Carbohydrates are essentially energy giving foods. Although the body can convert fats and proteins into energy, carbohydrates (which are broken down into glucose) are our bodies first choice for energy production and the only source that our brain is capable of using for energy (1). Carbohydrates are also an important source of fibre, various phytochemicals and micronutrients. There are two main types of carbohydrates in our society today: refined carbohydrates and whole carbohydrates. These have vastly different effects on women’s hormones, overall health and menstrual cycle. They also have a profound effect on how easily women transition into menopause.
What effect do refined carbohydrates have on hormones?
Refined carbohydrates are foods that have been processed and stripped of their fibre and/or micronutrients. The best example of this is refined sugar. Refined sugar that originates from sugar cane, beetroots or corn has been completely stripped of all fibre and nutrition until only the sugar remains. Refined sugar is found in processed sweets, chocolates, lollies, cakes, ice creams, muffins and worst of all soft drinks (soda). Refined sugar is also hidden in many other foods like yogurts and pasta sauces. Refined carbohydrates are usually whole grains that have been stripped of their outer layers which contain most of the fibre and micronutrients of the grain. Examples include white flour found in bread, cakes, pastries etc as well as white pasta and white rice.
Raises insulin levels and testosterone levels: each time sugar is ingested insulin is secreted from the pancreas to help move sugar out of the blood and into the cells. Refined sugar required a lot of insulin to be secreted. Over time this can lead to insulin resistance which is known to raise testosterone levels in women. High testosterone also leads to symptoms like weight gain, mood disturbances, acne, hair loss and facial hair. This is most common in women with PCOS (polycystic ovarian syndrome) (3)
Associated with acne: blood sugar spikes cause inflammation throughout the body, this also causes the skin to produce more sebum which can produce acne. Both inflammation and high sebum production can produce acne. In fact, a review on diet and acne established high glycemic foods (sugar) to be the largest influencing factor in the presence of acne compared to all other foods studied. (2)
Can lead to estrogen dominance symptoms. Sugar, especially if the diet is also high in saturated fat has negative effects on the liver and the gut. These organs are largely responsible for the safe elimination of used up estrogen in the body. If these organs can not remove estrogen efficiently much of the estrogen gets reabsorbed and recirculates in the bloodstream. This leads to estrogen dominance symptoms like heavy periods, PMS and increases the risk of developing estrogenic cancers like breast cancer. (4)
Worsens period pain: In a study examining dietary choices and primary dysmenorrhea (period pain), high glycemic foods in particular soft drinks were found to be most strongly associated with increased severity of pain. (5) (6)
Can worsen thyroid function: there is a fairly well-established link between thyroid and diabetes, it is believed that blood sugar levels affect the thyroid and the thyroid can also affect blood sugar (7). Sugar itself can worsen Hashimoto’s symptoms (hypothyroid) likely by creating inflammation and gut dysbiosis.
Associated with poor mental health: diets high in sugar and high in GI foods have been found to cause an increased risk of developing depression in women (8) Sugar has also found to weaken ones ability to handle stress long term (9) Low blood sugar which occurs from either not eating enough or from consuming high sugar foods too often is well associated with anxiety and generalised anxiety disorder (10) all of these will respond to the menstrual cycle accordingly and for most women will be exacerbated premenstrually.
Worsens Fertility Outcomes: Diets high in sugar raise insulin too high which can interfere with ovulation. Lack of ovulation is the biggest issue of infertility in women and is evident mostly in women with PCOS (14).
Worsen Perimenopause symptoms: A large study examining the total carbohydrate index and carbohydrate load of women in perimenopause found a significant association between women who ate high GI especially refined sugars and insomnia during perimenopause (17).
Effects of whole food carbohydrates on hormones:
As sugar and refined carbohydrates have such an array of negative health effects especially on women’s hormones and fertility it is easy to think that the lower the total carbohydrates the better. However, whole carbohydrates are different. Whole carbohydrates are foods found in their whole form and include whole grains like oats, barley, rye, spelt, brown or wild rice, millet, quinoa and whole wheat, lentils, beans, vegetables, starchy vegetables like potatoes and sweet potatoes and whole fruits. Although some processing may be necessary for optimal digestion, carbohydrates that still retain the majority of their fibre and nutrient profile are generally healthful for the body provided our gut and digestion are not compromised (some people may have a difficult time digesting high-fibre foods like whole grains as well as have intolerances to gluten or fructose until healing is restored to the gut)
Assists with steady blood sugar levels that prevent insulin-resistant PCOS and diabetes. Wholegrains, in particular, have shown some of the most impressive results in studies in preventing type 2 diabetes and insulin resistance (as well as assisting with weight loss) (11)(12) one study concluded that higher consumption of whole grains was able to reduce the risk of developing PCOS by 64% (13).
Improves improve estrogen dominance symptoms and PMS. Wholefood carbohydrates contain high amounts of fibre. Fibre has been shown to help bind used-up estrogens in the gut and safely remove them from the body before they recirculate and lead to estrogen excess which causes symptoms of PMS as well as heavy and painful periods (14).
Helps improve fertility. The most comprehensive study conducted on diet and fertility is the Nurses Health Study. The study found that the number of carbohydrates in the diet was as important as the type. Women whose diet contained at least 60% calories from whole carbohydrates tended to be a healthier weight and have better fertility outcomes than women who avoided carbs or women than ate very high carb with diets high in refined sugar (15).
Helps maintain regular menstrual cycles. While high sugar diets can lead to irregular or absent ovulation, the same can be said about low carbohydrate diets. Cutting carbohydrates too low for too long has been shown to cause irregular cycles or missing cycles (amenorrhea) in adolescents and adult women. This is usually observed in women following strict keto-type diets if the low carbohydrate diet is maintained for a longer period of time (16).
Improves overall health and symptoms of peri-menopause. During a woman reproductive years, the hormones estrogen and progesterone help to protect against many chronic health conditions like cardiovascular disease, diabetes and cancer. Men have a higher risk for these diseases than women until menopause. At menopause, the drop in hormones leads to an increased risk of all chronic diseases that often surpass the risk in men. A large study concluded that regular consumption of whole grains in menopause had the ability to reduce the risk of all-cause mortality by 17%. (18) Whole carbohydrates are also a valuable source of phytoestrogens which have been shown in studies to help reduce menopausal symptoms like hot flashes to a small degree while also being protective against breast cancer (19).
Help stabilise mood. Some studies suggest that whole grains may have a balancing effect on the neurotransmitter serotonin (20). As serotonin drops pre-menstrually with dropping hormones it is responsible for some of the mood-related symptoms associated with PMS. Wholegrains and other whole carbohydrates are anti-inflammatory and so can also reduce the risk of depression and other mental health disorders by means of reducing inflammation.
How to eat carbs:
For optimal hormone health focus on the quality of the carbohydrates and not the number of carbohydrates. Whole food carbohydrates like whole grains and legumes are often already balanced with plenty of protein to help stabilize blood sugar levels. They are slow-release carbohydrates which means they do not create the sugar highs and lows that disrupt hormone balance. They’re also loaded with lots of fibre and micronutrients (vitamins and minerals) which are health-promoting for all areas of our health.
• Ditch the processed refined sugar. Switch up refined sugar for healthier natural sweeteners with lower GI’s like coconut sugar or maple syrup etc (but these should only be eaten in moderation)
• Switch white bread, white pasta, and white rice to good quality whole grain varieties and
• Start adding a larger variety of good grains, legumes, vegetables, nuts seeds, and whole fruits.
• Avoid drinking fruit juice and eat whole fruits or blend fruits into smoothies instead.
• Keep a lookout for unnecessary added sugar in foods (like nut butters, pasta sauces, and yogurts, even healthy ones)
• Cut out alcohol as this contains a lot of sugar and isn’t good for hormones on the whole
As always hormonal imbalances are very complex and it is unlikely that carbohydrates are the sole cause of a hormonal imbalance, most of the studies cited above also mentioned that sugar in combination with saturated fat lead to even poorer health outcomes. Having said that nearly all hormonal imbalances will improve in the absence of refined carbohydrates (especially refined sugar) and with the addition of fibre containing whole carbohydrates.