Menopause at 48 years old. Menopause at 48: Understanding Symptoms, Signs, and Treatment Options

06.03.197811.11.2021 by alexxlab

When does menopause typically start. What are the most common symptoms of menopause. How long do menopausal symptoms usually last. What treatment options are available for managing menopause symptoms. Is hormone therapy safe for menopausal women. How does menopause impact overall health and longevity. What lifestyle changes can help ease the transition through menopause.

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The Timing and Significance of Natural Menopause

Natural menopause, defined as the final menstrual period, typically occurs around age 51 for women in Western countries. However, the age of onset can vary widely, with some women experiencing menopause in their 40s and others not until their late 50s. Understanding the timing of menopause is crucial, as it can have significant implications for a woman’s health and longevity.

Research has shown that the age at which a woman experiences natural menopause may be an important marker of overall health and aging. Several studies have found associations between later menopause and various health benefits:

Longer overall life expectancy
Reduced risk of cardiovascular disease
Lower mortality rates from heart disease and stroke
Better bone density and reduced risk of osteoporosis
Improved cognitive function in later life

However, it’s important to note that later menopause is not universally beneficial. Women who experience menopause at a later age may have an increased risk of certain hormone-sensitive cancers, including breast, endometrial, and ovarian cancers.

Common Symptoms and Signs of Menopause

As women approach menopause, they may experience a variety of symptoms due to hormonal changes. The most frequently reported menopausal symptoms include:

Hot flashes and night sweats
Irregular periods
Mood changes and irritability
Vaginal dryness and discomfort
Sleep disturbances
Weight gain and slowed metabolism
Thinning hair and dry skin
Loss of breast fullness

Do all women experience the same menopausal symptoms? The short answer is no. The severity and duration of symptoms can vary greatly among individuals. Some women may have minimal discomfort, while others experience significant disruptions to their daily lives.

The Menopausal Transition: Perimenopause to Postmenopause

The journey through menopause is not a sudden event but rather a gradual transition that occurs over several years. This transition period is often divided into three stages:

Perimenopause

Perimenopause typically begins in a woman’s 40s, but can start as early as the mid-30s. During this stage, the ovaries gradually produce less estrogen, leading to fluctuations in hormone levels. Periods may become irregular, and some menopausal symptoms may begin to appear.

Menopause

Menopause is officially diagnosed when a woman has gone 12 consecutive months without a menstrual period. At this point, the ovaries have stopped releasing eggs and producing most of their estrogen.

Postmenopause

The years following menopause are referred to as postmenopause. During this time, menopausal symptoms may ease for many women, but the health risks associated with decreased estrogen levels continue to rise.

Factors Influencing the Timing of Menopause

While the average age of menopause is around 51, various factors can influence when a woman experiences her final menstrual period:

Genetics and family history
Smoking (associated with earlier menopause)
Body mass index (BMI)
Ethnicity and race
Socioeconomic status
Diet and nutrition
Reproductive history (e.g., number of pregnancies)
Certain medical conditions and treatments

Can lifestyle choices affect the onset of menopause? Research suggests that certain habits, particularly smoking, can lead to earlier menopause. Conversely, maintaining a healthy weight and balanced diet may help delay the onset of menopause.

Health Implications of Early and Late Menopause

The timing of menopause can have significant health implications for women. Early menopause, occurring before age 45, has been associated with:

Increased risk of cardiovascular disease
Higher risk of osteoporosis and fractures
Potential cognitive decline
Increased risk of certain cancers

On the other hand, late menopause (after age 55) may offer some health benefits but also comes with risks:

Reduced risk of cardiovascular disease and osteoporosis
Potential for improved cognitive function
Increased risk of breast, ovarian, and endometrial cancers

How does the timing of menopause affect a woman’s overall health trajectory? The age at which a woman experiences menopause can influence her long-term health risks and may guide preventive health strategies.

Managing Menopausal Symptoms: Treatment Options and Lifestyle Changes

While menopause is a natural biological process, the associated symptoms can be disruptive to daily life. Fortunately, there are various treatment options and lifestyle modifications that can help manage these symptoms:

Hormone Therapy (HT)

Hormone therapy, involving estrogen and sometimes progesterone, remains one of the most effective treatments for menopausal symptoms, particularly hot flashes and vaginal dryness. However, HT is not without risks and should be used at the lowest effective dose for the shortest duration necessary.

Non-Hormonal Medications

For women who cannot or choose not to use hormone therapy, several non-hormonal medications can help manage specific symptoms:

Low-dose antidepressants for hot flashes
Gabapentin for hot flashes and sleep disturbances
Ospemifene for vaginal dryness and painful intercourse

Lifestyle Modifications

Simple changes in daily habits can often provide significant relief from menopausal symptoms:

Regular exercise
Stress reduction techniques (e.g., yoga, meditation)
Maintaining a healthy weight
Avoiding trigger foods and beverages (e.g., spicy foods, caffeine, alcohol)
Dressing in layers to manage hot flashes
Improving sleep hygiene

Which lifestyle changes are most effective for managing menopausal symptoms? While individual responses may vary, many women find that a combination of regular exercise, stress management, and dietary adjustments can significantly improve their quality of life during the menopausal transition.

The Role of Diet and Nutrition in Menopause

A healthy diet can play a crucial role in managing menopausal symptoms and promoting overall health during this transitional period. Key dietary considerations include:

Calcium and vitamin D for bone health
Phytoestrogens (found in soy products, flaxseeds, and certain fruits and vegetables)
Omega-3 fatty acids for heart and cognitive health
Adequate protein intake to maintain muscle mass
Foods rich in antioxidants to support overall health

Can certain foods help alleviate menopausal symptoms? Some studies suggest that foods rich in phytoestrogens may help reduce hot flashes and other menopausal symptoms, although more research is needed to confirm these effects.

The Importance of Regular Health Screenings During and After Menopause

As women transition through menopause, regular health screenings become increasingly important. Key screenings and check-ups include:

Mammograms for breast cancer detection
Bone density scans to assess osteoporosis risk
Lipid profiles to monitor cardiovascular health
Pap smears and pelvic exams
Thyroid function tests
Colonoscopies for colorectal cancer screening

How often should postmenopausal women undergo health screenings? The frequency of screenings may vary based on individual risk factors and health history. It’s essential for women to consult with their healthcare providers to develop a personalized screening schedule.

In conclusion, menopause is a significant life transition that affects women in various ways. Understanding the timing, symptoms, and health implications of menopause can empower women to navigate this change more effectively. By working closely with healthcare providers and adopting healthy lifestyle habits, women can manage menopausal symptoms and promote long-term health and well-being. As research in this field continues to evolve, our understanding of menopause and its impact on women’s health will undoubtedly expand, leading to improved strategies for supporting women through this important life stage.

The Timing of the Age at Which Natural Menopause Occurs

Obstet Gynecol Clin North Am. Author manuscript; available in PMC 2012 Sep 1.

Published in final edited form as:

PMCID: PMC3285482

NIHMSID: NIHMS353085

Department of Public Health Sciences and Division of Epidemiology, School of Medicine, University of California, Davis, One Shields Avenue, Med Sci 1C, Davis, CA 95616 USA

Keywords: Menopause, Smoking, Parity, Race/ethnicity, Socioeconomic status, Age, Genetics, Family history, Diet

See other articles in PMC that cite the published article.

The age at the final menstrual period holds intrinsic clinical and public health interest because the age at which natural menopause occurs may be a marker of aging and health.^1–3 Later age at natural menopause has been associated with:

longer overall survival and greater life expectancy⁴ and reduced all-cause mortality⁵;
reduced risk of cardiovascular disease^4,6–11 and mortality from cardiovascular¹² and ischemic heart disease,¹³ stroke,¹⁴ angina after myocardial infarction,¹⁵ and atherosclerosis¹⁶;
less loss of bone density,¹⁷ and a reduced risk of osteoporosis¹⁸ and fracture¹⁹;
but an increased risk of breast,^20,21 endometrial, and ovarian^4,22–25 cancers.

In addition, women who have undergone bilateral oophorectomy under the age of 45 years have been observed to be at increased risk of mortality from cardiovascular disease, particularly if they were not treated with estrogen.²⁶ However, women who underwent natural menopause before age 45 years had an increased risk of ischemic heart disease that was not attenuated by use of hormone therapy.²⁷ Further, early menopause has been associated with earlier decline in cognitive function.^28–30 Because 40 million women in the United States alone and several hundred million worldwide³¹ experienced the menopausal transition between 1990 and 2010 due to the aging of the baby boomer generation,³² millions of women are undergoing or have recently undergone the menopause transition, and the timing of their final natural menstrual periods could have important clinical and health implications, because one third of women’s lives is spent postmenopause.

Although menopause is a universal phenomenon among women, the timing of the onset and the duration of the menopausal transition and the timing of the final menstrual period are not.³³ Most of our knowledge and perceptions of menopause have been based largely on studies of white women, and many have been studies of clinic-based, rather than population-based, samples of women. Thus, until recently, much of the knowledge about the timing of the natural final menstrual period has been affected by the nature of the samples of women studied and a number of other methodologic differences in the studies of this phenomenon, which must be considered in comparing and summarizing their results.

METHODOLOGIC CONCERNS

Most studies of the menopausal transition have been cross-sectional, rather than longitudinal, in design, providing an opportunity for distortion of the true picture of the timing of the final natural menstrual period, particularly for understanding factors that precede and may affect the timing of menopause. Further, definitions of menopause or the final menstrual period have varied from study to study in terms of the number of months of amenorrhea considered to represent in retrospect the final menstrual period. Studies have also varied with regard to which factors have been included in multivariable analyses that control simultaneously for the effects of multiple variables, which also makes the studies not directly comparable.

The analysis of age at natural menopause in a number of studies has been calculated as a simple mean, rather than using the less-biased survival or multivariable time-to-event analytic approaches. These last two approaches include more information and observations for every woman studied, because all women are included but withdrawn or censored when they experience surgical menopause, start using menopausal hormone therapy or oral contraceptives (OC; which generally masks the natural cessation of menses), or are still premenopausal.³⁴ Also, the accuracy of reporting of age at menopause can vary by whether menopause was natural and by duration from the time of the final menstrual period to the time of the interview about menopause, the latter being directly affected by the age group of the study sample. ³⁵ Further, in some studies that have reported age at menopause, it is unclear if the age at the final menstrual period is being reported, the more frequent approach, or if the age at cessation of menses plus 1 year of amenorrhea, the World Health Organization’s definition of menopause.³¹ is what is reported, a more rare occurrence.³⁶ Most studies do not use a hormonally based definition of menopause.

Recently, more information has been published regarding differences in the timing of menopause experienced by samples of women of different socioeconomic, racial/ethnic, and lifestyle backgrounds, and standardization of instruments and definitions has increased, resulting in a fuller, clearer, and more insightful picture regarding the underlying physiology.

SUMMARY OF UNDERLYING PHYSIOLOGY

Menopause is defined as the cessation of menstruation which reflects cessation of ovulation owing to a loss of ovarian follicles, which in turn results in reduced ovarian production of estradiol, the most biologically active form of estrogen,^37,38 as well as increased circulating concentrations of follicle-stimulating hormone (FSH) and decreased concentrations of inhibin, which inhibits the release of FSH. ³⁷ Age at menopause may be more sensitive to varying rates of atresia of ovarian follicles³⁹ than to the absolute number of oocytes depleted,⁴⁰ but menopause is reached when depletion of follicles reaches approximately 1000 (from a peak of 5 million follicles at mid-gestation and 2 million at birth).^41,42 The age at which sufficient depletion of follicles occurs is affected by the number of follicles achieving migration to the gonadal ridge during gestation, their mitotic abilities until mid-gestation, and the rate of follicular atresia.^42,43

As circulating estrogen concentrations decline during the menopausal transition, variations in the regularity, timing, and nature of menstrual bleeding may occur.⁴⁴ As menstrual cycles become increasingly irregular, bleeding may occur after an inadequate luteal phase or without ovulation,⁴⁴ usually indicated by a short luteal phase, characteristic of women over the age of 40 years. ^45,46 Such cycles may be associated with insufficient FSH (or insufficient FSH responsiveness of the follicle) in the follicular phase, in turn resulting in lower luteal phase estrogen and progesterone secretion. Lack of a corpus luteum, resulting in estrogen secretion (even hyperestrogenicity^45,47) unopposed by progesterone, may lead to profuse bleeding.

The nature and timing of bleeding may vary both within and between women. What is known about the host, environmental, or lifestyle factors that may affect such variation is summarized herein. Although some factors have been identified that are associated with early age at natural menopause, the relation of many has not been examined, and most have not been examined in relation to duration of the perimenopause.

Factors Related to Timing of Menopause

Results from cross-sectional studies have indicated that endocrine changes characteristic of the onset of the perimenopause begin at around age 45. ⁴⁸ The median age at menopause among white women from industrialized countries ranges between 50 and 52 years and at onset of the perimenopause is 47.5 years,^49–53 with slight evidence of increasing age at menopause over time.^53–57 These onsets seem to vary by race and ethnicity^58–60 and are affected by demographic and lifestyle factors.^{50,51,55,57–69} Although some studies have reported no familial relationship, 1 study has reported that age at menopause was positively associated with maternal age at menopause,⁶¹ and 1 recent study has shown genetic control of age at menopause in a study of twins.⁷⁰ However, a number of potentially modifiable factors which may affect estrogen metabolism, including body mass index (BMI), diet (particularly calories and alcohol intake), and passive smoke exposure have not been examined, nor has the time-varying effect of these and of the other factors that have been previously identified been examined in longitudinal analyses of sufficiently large and diverse study populations.

Sociodemographic Differences

International and geographic differences

Several studies have indicated that women living in developing countries (including Latin America, Indonesia, Singapore, Pakistan, Chile, and Peru) experience natural menopause several years earlier than those in developed countries.^71–76 Some work has also indicated that women living in urban areas have a later natural menopause than women in rural areas.⁶² Women living at high altitude in the Himalayas or in the Andes of Peru undergo natural menopause 1 to 1.5 years earlier than those living at lower altitudes or in less rural areas.^72,77–79 It is unclear whether these geographic and international differences in the age at natural menopause reflect genetic, socioeconomic, environmental, racial/ethnic, or lifestyle differences and whether and how these affect physiology.

Racial/ethnic differences

Some studies have reported that African American⁵⁹ and Latina^58,60 women have natural menopause about 2 years earlier than white women. However, 1 small study in Nigeria reported the average age at menopause to be 52.8 years,⁸⁰ over 1 year later than that generally reported for white women in industrialized nations. Mayan women, despite their high parity (see Reproductive History), have been reported to experience natural menopause fairly early, at about age 45.⁸¹ In contrast, Asian women tend to have similar age at menopause to Caucasian women,^58,82 although Thai women have been reported to have a lower median age at menopause, at age 49.5 years, despite their high parity,⁸³ and Filipino Malay women have been reported to have an earlier average age at natural menopause at 47 to 48 years.⁸⁴

Differences by socioeconomic status

A number of studies have observed that lower social class, as measured by the woman’s educational attainment or by her own or her husband’s occupation, is associated with an earlier age at natural menopause.^{51–54,57,58,61,71,85,86} However, results from a British birth cohort indicated that early life socioeconomic status (SES) was more strongly associated than adult status with age at natural menopause,⁸⁷ although even the relation of early life SES was greatly attenuated when adjusted for childhood cognitive ability and having been breastfed. ⁸⁸ One study found that education was more strongly associated with age at natural menopause than occupation.⁵² Most studies that have examined the relation of marital status have found that single women undergo an earlier natural menopause, and this association cannot be explained by nulliparity.^52,89,90

Health-Related Influences

Menstrual and reproductive history

The age at which the final natural menstrual period occurs may be a marker for hormonal status or changes earlier in life.⁹¹ In the landmark Treloar longitudinal study of largely white, well-educated women, those whose median menstrual cycle length between the ages of 20 and 35 years was fewer than 26 days underwent natural menopause 1.4 years earlier than women with cycle lengths between 26 and 32 days, whereas a later natural menopause (mean = 0.8 year later) was observed in women with cycle lengths of 33 days or longer.⁹² In addition, 9 or more days of variability in cycle length has been associated with a later age at natural menopause in this and other studies,^52,59 although 1 study reported an earlier natural menopause in women with irregular menses. ⁵³

Increasing parity, particularly among women of higher SES, has also been associated with later age at natural menopause,^{50–52,55,57,58,61,90,91,93–96} consistent with the theory that natural menopause occurs after oocytes have been sufficiently depleted.⁹³ Although some studies have reported no familial relationship, 1 study reported that women’s age at natural menopause was positively associated with their mother’s age at natural menopause,⁶¹ and 1 study of twins showed genetic control of age at natural menopause.⁷⁰ Age at menarche has been fairly consistently observed not to be associated with age at menopause, after adjusting for parity and cycle length,^{52,53,55,83,89,97,98} as have prior spontaneous abortion, age at first birth, and history of breastfeeding.^52,97,98

A number of studies have reported that women who have used OCs have a later age at natural menopause.^{52,58,61,63,72,98} an observation that is also consistent with the theory that OCs delay depletion of oocytes. However, the finding has not been wholly consistent across studies, because 1 study reported that this delay became nonsignificant after a time-dependent adjustment for when OCs were used,⁵² and another study reported that OC users had a significantly earlier natural menopause than nonusers, although this association was not consistent across 5-year age groups.⁵⁰

Body mass and composition

Several studies have examined the relation of body mass to age at menopause, with inconsistent findings. Some studies have reported that both increased BMI (indicated by weight over height squared) and upper body fat distribution (indicated by waist-to-hip ratio) were associated with later age at natural menopause^{50,57,96,99,100} and increased sex hormone concentrations.¹⁰⁰ However, at least as many other studies have reported no significant association of BMI with age at natural menopause.^{51,52,54,59,101,102} Some studies have found a relationship between lower weight⁶⁹ or increased upper body fat distribution¹⁰¹ and earlier age at natural menopause, particularly among smokers. One study reported earlier natural menopause in women on weight reduction programs or who had gained more than 26 pounds between the ages of 20 and 45 years.⁵⁹

Some of these apparently inconsistent findings may be explained by differences in study design (cross-sectional or retrospective vs prospective) or analysis (eg, inadequate or varying control of confounding variables or survival analysis vs. comparison of crude means). In general, the better designed and analyzed studies have shown no relation of body mass or body fat distribution to age at the final natural menstrual period. Although body mass and composition may be related to age at natural menopause, they are also related inversely to physical activity, alcohol consumption, and education, and positively related to infertility and parity.¹⁰³ Further research is needed in which all of these potentially confounding variables are simultaneously controlled in the statistical analyses of data from large study samples to be able to assess adequately the independent contribution or interactive effect of body mass and composition and these other factors on the age at the natural final menstrual period and duration of menopause transition, using appropriate longitudinal study design and data analysis techniques.

Familial, genetic, and early childhood factors

In recent years, studies of factors related to age at natural menopause have begun to focus on genetic factors that may be related. Results of family and twin studies suggest that familial and genetic factors may play an important role, with estimates of heritability ranging from 30% to 85%.^70,104,105 In 1 relatively large cross-sectional study and 1 large longitudinal British birth cohort study, a strong association was found between mothers’ and daughters’ ages at natural menopause,^88,106 which have also been found in a few other smaller studies,^107–109 but few longitudinal studies have investigated this relationship. One European genome-wide association study of nearly 3000 women identified 6 single nucleotide polymorphisms in 3 loci on chromosomes 13, 19, and 20 associated with age at natural menopause.¹¹⁰ A Dutch study showed that polymorphisms of an estrogen receptor gene were associated with earlier natural and surgical menopause. ¹¹¹ Results of genome-wide association studies, using samples from thousands of women in the Nurses’ Health Study and the Women’s Genome Health Study, identified 13 single nucleotide polymorphisms on 4 chromosomes that were associated with age at menopause.¹¹² Analyses of candidate genes from 9 biologically plausible pathways, using the same samples from the same women in these 2 studies, indicated that the steroid hormone metabolism and biosynthesis pathways were associated with age at natural menopause and that genes involved in premature ovarian failure were also significantly associated with age at menopause.¹¹³ Two single nucleotide polymorphisms of the tumor necrosis factor receptor family have also been shown to be significantly associated with age at natural menopause.¹¹⁴

A number of analyses have been conducted on prospective data collected across the lifespan from a nationally representative birth cohort of nearly 1600 British women born in 1946 and followed to age 53 years, the Medical Research Council National Survey of Health and Development. These analyses have revealed that women who had a low weight at 2 years of age had an earlier natural menopause,¹¹⁵ whereas those who were heaviest at 2 years of age had a later natural menopause.⁸⁹ Those who were breastfed had a later natural menopause.¹¹⁵ Another cohort study in England also found that low weight at 1 year of age was associated with earlier natural menopause.¹¹⁶ However, an Australian twin study and the English cohort study found no association of birth weight with age at natural menopause.^116,117 The British birth cohort and other cohort studies have shown that poorer cognitive ability in childhood was associated with earlier natural menopause,^118–120 suggesting that perhaps markers in early life may determine not only age at natural menopause, but may also predict the adverse health outcomes that are associated with early age at menopause. Further, additional findings from the British birth cohort indicate that women whose parents divorced early in their lives had an earlier natural menopause than other women, suggesting that early life stressors may also be related to early menopause. ^87,88

Environmental Influences

Active and passive smoke exposure

Perhaps the single most consistently shown environmental effect on age at menopause is that women who smoke stop menstruating 1 to 2 years earlier than comparable nonsmokers.^{50,51,55,57–59,61,63–68,86,96,121} and have a shorter perimenopause.¹²² Some studies have shown a dose–response effect on atrophy of ovarian follicles, in that heavy smokers have an earlier natural menopause than light smokers.^{61,67,69,123,124} Former smokers have only a slightly earlier age at natural menopause than those who never smoked, and increased time since quitting diminishes the difference.^123,125 The latter observation of only a slightly earlier natural menopause in former smokers is inconsistent with the presumed toxic effect of smoking on ovarian follicles, resulting in their atrophy and thus earlier menopause, because such an effect should be nonreversible so that former smokers would also experience the earlier natural menopause observed in current smokers. If the dose–response effect is a true effect, the apparent paradox might partly be explained by fewer years of smoking and thus toxic exposure to the ovaries in former smokers than in current smokers of similar age.

The polycyclic aromatic hydrocarbons in cigarette smoke are known to be toxic to ovarian follicles^126,127 and thus could result in premature loss of ovarian follicles and early natural menopause among smokers. Because drug metabolism is enhanced in smokers,¹²⁸ estrogen also may be more rapidly metabolized in the livers of smokers, which could lead to an earlier reduction of estrogen levels.⁹⁹ Further, smoking has also been observed to have antiestrogenic effects.¹²⁹ Greater prevalence of hysterectomy among premenopausal smokers than nonsmokers^100,123 apparently does not account for smokers having an earlier natural menopause.¹³⁰ Only 1 study has shown that nonsmoking women whose spouses smoked had an age at natural menopause resembling that of smokers¹³¹; thus, very little is known about the effect of passive or secondhand smoke exposure on the age at which the final natural menstrual period is experienced.

Occupational/environmental factors

Although almost nothing is known about the relations of occupational or other environmental factors to age at the final natural menstrual period and duration of the menopausal transition, occupational exposures and stressors (such as shift work, hours worked, hours spent standing, and heavy lifting) have been related to increased risk of adverse pregnancy outcomes^132–135 and changes in menstrual cycle length and variability as well as fecundability.^136–139 In addition, such environmental exposures as dichlorodiphenyltrichloroethane and polychlorinated biphenyls have been shown to have estrogenic activity and to be associated with an increased risk of breast cancer,^140,141 although this association has not been consistently observed.^142,143 Thus, the presumed endocrine effects of such exposures make it reasonable to expect that occupational and environmental exposures may be related to endocrine disruption that is reflected in altered age at natural menopause. One study showed a modest effect on age at natural menopause in women in Seveso, Italy, who were exposed to 2,3,7,8-tetrachlorobenzo-p-dioxin, a halogenated compound that may affect ovarian function, during a chemical plant explosion in 1976.¹⁴⁴ Another study showed that exposure to 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene was also associated with earlier natural menopause.¹⁴⁵

Physical activity

Physical activity is associated with a number of changes in hormonal parameters [estradiol, progesterone, prolactin, luteinizing hormone (LH), and FSH), both during and after intense physical activity.^146–148 The concentrations of these hormones tend to be lower at rest among women who are physically active.^{146,147,149,150} Also, athletes tend to have a later age at menarche and increased occurrences of anovulation¹⁵¹ and amenorrhea¹⁵² and, among those who menstruate, a shortened luteal phase and reduced mean and peak progesterone levels. ^104,149 Although physical activity is associated with decreased concentrations of reproductive hormones and frequency of ovulation, few studies have examined the effect of exercise on age at natural menopause, although 1 modestly sized study reported no relationship,⁵⁹ and 1 large study of Chinese women showed a later age at natural menopause associated with leisure time physical activity during adolescence and adulthood.⁹⁴

Diet

One early study from Papua, New Guinea, suggested that malnourished women ceased menstruation about 4 years earlier than well-nourished women,¹⁵³ consistent with other studies showing that women with greater weight^62,69 and height⁸⁹ may have a later age at natural menopause. Findings regarding the relationship of specific dietary patterns to age at menopause have been inconsistent. For example, vegetarians were observed to have an earlier age at natural menopause in 1 study,¹⁵⁴ whereas another study in Japan reported that higher green and yellow vegetable intake was significantly associated with later age at natural menopause. ¹⁵⁵ Further, a large cross-sectional study of Japanese women found that higher intakes of fat, cholesterol, and coffee were significantly associated with earlier natural menopause after controlling for age, total energy, parity, menarche age, and relative weight.¹⁵⁶ A longitudinal study of nearly 5000 German women observed that high carbohydrate consumption and high intake of vegetable, fiber, and cereal products were related to an earlier age at natural menopause, whereas higher intake of total fat, protein, and meat were associated with a later natural menopause.¹⁵⁷ The large, prospective Shanghai Women’s Health Study found that higher total intake of calories, fruits, and protein was significantly associated with later age at natural menopause, whereas vegetable, fat, soy, and fiber intakes were not significantly related to age at menopause.⁹⁴ Inclusion of meat in the diet of vegetarians has been observed to increase the episodic releases of LH and FSH and the length of the menstrual cycle. ¹⁵⁸ Thus, meat may modify the interaction of hormones along the hypothalamic-pituitary-ovarian axis. A couple of studies have reported that increased meat or alcohol consumption is significantly associated with later age at menopause, after adjusting for age and smoking.^61,121 Dietary fiber (whose intake tends to be inversely related to meat intake) may interrupt enterohepatic circulation of sex hormones, leading to the lower circulating estrogen concentrations among vegetarian women.¹⁵⁹ Nonetheless, a low-fat, high-carbohydrate intervention diet to prevent breast cancer in over 2600 women with extensive mammographic density followed for an average 7 years did not influence the timing of natural menopause, except a significantly earlier natural menopause was observed in those with low BMI who were on the intervention diet.¹⁶⁰

Premenopausal women administered soy have shown increased plasma estradiol concentrations and follicular phase length, delayed menstruation, and suppressed midcycle surges of LH and FSH. ¹⁶¹ Among postmenopausal women fed soy, FSH and LH did not decrease significantly, nor did sex hormone-binding globulin increase, and little change occurred in endogenous estradiol or body weight, although a small estrogenic effect on vaginal cytology was observed.¹⁶² However, the role of dietary fiber, phytoestrogens, fat, protein, and other nutrients in affecting age at menopause and duration of the perimenopause remains to be systematically studied, but has potentially important implications for prevention of chronic disease in midlife and older women.

CONCLUSION

Despite important methodologic differences, the limitations in the study designs used and the populations studied in the accumulating literature regarding factors that affect the age at which the natural final menstrual period is experienced, an interesting and complex picture is emerging. A number of demographic (eg, education, employment, race/ethnicity), menstrual and reproductive (eg, parity and OC use), familial and genetic, and lifestyle (eg, smoking, weight, physical activity and diet) factors seem to be important determinants of the age at which natural menopause occurs. Smoking, lower parity, and lower SES have been found fairly consistently to be associated with earlier menopause, an indicator of reduced longevity. However, the relationships with African American and Latina race/ethnicity, vegetarian diet, and undernutrition, body mass and composition, and physical activity have been inconsistent, possibly owing to varying methodologic approaches and limitations ().

Table 1

Factors related to earlier and later age at natural menopause

Factors Consistently Related to Earlier Age at Natural Menopause (References)	Factors Inconsistently Related to Age at Natural Menopause (References)
Low socioeconomic status^{51–54,57,58,61,71,85–88}	Race/ethnicity^{58–60,80–84}
Low/parity^{50–52,55,57,58,61,90,91,93,96}	Body mass index or body com position^{50–52,54,57,59,62,69,98–101}
Not using oral contraceptives^{50,52,58,61,63,72,98}	Physical activity^59,94
Active smoking^{50,51,55,57–59,61,63–69,86,96,121,124–126}	Dietary (vegetable, meat, fat, fiber) intake^{61,121,153–157,160}

Other relationships remain largely unexplored (eg, passive smoke exposure and occupational and other environmental exposures). Therefore, much remains to be learned about how these factors affect follicular atresia and hormone levels and thus determine the onset and potentially the duration of the perimenopause and the timing of the final menstrual period. Furthermore, increased understanding of the underlying physiologic mechanisms of these influences needs to include potential genetic, metabolic, and racial/ethnic differences in physiologic responses to lifestyle factors and other environmental exposures and the interaction of genetic factors with these lifestyle and environmental factors. Increasing knowledge about these relationships ultimately offers women and their health care providers enhanced understanding and choices, based on greater knowledge, to deal with the individual presentations of menopause.

ACKNOWLEDGMENTS

The Study of Women’s Health Across the Nation (SWAN) has grant support from the National Institutes of Health (NIH), DHHS, through the National Institute on Aging (NIA), the National Institute of Nursing Research (NINR) and the NIH Office of Research on Women’s Health (ORWH) (Grants NR004061; AG012505, AG012535, AG012531, AG012539, AG012546, AG012553, AG012554, AG012495). Dr Gold was supported by AG012554. The content of this article is solely the responsibility of the author and does not necessarily represent the official views of the NIA, NINR, ORWH or the NIH.

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