The Significant Impact of Hormonal and Dietary Influences on Brain Health

Jonathan Vellinga, MD

I’m sure you’ve heard it before: we are holistic beings, and our bodies and minds are connected in many complex and important ways. The brain is an excellent example of this interconnectedness. As you may have seen in our previous article about brain health, if your brain is unhealthy, it can affect your mind, body, and even your personality. The body can affect the brain too, and we recently focused on the effects of high blood sugar and insulin resistance on brain health. Nutrition and hormones are another two key factors that can affect your brain and mental health at every stage of life.

Hormonal and Dietary Influences on Brain Health

Nutritional effects make sense, but how can hormones affect your brain? Don’t we usually hear about them in relation to reproduction?

While hormones certainly play a starring role in our reproductive systems, they also have a huge effect on brain health. Humans have many different types of hormones in our bodies, influencing everything from mental health and stress levels to reproductive and even gut health. Insulin is actually a hormone, and its correlation to brain health is talked about in-depth in this article. “Happy hormones” that are also neurotransmitters, such as oxytocin, endorphin, and serotonin are widely known to contribute to brain function, happiness, and overall mental and brain health (1).

Perhaps less well-known as brain health influencers are steroid hormones, which are a set of hormones that contain both glucocorticoids (cortisol) and sex hormones (estrogen, testosterone, etc.) (2).

What are glucocorticoids?

Glucocorticoids, of which cortisol is the most well-known, are released in response to stressful situations. They work quickly to alter both the body and brain’s responses to create optimal performance during a stressful event (3). If stress is experienced too often, cortisol levels can end up either severely elevated or lowered, meaning weakened synapses, altered dendritic branching, and overall lowered mood, functioning, and psychological health (3, 4). Unfortunately, this can also lead to impaired memory in both children and adults and can contribute to the development of dementia and Alzheimer’s disease as we grow older (4).

How can hormones like estrogen and testosterone affect the brain?

Sex hormones, including estrogen, progesterone, testosterone, and androstenedione, are all key factors that can prevent cognitive decline and mental health problems. Both men and women produce all four of these hormones, in varying amounts. These hormones may all act as neuroprotectors, exhibiting powerful antioxidant properties and increasing neural function, resilience, and survival (4). When sex hormone levels decrease due to age, menopause, or other factors, the decrease is correlated with an overall drop in neural function, and more specifically can lead to mitochondrial and synaptic dysfunction, neuroinflammation, and an increased risk of age-related cognitive disorders (4).

Effects of the “maternal hormones,” estrogen and progesterone, on the body and brain are crucial. Estrogen contributes to memory, emotional function, cognition through stimulating neuron growth and neuroplasticity, and even offers some protection for the brain during a stroke (4). Estrogen can increase blood flow and glucose uptake in the brain, improving overall brain energy metabolism (5). BDNF (brain-derived neurotrophic factor), which plays a crucial role in neurotransmitter modulation as well as neuronal survival, growth, and overall plasticity, is also associated with healthy female sex hormone levels (5).

Large fluctuations in these hormones are correlated with reduced verbal memory, attention, and processing skills - thus contributing to conditions like “pregnancy brain”! Outside of pregnancy, hormone changes across the menstrual cycle can cause changes in brain reactivity, leading to slight but sometimes perceptible differences in cognitive ability in some women (4). The effects of hormonal fluctuation in women long-term could account for why there are higher instances of and faster decline in neurodegenerative diseases like Alzheimer’s (4, 5).