Study in mice finds dietary levels of genistein may adversely affect female fertilityNovember 14, 2017
CHAMPAIGN, Ill. -- Exposure to the phytoestrogen genistein prior to conception may adversely affect female fertility and pregnancy outcomes, depending on the dosage and duration of exposure, a new study in mice suggests.
Chronic preconception exposure to genistein affected pregnancy rates in mice and was associated with prolonged labor, smaller litters and pups, and higher rates of pup mortality, scientists at the University of Illinois report in a paper accepted for publication in the journal Reproductive Toxicology.
The findings add to a growing body of research that raises troubling questions about the potential health risks of long-term exposure to plant-based estrogens. Genistein is an isoflavone found in soy foods and dietary supplements, and, like other plant estrogens, may be consumed by women to relieve menopausal conditions such as hot flashes, weight gain and depression.
Genistein is among the chemicals that the National Institute of Environmental Health Sciences classifies as endocrine disruptors because they can interfere with bodily systems that are controlled by hormones.
"This is one of the first studies to look at long-term exposure to genistein in adult populations," said Jodi A. Flaws, a professor of comparative biosciences at Illinois and a co-author of the paper. "Many women are taking dietary supplements that contain genistein, and there is very little information on its potential effects on reproduction in adult women."
In a prior study, Flaws and her colleagues observed that treatment with another phytoestrogen found in licorice inhibited the ability of isolated ovarian follicles to grow and make sex steroid hormones. Food science and human nutrition professor William G. Helferich, the director of the Botanical Estrogen Research Center at the university, collaborated on that and the current study.
Extending that work, the researchers examined how chronic genistein exposure affected sex steroid hormone levels and pregnancy outcomes. Adult female mice in the current study were fed a diet containing 300, 500 or 1,000 parts per million of genistein, while their counterparts in the control group consumed food that was soy- and phytoestrogen-free.
The groups of mice that consumed the genistein were exposed to it for 30, 60, 150 or 240 days, which produced blood serum concentrations equivalent to those found in women who consume soy foods or supplements, said Illinois alumna Shreya Patel, who conducted the research as a doctoral student at the university.
"When we looked at animals exposed for 30 days, the gestation time - the length of time they were pregnant - was decreased, similar to premature births," Flaws said. "And after 60 days' exposure, they had fewer pups in their litters."
After 150 days, the mice that consumed 500 ppm or 1000 ppm of genistein were less likely to become pregnant after mating. Only 83 percent of the females in either of those groups were fertile, the researchers found.
After 240 treatment days, only 50 percent of mice in the 300-ppm group were fertile compared with 67 percent of those in the control group. However, genistein appeared to boost fertility rates among the two highest dose groups: 83 percent in the 500-ppm group and 100 percent in the 1,000-ppm group conceived.
"In order to say definitively that genistein was having a protective effect on fertility we would have had to continue the study longer," Patel said. "But that was a very interesting finding, which correlates with current knowledge and literature about genistein having a protective effect on certain health indicators."
While mice in the 240-day treatment group that gave birth bore normal-sized litters, they often killed their pups, and the pups were much smaller than peers of similar age.
Although the findings are preliminary, the researchers said that little is known about the potential effects of long-term phytoestrogen use, and women should be cautious about their exposure, especially if they plan to conceive in the near future.
"While women are consuming these dietary estrogenic supplements, this is an uncontrolled experiment in which the safety and efficacy are unknown," Helferich said.
"With endocrine disruptors, it's the dose that makes the poison," said Patel, who currently is in a postdoctoral program at Northwestern University. "People should be aware of what they're consuming, and some supplements may not be what they claim to be. It's probably best to consult a doctor or a dietitian."
The research was supported by the National Institutes of Health, a Billie A. Field Fellowship and the Botanical Estrogen Research Center.
University of Illinois at Urbana-Champaign
Related Fertility Articles:
Article explores unique ethical issues for children with differences of sex development on whether or not they should pursue fertility preservation.
Two University of Colorado Boulder scientists have discovered how fat levels in a tiny soil-dwelling roundworm (C. elegans) can tip the balance between whether the worm makes eggs or sperm.
A Washington State University researcher has found that the uterus in female mice contains enzymes that can break down semen, making it less gel-like, more watery, and therefore easier to swim in.
Researchers at the University of Montreal Hospital Research Center (CRCHUM) have discovered a possible new explanation for female infertility.
Nearly one-fourth of transgender individuals in Toronto, Canada, regard their own fertility as important, but most lack knowledge regarding and access to reproductive options, a new survey finds.
Scientists have developed a low-cost and easy-to-use smartphone attachment that can quickly and accurately evaluate semen samples for at-home fertility testing, providing a potentially helpful resource for the more than 45 million couples worldwide who are affected by infertility.
A Michigan State University researcher has received a $1.65 million grant that looks to bring a better understanding about fertility treatments in women by studying the effect of hormones on ovulation and reproduction in cows.
The first large-scale study of its kind has revealed that Canadian men generally lack knowledge about the risk factors contributing to male infertility.
The maths of collective behavior has provided a new technique for selecting the best semen for artificial insemination in livestock.
Individual small RNAs are responsible for controlling the expression of gonadoliberin or GnRH (Gonadotropin-Releasing Hormone), a neurohormone that controls sexual maturation, the appearance of puberty, and fertility in adults.
Related Fertility Reading:
Taking Charge of Your Fertility, 20th Anniversary Edition: The Definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health
by Toni Weschler (Author)
In celebration of its 20th anniversary, a thoroughly revised and expanded edition of the leading book on fertility and women’s reproductive health.
Since the publication of Taking Charge of your Fertility two decades ago, Toni Weschler has taught a whole new generation of women how to become pregnant, avoid pregnancy naturally and gain better control of their gynecological and sexual health by taking just a couple minutes a day using the proven Fertility Awareness Method.
Now, this 20th Anniversary Edition has been thoroughly revised and fully updated... View Details
The Impatient Woman's Guide to Getting Pregnant
by Jean M. Twenge PhD (Author)
Comforting and intimate, this “girlfriend” guide to getting pregnant gets to the heart of all the emotional issues around having children—biological pressure, in-law pressures, greater social pressures—to support women who are considering getting pregnant.
Trying to get pregnant is enough to make any woman impatient. The Impatient Woman’s Guide to Getting Pregnant is a complete guide to the medical, psychological, social, and sexual aspects of getting pregnant, told in a funny, compassionate way, like talking to a good friend who’s been through it all. And in fact,... View Details
Making Babies: A Proven 3-Month Program for Maximum Fertility
by Sami S. David (Author), Jill Blakeway (Author)
MAKING BABIES offers a proven 3-month program designed to help any woman get pregnant. Fertility medicine today is all about aggressive surgical, chemical, and technological intervention, but Dr. David and Blakeway know a better way. Starting by identifying "fertility types," they cover everything from recognizing the causes of fertility problems to making lifestyle choices that enhance fertility to trying surprising strategies such as taking cough medicine, decreasing doses of fertility drugs, or getting acupuncture along with IVF. MAKING BABIES is a must-have for every woman trying... View Details
Soil Fertility And Fertilizers, 8Th Edition
by Tisdale, Nelson Havlin (Author)
Paperback International Edition ... Same contents as in the US edition at Low Cost !! View Details
The Fertility Diet: Groundbreaking Research Reveals Natural Ways to Boost Ovulation and Improve Your Chances of Getting Pregnant
by Jorge Chavarro (Author), Walter C. Willett (Author), Patrick J. Skerrett (Author)
The Fertility Diet reveals startling new research from the landmark Nurses' Health Study, which shows that the food you eat can boost your fertility. The book prescribes ten simple changes in diet and activity that can increase your chances of getting pregnant.These changes include: Cutting back on red meat and trans fats Getting protein and iron from veggies and nuts Choosing whole-fat milk and even ice cream Drinking coffee, tea, and alcohol in moderation Losing weight (if needed) and exercising
The Nurses' Health Study exhaustively examined... View Details
Fertility Foods: 100+ Recipes to Nourish Your Body While Trying to Conceive
by Elizabeth Shaw (Author), Sara Haas (Author), Sonali Ruder (Foreword)
A complete dietary program for women seeking healthy pregnancy. Created by RDN certified experts, Fertility Foods provides you with powerful nutritional benefits and more than 100 recipes.
Struggling with infertility can be one of the most frustrating experiences for women looking to conceive. Rather than juggle multiple prescription medications all while scheduling an endless series of doctors’ visits, Fertility Foods helps you to seek better results—just by changing your diet!
As you prepare to enter one of the most significant times in your life, you owe it... View Details
Spring Snow: The Sea of Fertility, 1
by Yukio Mishima (Author)
Yukio Mishima’s Spring Snow is the first novel in his masterful tetralogy, The Sea of Fertility. Here we meet Shigekuni Honda, who narrates this epic tale of what he believes are the successive reincarnations of his friend, Kiyoaki Matsugae.
It is 1912 in Tokyo, and the hermetic world of the ancient aristocracy is being breached for the first time by outsiders — rich provincial families unburdened by tradition, whose money and vitality make them formidable contenders for social and political power. Shigekuni Honda, an aspiring lawyer and his... View Details
Fertility, Cycles & Nutrition 4th Edition
by Marilyn M. Shannon (Author), The Couple to Couple League (Editor)
This new fourth edition explains cycle irregularities and nutritional values to improved and understand our body balance; invaluable to Natural Family Planning couples. View Details
Yes, You Can Get Pregnant: Natural Ways to Improve Your Fertility Now and into Your 40s
by Aimee Raupp MS LAc (Author)
The complete guide to getting pregnant and improving fertility naturally √õ even if you√åve been told your chances of conception are low
Worried about your ability to have children in the next five years? Have you been trying to get pregnant for a while now and it√ås just not happening? Does it seem like every woman you know is having a hard time getting pregnant and you don√åt want that to be you when you√åre ready? Do you want natural, non-invasive options to conceive?
If you answered √èyes√ì to any one of these questions, Yes, You Can Get... View Details
Our Stolen Future: Are We Threatening Our Fertility, Intelligence, and Survival?--A Scientific Detective Story
by Theo Colborn (Author), Dianne Dumanoski (Author), John Peterson Myers (Author)
"A critically important book that forces us to ask new questions about the synthetic chemicals that we have spread across this earth."—former vice president Al Gore, author of An Inconvenient Truth
Our Stolen Future examines the ways that certain synthetic chemicals interfere with hormonal messages involved in the control of growth and development, especially in the fetus.
The developing fetus uses these natural hormonal messages, which come from both from its own hormone system and from its mother, to guide development. They influence virtually all of... View Details