Fat, Carbs and the Science of Conception
Scattered hints in the medical literature that protein in the diet may influence blood sugar, sensitivity to insulin and the production of insulin-like growth factor-1—all of which play important roles in ovulation—prompted us to look at protein's impact on ovulatory infertility in the Nurses' Health Study.
We grouped the participants by their average daily protein intake. The lowest-protein group took in an average of 77 grams a day; the highest, an average of 115 grams. After factoring in smoking, fat intake, weight and other things that can affect fertility, we found that women in the highest-protein group were 41 percent more likely to have reported problems with ovulatory infertility than women in the lowest-protein group.
When we looked at animal protein intake separately from plant protein, an interesting distinction appeared. Ovulatory infertility was 39 percent more likely in women with the highest intake of animal protein than in those with the lowest. The reverse was true for women with the highest intake of plant protein, who were substantially less likely to have had ovulatory infertility than women with the lowest plant protein intake.
That's the big picture. Computer models helped refine these relationships and put them in perspective. When total calories were kept constant, adding one serving a day of red meat, chicken or turkey predicted nearly a one-third increase in the risk of ovulatory infertility. And while adding one serving a day of fish or eggs didn't influence ovulatory infertility, adding one serving a day of beans, peas, tofu or soybeans, peanuts or other nuts predicted modest protection against ovulatory infertility.
Eating more of one thing means eating less of another, if you want to keep your weight stable. We modeled the effect that juggling the proportions of protein and carbohydrate would have on fertility. Adding animal protein instead of carbohydrate was related to a greater risk of ovulatory infertility. Swapping 25 grams of animal protein for 25 grams of carbohydrates upped the risk by nearly 20 percent. Adding plant protein instead of carbohydrates was related to a lower risk of ovulatory infertility. Swapping 25 grams of plant protein for 25 grams of carbohydrates shrank the risk by 43 percent. Adding plant protein instead of animal protein was even more effective. Replacing 25 grams of animal protein with 25 grams of plant protein was related to a 50 percent lower risk of ovulatory infertility.
These results point the way to another strategy for overcoming ovulatory infertility—eating more protein from plants and less from animals. They also add to the small but growing body of evidence that plant protein is somehow different from animal protein.
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Member Comments
Posted By: Darwinia @ 04/04/2008 1:30:45 AM
Comment: Sorry the last comment I made should have posted 1/17/08 ish but the system wouldn't let me..... To date: tried the food recommendations and liked the chages I saw overall (it's not much different than a medditeranean style eating plan.) Also went on Progesterone due to my "age" and pretty much got pregnant a month after starting both. Whose to say which helped the most but I am now over 3 months along...yea!
Rockaway apparently didn't read the article at all......and the stuff about body size???? please list a study conducted long term that verifies the underweight/overweight fertility issues. I've seen anectdotal work but nothing truely serious. I know plenty of examples from both sides of the fence who have gotten pregnant easily (under 35yrs old). Lets try to stick to the science being discussed unless people want to provide 1 deg sources.
Best wishes to everyone dealing with ovulatory infertility and looking for answers....
Posted By: Darwinia @ 04/04/2008 1:16:03 AM
Comment: Some more to add.....running is not unhealthy when pregnant or trying to get pregnant. I mentioned it only in that my asthma makes me uncomfortable. Comfort is the key- if your exercise of choice is comfortable while pregnant and you see a Doc regularly, continue to do it. Many of my running friends were fine well into their 7th month.
PCOS is not covered under this article/research. JUST general ovulatory infertility.
This article is from a well respected group of scientists conducting multiple research studies. Please go to http://www.channing.harvard.edu/nhs/publications/2005.shtml to get an idea of some of their other journal published work. You can also find the questionnaires used for their studies on the site. This 'fertility and diet' article first appeared in the November 1, 2007, issue of Obstetrics & Gynecology (a journal.) It's not just someone's opinion and, as the author states, they were trying to provide solid research data to verify or refute the dearth of opinions and unsubstantiated advice out there. It's the first of it's kind to look at fertility and diet over such a long time period.
Fertilityfile.com (while not the blog referred to below) gives lots of info (including an opinion on this article) from the perspective of a reproductive endocrinologist. Check it out if you have time.
Also wanted to clarify my choice of 'Dawinia'- a pointed response to 'evolutionist'- but NOT meant in the false scientific vein of social darwinism. Darwin's paradigm shattering contribution was that life has and will change through time- period.
In response to eandj62204 - 'Chemicals' are a worth while option for some us looking at our clock and considering IVF or other treatments. Please don't judge us. I would take a chemical any day of the week to prevent another miscarriage and save my child.
Posted By: skinnyminny2 @ 03/31/2008 1:41:12 PM
Comment: Being too thin decreases fertility, too. I'm 25 lb underweight with very little body fat and have not had a period in over a year.
It's easy for me to stay like this because it's the fat ones who get ripped on, not us skinnies.