When we hear the word cholesterol, most of us immediately think of heart disease—but there's much more to the story. Cholesterol plays a much broader role in women's health, especially after 40. From hormone production to bone support, understanding how cholesterol interacts with oestrogen, thyroid health, and inflammation can help you make informed choices for long-term wellbeing.
Why Cholesterol Balance Shifts After 40
Oestrogen does more than regulate cycles and mood—it influences cholesterol metabolism. It tends to raise HDL ("good" cholesterol) and lower LDL ("bad" cholesterol), which helps protect the cardiovascular system.
As oestrogen naturally declines during perimenopause and menopause, LDL cholesterol and triglycerides often rise, while HDL may decrease. This shift partly contributes to the increase in cardiovascular risk seen in midlife women, alongside other factors such as weight changes, diet, and genetics.
Cholesterol and Bone Health: An Emerging Connection
Cholesterol is usually discussed in relation to heart health, but scientists are also exploring its effects on bones. Here's what emerging research suggests:
Some studies suggest that low or dysfunctional HDL may be linked with reduced bone density.
Oxidised LDL—a "damaged" form of LDL—has been shown in lab studies to disrupt bone-building cells (osteoblasts) and stimulate bone-resorbing cells (osteoclasts).
Chronic inflammation, which is influenced by cholesterol and triglyceride levels, is a well-known driver of bone loss.
While this research is promising, it is still developing. Cholesterol management is not currently a standard strategy for preventing osteoporosis, but maintaining balanced cholesterol may indirectly support bone health.
Cholesterol: More Than Just a Number
Cholesterol is a waxy, fat-like substance that your body actually needs. It is essential for building cell membranes, producing hormones such as oestrogen, progesterone, testosterone, and cortisol, and supporting digestion via bile acids.
Your liver makes 70–80% of your cholesterol, while the rest comes from food. This means that diet is only one factor—how your body produces, processes, and clears cholesterol is just as important.
Thyroid Health and Cholesterol
Thyroid hormones (T3 and T4) help the liver clear LDL cholesterol from the blood. When thyroid function is low (hypothyroidism), LDL remains in circulation longer, which can raise total cholesterol. This is why thyroid function testing is often recommended when cholesterol levels are unexpectedly high.
Inflammation, Oxidative Stress, and Ageing
From about age 40, inflammation markers such as IL-6 and TNF-α tend to rise, especially with higher body fat. This low-grade inflammation can increase LDL and triglycerides, lower HDL, contribute to insulin resistance, and promote oxidative stress (damage from free radicals).
One consequence of oxidative stress is oxidised LDL. This unstable form of cholesterol not only promotes atherosclerosis but may also play a role in disrupting bone cell function.
The Vitamin D Connection
Vitamin D is crucial for bone strength, muscle function, and immune health—yet many women remain deficient, even in sunny climates. Optimising levels through safe sun exposure, food sources, or supplements can make a meaningful difference for overall health, particularly for bones.
While vitamin D deficiency is not a major cholesterol driver, it is a critical factor in healthy ageing.
Practical Steps You Can Take
Genetics contribute to cholesterol and hormone changes, but lifestyle has a powerful influence. Some evidence-based strategies include:
Regular testing: cholesterol, thyroid, and vitamin D
Eating an anti-inflammatory diet: whole foods, colourful vegetables, healthy fats
Exercise: especially weight-bearing and strength training for both heart and bone health
Managing stress and sleep: to reduce inflammation and support hormone balance
Supporting liver health: since the liver is central to cholesterol production and clearance
Minimising smoking and excess alcohol, which both worsen cardiovascular and bone outcomes
The Takeaway
Cholesterol is not the enemy—it is an essential building block for hormones, cells, and digestion. But as oestrogen declines and other age-related changes occur, cholesterol balance can shift, becoming a risk factor for both cardiovascular and possibly skeletal health.
By understanding these connections and focusing on lifestyle adjustments, women over 40 can take proactive steps to stay strong, balanced, and resilient in the years ahead.
If you'd like personalised support for cholesterol, thyroid, or bone health, I'd love to help. Book a free discovery call and let's create a plan that works for your body.
