Seed cycling and why I no longer partake in this “hormone balancing” ritual. Listen to my podcast episode on this here.

 

What is seed cycling?

Seed cycling is the act of consuming specific seeds during the two halves of your cycle (i,e. follicular seeds and luteal seeds) in order to “balance your hormones” via the various lignans (phytoestrogens), essential fatty acids (EFAs), and micronutrients that make up the seeds. However, the conclusions of the studies are based on an incomplete understanding of how the chemistry of plants and food interact with our unique hormone physiology. We know that it takes more than just a week of one thing to regulate your hormones. This wellness trend seems to have blown over the last 10 years. Honestly, I don’t see any harm in it, although a bit misleading. I do, however, see good intentions behind using food (4 different seeds in this case) to regulate hormones. Unfortunately, most of us need more than this practice to regulate our intricate hormone systems. There is truth in that seeds are incredibly nutrient dense and can provide some slight hormone effects, but this fact has been exaggerated.

 

My experience with seed cycling:

I was never strict with SC because I couldn’t consume the sesame anyway, as I am allergic. However, I was incredibly intrigued by the practice. I remember stopping the pill and trying everything to get my cycle back. Amidst it all, I had tried seed cycling. It didn’t do any harm, but it also didn’t bring back my cycle, at least not alone. Just like you do, I have a unique body, and just because something didn’t work for me, doesn’t mean I will discredit it based on my experience alone. Although I don’t strictly cycle my seeds, I do enjoy the seeds very freely. But after a year of seeing health experts bash nuts and seeds all together, and other health experts preaching seed cycling, I wanted to do a deep-dive into the research both for and against seed cycling, make a conclusion myself, and share it with you all. 

I am open to anecdotal data (meaning perhaps we don’t have research on it but it is working for thousands of women), while also keeping in mind that there is a standard placebo effect of about 30% for anyone who tries anything. This doesn’t make it bad or harmful, it just is. For example, many women sync with the moon phases and end up getting their cycles back due to the interconnectedness with the mother moon and earth. I will say, SC has never been a go-to in my private practice. Nutrition, lifestyle (stress reduction), herbal medicine, and appropriate supplementation are my go-to's!

 

The data:

Let’s get into these studies that are pro-seed cycling. We have found and can conclude that:

• Flax, sesame, pumpkin, and sunflower seeds are rich in Vitamin E, omega-3, and omega-6 fatty acids, which are essential for hormone production and ovarian follicle health.
• Zinc is one of my favorite micronutrients for hormone health and is found in pumpkin and sesame seeds. Zinc helps to improve the formation of the corpus luteum (the temporary gland formed from the ruptured follicle post-ovulation and that secretes progesterone during your luteal phase), and prepares the endometrium for implantation if that occurs. 
• Also, seeds and nuts (especially brazil nuts), are high in selenium which support liver detoxification which promotes healthy estrogen levels, ovulation, and overall fertility. 
• Lignans are found in flax and sesame seeds and are converted to enterolactone in a thriving gut flora which helps to balance estrogen levels. 

On the contrary, it is hard to find credible studies with references on seed cycling, and many of the notable ones were done on dairy and beef cows who had been induced, were lactating, or other circumstances that were unrelatable to our human, menstruating bodies and seed consumption throughout our cycles. Furthermore, these studies didn’t cycle the seeds, but rather the cows were given large doses of one or two of the same seeds daily, for weeks to months, and there still weren't very relevant hormone changes. 

 

The benefits of each of these four seeds:

Flaxseed:

They have been shown in studies to improve ovulation and to lengthen luteal phase time. These both result in healthy levels of estrogen to progesterone.

I do want to note the high phytoestrogen content of flaxseeds and that this may interfere with ovulation in a negative way. Phytoestrogens are anti-estrogenic for women in their reproductive years which can lower natural levels of estrogen and lighten periods. Everyone is different, see what works for you!

It has also been shown to regulate our stress response (HPA axis) by lowering cortisol levels which is a win win! Less stress hormones means better sex hormone production and utilization. 

Has been shown to decrease A1C levels in type 2 diabetes, therefore a great addition if you have PCOS with insulin resistance or elevated blood sugar. 

Sesame seed:

Another great option for women with PCOS as studies have shown that daily consumption of 50g of sesame seeds for 5 weeks decreased DHEAS (hormone precursor) by 18% and increased SHBG (binds to excess free testosterone in PCOS women) by 15%.

Organic tahini butter is a great option!

Pumpkin seed:

High zinc profile which we discussed the benefits of earlier.

Sunflower seed:

Sadly there is minimal research to prove this seed's impact on hormone levels aside from a slight increase in progesterone for some of the women in some of the studies. It is my favorite tasting seed though!

 

My recommendations:

Choose 1-2 seeds to consume daily, depending on your health goals. The daily serving size is 1 tbsp of each seed, ground or in a creamy seed butter form, for at least 3 months to reap the full benefits. If you struggle with PCOS, sesame seeds will be your ally. If you are struggling with PMS, or want to optimize your overall health, you can add in daily flax to your way of eating and living. 

Don’t stress about cycling them and getting it right. If you enjoy the ritual, and don’t experience any PMS, stick with the cycling! I am all for rituals when it comes to our beautiful and divine feminine cycles! I will still include the seeds in our grocery lists and in our app’s phase-friendly recipes for those who enjoy it. 

 

Final thoughts:

To summarize, seeds are incredibly healthy and are nutrient powerhouses. But to reap the benefits from them, and this is proven in reputable scientific studies, you need to have a good amount of them, daily. We know that the body utilizes both macro and micronutrients differently throughout the four phases of our cycle. This being said, our bodies usually need more quantity of and regular consumption of the seeds in order to reap the full benefits. So, again, not shaming seeds because I do LOVE them. But, changing them up may not be the best for your hormone health. 

 

Notable references:

Li X, Yuan JP, Liu X, Wang JH. [Lignan: an important natural estrogen from plants]. Zhongguo Zhong Yao Za Zhi. 2006 Dec;31(24):2021-5, 2093. Chinese. PMID: 17357545.

Ambrose DJ , et al. Lower pregnancy losses in lactating dairy cows fed a diet enriched in Alpha-linolenic acid. J Dairy Sci. 2006 Aug;89(8):306674.

Ceko MJ , et al. XRay fluorescence imaging and other analyses identify selenium and GPX1 as important in female reproductive function. Metallomics. 2015 Jan;7(1):7182.

Colazo MG , et al. AI in CIDR treated beef heifers given GnRH or estradiol cypionate and fed diets supplemented with flax seed or sunflower seed. Theriogenology.  2004 Apr 15;61(6):111524.

Cordeiro MB , et al. Supplementation with sunflower seed increases circulating cholesterol concentrations and potentially impacts on the pregnancy rates in Bos indicus beef cattle. Theriogenology.  2015 Jun;83(9):14618.

Coyral-Castel, S et al. Effects of unsaturated fatty acids on progesterone secretion and selected protein kinases in goat granulosa cells. Domest Anim Endocrinol. 2010 May;38(4):27283.

Kamada H, et al. Effects of selenium supplementation on plasma progesterone concentrations in pregnant heifers. Anim Sci J.  2014 Mar;85(3):2416.

Medjakovic S , et al. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors. Fitoterapia.  2016 Apr;110:1506.

Phipps WR , et al. Effect of flax seed ingestion on the menstrual cycle. J Clin Endocrinol Metab. 1993 Nov;77(5):12159.

Richter D , et al. Effects of phytoestrogen extracts isolated from pumpkin seeds on estradiol production and ER/PR expression in breast cancer and trophoblast tumor cells. Nutr Cancer. 2013;65(5):73945.

Salehi R , et al. Effects of prepartum diets supplemented with rolled oilseeds on calf birth weight, postpartum health, feed intake, milk yield, and reproductive performance of dairy cows. J Dairy Sci. 2016 May;99(5):35843597.

Thangavelu, G. Fecal and urinary lignans, intrafollicular estradiol, and endometrial receptors in lactating dairy cows fed diets supplemented with hydrogenated animal fat, flaxseed or sunflower seed. Journal of Reproduction and Development. 2008 Volume 54 Issue 6 Pages 439-446

Tian X , et al. Zinc depletion causes multiple defects in ovarian function during the periovulatory period in mice. Endocrinology. 2012 Feb;153(2):87386.

Wu, W. et al. Sesame ingestion a affects sex hormones, antioxidant status, and blood lipids in postmenopausal women. The Journal of Nutrition, Volume 136, Issue 5, May 2006, Pages 1270–1275,

Zachut M, et al. Effects of dietary fats differing in n6: n3 ratio fed to high-yielding dairy cows on fatty acid composition of ovarian compartments, follicular status, and oocyte quality. J Dairy Sci. 2010 Feb;93(2):52945.