CHANGE OF LIFE: The science behind the menopause

By: 

Amanda Moore BSc, DipION, MBANT Nutritional Therapist, ION Female Health Clinic

Issue: 
Spring
Year of publication: 
2009

Wisdom, energy and freedom – these are meant to be the rewards of the menopause. For many women, finally being free of cyclical menstrual hormone changes can be a great relief and this can be a rewarding and empowering stage of a woman’s life. Equally, however, reported symptoms of fatigue, weight gain, mood swings, anxiety, hot flushes, insomnia, headaches and hair loss, together with an increased risk of breast cancer, osteoporosis and heart disease lead many to treat this natural mid-life process as a pathological process that needs medical intervention. Understanding the biochemistry of this intense period of change and what a woman can do during this time to manage symptoms herself can be very empowering and is particularly important given major concerns about the safety of HRT that have surfaced in recent years.

UNDERSTANDING MENOPAUSE

The term ‘menopause’ refers to the point at which menstruation ceases, marking the end of a woman’s reproductive years. The period of intense hormonal shifts experienced in the years around menopause is often referred to as the climacteric or peri-menopause – however, since the STRAW (Stages of Reproductive Ageing) criteria were published in 2001, ‘menopause transition’ is the preferred scientific term.

Initially the menstrual cycle becomes irregular with late menopause transition being reached when two consecutive cycles are missed. On average, women are 47 when they enter menopause transition and 51 when they have their last period. An earlier menopause can occur in women with a low body weight, smokers or those who have not borne children. Some women are also forced into early menopause by medical intervention, such as following a hysterectomy or after undergoing cancer treatment.

A woman’s lifetime supply of approximately one million eggs in the ovaries declines steadily over time and few remain by menopause transition. Those that do remain become increasingly resistant to gonadotrophins, FSH (follicle stimulating hormone) and LH (luteinizing hormone), which control the female reproductive cycle. The cycles of older women are marked with substantial increases in FSH and LH concentrations, with variable, erratic oestrogen levels and low luteal phase progesterone. The cycle lengths become irregular and, on average, 52 per cent of cycles are anovulatory in women over 46. At times, oestrogen levels can be unusually elevated, even in the luteal phase, causing oestrogen-related symptoms such as mood swings, headaches, heavy blood loss and breast tenderness.

During the last year of the menopause transition, the oestrogen levels decrease very rapidly. The decline in ovarian oestrogen and progesterone and the rising FSH and LH prompt the onset of menopause. The adrenal glands and fat cells then become the primary source of oestrogen production. Androstenedione, produced by the adrenal glands, is converted to oestrone in the adipose tissue. This is one of the reasons why women naturally increase body fat during this time and why leaner women often have a more difficult menopause. Since the adrenals also have an important role, levels of stress can influence how a woman copes with the menopause and what symptoms she has.

There are oestrogen receptors in women’s bones, brain, blood vessels, central nervous system and skin, so it is not surprising that changes are experienced in all these areas when oestrogen levels decline. Hot flushes are the most debilitating symptom of the menopause and they contribute to insomnia, irritability and poor concentration. Three quarters of women experience hot flushes, though only 30 per cent seek medical help. Scientists do not yet have an exact understanding of what causes hot flushes but it is thought that the hypothalamus is involved and that they may be linked to LH surges. Declining oestrogen levels also play a part because flushes are virtually eliminated with oestrogen therapy. Declining oestrogen levels, which reduce blood flow and the elasticity of vaginal tissues, can lead to urinary problems, bleeding and changes in pH, making infections of bacteria and yeast more common.

The incidence of depression, irritability, loss of memory and poor concentration increase from the menopause transition. Oestrogen has a modulating effect on a number of neurotransmitters including mood-elevating serotonin. Low oestrogen levels in the body also reduce production of the anti-anxiety neurotransmitter GABA, leading to increased anxiety. Oestrogen is important for bone health because it slows down the activity of the osteoclasts, which break down bone. Interestingly, HRT slows down osteoclast activity but does not increase bone density. A lack of progesterone postmenopause also contributes to a reduction in bone density, as progesterone is necessary to promote the bone-building activity of osteoblasts. Supplemented natural progesterone has been shown to increase bone density in some women, although there has also been research that has shown there to be no benefit. Serious bone loss is certainly not an inevitable part of menopause; diet and exercise can be very helpful in maintaining bone density.

THE IMPORTANCE OF DIET
Natural treatment strategies focus on both symptom relief and disease prevention and may include dietary changes, nutritional supplements, herbs and lifestyle choices. Perimenopausal PMS symptoms are worse in women with a poor diet. A healthy hormone-balancing diet that includes wholegrains, plenty of fruit, vegetables, lean meat and fish are very beneficial. The diet should also be low in saturated fat, stimulants and sugar. Omega-3 essential fatty acids found in linseeds, hemp seeds and oily fish have been shown to help hormone-related depression, reduce cholesterol and may help protect against breast cancer. The results of a recent controlled trial have shown that fish oil supplements reduce hot flushes and mood symptoms.

Phytoestrogens have recently attracted a lot of attention regarding their role in menopause. They are compounds produced naturally in plants that mimic the biological effects of oestrogen by binding to and activating oestrogen receptors in the body. The most common phytoestrogens in the Western diet are isoflavones (found in soya foods, beans and some fruits) and lignans (found in flaxseed, wholegrains and nuts). Epidemiological data from Asian countries, where the diet does naturally contain large amounts of phytoestrogens, suggests they may alleviate some symptoms such as hot flushes. Isoflavone supplements have been shown to have a protective effect on bones, reducing bone resorption and loss, and they have also been reported to improve cholesterol balance and protect against breast cancer. Soya foods, however, have received bad press recently. In vitro and animal studies suggest that isoflavones – especially genistein found in soya – may stimulate the growth of oestrogensensitive tumours, which has made a number of people concerned about increasing soya foods in their diet.

Alcohol should also be limited as it intensifies PMS symptoms in the menopause transition and may make hot flushes worse. Coffee should also be avoided as it can contribute to anxiety and may influence breast tenderness and bone density.

SUPPLEMENTARY SUPPORT
The most beneficial herbal treatments used to support the menopause are black cohosh and dong quai as they are known to help lessen hot flushes and mood swings. St John’s Wort is one of the most heavily studied botanicals for treatment of depression and it appears to have a synergistic effect when used together with black cohosh for menopausal women who experience mood symptoms, as does the herb agnus castus. Antioxidant nutrients such as vitamins E and C and bioflavonoids can be beneficial in supporting the cardiovascular system and also for breast health.

STRESS AND WEIGHT GAIN
It is normal for women to gain weight – approximately a stone – during the menopause, as the body’s metabolic rate naturally falls and adipose tissue becomes the key producer of the hormone oestrogen. Weight-bearing and cardiovascular exercise is important to minimise this weight gain and it also improves bone density, cardiovascular and emotional health. Yoga, meditation and other relaxation techniques may help symptoms of stress and anxiety, as menopausal women are more vulnerable to the negative effects of stress. It’s important to remember that the menopause is a completely natural process and that, with appropriate physical, mental and nutritional support, the negative effects of the menopause can be minimised.

 

Keywords: 
WOMEN'S HEALTH, Menopause, Women, Hormones, Menstrual Cycle, Oestrogen, Progesterone, LH, FSH, Phytoestrogens, Isoflavones
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