A recent study by Harvard researchers examined the diet and lifestyles of 18,555 nurses trying to get pregnant over the course of 8 years. They found several common dietary choices corresponded to ovulatory infertility, which accounts for at least a quarter of all cases of infertility. Their findings are presented in “The Fertility Diet” (Chavarro, Jorge E., M.D., Willett, Walter C., M.D., and Skerrett, Patrick J. 2008. McGraw-Hill).
If you are reading this blog, you probably already eschew the following dietary villains. However, whether you are struggling with some nasty cravings or not, it’s always good to have yet another reason to keep away from these health and fertility thwarting no-no’s!
1. TRANS FATS – It was found that consuming a mere 4 grams of trans fat a day – about the amount in one donut or a small order of fast food fries – doubled the risk of ovulatory infertility. Moreover, each additional 2% increase of trans fat consumption translated into an additional 73% greater chance of infertility.
Trans fats, reason the authors, increase insulin resistance, spiking blood sugar and creating inflammation in the body, a major factor in ovulation problems.
Furthermore, while cutting trans fats from your diet alone increases your odds of conceiving, replacing them with healthy mono- and poly- unsaturated fats, such as those found in avocados, nuts and seeds, actually boosts reproductive chances even more!
2. RED MEAT – In the nurse’s study, those with the highest intake of red meat were 39% more likely to have ovulation problems versus those with the lowest, while those with the highest intake of plant protein were significantly less likely to have ovulatory infertility than those with the lowest. Even one serving of beef a day proved disastrous to those trying to conceive. An abundance of protein from fruit, vegetables, nuts and beans, however, actually offered some protection from ovulatory infertility.
Yet another reason plant protein is far superior to animal protein!
3. LOW-FAT DAIRY – The nurse’s study found that the higher the intake of low- or no- fat dairy products, the greater the difficulty conceiving. However, it also appeared that the higher the intake of full-fat dairy, the lesser the problems one had conceiving.
This, according to the researchers, is due to the hormones found in milk. One might think they are safe if they consume organic milk, but BST, or bovine growth hormone aside, most of the hormones come from the cows themselves. Dairy is big business, and to keep up with demand, most cows on commercial farms are milked 300 days a year, pregnant or not. During the late stages of pregnancy, milk can contain up to 33% more estrogen than milk produced by non-pregnant cows. Moreover, cows and bulls are bred for their milk-producing genes, which results in higher levels of milk-producing hormones.
The problem comes with separating the fat from the water part of hormone-laden milk because some hormones (e.g. estrogen, progesterone, and some androgens) attach themselves to fat while others (e.g. androgens, insulin-like growth factor-1, and prolactin) are water-soluble. When the fat is removed from milk, it is left with a dominance of water-soluble hormones, which can interfere with our reproductive systems when consumed. When androgens, male hormones, dominate, it can prevent follicles from fully maturing. Insulin-like growth factor-1, on the other hand, suppresses the body’s production of sex-hormone binding globulin; this leads to hormonal imbalances. Prolactin is the hormone responsible for stimulating milk production and suppressing ovulation, which is why most women who breastfeed on demand experience a delay in the return of their menstrual cycles. So, you can see that consuming an excess of prolactin cannot bode well for ovulation!
It is obvious that fat-reduced dairy products can wreak havoc on our fertility, but what about dairy consumption in general? Although it appears the nurses saw an increase in fertility with the consumption of full-fat dairy, these findings conflict with some other studies. One such study showed that fertility declines faster with age in countries where milk consumption is the highest, while another suggested that dairy products contribute to blood sugar problems, a big factor in ovulatory infertility.
Therefore, suggest the authors, it is best to get our calcium and vitamin D from supplements, plant sources, and the sun. An abundance of green leafy vegetables and a few minutes in the sun a day should suffice!
4. SOFT DRINKS – According to the findings of the nurse’s study, the consumption of 2 or more soft drinks a day translated into a 50% greater chance of ovulatory infertility. The researchers attribute this to blood sugar spikes (the average soda contains 9-11 tablespoons of sugar!) and to overweight as a result of consuming too many empty calories such as those in soft drinks.
However, staying hydrated is very important to overall health as well as reproductive health. The best source for this? Good, pure H20!
So, skip the Happy Meal, and instead enjoy a diet rich in fruits, vegetables, avocados, nuts, seeds, leafy greens, sunshine and fresh water…hmmm. We’re doing okay, eh? ?
-Ardis