The Truth About Fertility and Aging
Science says you can increase fertility as you age simply by changing your diet. Is it true? We asked experts for the scoop
We generally think a lifelong focus on balanced diet is our best bet. But according to a new study published in the Proceedings of the National Academy of Sciences, manipulating the ratio of macronutrients we eat throughout our life may help enhance fertility and lifespan.
In the study, researchers put 858 mice on one of 25 different diets with various levels of protein, carb, fat and calorie counts. Fifteen months into the study, they measured the male and female mice for their reproductive success. In both genders, lifespan seemed lengthened on a high-carb, low-protein plan, while reproductive function was boosted on high-protein, low-carb diets.
This research is still new, but the scientists involved think it may be a better strategy for reproductive success than current treatments. "As women increasingly delay childbearing, the demand for assisted reproductive technologies increases," says study author Dr. Samantha Solon-Biet from the Charles Perkins Centre at the University of Sydney. "With further studies, it's possible that instead of women with subfertility resorting immediately to invasive IVF techniques, an alternative strategy may be developed to change the ratio of dietary macronutrients to improve female fertility. This would avoid the need for medical intervention, except in the most severe cases."
To help us put nutrition, aging, and fertility into perspective, we consulted a few experts.
Why protein for pregnancy?
It makes sense that protein would enhance fertility, according to dietitian Jessica Marcus, R.D. "Protein should be top of mind during the perinatal period, because it's necessary for building cells and tissues and crucial to fetal growth," she explains. "In fact, a mother who's eating adequate calories but inadequate protein can gain plenty of weight herself but end up with a low birthweight baby. Inadequate intake can also contribute to swelling. Good sources are beans, legumes, nuts and seeds, poultry, lean meats, dairy and fish."
While protein needs may be more pronounced as you're trying to get pregnant, there's still a lot we don't know. "I would caution women to not start eating 20 oz steaks three times a day," says Liz Weinandy, MPH, RD, LD, an outpatient dietitian at The Ohio State University Wexner Medical Center who has also covered the OB/GYN population. "If a woman wanted to go a little higher in protein intake, that would be fine-but focus on eating lean sources that are not highly processed. In other words, decrease lunch meats, hot dogs, and salami and increase lean sources, like eggs of chicken, a few times a week." (And avoid these 6 Foods that Are Off-Limits During Pregnancy.)
Do any other foods or food groups enhance fertility?
According to Marcus and Weinandy, focusing on balance is especially effective. It sounds easy, but most women aren't there. "Plant foods like fresh vegetables, fruits, and whole grains should be the foundation of the diet," Marcus says. "They provide all-star prenatal vitamins, minerals, and phytonutrients like folate for preventing neural tube defects, iron to sustain the increased blood volume, calcium for bone formation and fluid regulation, and vitamin C for tooth and bone development."
Focusing on key fats may also be effective. "Full-fat dairy products like whole milk and yogurt may increase fertility too," says Weinandy. "This goes against conventional wisdom and current guidelines that everyone, including women trying to conceive, should consume low-fat or fat-free dairy products. Some experts believe there are compounds found in full-fat dairy products that are beneficial for conception."
While research on fats is still early and speculative, those who are looking to conceive may want to consider it. "If a women is following an overall healthy diet, two to three servings of full fat dairy products a day is a worth a try," Weinandy says, who cautions that this may not work if you're not eating an otherwise-balanced diet. "In addition, more healthy fats may also support conception. In particular, the omega-3s found in avocados, fatty fish, olive oil, and nuts and seeds are all a good start. Replacing less healthy fats with these healthier ones is ideal." (Get a better understanding of these Fertility Myths: Separating Fact from Fiction.)
Is nutrition more important for fertility as we age?
It's important to remember that fertility is individual, and peaks at unique points for all of us. "After that, conceiving becomes increasingly more difficult," says Marcus. "The more we can do to maintain a healthy body, the better our chances. While we can't control the aging process, we can control what we eat and give the body the right building blocks to create healthy cells and tissues, setting a strong foundation for a successful pregnancy."
Since fertility generally declines as we age, making smarter daily choices are crucial as women look to carry children later in life. "Likely everything around being healthy is bit more important to fertility as we get older," says Weinandy. "Making sure to get enough sleep, regular activity and lowering stress levels in addition to eating a balanced and healthy diet are all important to our health in general, so why wouldn't they be for conception too?"
According to Weinandy, the most beneficial strategy for enhancing fertility in older reproductive ages is following an overall healthy diet pattern. "I think we are always looking for a specific food or nutrient to add or take out of our diet, but that's missing the boat," she says. "I would like women of any age, and especially those trying to conceive, to look at the bigger picture and make sure they are getting in plenty of fruits and vegetables, mostly whole grains, healthy fats, and so forth. Sometimes we get so focused on a single nutrient-like protein, in this case-that we spin our wheels with not much to show for it."
What can you do now?
According to Marcus and Weinandy, these are steps women who are already pregnant can take:
• Focus on an overall healthy diet pattern with adequate protein, plenty of fruits and vegetables, mostly whole grains, legumes and healthy fats like those found in fish, nuts, avocados and olive oil.
• Make sure your diet is varied to avoid any vitamin and mineral deficiencies, and you're not eating the same foods day after day.
• Opt for regular meals and snacks based on protein, fiber, and healthy fats, which can help keep blood sugar levels stable. This helps insulin levels stabilize, and sets off a cascade of healthy hormone levels throughout the body.
• A prenatal vitamin can help fill in any dietary gaps. Try a food-based vitamin since they tend to be better absorbed.
• Choosing mostly whole, minimally processed foods is ideal.
• Put in the time it takes to eat well, since it affects not only your fertility but also the baby's development in the womb and after birth.
• Don't beat yourself up about your diet. Small amounts of "junk" food are inevitable and OK.