seed cycling because I just became tired of eating the seeds.
While there’s no real data to support seed cycling, as long as you have no allergies to seeds and can afford to purchase them, there aren’t any serious risks to including seeds in your daily diet.
Variations across the menstrual cycle can be normal, yet some changes may indicate an underlying issue that medical care could help resolve. If you experience symptoms of PCOS, irregular bleeding, painful periods, infertility, or irregular periods, it’s worth getting checked out by your healthcare provider. You can use Clue to track your symptoms so you can give your provider more information about your body and symptoms.
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