HEALTH NEWS

Cartilage and Brain Health Linked with Mitochondria and Circadian Rhythm

By Dr. Linda J. Dobberstein, DC, Board Certified in Clinical Nutrition

May 24, 2021

There is a new, innovative perspective pertaining to joint and cartilage health and its connection to our cognitive health. In Western healthcare, these systems are viewed separately; however, aging and a decline in function of these tissues and organs are not as separate as originally thought. Systemic chronic inflammation and disrupted circadian rhythms adversely affect mitochondria through the body. This is especially evident in aging in relation to joint and brain health.

Chronic Wear & Tear

Chronic low-grade wear-and-tear inflammation is not quite the same type of inflammation that you see when you badly sprain your ankle. With an acute sprain and inflammation, you see black and blue marks and very swollen tissues. Chronic low-grade inflammation is more subtle.

Chronic low-grade inflammation happens throughout your body and may affect some systems more than others. It can make you feel older than your biological age. It may make you feel stiff and achy. You may not feel as physically and mentally spry as you did as a kid or even a few years ago.

Some amounts of daily oxidative stress and inflammation are normal and essential for cell function and life. It is the chronic burden of overload and unrepaired inflammation that builds up and causes aging.

In this article, I explore some of the new research on chronic low-grade inflammation, its affect on mitochondria and the overlapping connection for cartilage, joints, and brain health.

Chronic Inflammation and Joints

Chronic low-grade inflammatory stress results in the breakdown of cartilage cells and surrounding joint tissues. Excess wear and tear from physical overload with lifting and/or trauma, chronic sitting and poor posture, along with insufficient nutrients and age are commonly recognized factors that lead to cartilage loss, joint deterioration, and disc herniation. Other issues of chronic inflammation with obesity, blood sugar dysregulation, elevated cholesterol, and high blood pressure also contribute to greater likelihood and even earlier onset of cartilage and joint deterioration.

Cartilage, Mitochondria, and Mitophagy

Chronic low-grade inflammation stresses mitochondria function, the energy producing engines in your cells. This low-grade wear and tear is like having the brake pads on your bicycle slightly engaged and rubbing against the wheel when you pedal. It makes mitochondria work harder to generate the same energy. Over time, this causes mitochondria to get worn-out and broken. Mitochondria clean-up and repair demands increase.

Your body has a repair process for mitochondria called mitophagy. Mitophagy (mi-tah-pha-gee) is an essential cellular clean-up process that removes damaged or dysfunctional mitochondria. Chronic low-grade inflammation (and acute inflammation) adds to the burden of normal mitochondria repair.

When mitophagy processes are overwhelmed and do not keep up with their work, it results in further breakdown of mitochondria. When this happens inside joints, cartilage cells become stressed, dehydrate, die, and then erode. This subtle and often relatively silent process causes a cascade of joint deterioration over the course of years and a lifetime. It can lead to the subsequent loss of cartilage and joint pain. Research indicates that healthy mitophagy and protection of mitochondria are essential and critical to maintenance and support of cartilage and joint health.

Brain, Mitochondria, and Mitophagy

A similar process of mitochondria stress and mitophagy breakdown applies to brain health. Efficient clean-up of old, worn-out mitochondria through mitophagy is crucial for mitochondria, brain function, and nerve health.

When mitophagy is disrupted, or gets backed-up in the brain, amyloid beta and tau proteins build-up between nerve connections. This is not helpful as it results in additional repetitive injury to mitochondria and cells and creates more cellular trash. As trash levels increase, it creates more oxidative stress on mitochondria, which puts more wear and tear on nerves and cellular energy production. This creates a vicious cycle of more mitochondria dysfunction and mitophagy impairment. Mental and cognitive function is not as sharp and declines.

Broken mitophagy is a bit like having a broken washing machine. Laundry does not get done and it affects the whole family. It disrupts the normal routine of life. Now put it in context of your joints and brain and imagine if it were to happen for years and decades. Mitophagy breakdown and mitochondrial stress is a convergence point that links joint and cartilage breakdown and cognitive decline.

Convergence Point

Researchers have described the highly complex interplay of chronic inflammation and mitochondrial dysfunction in cartilage-joint deterioration that precedes and coexists with overstimulation of microglial cells (nerve clean-up cells) in the spinal cord and brain, and a leaky blood brain barrier. This combination of factors lends to a greater presence of brain inflammation or neuro-immuno inflammation linked with the development of cognitive decline and memory loss.

Research Reveals Joint Changes are Risk Factor and Precede Cognitive Changes

Various studies like a 2015 retrospective population study in Taiwan identified that joint issues were an independent risk for cognitive decline. A recent 2020 study showed surprising and concerning findings in the brains of patients with worn-out joints.

Researchers used special scans to measure parts of the brain in 372 older adults. Analysis of data and imaging studies showed individuals with joint deterioration had diminished hippocampal size with a faster rate of decline compared to those without joint problems. This was found even when other factors like age, education, gender, and the APOE4 genotype were factored in. Both groups of participants had normal cognitive function.

This is of significant concern as the hippocampus is the memory center of your brain. It is also involved with helping you learn new things, spatial navigation, and is part of the ‘moral brain’. Atrophy or a decline in the size of the hippocampus means a loss of neurons, which ultimately affects memory and cognitive function.

Disrupted Circadian Rhythms

When you have your morning cup of coffee with family or friends, you may check-in on how they slept. If those conversations reveal a lot of sleep difficulties, it may expose clues about their circadian rhythms and how in sync it is or is not. Disrupted circadian rhythms lead to poor sleep and may make you feel grumpy and exhausted the rest of the day. It also affects the very cleaning processes discussed in this article.

Disrupted circadian rhythms contribute to additional inflammatory load on mitochondria and mitophagy activities and contributes to cartilage cell breakdown. Out of sync circadian rhythms, irregular sleep and eating schedules are proinflammatory and contribute greatly to obesity and blood sugar dysregulation, which also adversely impacts joint and brain health.

Disrupted circadian functions alter hormone secretions like melatonin, thyroid-stimulating hormone and cortisol, which provoke a cascade of pro-inflammatory effects and subsequent cartilage and joint deterioration. These factors disturb mitochondrial function and mitophagy, which distress your cartilage cells, brain, and the rest of your body.

Aging well requires that you protect mitochondria, support and manage your daily wear and tear, and keep regular 24/7 schedules with meals and sleep-wake times for healthy circadian rhythms. Do you wake “bright-eyed and bushy-tailed” or are your dragging your feet in the morning? Or are your days and nights mixed up? Do you feel older than your chronological age? Do you have chronic aches and pains out of proportion to the work that you do? Do you feel mentally sluggish, exhausted, and more forgetful? The two most fundamental steps for health, repair, and aging well for your joints, brain, and whole body is to get your circadian rhythm back on track and protect your mitochondria.