Category Archives: osteoarthritis

Insulin Resistance, the silent killer and root cause of modern chronic disease.

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Insulin is much more than a blood sugar hormone. Produced by the pancreas primarily in response to carbohydrate and sugar consumption, insulin is a master anabolic signal that dictates how every cell in your body grows, uses energy, and repairs itself. When insulin levels are healthy, it keeps the body in a state of “build and store.” When insulin resistance (IR) develops, the body loses its ability to hear this signal, leading to systemic breakdown. Instead of “build and store” the body deteriorates, causing loss of muscle mass, strength, energy production, memory and cognitive function, bone strength, brain cells and connections, ability of blood vessels to relax, ability for the heart to pump blood, ability to achieve restorative sleep, ability of the liver and kidneys to clear toxins from the body, even the ability to reproduce resulting in infertility and erectile dysfunction. Visceral fat stores increase to destructive levels resulting in obesity and obesity-related complications including chronic inflammation which further drives IR to higher levels.

IR is a root cause of cardiovascular disease (heart attack, stroke, hypertension, heart failure), many kinds of cancer (directly linked to breast, prostate and colon cancer), kidney failure, heart failure, dementia, osteoporosis, osteoarthritis, and much more.  IR is causally linked or a contributor to, every chronic non-communicable disease of modern civilization.

WHAT IS INSULIN RESISTANCE?

Insulin resistance is the inability of cells and organs to respond normally to insulin signaling. Every cell of every organ has insulin receptors that initiate action by the cell and organ.

WHAT CAUSES INSULIN RESISTANCE?

There are many causes of IR. Stress hormones (cortisol, adrenaline), inflammation, and high insulin levels themselves (response to dietary sugar and refined carbohydrates), each alone and in combination, cause immediate (within minutes to hours) insulin resistance. When these conditions persist over time insulin resistance becomes a chronic state. As fat cells grow in size, they reach a point where there is inadequate blood flow to the cells themselves and macrophages (immune cells that reside between the fat cells, most prominently in visceral fat) produce inflammatory chemicals called cytokines. Cytokines flow through the blood stream and effect every organ and every cell in the body creating a state of chronic inflammation which further worsens IR, creating a vicious cycle. As IR continues the pancreas produces increasingly higher amounts of insulin to maintain normal blood sugar levels but eventually IR becomes so great that blood sugar levels move into the “pre-diabetes” and eventually the diabetes range. IR builds for years to decades before blood sugar regulation fails. By the time blood sugar levels are “abnormal” insulin resistance has done great damage throughout the body.

Most doctors tragically do not order fasting insulin levels as routine blood tests. Fasting insulin levels rise long before fasting blood sugars and hemoglobin A1c start to rise. Meanwhile the damage progresses under the radar of routine testing.

1. Metabolic Engines: Muscle and Liver

Muscle

  • Normal Action: Insulin acts as a key that opens “doors” (GLUT4 receptors) to let glucose in for fuel. it also stimulates protein synthesis. Protein synthesis is essential to maintaining and increasing muscle mass and strength.
  • Insulin Resistance Effect: The “doors” stay locked. Glucose stays in the blood, and the muscle becomes “starched,” leading to sarcopenia (muscle wasting) and fatigue. The muscle can no longer utilize dietary protein to maintain or increase muscle mass.

Liver

  • Normal Action: Tells the liver to stop producing glucose and start storing it as glycogen or converting excess into fat.
  • Insulin Resistance Effect: The liver ignores the “stop” signal and keeps pumping out glucose while simultaneously ramping up fat production. This results in Non-Alcoholic Fatty Liver Disease (NAFLD).

2. Fat Cells (Adipose Tissue)

Visceral (Deep Fat) vs. Subcutaneous (Under Skin)

  • Normal Action: Insulin promotes fat storage and inhibits the breakdown of stored fat (lipolysis).
  • Insulin Resistance Effect: Fat cells—especially visceral ones—become “leaky.” They spill free fatty acids into the bloodstream and release inflammatory cytokines. This causes weight gain that is biologically difficult to lose because high insulin levels keep the “fat-burning” switch permanently off.

3. The Vital Organs: Heart, Kidneys, and Arteries

Heart and Arteries

  • Normal Action: Insulin stimulates the release of nitric oxide, which helps arteries relax and dilate.
  • Insulin Resistance Effect: Nitric oxide production drops, causing arteries to stiffen (hypertension). High insulin also damages the endothelial lining, leading to atherosclerosis (plaque buildup). This is the primary driver of heart failure, heart attacks and strokes.

Kidneys

  • Normal Action: Helps regulate sodium reabsorption.
  • Insulin Resistance Effect: The kidneys hold onto too much salt, increasing blood pressure. Over time, high blood sugar and inflammation damage the filtering units, leading to chronic kidney disease (CKD).

4. The Brain, Memory, and Sleep

Brain and Memory

  • Normal Action: Insulin crosses the blood-brain barrier to regulate appetite and support synaptic plasticity (the basis of learning).
  • Insulin Resistance Effect: Often called “Type 3 Diabetes,” brain IR starves neurons of energy and allows amyloid plaques and neurofibrillary tangles to build up. Worse, the brain is unable to utilize glucose to meet energy demands it starts to malfunction. This is a direct pathway to Alzheimer’s disease and dementia. As the small arteries in the brain become atherosclerotic and unable to deliver adequate oxygen and nourishment to brain cells small areas of the brain become permanently damaged eventually leading to vascular dementia.

Sleep

  • Insulin Resistance Effect: IR is heavily linked to Obstructive Sleep Apnea. (OSA) High insulin affects the central respiratory drive and increases fat deposits around the neck (a major contributor to obstructive sleep apnea), disrupting sleep cycles and creating periods of inadequate oxygen flow to the brain resulting in the acute stress response and awakening with each apneic event. Even without OSA, high insulin levels impair the production of melatonin which is essential to normal-restorative sleep. Throughout the day the brain accumulates metabolic toxins that must be cleared through the glymphatic system at night during sleep. As sleep is impaired this clearance system is disrupted, contributing to structural damage and functional loss. Sleep disruption and apneic episodes are stressful events, increasing stress hormones which then worsen IR, creating another vicious cycle. One night of sleep disruption causes acute IR. Chronic sleep disruption contributes to chronic IR.

5. Immunity and Structural Health

Immune System

  • Action: High insulin/glucose impairs white blood cell function.
  • Effect: Chronic inflammation (high CRP levels) and a weakened defense against infections. This is why diabetics often have poor wound healing. As normal immune regulation is impaired the immune system both over-reacts and under-reacts. Under-reaction increases risk of infection. Over-reaction produces cytokine storms seen with Covid-19 and other infections. Chronic inflammation worsens IR creating another vicious cycle. Chronic inflammation contributes to most chronic diseases.

Bone and Joints

  • Action: Insulin is bone-building.
  • Effect: IR leads to poor bone quality (despite high density) and osteoarthritis due to systemic inflammation and the “glycosylation” (sugar-coating) of joint cartilage, making it brittle.

6. The Pancreas: Beta and Alpha Cells

  • Normal Action: Beta cells produce insulin; Alpha cells produce glucagon (which raises sugar). They balance each other.
  • Insulin Resistance Effect:
    • Beta Cells: Work overtime to produce massive amounts of insulin to compensate, eventually “burning out” and dying. This can produce per4manent irreversible damage to the pancreas.
    • Alpha Cells: Become resistant to insulin’s “stop” signal and keep secreting glucagon, further raising blood sugar levels which in turn cause higher insulin secretion, both of which worsen IR, creating another vicious cycle.

7. Reproductive Effects: Infertility

  • In Women: High insulin stimulates the ovaries to produce excess testosterone, which is the primary driver of Polycystic Ovary Syndrome (PCOS) and infertility.
  • In Men: IR is a leading cause of low testosterone and erectile dysfunction (due to the arterial damage mentioned above).

Summary of Systemic Effects

ConditionPrimary Mechanism of Insulin Resistance
AtherosclerosisEndothelial dysfunction, high triglycerides, low HDL, increased TG/HDL ratio, increased small dense LDL and remnant particles, increased endothelial permeability.
DementiaNeuronal glucose starvation and plaque buildup, brain small vessel disease, disruption of blood brain barrier.
Chronic InflammationRelease of cytokines from visceral fat.
Heart FailureStiffening of the heart muscle and high blood pressure.
DiabetesPancreatic beta cell and alpha cell damage

Insulin’s Role vs. Insulin Resistance (IR)

Organ/SystemNormal Insulin ActionEffects of Insulin Resistance
LiverStops glucose production; stores glucose as glycogen.The liver ignores the “stop” signal, pumping out sugar even when you haven’t eaten (fatty liver).Fatty liver disease is the greatest cause of liver failure in the US.
MusclePrimary site for glucose uptake; promotes protein synthesis.Muscles can’t take in fuel efficiently, leading to fatigue and muscle wasting (sarcopenia). Muscle cells cannot use amino acids from dietary protein to maintain or build muscle. Elderly lose muscle and strength, resulting in falls, fractures and head trauma. Loss of muscle (the major sink for blood sugar after a meal) further increases duration and degree of blood sugar and insulin rise after a meal, which in turn increases IR. (vicious cycle)
Fat (Adipose)Stores fat; inhibits the breakdown of stored fat.Fat cells leak fatty acids into the blood, leading to high triglycerides and visceral fat gain. Macrophages (immune cells) produce inflammatory cytokines which circulate through the body contributing to chronic inflammation which worsens IR, another vicious cycle.
BrainRegulates appetite, memory, and cognitive function.Linked to “Type 3 Diabetes”; impaired memory and increased risk of neurodegeneration. Brain loses ability to meet energy demands and clear toxins. Insulin resistance in the brain explains memory loss, cognitive impairment, loss of neurons and synapses, loss of neuroplasticity. BDNF (brain derived neurotrophic factor) production is decreased by IR.
ArteriesStimulates nitric oxide for vasodilation (keeps vessels flexible).Reduced nitric oxide causes vessels to stiffen, raising blood pressure and plaque buildup. This is called endothelial dysfunction, the precursor to heart attack, stroke, peripheral vascular disease and a root cause for neuropathy and amputations.
HeartRegulates fuel use (switching between glucose and fats).The heart becomes “metabolically inflexible,” increasing the risk of heart failure.
KidneyManages sodium reabsorption and filtration.High insulin causes the kidneys to hold onto salt, driving up blood pressure and damaging filters. Oxidative stress leads to kidney failure.
Immune SystemModulates inflammation and helps T-cell function.Creates a state of “chronic low-grade inflammation” and weakens the response to infections.
BoneStimulates bone-forming cells (osteoblasts).Bone quality decreases; despite higher bone density in some cases, the bones are more brittle.
JointsMaintains cartilage and reduces systemic inflammation.High insulin promotes pro-inflammatory cytokines, accelerating osteoarthritis and gout.

 A meal with sugar and refined carbohydrates causes excessive swings in blood sugar and insulin levels, creating insulin resistance and downstream damage. Alcohol consumption contributes to this process. Fat consumption does not cause a rise in blood sugar or insulin levels. Protein consumption produces a minimal rise in insulin levels in the absence of IR.

Fat storage can occur through hyperplasia (increase in number of fat cells) or hypertrophy (increase in size). Some ethnic groups are more prone to hypertrophy (south and east Asian). Hypertrophy in visceral fat (fat around the internal organs as opposed to fat under the skin) results in macrophage production of inflammatory cytokines. Eventually, the fat cells themselves can literally burst from too much volume.

 In my next post, I will discuss what we can do to prevent and reverse IR.

REFERENCES

Chadt A, Al-Hasani H. Glucose transporters in adipose tissue, liver, and skeletal muscle in metabolic health and disease. Pflugers Arch. 2020 Sep;472(9):1273-1298. doi: 10.1007/s00424-020-02417-x. Epub 2020 Jun 26. PMID: 32591906; PMCID: PMC7462924.

https://pmc.ncbi.nlm.nih.gov/articles/PMC7462924/

Fujita S, Rasmussen BB, Cadenas JG, Grady JJ, Volpi E. Effect of insulin on human skeletal muscle protein synthesis is modulated by insulin-induced changes in muscle blood flow and amino acid availability. Am J Physiol Endocrinol Metab. 2006 Oct;291(4):E745-54. doi: 10.1152/ajpendo.00271.2005. Epub 2006 May 16. PMID: 16705054; PMCID: PMC2804964.

https://pmc.ncbi.nlm.nih.gov/articles/PMC2804964

Vargas E, Joy NV, Carrillo Sepulveda MA. Biochemistry, Insulin Metabolic Effects. [Updated 2022 Sep 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK525983/

https://www.ncbi.nlm.nih.gov/books/NBK525983/

Bugianesi E, Moscatiello S, Ciaravella MF, Marchesini G. Insulin resistance in nonalcoholic fatty liver disease. Curr Pharm Des. 2010 Jun;16(17):1941-51. doi: 10.2174/138161210791208875. PMID: 20370677.

https://pubmed.ncbi.nlm.nih.gov/20370677/

Cardillo C, Nambi SS, Kilcoyne CM, Choucair WK, Katz A, Quon MJ, Panza JA. Insulin stimulates both endothelin and nitric oxide activity in the human forearm. Circulation. 1999 Aug 24;100(8):820-5. doi: 10.1161/01.cir.100.8.820. PMID: 10458717.

https://pubmed.ncbi.nlm.nih.gov/10458717/

Ke JF, Wang JW, Zhang ZH, Chen MY, Lu JX, Li LX. Insulin Therapy Is Associated With an Increased Risk of Carotid Plaque in Type 2 Diabetes: A Real-World Study. Front Cardiovasc Med. 2021 Feb 1;8:599545. doi: 10.3389/fcvm.2021.599545. PMID: 33598483; PMCID: PMC7882504.

https://pubmed.ncbi.nlm.nih.gov/33598483/

Brosolo G, Da Porto A, Bulfone L, Vacca A, Bertin N, Scandolin L, Catena C, Sechi LA. Insulin Resistance and High Blood Pressure: Mechanistic Insight on the Role of the Kidney. Biomedicines. 2022 Sep 23;10(10):2374. doi: 10.3390/biomedicines10102374. PMID: 36289636; PMCID: PMC9598512.

https://pubmed.ncbi.nlm.nih.gov/36289636/

Kumar M, Dev S, Khalid MU, Siddenthi SM, Noman M, John C, Akubuiro C, Haider A, Rani R, Kashif M, Varrassi G, Khatri M, Kumar S, Mohamad T. The Bidirectional Link Between Diabetes and Kidney Disease: Mechanisms and Management. Cureus. 2023 Sep 20;15(9):e45615. doi: 10.7759/cureus.45615. PMID: 37868469; PMCID: PMC10588295.

https://pmc.ncbi.nlm.nih.gov/articles/PMC10588295/

Banks WA, Owen JB, Erickson MA. Insulin in the brain: there and back again. Pharmacol Ther. 2012 Oct;136(1):82-93. doi: 10.1016/j.pharmthera.2012.07.006. Epub 2012 Jul 17. PMID: 22820012; PMCID: PMC4134675.

https://pubmed.ncbi.nlm.nih.gov/22820012/

Rahman MS, Hossain KS, Das S, Kundu S, Adegoke EO, Rahman MA, Hannan MA, Uddin MJ, Pang MG. Role of Insulin in Health and Disease: An Update. Int J Mol Sci. 2021 Jun 15;22(12):6403. doi: 10.3390/ijms22126403. PMID: 34203830; PMCID: PMC8232639.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8232639/

Scherrer U, Sartori C. Insulin as a vascular and sympathoexcitatory hormone: implications for blood pressure regulation, insulin sensitivity, and cardiovascular morbidity. Circulation. 1997 Dec 2;96(11):4104-13. doi: 10.1161/01.cir.96.11.4104. PMID: 9403636.

https://pubmed.ncbi.nlm.nih.gov/9403636/

Affuso F, Micillo F, Fazio S. Insulin Resistance, a Risk Factor for Alzheimer’s Disease: Pathological Mechanisms and a New Proposal for a Preventive Therapeutic Approach. Biomedicines. 2024 Aug 19;12(8):1888. doi: 10.3390/biomedicines12081888. PMID: 39200352; PMCID: PMC11351221.

https://pmc.ncbi.nlm.nih.gov/articles/PMC11351221/

Park MH, Kim DH, Lee EK, Kim ND, Im DS, Lee J, Yu BP, Chung HY. Age-related inflammation and insulin resistance: a review of their intricate interdependency. Arch Pharm Res. 2014 Dec;37(12):1507-14. doi: 10.1007/s12272-014-0474-6. Epub 2014 Sep 20. PMID: 25239110; PMCID: PMC4246128.

https://pubmed.ncbi.nlm.nih.gov/25239110/

Hardy OT, Czech MP, Corvera S. What causes the insulin resistance underlying obesity? Curr Opin Endocrinol Diabetes Obes. 2012 Apr;19(2):81-7. doi: 10.1097/MED.0b013e3283514e13. PMID: 22327367; PMCID: PMC4038351.

https://pmc.ncbi.nlm.nih.gov/articles/PMC4038351/

THIS WEBSITE PROVIDES INFORMATION FOR EDUCATIONAL PURPOSES ONLY. CONSULT YOUR HEALTH CARE PROVIDER FOR MEDICAL ADVICE.

Eat clean, drink filtered water, love, laugh, exercise outdoors in a greenspace, get some morning sunlight, block the blue light before bed, engage in meaningful work, find a sense of purpose, spend time with those you love, AND sleep well tonight.

Doctor Bob

Omega-3 fatty acids, Pain and Arthritis

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Before modern pharmacy an early treatment for Rheumatoid Arthritis (RA) was cod liver oil, rich in omega-3 fats and vitamin D. A 2013 study demonstrated that consumption of cod liver oil resulted in a reduction of daily diclofenac in Rheumatoid Arthritis. As early as 1959 cod liver oil was recommended for arthritis in the medical literature. A 2017 review of marine omega-3 fats for arthritis pain found moderate quality evidence in rheumatoid arthritis patients. A 2024 review of prevention and treatment for RA suggested that a diet rich in fiber, vitamins, omega 3 and low glycemic index foods contributes to protection from RA. A comprehensive review of omega-3 fatty acids for RA included analysis of several studies and concluded that omega-3 was a valuable therapeutic option to improve pain symptoms, tender joint count, duration of morning stiffness and the frequency of NSAID consumption. A 2019 review of cumulative data on omega-3 fats to combat autoimmune diseases concluded:

“The promising findings coming from the cumulative research work over the last decade solidified the role of ω-3 PUFAs as a potential candidate to prevent or even treat such autoimmune diseases as type 1 diabetes, RA, SLE, MS”

A 2024 review of marine omega-3 PUFA (polyunsaturated fatty acids) for RA reported:

“Altogether the data reported in this review show that anti-inflammatory interventions, i.e., high fish consumption or supplements containing n-3 PUFAs, should be the standard of care, along with pharmacotherapy, in treating patients with RA.”

And here is a graphic from that article showing the effect of SPMs (specialized pro-resolving mediators, derived from omega-3s):

What about osteoarthritis?

A multicenter randomized double blind placebo controlled trial of krill oil containing 0.60 g EPA/d, 0.28 g DHA/d, 0.45 g astaxanthin/d demonstrated improvements in pain, stiffness and physical function.

Some omega-3 supplement studies have demonstrated no significant pain relief in osteoarthritis. Those studies did not reduce the consumption of pro-inflammatory n-6 fatty acids which compete with omega-3 fats for the enzymes which can lead to pro or anti-inflammatory mediators. They also did not measure the omega 6/omega 3 ratio in blood or tissues. Nor did they measure the omega-3 index (% of omega-3 achieved in red blood cell membranes, the gold standard for evaluating tissue levels achieved) This 2018 analysis stated:

“High Omega-3 (n-3) polyunsaturated fatty acids (PUFAs) are associated with lower levels of inflammatory mediators, anti-nociception, and adaptive cognitive/emotional functioning. High Omega-6 (n-6) PUFAs are associated with inflammation, nociception, and psychological distress. While findings related to n-3 supplementation in knee OA are mixed, consideration of the n-6:n-3 ratio and additional outcome measures may provide improved understanding of the potential relevance of these fatty acids in OA”

The authors went on to access blood n-6/n-3 ratios in patients with OA and found the following:

“The high ratio group reported greater pain and functional limitations, (all p’s<0.04), mechanical temporal summation (hand and knee, p<0.05), and perceived stress (p=0.008) but not depressive symptoms.”

“In adults with knee pain, a high n-6:n-3 ratio is associated with greater clinical pain/functional limitations, experimental pain sensitivity, and psychosocial distress compared to a low ratio group.”

The anti-inflammatory diet that I follow and recommend eliminates the major sources of excess omega-6 in the diet, specifically the “vegetable oils” which are actually seed, grain, and legume oils predominated by soy oil, corn oil, peanut and cottonseed oil present in cooking “vegetable oils” and processed foods. A table that displays the ratio of omega 3 to omega 6 in various oils can be found here. Note that this table does not reveal the amounts of MUFA (mono unsaturated fatty acids) which are arguably “heart healthy”. Nor does it address the important issue of protective polyphenols and anti-oxidants (such as in Extra Virgin Olive oil aka EVOO). So do not make choices of oil based only on the omega-3/6 ratio.

Another consideration in choosing oils for cooking (as opposed to salad dressing) is the smoke point. Under high heat, oils are subject to oxidation which creates a proinflammatory effect when consumed. Refined Avocado oil has the highest smoke point (520 degrees F). But we digress. Back to pain and arthritis.

An article just published in Nutrients reviewed Omega-3 Supplementation and Its Effects on Osteoarthritis.

“omega-3 polyunsaturated fatty acids (PUFA) have demonstrated an influential role in the progression of OA, resulting in the reduction of cartilage destruction, inhibition of pro-inflammatory cytokine cascades, and production of oxylipins that promote anti-inflammatory pathways.” 

“Research has demonstrated a positive effect on the modulation of OA symptoms through diet and exercise to promote an anti-inflammatory environment. More specifically, omega-3 PUFAs have demonstrated a reduction in inflammatory biomarkers and cartilage degradation, counteracting the natural disease state of OA. In addition to their chondroprotective role, omega-3 supplementation has been shown to have indirect positive effects on muscle tissue recovery following exercise, which is necessary to prevent the progression of OA and maintain an independent, healthy lifestyle. The effects of omega-3 supplementation on the disease state of OA and its symptoms remain inconclusive. Further clinical trials utilizing human participants are warranted to provide a conclusive recommendation on standardized supplementation of omega-3 for the modulation of osteoarthritis.”

Given the cardioprotective effects, discussed in my last post (including an 80% reduction in sudden death at the highest quintile of omega-3 index) and other benefits (reduction in all cause mortality with high tissue levels), there are many reasons to include large amounts of low mercury fatty fish (wild Alaskan salmon, sardines, herring, trout) in the diet and to consider supplementation when your omega 3 index is < 8%. Likewise, in the presence of arthritis and pain, getting tissue levels of omega 3 up and reducing excessive pro-inflammatory omega 6 will likely provide significant benefit.

Here is a graphic with the omega 3 content of some foods.

And another:

As mentioned in my previous post about omega-3 and cardiovascular health, 1800 mg of omega-3 FA daily is adequate in most people to achieve and omega-3 index of 8%, the level at which cardiovascular protection is greatest.

THIS WEBSITE PROVIDES INFORMATION FOR EDUCATIONAL PURPOSES ONLY. CONSULT YOUR HEALTH CARE PROVIDER FOR MEDICAL ADVICE.

Eat clean, drink filtered water, love, laugh, exercise outdoors in a greenspace, get some morning sunlight, block the blue light before bed, engage in meaningful work, find a sense of purpose, spend time with those you love, AND sleep well tonight.

Doctor Bob