Diet and Exercise
Optimizing a man’s fertility potential involves improving the environment for sperm production as much as possible. If a man’s general health is not good, this can have a negative impact on his sperm quality and function. A balanced diet and a good exercise regimen can help to maintain his overall health and therefore increase his chances of conceiving a child.
Regular Exercise and Sperm Quality
Regular exercise can help men with their cardiovascular health as well as achieve and maintain a healthy weight. In terms of male fertility potential, it does appear that exercise can play a positive role in improving semen parameters, but with some caveats. Of course, men with significant health problems should check with their primary care physician before starting on an exercise regimen.
Clearly, studies have shown that a sedentary lifestyle is not good for a man’s general health as well as fertility potential. Therefore, some form of physical activity is a good recommendation for essentially all men trying to conceive. [Gaskins AJ. BrJSportsMed 2015]. Exercise as part of a healthy weight loss program in obese men has also clearly been shown to play a beneficial role in improving semen parameters. [Hakonsen LB. ReprodHealth 2011]
In general, the literature appears to support the fact that “moderate” exercise can improve semen parameters in men. [Maleki BH. Reproduction 2017] A good general definition of “moderate” exercise can be found with the American Heart Association’s current recommendations for physical activity which include:
1) At least 30 minutes of moderate-intensity aerobic activity a day at least five days per week (for a total of 150 minutes per week) or at least 25 minutes of vigorous aerobic activity at least three days per week (for a total of 75 minutes per week), or some combination of moderate and vigorous activity
and
2) Moderate- to high-intensity muscle-strengthening activity at least two days per week
Exact definitions of “moderate” activity beyond this are not easily made, but certainly playing serious competitive sports or being an elite/professional athlete often takes one out of the “moderate” zone for exertion. There are concerns that men who participate in very strenuous physical activity can harm sperm production and quality through a combination of overall stress on the body, increased scrotal temperatures, hormone imbalances, and oxidative stress on the cells. [duPlassis SS. OpenReprodSciJ 2011] Several studies have confirmed that men who participate in more vigorous/high intensity exercise have the potential for lower semen parameters than men who exercise more moderately [Vaamonde D. FertSteril 2009][Maleki BH. Reproduction 2017]. Studies have found that high mileage runners (average of 67 miles/week) have on average lower total motile sperm counts and testosterone levels than either moderate mileage runners (average of 33.5 miles/week) and sedentary controls. [DeSouza MJ. IntJSportsMed 1994]. Another study of 24 long distance runners looked at semen parameters at baseline and while they were training for a marathon. Sperm counts dropped from 133 million/cc to 71 million/cc as the runners ramped up the intensity of their training, and morphology also dropped from 15% to 11% (motility was unchanged in this study) [Jensen JE. FertSteril 1995].
A FEW SPECIFIC EXERCISE TIPS FOR MEN TRYING TO OPTIMIZE THEIR FERTILITY POTENTIAL
1) Avoid tight biking-style shorts. It is common for men to wear tighter pants or underpants when they exercise, to offer more support in the scrotal area (such as running tights, biking shorts, or compression shorts). However, one of the primary ways the body regulates its temperature is for the scrotum to relax and increase its surface area for release of heat. Very tight workout pants prevent this scrotal relaxation and can result in increased scrotal temperatures, which can have a negative impact on sperm production.
2) Avoid excessive bicycle riding. The combination of the riding position, narrow biking seat, time in the saddle and tight biking shorts all combine to produce a negative environment for sperm quality. [Lucia A. JApplPhysiol 1996]. Biking has been associated with decreased semen parameters, with the degree of effect depending on the posture, duration, and intensity of the workouts. [Jung A. IntJAndrol 2008] A 2011 study found that biking more than 5 hours a week was associated with a significant decrease in sperm counts. [Wise LA. FertSteril 2011]. Short bike rides (totally less than 5 hours per week) are not likely to make much of a difference, especially if you don’t wear tight biking shorts.
OVERALL RECOMMENDATIONS FOR EXERCISE
It seems clear that being sedentary and inactive is not good for sperm, so incorporating regular moderate exercise into a man’s weekly schedule can help to improve fertility potential. However, like many things in life, too much of a good thing can prove detrimental. Although “moderate” has not been definitively defined, training for a marathon (or the equivalent in other forms of exercise) is probably not a good idea for men with abnormal semen parameters when they are trying to conceive. Other general recommendations would be to not wear extremely tight underwear/running pants which compress the scrotum tightly against the man’s hot body. Keep cycling to less than 5 hours per week and (again) try to avoid wearing tight biking shorts. And obviously avoid hitting the sauna or hot tub after your workout.
Dietary Recommendations for optimizing male fertility potential
Multiple studies have shown an association between a healthful, well-balanced diet and improved semen parameters. There is no one set “male fertility diet”; rather, there are general guidelines about foods that have been found to be either helpful or detrimental to optimal sperm production. The goal is to make dietary changes that are sustainable. If you try to make changes that are too radical to maintain, chances are that you’re not going to stick to them, and so you won’t see any real improvements in fertility potential—plus you might stress yourself out in the process. The guidelines I present here are designed to encourage overall better dietary choices without being too strict to maintain.
From the available scientific literature, there seem to be two primary ways in which a man’s dietary choices can influence his fertility potential.
#1) Some food and dietary patterns have been associated with improved sperm quality
#2) Environmental toxins that can be associated with food-related contamination can exert a detrimental effect on semen parameters.
Let’s look at these two topics in more detail.
GOOD FOODS FOR MALE FERTILITY
In general, the goal is to aim for a well-balanced diet, with a focus on healthy foods that have been shown to be “sperm-friendly”. Here are some general recommendations that have been found to be helpful for improving semen parameters as well as potentially decreasing DNA damage of sperm [Oostingh EC. FertSteril 2017][Jurewicz J. Urology 2016][LaPointe S. FertSteril 2023]:
1) Fresh fruits and vegetables. Try to get at least five to six servings per day if possible. Green leafy vegetables are an especially good natural source of beneficial folic acid. If you can find and afford organic produce, it will reduce your exposure to pesticide residues.
2) Lean protein in moderate amounts. Good choices include:
a) Fish (but stay away from types that are often high in mercury, including swordfish, king mackerel, shark, and tilefish)
b) Skinless chicken and turkey
c) Legumes (beans, lentils, peas)
d) Nuts (including nut butters) and seeds
e) Egg whites
f) Low-fat dairy (skim or 1 percent milk, low-fat cheeses such as cottage cheese, feta, Camembert, and ricotta)
g) Oatmeal.
3) Complex carbohydrates. While carbs have gotten something of a bad rap lately in terms of general health and maintaining a healthy weight, the intake of a moderate amount of complex carbohydrates should be fine for sperm production. Whole, unprocessed carbohydrates provide energy, nutrients, and fiber and don’t spike your blood sugar the way highly processed carbs do. Instead of white bread and pasta, look for whole-grain types. Go for rolled or steel-cut oats instead of instant oatmeal (which is often high in sugar, too). Try different whole grains such barley, quinoa, brown rice, or wild rice. Pick sweet potatoes, corn, lima or butter beans, peas, lentils, and other types of beans instead of white potatoes. And, of course, fruits and non-starchy vegetables provide carbohydrates as well as other nutrients.
4) Unsaturated fats. These can help lower LDL (bad) cholesterol, and some can improve levels of HDL (good) cholesterol. Unsaturated fats come from plants and fish sources and are liquid at room temperature. Good sources of this type of fat include vegetable and seed oils (such as olive, canola, peanut, flaxseed, safflower, and sunflower), nuts (for example, pecans, almonds, and hazelnuts), and seeds (including sesame, pumpkin, and sunflower). Multiple studies have shown that an increased intake of fish and seafood have also been associated with improved semen parameters likely secondary to their high levels of long chain omega-3 fatty acids. Oily fish, such as salmon, tuna, herring, sardines, and anchovies, are thought to be especially high in these fatty acids. [Minguez-Alarcon L. IntJHygEnvHealth 2018].
Dietary Stategies
For men who are looking for some more concrete dietary guidelines, a 2018 study showed that any of following healthy dietary plans were associated with improvements in semen parameters: DASH (Dietary Approach to Stop Hypertension], HEI (Healthy Eating Index), aMED (alternate Mediterranean Diet), and AHEI (Alternative Healthy Eating Index). [Efrat M. FertSteril 2018]. Consistency with one’s diet appears to be an important factor as a 2017 study found that closer adherence to a healthy diet plan was associated with a higher improvement in semen parameters. [Oostingh EC. FertSteril 2017]
THE BAD FATS
Some fat in the diet is necessary for good health, but make sure you’re eating more of the healthful types of fats mentioned above, and less of these problematic fats:
1) Saturated fats. These come largely from animal products, such as high-fat dairy products (butter, cream, ice cream, whole milk), high-fat cheeses (cheddar, Swiss, Gouda, Parmesan, Gruyere, cream cheese), fatty cuts of meat (including bacon and lard), and poultry skin. Saturated fats can also be found in some plant sources, such as palm and coconut oils. If the fat is solid at room temperature, then it is saturated. [Attaman JA. HumReprod 2012]. Low fat dairy products (such as skim milk) do not appear to negatively impact male fertility. [LaPointe S. FertSteril 2023]
2) Meat intake. In terms of total meat intake, increased levels have not been associated with a change in fertility potential. In fact, intake of seafood has been associated with some potential benefits to sperm quality as described above. Leaner meats (e.g. chicken and turkey) have not been associated with decreases in semen parameters, but there is conflicting evidence on sperm quality and the intake of organ meats (e.g. liver) [Lapointe S. FertSteril 2023] However, increased red meat intake (e.g. beef and pork) has been associated with lower fertility potential in men. [Afeike MC. Epidemiol 2014] If eliminating red meat is not an option, you can try to limit intake to about 18 ounces per week, and go for leaner cuts of beef (such as eye round, sirloin tip, top round, bottom round, and top sirloin) and pork (such as loin and tenderloin). Processed meats should also be avoided if possible as these have been associated with lower sperm quality as well. Examples of processed meat include hamburger, hot dogs, salami, and bologna. [Afeiche MC. JofNutr 2014]
3) Fried foods. They often contain unhealthy saturated and trans fats, plus lots of calories.
4) Trans fats. Avoid these, which are vegetable oils that have undergone an industrial process to solidify them to extend their shelf life. They’ve been shown to raise LDL (bad) cholesterol and lower HDL (good) cholesterol—exactly the opposite of what you want. They’re often found in processed baked goods (cookies, pie crusts, cakes, pizza dough, hamburger buns), snack foods (crackers, chips, cookies, candy, prepackaged popcorn), fried foods, frozen dinners, and some types of margarine. Food producers are required by law to list trans fats on a product’s Nutrition Facts label, and you can also check the ingredients list for the words “hydrogenated” and “partially hydrogenated,” which tell you that the product contains trans fats. [Chavarro JE. FertSteril 2011]
IS SOY A PROBLEM?
Soy products—tofu, edamame, soy sauce, soy milk, soy flour—contain phytoestrogens, substances with known weak estrogenic (female hormonal) activity. Several studies have shown a possible link between regular soy product consumption and decreased semen parameters. [Chavarro JE. HumReprod 2008] Although these findings are controversial, I recommend that men avoid regular soy intake while trying to conceive.
SUGAR: NOT SO SWEET
Simple sugars spike blood glucose levels and offer lots of calories with little nutrition. Sugar added food and beverages have also been correlated with decreased semen parameters in multiple studies. [LaPointe S. FertSteril 2023] I suggest you avoid them when possible. In addition to the obvious suspects, such as sweetened drinks (sugary soda, sweetened tea, fruit juice), candy, cookies, cake, and jams and jellies, you might be surprised by the sugar content in ketchup, sauces, and dressings. Read labels and look for the various names that sugar hides under: sucrose, glucose, fructose, lactose, maltose, raw (or brown or beet) sugar, molasses, evaporated cane juice, cane sugar, maple sugar or syrup, high fructose corn syrup, and turbinado sugar. [Chiu YH. HumReprod 2014]
Pesticides and Toxins and their potential impact on sperm
Many foods that are generally considered to be “healthy” and sperm friendly can unfortunately also be contaminated with environmental toxins. This can occur in the form of pesticides applied to otherwise healthy fruits and vegetables as well as heavy metals that can accumulate through the food chain in fish and shellfish.
In this website, the term “pesticides” will be used to describe chemical agents that are used by the agriculture industry to control insects, weeds, rodents, and fungus. The use of these agents are very common, with at least 60% of agricultural products in the United States testing positive for contamination by at least 1 pesticide. [Chiu Y JofNutr 2015]. Multiple pesticides (such as pyrethroids, organochlorines, and organophosphates) have been found to have a negative impact on semen parameters. This negative effect has been postulated to be due to factors such as endocrine disruption, increased oxidative stress, and damage to the testicular germinal epithelium. Deceased sperm counts and motility have been documented in higher frequency in men with increased levels of pesticide-exposed foods. [Chui Y HumRepro 2015] In other words, the ingestion of pesticide-contaminated foods can potentially more than offset the otherwise positive impacts of increased fruit and vegetable intake.
In terms of seafood intake, animal and lab studies have shown a negative impact of heavy metal intake (such as mercury) on sperm production and quality. Interestingly, the negative impact of these heavy metals may be compensated for by the overall positive intake of fish of seafood on spermatogenesis.
Strategies for Addressing Dietary Toxins
HEAVY METALS
In terms of heavy metal contamination, a good strategy is to continue to eat seafood (and especially the oily fish listed previously) but try to avoid species which are known to harbor high levels of mercury. These include: king mackerel, marlin, orange roughy, shark, swordfish, tilefish, and tuna. For most people, all of these would be fairly easy to avoid with the exception of tuna, but tuna consumption represents the #1 source of mercury in the US diet. [Natural Resources Defense Council- NRDC]
PESTICIDES
In terms of pesticide exposure, there are 3 basic strategies that can be employed to try and minimize exposure:
1) Consume less foods that are known to have increased pesticide contamination
2) Eat “organic” products, especially of the fruits and vegetables that are known to usually have more pesticide exposure
3) More vigorously wash your fruits and vegetables prior to consumption
Focus on Produce Less Likely to Have Pesticide Exposure
Various types of fruits and vegetables typically have different levels of pesticide contamination in the United States. The differences are due to both physical aspects of the food as well as their susceptibility to insect and fungal damage. The Environmental Working Group (EWG) have put together a list of “Dirty Dozen” and “Clean 15”which denotes the fruits and vegetables which generally have the highest and lowest rates of pesticide contamination in this country.
Dirty Dozen Clean 15
Strawberries Avocados
Spinach Sweet corn
Nectarines Pineapple
Apples Cabbage
Grapes Eggplant
Peaches Honeydew melon
Cherries Kiwi fruit
Peas Cantaloupe
Tomatoes Cauliflower
Celery Mushrooms
Kale Onions
Potatoes Frozen sweet peas
Papaya
Asparagus
Broccoli
Eating Organic
One potential strategy to reduce pesticide consumption is to try and consume products labelled “organic”, especially for foods from the “Dirty Dozen”. To be designated as organic, farms need to be able to prove that they are not using any artificial pesticides or fertilizer in the growing of their produce. Since fertilizers can stay in soil for quite some time and pesticides can blow in on the wind or wash in from other areas after a rain, organic foods do not entirely eliminate pesticide exposure, but does decrease it significantly. This approach is certainly more expensive, but studies have shown that organic-based diets does have the potential to improve semen parameters in men. [Chiu Y HumRepod 2015]
Washing Your Foods
There is evidence that taking some additional time to more thoroughly wash your produce can potentially remove some of the pesticides that are present. The effectiveness depends on the particular fruit or vegetable as well as the type of cleaning used. This website is not going to provide in-depth tips on how to wash each different type of fruit and vegetable but a quick Google search will reveal recommended specifics for each type of produce. Most use some combination of soaking in either a salt, white vinegar, or baking soda formula, usually for times ranging between 2 to 20 minutes. The vegetables are then either rinsed, spun, wiped down with a damp towel, or scrubbed with a brush depending on how hard or soft the skins are.
Conclusion on Dietary Recommendations
Clearly, the “Western Diet” (processed foods, simple carbohydrates, increased animal proteins + trans/saturated fats, decreased dietary fiber) has been associated with decreased semen parameters and fertility in men. Following a healthier Mediterranean diet has been shown to have a protective effect on sperm numbers and quality. Vegeterian diets have mixed findings in terms of male infertility whereas they have high levels of helpful antioxidants, but they can also contain large amounts of estrogenic compounds as well as pesticide contamination.[Ferramosca A. IntJMolSci 2022]