This episode of Longevity by Design is the second of a two-part series in which Dr. Jennifer Garrison discusses women's health and the menopausal transition. In this episode, Dr. Garrison talks about reproductive health, the hormonal fluctuations women experience during their life, and the health implications of menopause.
About Dr. Jennifer Garrison
Our guest today is Dr. Jennifer Garrison. Jennifer Garrison, PhD, is a passionate advocate for women’s health and is pioneering a new movement to advance science focused on female reproductive aging. She is the Co-Founder and Director of the Global Consortium for Reproductive Longevity & Equality (GCRLE) and an Assistant Professor at the Buck Institute for Research on Aging. She also holds appointments in the Department of Cellular and Molecular Pharmacology at UCSF and the Leonard Davis School of Gerontology at USC. Her research lab studies the role of inter-tissue communication in systemic aging and how changes in the complex interactions between the ovary and brain during middle age.
Dr. Garrison is a PhD scientist who studies ovarian function and women's health. While she discusses evidence-based claims in this discussion, she is not a medical doctor. Please consult with your physician to address your health needs.
What are the differences between perimenopause and menopause?
To begin, Dr. Garrison defined the different menopausal stages. She also describes the physiological processes in a woman’s body as she moves through the various menopausal stages and the commonly associated symptoms.
What are the menopausal stages?
- Perimenopause/menopausal transition: The period of a woman’s life leading up to menopause. Perimenopause can last between four and ten years.
- Menopause: Menopause refers to the single day in a woman’s life in which she has not had a period for 12 months.
- Postmenopause: The remainder of a woman’s life after menopause.
What triggers the onset of perimenopause?
The number and the quality of eggs a woman has starts to decline before her own birth and continues to decline throughout her life. And once a woman has no remaining eggs, she no longer has menstrual periods, leading to perimenopause and eventually menopause, explains Dr. Garrison.
A woman also reaches a point in her life when levels of reproductive hormones begin to drop. This decline in estrogen and progesterone is what causes perimenopause to begin. While many women experience this decline during their forties, the age that perimenopause begins can vary. [1,2]
What are the symptoms of perimenopause?
Ovaries are best known for their ability to store eggs but also produce multiple chemicals and hormones vital for general health. The decline in these hormones is associated with symptoms experienced during perimenopause.
Levels of these hormones decline with age, leading to a host of negative symptoms, including mood changes, hot flashes, trouble sleeping, vaginal dryness, sexual dysfunction, bone loss, and irregular periods (shorter or longer cycles or lighter or heavier bleeding). [1,2]
How does menopause impact overall health?
In part one, Dr. Garrison discusses the correlation between menopause and chronic diseases. But are the correlations between chronic disease and menopause independent of age? In other words, do older postmenopausal women have an increased risk of chronic diseases compared to younger postmenopausal women?
Surprisingly, Dr. Garrison explains that the health implications of menopause are independent of age. "The increased risk for chronic disease is completely dependent on ovarian function—once a woman loses function in her ovaries, she experiences health decline in other ways, says Dr. Garrison. "It's shocking and destructive, these health effects that happen after ovaries stop functioning in a woman's body. It shortens their lifespan and causes brittle bones, osteoporosis, cognitive decline, and increased risk of stroke and cardiovascular disease."
Dr. Garrison further discusses how menopause is viewed within healthcare in younger versus older women. "What's striking about early menopause is that when young women go through menopause, it's considered a serious medical condition," says Dr. Garrison. "The medical community treats early menopause as incredibly serious and will prescribe hormones to help improve the woman's condition." Conversely, the medical community views menopause in older women as a result of simply getting older. "It's just dramatically different how we treat exactly the same condition in younger versus older women," she concludes.
Menstrual cycle phases
- Follicular phase: Matures the egg, preparing it for ovulation.
- Ovulation: Between the follicular and luteal phases, a mature egg is released from the ovary during ovulation.
- Luteal phase: Prepares the uterus for pregnancy.
- Menstruation: In the absence of pregnancy, the uterine lining will shed, resulting in a period.
The impact of hormonal shifts on women's health and longevity
Hormones are chemical messengers that can signal over a long distance in the body. For example, hormones can signal between different brain regions, between the brain and the uterus, between fat tissue and the brain, and so on. Hormones are made and released from one area of the body, travel to another region, and then act on cells and organs to perform a function.
Women undergo significant hormonal changes as they age. In this episode, Dr. Garrison discusses hormonal fluctuations experienced at both younger and older ages.
How do hormone levels shift postmenopause?
After menopause, estrogen and progesterone decline while follicle-stimulating hormone (FSH) and luteinizing hormone (LH) tend to increase. The extent to which these hormones fluctuate differs between women. Larger hormonal fluctuations correlate to the severity of symptoms experienced. “Some women are fortunate not to experience most perimenopause symptoms while others have really severe symptoms. It depends on where your hormone levels end up,” she explains.
Do ovaries still produce hormones after menopause?
Ovaries continue to produce hormones after menopause; ovaries still produce small amounts of androgens (steroid hormones) that can get converted to estrone. Estrone can then be converted to estradiol in the peripheral tissue. Therefore, postmenopausal women have some estrogen in the body—albeit significantly less than premenopausal women.
Why do women gain visceral fat postmenopause?
According to Dr. Garrison, "We don't fully understand why women gain visceral fat postmenopause. However, there's no question that when estrogen levels decline at menopause, visceral fat goes up." Declining estrogen levels are also associated with bone mass, muscle mass, and strength decreases. 
Does the postmenopausal estrogen decline increase cardiovascular disease risk?
“Absolutely—estrogen and possibly also progesterone—are associated with increased cardiovascular disease postmenopause.” She notes that estrogen plays a role in lipid markers and cardiovascular health. 
Do lower estrogen levels affect cognitive function?
Dr. Garrison states that changes in estrogen levels can disrupt bioenergetics. "The brain is very dependent on energy consumption, so any disruptions to brain bioenergetics can wreak havoc," she explains. Estrogen is also important for different brain regions involved in learning, language, and judgment. "In postmenopausal women's brains, estrogen loss is responsible for changes in dendritic spines, which are important for memory." [1,2]
Does genetic background impact perimenopausal symptoms?
Preliminary data shows that the type and severity of symptoms experienced during perimenopause may differ in those with different genetic backgrounds. "Evernow put out a study that looked at changes and differences between women of different genetic backgrounds and how they're experiencing perimenopause and menopause. They saw some really interesting trends—black women were more likely to experience more severe symptoms and differences in which symptoms were more prevalent than white women.”  Dr. Garrison notes that further research is warranted to assess why the data shows an impact of genetic background on perimenopausal symptoms.
Monteleone, P., Mascagni, G., Giannini, A. et al. Symptoms of menopause — global prevalence, physiology and implications. Nat Rev Endocrinol 14, 199–215 (2018). https://doi.org/10.1038/nrendo.2017.180
What can women do to promote health and longevity?
Stay physically active: Evidence supports moderate physical activity—getting up and moving throughout the day—is beneficial for women’s health. She also notes significant benefits from getting outside and walking.
Maintain muscle mass: Significant evidence shows the benefits of maintaining muscle mass for longevity, which can be challenging for postmenopausal women. “It becomes really difficult to maintain muscle mass after menopause because of all the changes discussed. It is important that older women engage in weight-bearing exercises and get their heart rate up a little bit every day.”
- Monitor calcium and vitamin D levels: Dr. Garrison encourages postmenopausal women to pay attention to calcium and vitamin D levels. Regularly monitoring calcium and vitamin D levels can determine if they need to be modified.
Advice for women in the menopausal transition
Dr. Garrison is optimistic about the changing tide for women in perimenopause. She mentions the importance of finding a good healthcare provider and a community. Two resources that Dr. Garrison wants women to be aware of are:
- The North American Menopause Society (NAMS) lists physicians certified and trained in treating women in perimenopause and menopause.
- A patient advocacy group called The National Menopause Foundation has resources for women going through perimenopause.
 Santoro, N., Roeca, C., Peters, B. A., & Neal-Perry, G. (2021). The Menopause Transition: Signs, Symptoms, and Management Options. The Journal of clinical endocrinology and metabolism, 106(1), 1–15. https://doi.org/10.1210/clinem/dgaa764
 Monteleone, P., Mascagni, G., Giannini, A. et al. Symptoms of menopause — global prevalence, physiology and implications. Nat Rev Endocrinol 14, 199–215 (2018). https://doi.org/10.1038/nrendo.2017.180