Best Foods For Shrinking Fibroids

Overview 

Introduction

Brief explanation of fibroids and their prevalence

Fibroids, commonly referred to as uterine fibroids or myomas, are benign, non-cancerous growths which develop in the uterine smooth muscle as part of the lining of the uterus, affecting up to 68.8% of women of reproductive age.¹ In a recent study studying the prevalence of uterine fibroids, Lou et al., 2023 concluded the number of cases globally has increased in recent years and was found to be most common in women between the age of 35-44 years.

Importance of diet in managing fibroids

Research evidence shows a link between the presence of fibroids and heavy menstrual bleeding, which contributes to iron-deficiency anaemia and ultimately a reduced quality of life. The occurrence of fibroids has several social and economic implications, from lack of income from patients taking time off work or risk of infertility to the cost of treatment options, including magnetic resonance-guided focused ultrasounds, hysterectomies or myomectomies, and therapies including tranexamic acid and oral contraceptives which puts strain on public healthcare due to the large population of women affected². Due to these implications, it is important to manage nutrition and diet, two significant epidemiological risk factors associated with the development of these growths. 

Purpose of the outline: Identifying the best foods for shrinking fibroids

Current research has published their findings on the association between decreased consumption of fruits and vegetables and vitamin D deficiency with the pathogenesis of uterine fibroids, by which upping their dietary intake may provide a solution for their shrinkage. 

Understanding fibroids

Definition and types of fibroids

Fibroids are defined as benign tumours that form within the uterine wall. They are thought to be associated with increased levels of the oestrogen and progesterone hormones that aid tumour growth in women of reproductive age. It is important to treat and manage uterine fibroids as when left untreated, they can impact the quality of life of affected women due to incidences of heavy and/or prolonged menstrual bleeding, also referred to as menorrhagia, which, when severe, can cause iron-deficiency anaemia.³

Fibroids are classified into three main types: 

1. Intramural fibroids
2. Subserosal fibroids
3. Submucosal fibroids

Intramural fibroids are the most common type of fibroid, frequently found within the muscular layer of the uterine wall, while subserosal and submucosal fibroids are less commonly found in the pelvis and inside the uterus respectively.¹³

Common symptoms and risk factors¹⁴

Although most women with fibroids do not present with symptoms, the Office on Women’s Health outlines the most common presentations:

• Heavy and/or painful menstrual bleeding
• Iron-deficiency anaemia
• Distended lower abdomen
• Frequent urination
• Pain during sexual intercourse
• Lower back pain
• Complicated pregnancy
• Infertility

 Risk factors for uterine fibroid formation include:⁴

• Age
• African American ethnicity
• Obesity
• Family history
• High blood pressure
• Vitamin D deficiency
• Diet

Age

The prevalence of uterine fibroids increases with age, being the most significant risk factor, correlating with increased use of an ultra-scan of the uterus during pregnancy with peak diagnosis in women around the age of 50 years old. The risk of fibroid formation is lowest outside of reproductive age, with little to no incidence before puberty and during menopause.⁵

Ethnicity

The incidence of fibroid growth has been suggested to be elevated in women of African American descent in comparison to Caucasians, with research by Baird DD et al., 2003 concluding the cumulative incidence of uterine fibroids is 80% in African American women compared to a lower 70% in Caucasians.⁶ However, due to the asymptomatic nature of fibroids, a lack of routine screening for their growth in women of reproductive age, and the limited number of large-scale research studies into the biological basis of these claims, the claim that ethnicity is a contributing risk factor needs to be treated with caution.⁷

Obesity

Obesity is a cardiometabolic risk factor which has been found to increase the likelihood of fibroid formation. Uterine fibroid pathogenesis has been attributed to increased levels of adipocyte-releasing signalling molecules known as adipokines, which contribute to upregulated inflammatory pathways involved in tumour proliferation. Similarly, increased levels of fatty triglycerides, also known as dyslipidaemia, have a positive association with an elevated number of pro-inflammatory cytokines such as neutrophils and lymphocytes, which, as previously discussed, contribute to the formation of fibroids8. Taking these factors into account, it was proposed that inflammation triggers an intracellular inflammatory cascade within myometrial smooth muscle cells, which ultimately results in hyper proliferation, extracellular matrix deposition and collagen production within the uterine myometrium. The risk of fibroid growth as a result of obesity is further driven by oxidative stress as a result of genomic oxidation mediated by NOX4 and TGFB3 signalling at the MED12 locus. A meta-analysis of 24 studies with over 325000 participants supports these hypotheses as a strong positive correlation was found between individuals with a higher BMI and incidence of fibroid formation.⁸ 

Family history

Only a few studies have investigated the predictive value of family history for fibroids but concluded a significant association between positive family history and 20% and 30% increased risk of fibroid progression in African American and Caucasian women, correspondingly.¹⁵ Despite limited research in this field, a family history of fibroids has been associated with an increased risk of fibroid formation based on genetics. Genetic causes of fibroid growth have been attributed to the mutations in the fumarate hydratase gene found in rare familial syndromes and the chance of inheriting variations in the vascular endothelial growth factor (VEGF-A) gene, which under normal circumstances is responsible for stimulating angiogenesis, promoting the formation of new blood vessels. Variations in VEGF-A underlie increased angiogenesis, thus characterising menorrhagia, which is symptomatic in individuals with fibroids.⁹

Vitamin D deficiency

Research has shown that uterine fibroids express reduced Vitamin D receptors (VDR), which underlie Vitamin D deficiency. Additionally, vitamin D deficiency is 10x more prevalent in women of African American descent, further supporting the conclusion of increased prevalence of fibroid formation in this ethnic group.¹⁰

Diet

Diet is an epidemiologic risk factor which is associated with fibroid growth due to the ability of various dietary habits, nutrients and pollutants in food to influence hormones such as oestrogen, which contribute to increased mitotic rate which underlie somatic mutations in the pathogenesis of hormone-sensitive tumours. 

Best foods for shrinking fibroids 

Fruits and Vegetables are recognised as beneficial in reducing the risk for fibroid formation or, thereafter, for shrinking fibroids when women of reproductive age consume at least four servings per day. This is evidenced in studies that concluded a higher incidence of fibroid growth in women who consumed only one serving of fruits and/or vegetables. 

Fruits and vegetables are recognised as best for shrinking fibroids due to their production of phytochemicals, which is an essential part of their immune system to protect not only plants from bacteria and viruses but also benefits humans. In an individual’s diet, phytochemicals play a role in regulating fibroid pathogenesis and angiogenesis, however. literature has suggested that further studies are needed to ascertain their therapeutic effect. 

The best fruits and vegetables for shrinking fibroids include:

• Berries
• Citrus fruits
• Tomatoes
• Antioxidant vegetables e.g. Brussels sprouts, cabbage, cauliflower, broccoli and kale

Phytochemicals found in fruits and vegetables include:

• Cultivars 
• Curcumin
• Quercetin
• Indole-3-carbinol
• Lycopene
• Resveratrol

Cultivars

Cultivars are found in foods like strawberries, sweet potatoes and tomatoes. Cultivars, particularly those found in strawberries, possess the ability to induce apoptosis and increase the levels of reactive oxygen species (ROS) in uterine fibroid cells (leiomyoma cells). These mechanisms are useful in shrinking fibroids as they regulate a decrease in the amount of collagen, fibronectin, which is an important protein in tumour formation, and versican mRNA expression in these cells. 

Curcumin

Curcumin, which is found in turmeric and most popularly consumed in curried foods, has been identified as having the ability to contribute to shrinkage of fibroids through exerting antineoplastic activity to activate caspase-3 and caspase-9 expression, inhibit extracellular signal-related kinase 1 and 2, nuclear kappa-light-chain-enhancer of activated B cells, and decrease fibronectin expression in the effort to cause apoptosis and ultimately shrinkage of leiomyoma cells.

Quercetin and Indole-3-carbinol

Quercetin is predominantly found in citrus fruits and berries, while indole-3-carbinol is a compound formed from the consumption of green, antioxidant vegetables, such as Brussel sprouts, cabbage, cauliflower, broccoli and kale. Both quercetin and indole-3-carbinol can reduce the expression of collagen 1A1 and fibronectin in leiomyoma cells, alongside reducing their proliferative effect, enabling the reduction of fibroids. 

Lycopene

Lycopene is a carotenoid pigment found in tomatoes, which has also been associated with reducing the size of fibroids. 

Resveratrol

Resveratrol acts as an antioxidant found in berries, which also inhibits collagen 1A1 and fibronectin expression to prevent further fibroid growth. 

Herbal and nutritional supplements

Studies have found positive correlations between the consumption of herbal and nutritional supplements, including green tea extract, and vitamins and minerals like vitamin D, in decreasing the size and limiting the growth of uterine fibroids. 

Green tea extract

Evidence has supported the role of green tea extract, as it possesses an active component; the epigallocatechin gallate decreases the proliferative ability of leiomyoma cells and induces their apoptosis both in vitro and in vivo. This is supported by studies that found that women who drank green tea extract saw a significant shrinking of fibroids and the severity of their associated symptoms in comparison to women who did not. 

Vitamins and minerals

Vitamin D deficiency is associated with a greater risk of developing uterine fibroids. This is attributed to Vitamin D’s ability to downregulate the role of proliferating cell nuclear antigen and cyclin-dependent kinase 1 in signalling pathways corresponding with fibroid pathogenesis. Therefore, increase the consumption of foods fortified with vitamin D, including orange juice and milk.

Foods to avoid or limit

• Fish
• Foods with high glycaemic index (GI) and high glycaemic load (GL) 
• Alcohol
• Coffee

Fish

Fish have been associated with the risk of fibroid formation due to possessing pollutants such as polychlorinated biphenyls, which have been linked to increased prevalence of uterine fibroids in animals and, therefore, should be limited. However, this information needs to be extrapolated with caution to humans due to the lack of research. 

High GI and high GL

Foods containing high GI and high GL, including processed foods like crisps, sugar-containing beverages, fast foods, grains such as white bread and cereal, and potatoes, should be limited to reduce the risk of uterine fibroid formation. This is due to their ability to increase the availability of insulin-like growth factor I, which promotes the proliferation of leiomyoma cells during tumorigenesis. 

Alcohol

Prolonged alcohol consumption, specifically of beer, is correlated with having an increased risk of uterine fibroid growth, however, there are a lot of contradictory studies which argue the benefits of alcohol to treat hormone-related fibroid formation. 

Coffee

Evidence has concluded that coffee poses an increased risk of the development of fibroids in women above 35 years of age as a result of increasing levels of early follicular phase estradiol, which is responsible for the maturation of the female reproductive system.

Summary

It is important to manage diet to reduce the severity of associated symptoms, such as menorrhagia, to improve the quality of life for women suffering from uterine fibroids. Individuals should ensure the consumption of a range of fruits and vegetables, most specifically green vegetables and berries, due to their production of phytochemicals, which, through various mechanisms, benefit the shrinking of fibroids. Similarly, herbal and vitamin supplements including green tea and vitamin D have also been found to reduce the volume of fibroids. Foods to be limited or avoided include fish, foods with a high GI or GL index, alcohol and coffee due to posing an increased risk in the formation of fibroids. However, the number of studies investigating the relationship between different food groups and fibroid formation and/or shrinkage is limited in number and scope, and therefore, the information in this article should be treated with caution.