Insulin and the Impact of Lifestyle Factors

By Lyssa Balick, MS

Overview

Insulin resistance is a condition where your body does not respond properly to insulin and as a result, your body cannot easily absorb glucose from the bloodstream.  Over time, this can make it hard for your body to control glucose and may lead to type 2 diabetes and heart disease. Many people with insulin resistance have high levels of glucose and insulin circulating in their blood at the same time (1).

Both aging and lifestyle factors can affect the way your body produces insulin. Factors that lead to higher insulin resistance include:

• Genetic makeup or family history of diabetes.
• Age-related changes in glucose or carbohydrate metabolism.
• Lifestyle factors such as less activity, smoking, or eating more calories than your body needs.
• Obesity, especially around the abdominal area (2).

For women, the menopause transition may impact the body’s ability to process insulin as well. Dr. Hanah Polotsky is a medical doctor practicing in the Weill-Cornell Medical Center and Memorial Sloan-Kettering Cancer Center, New York. She recently completed a literature review on the topic and the evidence suggests that the incidence of metabolic syndrome (including insulin resistance) increases during menopause.   This is caused in part by changing hormones, weight gain and increased body fat in the abdominal region (3).
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While genetics and aging do have an impact, small changes in lifestyle factors can make a big difference.

How Can Lifestyle Factors Help?

Dr. John Kirwan oversees research in the area of aging, obesity and diabetes at the Cleveland Clinic in Ohio. He has conducted several studies that show that diet and exercise, alone or in combination, improved glucose and insulin response. One study, published in 2009 in the American Journal of Endocrinology and Metabolism, looked at lifestyle factors in obese, older people who had blood glucose levels in the pre-diabetic range. The 19 people enrolled in the study exercised about one hour a day, five days a week. Nine of the people also got dietary counseling on reducing calories by about 500 calories per day. After 12 weeks, those in the exercise group lost an average of 6.6 pounds and improved their exercise capacity. Those in the diet and exercise group lost an average of 18 pounds, needed to make less insulin and improved the way that their body's insulin responded to glucose (4). Follow up studies at the Cleveland clinic with pre-diabetic, overweight subjects has found that diet and exercise in combination improve factors of insulin resistance, inflammation, and weight loss. The dietary factors that are were most effective were those diets lower in calories and higher in fiber (5).

Dietary factors alone can help with insulin resistance, obesity, and inflammation, which are all factors in pre-diabetes. A recent study published in the Journal of Nutrition looked at how a Mediterranean diet high in olive oil, nuts, legumes, whole grains, fruits and vegetables affected body weight and markers of pre-diabetes. The study took healthy Australian adults over 65 years old and put them on either a Mediterranean diet or a standard Western diet for six months. The results found that those on the Mediterranean diet had lower triglycerides and lower oxidative stress (as measured by F2-Isoprostanes) compared to those on the Western diet, but glucose and insulin were not significantly different between groups. In addition, those that were on a Mediterranean diet had better measures of cognitive function (6, 7).

Culinary spices and herbs, also used in a traditional Mediterranean diet, can sometimes help level out blood glucose when consumed with meals. Researchers in Singapore reviewed the evidence on using culinary spices and spice extracts on controlling blood glucose and insulin levels. They found that spices like cinnamon, ginger, black cumin, fenugreek, and cloves reduced blood glucose and/or triglyceride levels directly after consumption (8).

Research on postmenopausal women has also demonstrated that lifestyle factors can improve insulin resistance or pre-diabetes. Dr. Polotsky has also observed how lifestyle changes can impact insulin resistance for women as they transition into menopause. She found that with her patients, brief walking 10-15 miles a week and small decreases in calories can prevent weight gain. It doesn’t take tremendous amount of exercise and diet changes to have a huge impact. She has seen how just a 5-10% weight loss can improve not only body weight, but insulin, cholesterol levels and even a better night’s sleep (3).

Is There Anything I Can Do?

As you age, many individual factors determine how your body processes insulin and glucose. However, staying active and maintaining a normal body weight can help. Some tips:

• If you aren’t active and are able, try adding some physical activity most days. Several studies have found that when older adults reduced sedentary time, they were less likely to have pre-diabetic glucose levels (8).
• If you are overweight, try for a modest weight loss. Gradual weight loss (5-10% of your body weight over a six-month period) can help reduce insulin resistance (3,4,5).
• A Mediterranean Diet, or any whole food-based approach, may help with both weight loss and to help with insulin resistance. Some small diet changes to try: incorporate culinary herbs and spices, vegetables, olive oil, nuts, lean protein, and whole grains on a regular basis while staying within your body's caloric needs (6, 7, 10).
• If you need help with lifestyle changes, it may help to see a health professional. They can run tests to help monitor your blood glucose levels and provide you with a detailed wellness plan.​

​While aging can contribute to insulin resistance which  makes it harder for your body to respond to insulin and manage your blood glucose, gradual lifestyle changes can reverse the indicators of pre-diabetes and improve your health overall. As we age, better habits can improve your life quality for decades.

References

1. "Prediabetes & Insulin Resistance." August 01, 2009. Accessed September 24, 2017. https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/prediabetes-insulin-resistance.
2. Centers for Disease Control and Prevention. National diabetes statistics report, 2017. Centers for Disease Control and Prevention website. Accessed September 24, 2017. www.cdc.gov/diabetes/pdfs/data/statistics/national-diabetes-statistics-report.pdf.
3. Polotsky, HN, and AJ Polotsky. "Metabolic implications of menopause. [Semin Reprod Med. 2010]. Accessed September 24, 2017. http://www.ncbi.nlm.nih.gov/pubmed/20865657.
4. Kelly, K , L Brooks, and T Soloman, et. al. (2009 ). "The glucose-dependent insulinotropic polypeptide and glucose-stimulated insulin response to exercise training and diet in obesity." American Journal of Endocrinology and Metabolism. Accessed October 1, 2017. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2692394/
5. Malin, S. K., Niemi, N., Solomon, et. al. (2012). “Exercise training with weight loss and either a high or low glycemic diet reduces metabolic syndrome severity in older adults.” Annals of Nutrition & Metabolism, 61(2), 135–141. Accessed October 1, 2017. http://doi.org/10.1159/000342084
6. Davis CR, Bryan J, Hodgson JM, Woodman R. et. al. A Mediterranean Diet Reduces F(2)-Isoprostanes and Triglycerides among Older Australian Men and Women after 6 Months. J Nutr. 2017 Jul;147(7):1348-1355. Accessed October 1, 2017. https://www.ncbi.nlm.nih.gov/pubmed/28566524
7. Knight, A., Bryan, J., Wilson, C., Hodgson, J., & Murphy, K. (2015). A randomised controlled intervention trial evaluating the efficacy of a Mediterranean dietary pattern on cognitive function and psychological wellbeing in healthy older adults: the MedLey study. BMC Geriatrics, 15, 55. Accessed October 1, 2017. http://doi.org/10.1186/s12877-015-0054-8.
8. Bi X, Lim J, Henry CJ. Food Chem. 2017 Feb 15;217:281-293. doi: 10.1016/j.foodchem.2016.08.111. Epub 2016 Aug 29. Accessed October 1, 2017. https://www.ncbi.nlm.nih.gov/pubmed/27664636?report=docsum.
9. Bankoski, A, T Harris and J McClain, et. al. "Sedentary Activity Associated With Metabolic Syndrome Independent of Physical Activity." [Diabetes Care 2011]. http://care.diabetesjournals.org/content/34/2/497.long (accessed October 1, 2017).
10. Salas-Salvadó, J., Bulló, M., Babio, N. et. al. “Reduction in the Incidence of Type 2 Diabetes With the Mediterranean Diet: Results of the PREDIMED-Reus Nutrition Intervention Randomized Trial.” Diabetes Care 34.1 (2011): 14–19. PMC. Web. 1 Oct. 2017. Diabetes Care, 34(1), 14–19. Accessed October 1, 2017. http://doi.org/10.2337/dc10-1288

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About the Author: Lyssa Balick, MS

Lyssa is a nutritionist with over twenty years of experience planning, conducting, and evaluating nutrition programs. Past experiences include a country wide evaluation of breastfeeding practices for UNICEF, writing parts of a national hunger prevention curriculum for Share Our Strength, and conducting an award winning, comprehensive preschool nutrition and cooking program for Port Discovery. She has taught nutrition at Community College and to Baltimore City teachers, counseled women and their families on nutrition and helped with program evaluation and implementation on a national, international and local level. Lyssa has a Masters Degree in Nutrition from the Tufts School of Nutrition and is a Certified Nutrition Specialist. When not working on nutrition projects, Lyssa can be found hiking, cooking, hanging out with family and friends, or collecting pieces for her midcentury modern side business.

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