Can obesity cause infertility?

First of all, what is infertility?

Infertility is a disease of the female and male reproductive system defined by the failure to achieve a pregnancy after 12 months or more of regular unprotected sexual intercourse. Unfortunately, infertility affects up to 15% of couples trying to get pregnant and can have multiple causes, including genetics, general health, fitness, diseases and diet. Moreover, many studies suggest that obesity can cause infertility.(1)

Five causes of female infertility

As mentioned earlier, female infertility refers to women trying to get pregnant with frequent, unprotected sex for at least a year with no success. A variety of factors that affect or interfere with the following biological processes include:

• Ovulation is when the mature egg is released from the ovary. The most common overall cause of female infertility is the failure to ovulate, which occurs in 40% of women with infertility issues.(2)
• Implantation failure refers to the failure of a fertilised egg to implant in the uterine wall to begin pregnancy. While the specific cause of implantation failure is unknown, possibilities include genetic defects in the embryo.
• Structural problems occur when the fallopian tubes are blocked, eggs are not able to move from the ovaries to the uterus, and sperm is not able to reach the egg for fertilisation.
• Polyps are noncancerous growths on the inside surface of the uterus. Polyps can interfere with the function of the uterus and make it difficult for a woman to remain pregnant after conception. Surgical removal of the polyps can increase the chances for a woman to get pregnant.

Polycystic ovary syndrome (PCOS) is one of the most common causes of female infertility. It is a condition in which a woman's body produces more androgens than normal. High levels of these hormones interfere with the development of ovarian follicles and release of eggs during ovulation.

Five causes of male infertility

Male infertility refers to when a man has a small chance of making his female partner pregnant. Typically, It depends on the quality of his sperm cells. Examples of male infertility include:

• Libido is more commonly referred to as sex drive, libido describes a person’s desire to have sex. This can be negatively affected by stress, anxiety or depression.
• Erectile dysfunction otherwise known as impotence, erectile dysfunction is when a man is unable to develop or maintain an erection.
• Sperm count is a count of the number of sperm in a sample of semen. An important aspect of semen quality is the number or concentration of sperm cells in a given amount of semen.
• Sperm motility is the ability of sperm to move (swim) properly through the female reproductive tract to reach the egg. Sperm motility is the percentage of moving sperm cells in a sample of semen.

Low Testosterone levels may be responsible for infertility in some men.

How can obesity cause infertility?

Firstly, let’s define obesity. Obesity refers to abnormal or excessive fat accumulation that presents a risk to health. Adults are generally considered obese if they have a body mass index (BMI) of 30 or above.

Researchers found obese women were much less likely to conceive within one year of stopping contraception than women in a healthy weight range.(3) Let’s look at this a little further.

Body fat affects the menstrual cycle through a range of hormonal mechanisms. The more excess weight and the more abdominal fat, the greater the risk of fertility difficulties. A fine hormonal balance regulates the menstrual cycle. Fatty tissue produces leptin, therefore overweight women have higher levels of this hormone. This can disrupt the hormone balance and lead to reduced fertility.

Excessive abdominal fat is also linked to insulin resistance and decreased levels of sex hormone-binding globulin (SHBG), which is a protein that is involved in the regulation of two sex-hormones: androgen and oestrogen.(4)

Like women, obesity can cause infertility in men. This is likely due to hormone problems, sexual dysfunction and other health conditions linked to obesity, such as type 2 diabetes and sleep apnoea. In fact, according to research weighing an extra 10kg may reduce male fertility by 10%.(5)

It’s important to highlight that being underweight (BMI under 18.5) can also reduce a woman's fertility by causing hormone imbalances that affect ovulation and the chance of getting pregnant. Compared to women in the healthy weight range, women who are underweight are also more likely to take more than a year to get pregnant. Additionally, a low BMI could reduce total sperm count and sperm concentration in men.(6,7)

Can exercise impact fertility?

In terms of health benefits, the amount of recommended exercise depends upon your goal, the type of exercise, and your age. Even doing a small amount of exercise is healthier than doing none. The UK government recommends that adults take part in at least 150 minutes of moderate intensity physical activity each week, in bouts of 10 minutes or more. In addition, this should include a mixture of aerobic, flexibility and strength exercises.

What's more, exercise has many benefits towards health, including increased fertility. Increasing moderate physical activity has positive effects on fertility for women and men, especially those with obesity, which may further indicate that obesity can cause infertility.(8)

Additionally, research shows that men who undergo regular exercise have higher testosterone levels and better semen quality than inactive men.(9)

On the other hand, too much exercise can change the energy balance in the body, and negatively affect the reproductive system. Excessive high intensity exercise has actually been linked with decreased fertility in certain women. This highlights that moderation is key. Therefore, If a person plans to increase activity, they should do so gradually. Interestingly, getting the right amount of zinc can help minimise the risk of negative effects caused by excessive exercise.(10,11)

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Diet and fertility: which foods and vitamins promote fertility and a healthy weight loss?

Luckily, there are a few natural ways to increase fertility. In recent years, scientists have conducted more research on dietary patterns and specific foods that couples should consider adding to or removing from their lifestyle to increase the chance of conception.(12)

In addition, low energy diets have significantly increased pregnancy rates. This might be because obesity can cause infertility.(13)

Some other dietary recommendations for boosting fertility include(14):

• Carbohydrates rich in fibre such as vegetables and whole grains, while avoiding refined carbohydrates that are high in sugar.
• Avoiding trans fats, which are present in many fried and processed food products.
• Swapping in some vegetarian sources of protein such as tofu for some animal protein.
• Choosing high-fat dairy such as whole milk, instead of low-fat products.

The following nutrients can also be beneficial towards promoting fertility:

• Antioxidants deactivate the free radicals in the body, which can damage both sperm and egg cells. Berries, fruits, vegetables, nuts, and whole-grains are rich in beneficial antioxidants, like vitamins C, E, and folate.(15)

• Zinc plays a role in fertilisation, DNA regulation, and embryo development. Sources of zinc include seafood, poultry, eggs, legumes, nuts, seeds, and soy products.(16)

• Iron is a mineral which is vital to form oxygen-carrying red blood cells. Iron deficiency (anaemia) may be associated with poor sperm quality and production. Iron-rich foods include red meat, spinach and dried apricots.(17)

It’s important to note that for women, fertility-boosting food recommendations are aimed at fighting infertility caused by problems with ovulation. Therefore, they won’t work for infertility that’s caused by physical conditions such as a block in the fallopian tubes.

Does vitamin D impact testosterone levels?

Another vitamin worth mentioning is vitamin D. Each time we find ourselves outside, exposed to the sun's rays, one of our bodies' responses is to produce vitamin D. Although the majority of our intake comes from the sun, it’s a fat-soluble vitamin. Therefore, vitamin D is naturally present in a few foods, such as mushrooms and hemp seed oil.(18)

A cross-sectional study done on 2299 males showed that vitamin D levels had a positive correlation with testosterone and androgen levels in men. Testosterone is a steroid hormone that stimulates development of male secondary sexual characteristics, produced mainly in the testes, but also in the ovaries and adrenal cortex. Moreover, it’s believed to regulate sex drive (libido), and the production of red blood cells and sperm. Although, results suggest that intake may increase testosterone levels, further RCTs are warranted to confirm this.(19,20)

Even though the human body produces vitamin D when exposed to sunlight, it does come with its limitations. To reduce the risk of developing skin cancer, apply sun cream, and avoid being outside during peak sun hours. In addition, depending on where you live in the world, it may not be feasible to come by enough sunlight exposure all year round.

Our Organic Hemp Seed Oil is a fantastic source of vitamin D. Yet it also contains vitamin E and omegas 3 and 6, all of which are needed to support your health. Try adding a spoonful to your daily routine to increase your intake. Its versatility means you could take it by the spoonful, use it in salad dressings, or even drizzle it over your favourite dishes.

Can ashwagandha have an impact on infertility and obesity?

Ashwagandha is an evergreen shrub with yellow flowers. The herb grows in India, the Middle East, and parts of Africa. People have used the herb as a medicinal plant for hundreds of years. The past 10 or so years has seen a huge rise in the range of products containing ashwagandha. This may seem odd, as prior to this movement the herb was restricted to alternative pharmacies. However, the scientific research on ashwagandha in the past decade, especially on the benefits of ashwagandha for fertility in men, is a reason for its growing popularity.

Chronic stress has been associated with a number of illnesses, one of these being obesity. Let’s take a look at this a little further. Researchers conducted a study, where 52 men took either ashwagandha or a placebo twice daily for 8 weeks. Interestingly, the outcome of this study suggests that ashwagandha can be used for body weight management in adults under chronic stress.(21)

In addition, ashwagandha has been described in Ayurveda as an aphrodisiac. Obese men are more likely to have higher estrogen levels, which can mess with sperm count, sperm concentration and the sperm motility. A review of several studies found that ashwagandha treatment increased sperm concentration, semen volume, and sperm motility in men with a low sperm count. What’s more, it also increased sperm concentration and motility in men with a normal sperm count.(22)

In Ayurveda, ashwagandha has been taken as a whole root powder as opposed to capsules containing ashwagandha extracts. Sourced straight from organic farmers in India, enjoy our Organic Ashwagandha Powder as part of a warm drink. You get genuine clarity, avoid additives, plus it’s convenient to use. Simply dissolve ¼-½ tsp of the powder in warm water or milk. You can take this daily or even twice a day for two to three months, depending on your needs.

To increase validity and reliability, ashwagandha’s effect on fertility and testosterone requires further studies. Although the signs of early research are promising for the proposed benefits of ashwagandha.

When to seek medical assistance to treat infertility

The majority of healthy couples under the age of 35 will conceive within a year of actively trying to get pregnant. Therefore, advice commonly given to couples under the age of 35 trying to conceive is to see a doctor after one year of unprotected sex that doesn’t result in pregnancy. However, couples over 35, should only wait six months before seeing a doctor. Couples should also see a fertility specialist if they have a history of multiple miscarriages or know that they have a genetic or medical condition that might affect their fertility.

Also, if you have a known occupation, hobby, or medical condition that is linked to a lower sperm count, you should talk to a doctor as soon as possible before you begin trying to conceive. They can do tests to ensure that you’re healthy and conception is recommended.

A fertility specialist will usually perform tests on both the man and woman. A man will provide a semen sample for a semen analysis and sperm count. The doctor will check the number of sperm per sample to determine if the sperm count is too low. An ultrasound may also be performed to look for problems in the scrotum, or ducts and tubes where the semen travels. A woman will have her eggs, ovaries, and uterus tested.

So, can obesity cause infertility?

Although there are associations between obesity and infertility, healthcare professionals often make assumptions about patients’ health or habits based on their size alone. This leads them to overlook problems or risk factors other than excess weight.

As a result, this might prevent patients from receiving the care or support they need. Additionally, It may also traumatise some patients and affect their trust in doctors. To stop this from happening, it’s essential for healthcare professionals to avoid stereotyping and stigmatising patients with larger bodies.

Infertility can have multiple causes and may depend on genetics, general health, fitness, diseases, diet and weight. Therefore, it is not just obesity that can cause infertility. Fortunately, being diagnosed with infertility doesn’t mean that you can't have a child. It may take some time, but a number of couples who experience infertility will eventually be able to have a child. Some will do so on their own, while others will need medical assistance.

Related readings

• What is the best diet for PCOS?
• What are the benefits of ashwagandha for men?