What is Insulin Resistance?
Insulin is the hormone whose main function is to process sugar in the bloodstream and carry it to fat, liver, and muscle cells to be stored for later use. When your body is flooded with too much insulin too much of the time, your cells can become resistant, or desensitized, to its effects. Insulin resistance over the long term will result in Metabolic Dysfunction.
Causes of Excess Insulin
The most common cause is the consumption of too much nutrient-poor carbohydrate. Other causes include: the use of artificial sweeteners, an insufficient protein intake, chronic stress, erratic or irregular mealtimes, over-exercising or lack of exercise, poor liver function, excess alcohol consumption or an existing hormonal imbalance – ie. excess cortisol or estrogen.
Symptoms of Insulin Resistance
Short-term side effects of high insulin include heart palpitations, sweating, poor concentration, weakness, anxiety, fogginess, fatigue, irritability, increased hunger and sugar cravings.
Over the long term, signs of excess insulin include a tendency to hold extra weight abdominally, around your hips or over your triceps; an inability to lose weight in spite of a healthy diet and regular exercise; water retention or a puffiness in the face and extremities, fatigue, burning feet at night, skin tags, infertility or irregular menses, erectile dysfunction, gout, vision changes or sleep disruption.
Beyond obesity and type 2 diabetes, metabolic syndrome is associated with an increased risk of heart disease, stroke, cancer, Alzheimer’s disease, reproductive abnormalities, androgen imbalance in women and osteoporosis.
Diagnosing Insulin Resistance/Metabolic Syndrome
In addition to the clinical symptoms above, according to the current medical guidelines, metabolic syndrome is diagnosed when three or more of the following risk factors are identified:
- Low levels of ‘good’ cholesterol (HDL)
- High levels of ‘bad’ cholesterol (LDL)
- Elevated triglycerides
- Increased waist to hip ratio
- High blood pressure
- Elevated fasting blood sugar
- Elevated fasting insulin
- High uric acid
Reversing Insulin Resistance
The following are the most important steps you can take to improve insulin receptor sensitivity and restore optimal metabolic function.
- Limit your sugar intake – Sugar in the form of high dose fructose impairs insulin sensitivity more than any other food. Examples of high dose fructose foods are: cakes, candy, fruit juice, dried fruit, agave, honey, sweetened milks. Whole fresh fruit okay to eat as it is considered a low dose fructose, which actually improves insulin sensitivity. The American Health Association recommends a maximum daily intake of sugar for women of 25g, and for men 37.5g. Most people eat close to 100g/day, so making this adjustment can make a huge difference.
- Increase your muscle mass – The more muscle you have the more sensitive it will be to insulin. With just 3 weeks of strength exercises for 30 minutes 3 times/week, you can increase your insulin sensitivity by 24%.
- Improve your stress response – Chronically elevated cortisol gives your body the message to increase abdominal fat storage and further depresses your metabolic rate by increasing muscle breakdown. Developing good self care that effectively lowers your cortisol levels and keeps you out of a regular ‘fight or flight’ response is essential. Some examples include: meditation, yoga, dancing, laughing with friends or walking in nature.
- Sleep – Chronic insomnia is a major cause of insulin resistance. Four consecutive nights of poor sleep (less than 5 hours) is enough to reduce insulin sensitivity by 30 percent.
- Supplement Magnesium – Magnesium deficiency can cause insulin resistance. A magnesium rich diet improves insulin sensitivity so well it can be used instead of Metformin – the insulin-sensitizing drug prescribed for pre-diabetes and PCOS. Magnesium rich foods include: green leafy vegetables, nuts and seeds and legumes. Stress and exercise deplete magnesium levels, so supplementation is often indicated. Magnesium glycinate is the best form of magnesium – usually 300-400mg/day taken with food.
Insulin Resistance is unfortunately increasingly common, affecting one in four adults. It is often the basis of other hormonal imbalances and it must be addressed in order for other imbalances to resolve and for optimal wellbeing.
Paolisso, G. (1997). Hypertension, Diabetes Mellitus, and Insulin Resistance: The Role of Intracellular Magnesium. American Journal of Hypertension, Vol 10, Issue 3, p.346-355
Basciano, H, Federico, L., Adeli, K. (2005), Fructose, insulin resistance, and metabolic dyslipidemia. Nutritional Metabolism. Feb 21;2(1):5..
Spiegel, K, Knutson, K, Leproult, R, Tasali, E, Van Cauter, E. (2005) Sleep loss: a novel risk factor for insulin resistance and Type 2 diabetes. Journal of Applied Physiology Vol. 99 no. 5, 2008-2019