May 2013 Issue

Eating to Fuel Fertility
By Bridget Swinney, MS, RD, LD
Today’s Dietitian
Vol. 15 No. 5 P. 38

The following excerpt from dietitian Bridget Swinney’s book Eating Expectantly can be used as a patient education resource to help your clients and their spouses address their fertility issues.

Editor’s Note: In the fourth edition of her book Eating Expectantly: Practical Advice for Healthy Eating Before, During and After Pregnancy, Bridget Swinney, MS, RD, LD, approaches this topic with even greater passion to help spread the word about how nutrition can make a huge difference in how a woman feels while she’s pregnant and how healthy her baby can be at birth and beyond.

In the book, Swinney discusses how incorporating healthier eating habits can improve fertility; how diet can increase a baby’s risk of diabetes, hypertension, and obesity; and how to make fast food and convenience foods healthier. She also provides tips for eating a clean, green diet. She’s even included QR codes throughout the book so clients and patients can use their smartphones to access links to chapter updates and websites, friendly notes, and occasional video messages from Swinney.

The book is written in chronological order, starting with preconception and moving on to general information clients and patients should know about pregnancy, followed by specific nutrition advice for each trimester. Swinney also provides general eating advice and specifics for high-risk pregnancies. A new chapter devoted to keeping baby’s environment safe explores topics such as organic eating, food safety, environmental chemicals, and safe cleaners and cosmetics. The book ends with information about healthful cooking ideas, breast-feeding, surviving the first weeks with baby, losing weight, and dining out.

The following excerpt is from the second chapter of Eating Expectantly, “Fueling Your Fertility,” which discusses how nutrition can improve fertility and how weight management, polycystic ovary syndrome, insulin resistance, cigarette smoke, alcohol, celiac disease, and other factors may play a role. The excerpt is written specifically for clients and patients and therefore serves as a patient education resource that nutrition professionals can use during counseling sessions. Feel free to cut out the article along the dotted line or visit and print out a copy of the PDF from the digital edition of the May issue so you can give it to clients and patients at the end of their visit.

Infertility, which is defined as not conceiving after one year of unprotected intercourse, affects about 10% to 15% of couples. Infertility testing and treatment is a costly and emotional “adventure” you may be able to avoid by taking a proactive approach when planning for pregnancy. The factors that can affect fertility include age, body weight, diet, smoking status or exposure to tobacco smoke, stress, alcohol consumption, exercise, environmental chemicals, medications, and street drugs.

There’s a good chance that simply improving your diet, becoming more active, more effectively dealing with stress, or just taking a vacation will help your odds of getting pregnant.

Weight Matters
One of the most important factors affecting fertility is weight. Conceiving is more difficult if you’re underweight or overweight. In fact, it’s believed that weight issues cause 12% of infertility.

Body fat seems to be the synchronizing factor (or the conductor) for the harmonious hormonal symphony that must take place in order for pregnancy to occur and be carried to term. Because fat cells make estrogen, having too many or too few fat cells affects the amount of estrogen in the body, which then affects fertility.1

It’s best to get close to your ideal weight before you seek help with fertility treatments since this simple change often can result in normal ovulation and pregnancy. It also can reduce the risk of pregnancy complications and of having a baby who’s too large or too small at birth.

A certain amount of body fat is needed for regular ovulation and menstrual cycles because some estrogen is produced in women’s fat stores. In fact, body weight changes of just 10% to 15% below normal can disrupt menstrual cycles.

If you’re seeking help for infertility, please make sure you’re not underweight. Research shows that being underweight increases your chances of having a low birthweight infant or a baby who’s born preterm.2 Some fertility treatments greatly increase your chances for having twins or other multiples, and this further increases the odds of having low birthweight infants.3

A maternal body weight closer to your ideal weight is best for conceiving and carrying a healthy baby to a healthy weight at term.

For women, excess body fat can affect the amount and types of circulating hormones, which influence fertility. It’s estimated that 25% of ovulatory infertility can be attributed to being overweight.4 Overweight is linked to polycystic ovary syndrome (PCOS), a cause of infertility. Insulin resistance, which can result from having PCOS or being overweight, also is related to infertility.4

But there’s good news: Studies show that overweight women have great success in conceiving once they’re closer to their ideal body weight. In fact, losing just 5% to 10% of total body weight can dramatically improve ovulation and pregnancy rates. In one small study, losing just 14 lbs drastically improved ovulation and pregnancy rates.5

An expanding waistline also can affect a man’s fertility. In fact, it’s double trouble if both partners are overweight because it increases the likelihood that it will take more than a year to get pregnant.6

Overweight men tend to have lower testosterone and increased estrogen levels, and decreased ejaculate volume. Men with a BMI greater than 35 are more likely to have a lower sperm count and higher numbers of sperm with DNA damage compared with normal-weight men.7 Sleep apnea, which is more common in men who are obese, also can cause a decrease in testosterone levels. Excess fat in the inner thighs and pubic region also may cause warmer temperatures in the pubic area, which is enough to alter sperm production.8

PCOS affects as many as 10% of women. Seventy-five percent of women diagnosed with PCOS are thought to have problems with infertility.9 The condition tends to run in families, so pay attention to whether women in your family have problems with irregular periods, acne past adolescence, excessive facial hair, or diabetes.

PCOS is caused by an imbalance of hormones—especially insulin—that leads to an overproduction of male sex hormones (or androgens), which can lead to small benign cysts on the ovaries; irregular, heavy, or no periods; acne; and excessive hair growth on the face and body (hirsutism). While being overweight often is common in women with PCOS, you can be of normal weight and still have it.

Other symptoms of PCOS may include unexplained fatigue; low blood sugar (hypoglycemia) after meals; lightheadedness; sweating; intense carbohydrate cravings; mood swings; hot flashes; recurrent spontaneous miscarriages; rough or velvety dark skin in skin folds such as the neck, armpits, or thighs (also called acanthosis nigricans); and sleep disorders such as sleep apnea.10

According to Angela Grassi, MS, RD, author of The PCOS Workbook: Your Guide to Complete Physical & Emotional Health, a healthy eating plan for PCOS often includes lower carbohydrate intake (but not a low-carb diet); a higher intake of lean protein and monounsaturated fats; making most grains whole; consuming a minimum of 25 g of fiber per day; and avoiding sweetened beverages, including juice and soda. Engaging in daily physical activity and using vitamin D supplementation also are beneficial.

Insulin Resistance, PCOS, and Fertility
Insulin resistance is when your body resists the normal action of insulin, the hormone that lets glucose into your cells. Because insulin doesn’t work as efficiently as it should, the amount of glucose in your blood increases, and your body secretes even more insulin. Abnormally high levels of insulin (hyperinsulinemia) cause inflammation and can lead to weight gain, high blood pressure, diabetes, heart disease, and sometimes PCOS. Insulin resistance is more common in people of Asian descent and Native Americans, Australian Aboriginals, and Pacific Islanders.

Not enough physical activity and a diet with too many processed carbs play a role in insulin resistance; weight gain also can trigger it. During pregnancy, some insulin resistance is normal because of hormones secreted by the placenta. However, when it becomes severe enough, it can result in gestational diabetes.

Insulin resistance is common in women with PCOS. Insulin and increased levels of testosterone and estrogen also affect the hypothalamus, which secretes more luteinizing hormone in the brain, which in turn stimulates the ovaries to make even more hormones,11 thus beginning the vicious cycle of PCOS. Your health care provider may check for high levels of hormones, including testosterone and luteinizing hormone, to help with the diagnosis of PCOS.

Being overweight increases insulin resistance. That’s why weight loss, a “smart carb” diet, and exercise are all keys to breaking the cycle of PCOS and increasing your chances of becoming pregnant.

Women involved in competitive sports (and those who just exercise a lot) sometimes reduce their body fat so much that they stop menstruating. Strenuous exercise, low body weight, and body fat are related to reproductive problems, including infertility. Regular exercise is important for good health and can improve or control many conditions that lead to infertility, including overweight, emotional stress, and PCOS. However, if you take exercise to the extreme and are having trouble conceiving, you may need to slow down.

If your partner is a dedicated athlete, encourage him to tone down his routine a bit or mix it up to keep the family jewels cool and unencumbered. If he’s a biker, ask him to switch to swimming or running for a while (or if he won’t stop biking, buy him a bike saddle with fertility-boosting engineering). If he likes to pound the pavement in the heat of summer, encourage him to run when it’s cool instead or to switch to the treadmill or elliptical at the gym. And remember, tight briefs and shorts may look good, but they’re not good for his fertility.12

Cigarette Smoke: Yours and Theirs
For women, the hazardous chemicals in cigarettes are poisonous to the ovaries because they decrease blood flow, interfere with estrogen production, and cause genetic abnormalities in the eggs. Women who smoke take twice as long to conceive and are more likely to have a miscarriage. The effects of smoking are dose responsive. While some of the damage that smoking does to ovaries is irreversible, stopping smoking can improve fertility rates.13

In men, smoking causes lower sperm count and motility plus abnormalities in sperm shape and function, and also can cause oxidative damage to sperm, which could be responsible for birth defects and other diseases.14

That said, tobacco is extremely addictive, and quitting is not easy. Because the effects on fertility depend on how much you smoke, start now by cutting down with the goal of quitting for good—for you and your partner.

Sidestream Smoke Also Snuffs Your Fertility
Sidestream (secondhand) tobacco smoke contains more than 7,000 chemicals, including at least 69 known to cause cancer. It’s estimated that 40% of nonsmokers are exposed to tobacco smoke. Sidestream smoke is just as bad as or even worse than the smoke inhaled by a smoker because it isn’t filtered. Recent research suggests that sidestream smoke, like mainstream tobacco smoke, may cause mutations in the DNA of sperm.15

While many a babe has been conceived after a New Year’s Eve party or other celebration, this is not a tradition you want to follow. Alcohol intake by men and women during the week of conception is associated with a higher risk of miscarriage. Alcohol can be found in semen shortly after drinking, thus it can directly interfere with conception and implantation, and it may impact early miscarriage. Even small amounts of alcohol increase the formation of free radicals and the amount of antioxidants you need, so if you were a regular drinker before, you may need to boost your antioxidant intake.16

For all these reasons, when you’re serious about trying to conceive, both men and women should avoid alcohol. If you choose to have that rare drink while trying to conceive, it’s safer for women to indulge during their period—the time when ovulation and conception are unlikely. For men, sex and alcohol don’t mix—at least when you’re trying to make a baby.

Celiac Disease and Gluten Sensitivity
While you can’t control whether you have celiac disease, you can control the disease through diet. Celiac disease, also called celiac sprue or gluten enteropathy, is an autoimmune disease that prevents people from properly digesting gluten, a protein found in wheat, rye, and barley. Research suggests there’s a higher rate of undiagnosed celiac disease in women having trouble conceiving. Untreated celiac disease also may be associated with recurrent miscarriage and other pregnancy problems such as low birthweight.

Celiac disease, once thought to be a rare disorder, now is estimated to affect as many as one in 133 people (both in the United States and Europe). However, less than 1% has been diagnosed.17 Symptoms can occur at any time in life and since the symptoms are sometimes vague and may not be gastrointestinal, celiac disease often is mis- or undiagnosed. One study showed the average time between the first symptoms and diagnosis was 11 years.18 Celiac disease is most common in first- and second-degree relatives with the disease.

If you suspect you have celiac disease, visit your health care provider. A simple blood test that looks for the presence of certain antibodies is one common test. A biopsy of the small intestine, done during an endoscopy, can confirm the diagnosis.

People whose tests for celiac disease are negative still may have some form of gluten sensitivity. The only way to know for sure is to try a gluten-free diet.

Eating Disorders
Amenorrhea (lack of menstrual periods) and oligomenorrhea (infrequent periods) often occur in women with anorexia nervosa and bulimia. Reproductive hormones also are reduced in women who maintain a lower-than-normal body weight. An increase in body weight and a balanced food intake will help restore normal reproductive functions.

If you have an eating disorder, you should try to resolve the underlying causes of the disorder for a permanent recovery. The eating habits and health problems associated with eating disorders vary from one disorder to the next. They can put your baby at risk for birth defects, low birthweight, or prematurity as well as being born large. So it’s best to get eating habits on track and make sure you’re not below your ideal body weight before pregnancy. Comprehensive programs involving a psychologist, physician, and dietitian are most helpful. The National Eating Disorders Association ( and Anorexia Nervosa and Related Eating Disorders ( also are helpful resources.

Emotional Stress
You can’t control all the stress in your life, but you may have more control than you think. Always saying yes to volunteer projects and in general overscheduling yourself can increase stress. Take an inventory of your stress and see how you can decrease it or deal with it in a healthful way. Make your health and stress level a priority.

Oxidative Stress and Antioxidants
You’ve heard much about antioxidants and their overall health benefits. In fact, they also play an important role in your fertility.

Free radicals also can damage the reproductive system and have been correlated with problems of sperm motility, sperm number, and DNA damage in sperm. Free radicals can affect virtually every step in the reproductive process, from egg maturation to pregnancy.19

That’s why an antioxidant-rich diet, like the Eating Expectantly Diet, for both moms- and dads-to-be, can improve fertility. Examples of antioxidants include vitamins C and E and folate plus carotenoids such as beta-carotene and lutein as well as minerals such as selenium, zinc, and copper. Folate and zinc have antioxidant properties that affect both male and female fertility.20-25

There are several ways scientists measure foods’ antioxidant activity. According to the USDA, a food’s antioxidant measurement doesn’t necessarily translate into antioxidant action in the body26; however, in the last few years, there have been more than 25 publications dealing with dietary antioxidants and their possible health benefits.27 The following foods are considered some of the richest in antioxidant capacity and should be included in your “before baby” diet and beyond:28,29

Fruits: blackberries, red currants, raspberries, strawberries, blueberries, oranges, pineapple, plums, and pomegranates

Vegetables: spinach, chile peppers, black and green olives, mushrooms, asparagus, arugula, radicchio, beets, broccoli, artichokes, and red peppers

Spices: clove, allspice, mint, sage, thyme, nutmeg, rosemary, saffron, tarragon, oregano, ginger, cinnamon, natural cocoa

Beverages: pomegranate, grape, prune, and cranberry juices (Espresso, coffee, and green and black teas also contain antioxidants but should be consumed in moderation.)

Nuts, seeds, and grains: walnuts, pecans, sunflower seeds, chestnuts, peanuts, pistachios, buckwheat, millet, and barley

Nutrition and Lifestyle Reign
Clearly, nutrition and lifestyle play a critical role in fertility. The information presented here is just a small glimpse into how important diet is—not only in the odds of conceiving but also in carrying a pregnancy to term and having a child who thrives. Before going through the expense and emotional roller coaster of fertility treatments, it’s wise for a woman who’s trying to conceive to work on improving her diet and that of her partner first. RDs are the perfect source of information for this highly motivated population.

— Bridget Swinney, MS, RD, LD, is a mother of two and author of the books Baby Bites, Healthy Food for Healthy Kids, and Eating Expectantly. She spreads the message about health and nutrition through her consulting practice, speaking engagements, writing, and media. The accompanying Eating Expectantly Cookbook, containing recipes and menus, arrives in the fall of 2013. More information is available at


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