Archive for December, 2013

Exercise for the Control of Blood Sugar and Diabetes

Diabetes is a disorder that is characterized by high levels of blood sugar which occurs due to changes in insulin production, insulin sensitivity, or both. This long term elevation in blood sugar levels has serious health effects. Specifically, long term elevations of blood sugar can damage small blood vessels. This damage may then affect vision, kidney and nerve function, bone health, and lead to increased risk of heart attack and stroke, etc.

The prevalence of diabetes is increasing worldwide. In 1985 it was estimated that 30 million people were diagnosed with the disease. Last year, the number of people diagnosed with diabetes was estimated at 371 million people, more than a tenfold increase. This trend for increasing rates of diagnosis is even greater in Canada, where it is estimated that the number of Canadians diagnosed between 1998 and 2009 increased by 230%. It is currently estimated that 2.4 million Canadians have diabetes, and that the incidence will continue to grow1.

One of the most important ways to manage diabetes is through physical activity. It is currently recommended that people with diabetes participate in both regular aerobic and resistance exercise. The participation in these forms of exercise has been shown to be effective in improving blood sugar regulation, reducing insulin resistance, substantially lowering the mortality risk in people with diabetes, and decreasing the risk of several other diabetes related complications (bone and muscle loss, foot ulcers, nerve damage, etc).

Insulin, Blood Sugar Regulation, and the Effects of Exercise
Insulin is a hormone produced in the pancreas that regulates carbohydrate (sugar) and fat metabolism in the body. When eating a meal, insulin is release from the pancreas, entering into the blood stream where it stimulates cells of the body (liver, muscles, fat cells) to take up sugar that was absorbed from food. The cells of the body then use sugar for energy or store it for future use.

In diabetes, the control of blood sugar is impaired. In type 1 diabetes, the cells of the pancreas that produce insulin are destroyed and insulin is not produced. This lack of insulin impairs body tissues to take up sugar. Furthermore, blood sugar levels cannot be properly regulated, remaining elevated. In type 2 diabetes, cells of the body become resistant to the effects of insulin, again leading to elevated levels of blood sugar. Moreover, as type 2 diabetes progresses, the pancreas can lose the ability to produce enough insulin, so there may be both a lack of insulin in addition to the loss of insulin sensitivity.

Exercise has been shown to be very effective in helping regulate blood sugar levels and improving the long term health of diabetics. Exercise has been shown to be effective in regulating blood sugar levels by stimulating active muscles to take up blood sugar without the need for insulin, effectively lowering blood sugar for at least 24 hours following exercise2. In addition to the non-insulin mediated absorption of sugar, exercise has been shown to lower the insulin resistance found in type 2 diabetes1.

To achieve blood sugar regulation benefits, people with diabetes should take part in both aerobic and resistance exercise. A minimum of 30 minutes per day for 5 days of the week should be allotted for aerobic exercise (e.g. brisk walking, swimming, jogging, bicycling, aerobics, dancing, etc) and at least two sessions per week of resistance exercise (weights and other forms of strength training) is recommended1.

Safety considerations with exercise and diabetes
For the majority of individuals with diabetes, participation at a moderate level (i.e. brisk walking) of physical activity is safe. However, individuals with certain pre-existing health concerns (autonomic or peripheral neuropathy, unstable angina, vision problems, or with presence of foot/leg ulcers), should speak to a health professional for further evaluation prior to starting a new exercise plan.

It is important to be aware that resistance training and vigorous aerobic activity (i.e. aerobics, jogging, brisk walking up an incline, etc.) can lead to an unsafe level of blood sugar in diabetics both during and post exercise. For example, vigorous exercise can cause low blood sugar (hypoglycemia) in diabetics who are on insulin or insulin secreting medications1-2. Thus it is important to first speak to a health care professional about how to safely monitor and regulate blood sugar before, during and after exercise.

Exercise is an essential component for the prevention and management of diabetes. It can help to regulate blood sugar levels, reduce risk of cardiovascular disease, and can reduce the risk of complications associated with diabetes.

If you have diabetes, or if you are at risk of developing diabetes, it is important that you ensure that your blood glucose levels are monitored and properly controlled. Diabetes treatment and blood glucose control should include a personalized diet and exercise plan that is tailored to one’s specific situation. In practice I help patients who are at risk of developing diabetes, or who have diabetes, to improve their blood sugar control through diet and exercise. If you have questions about diabetes, exercise, how to exercise safely with diabetes, or how Naturopathic Medicine can help you, please call 613-290-6115.

Graham Beaton is a Naturopathic Doctor practicing in Ottawa at the Ottawa Collaborative Care Centres.

1. Sigal, R.J. et al. Physical Activity and Diabetes – Canadian Diabetes Association Clinical Practice Guidelines Expert Committee. Can J Diabetes 37;2013:S40-44.
2. 2. Colberg, S. R. et al. Exercise and Type 2 Diabetes: the American College of Sports Medicine and the American Diabetes Association join position statement. Diabetes Care 2010;33(12):e147-e167.

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Exercise During Pregnancy and Infant Brain Development

Exercise and physical activity have been found to be important to improving one’s general health and in reducing risk of developing different diseases. Recently, there has been an increased amount of research looking into the effects of exercise during pregnancy on newborns. Two such studies were presented at the 2013 Society of Neuroscience’s annual conference in San Diego. Specifically, they looked to determine the effect of exercise during pregnancy on infant brain development. Taken together, results suggest that physical activity has a beneficial impact on brain development for children.

Study 1 – Maternal exercise during pregnancy improves object recognition memory in adult male offspring

Researchers from Dartmouth College in New Hampshire used Long Evans rats as subjects to examine the effects of maternal exercise on memory in their adult male offspring. In particular, pregnant female rats were divided into two groups following conception. In one group, exercise wheels were placed in their cages and the pregnant rats were free to exercise. In the second group, the pregnant rats were placed in cages that did not contain an exercise wheel. After the offspring were born, the wheels were removed from the cages of the “exercise” group and the rats in both groups remained with their mothers until they were weaned.

At 60 days post birth the ability of the male offspring to recognize objects from memory over a period of 24 hours was assessed. Findings revealed that rats whose mothers exercised during pregnancy, were better at recognizing objects, demonstrating improved memory, compared to rats whose mothers did not exercise during pregnancy. Moreover, rats whose mothers exercised were better able to recognize objects two weeks later, demonstrating improved long term memory capabilities.

Study 2 – Foetal brain development is influenced by maternal exercise during pregnancy
In this study, researchers at the University of Montreal recruited women who were in their first trimester of pregnancy and randomly assigned them to either an active (minimum 20 minutes of low intensity exercise 3 days per week throughout their pregnancy) or to a sedentary group, who did not exercise.

A short time after the children were born (e.g. 8-12 days), the electrical activity of the children’s brains in response to auditory cues were examined using EEG (i.e. electroencephalography – which uses electrodes placed on the scalp to measure underlying brain activity). Results of the study showed that exercise had a beneficial effect on the brain of the newborns such that infants born to active mothers had brainwave patterns that indicated that their brains were more mature compared to infants born to inactive mothers.

In conclusion, physical activity during pregnancy has been shown to benefit the brain development of newborns. These studies further reinforce the importance of physical activity and the role it plays in promoting and maintaining health.

Graham Beaton is a Naturopathic Doctor practicing in Ottawa. If you have questions about how Naturopathic Medicine can help during pregnancy, about prenatal health or for an appointment, please call 613-290-6115.

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Does walking affect the risk of developing breast cancer?

Graham Beaton BHSc, ND
Doctor of Naturopathic Medicine

Several studies have shown that the risk of developing postmenopausal breast cancer is lower in women who are physically active (1). To show this, studies typically compare breast cancer rates in women who participate in regular vigorous physical activity (jogging/running, tennis, racketball) to women who are physically inactive. While these studies clearly show why physical activity is important and suggest that postmenopausal women should participate in vigorous physical activity, many women will not participate in “vigorous” physical activity due to health concerns (for instance osteoporosis) or lack of interest. Thus a question that arises, is if a woman is unable or unwilling to participate in vigorous physical activity, can their risk of breast cancer be lowered with regular moderate physical activity (i.e. walking)? A recent study published in the journal Cancer Epidemiology, Biomarkers and Prevention looked to answer this question (2).

To explore the link between breast cancer and moderate physical activity, the researchers looked at cancer rates amongst postmenopausal women who participated in the CPS-II Nutrition Cohort (a prospective study of cancer incidence established by the American Cancer institute). The researchers collected information regarding levels of weekly physical activity (walking was the predominant form of physical activity) and categorized women into 3 separate groups: those who participated in moderate physical activity less than 3 hours per week, those active for 4 to 6 hours per week, and those who were active more than 7 hours per week.

Results of the study showed that women who were moderately physically active for more than 7 hours per week had a 14% lower risk of developing breast cancer compared to those who were moderately active for less than 3 hours per week. In accordance with previous results, results also confirmed that women who participated in vigorous activity had the greatest benefits, a 25% reduction in breast cancer risk.

These results provide evidence that physical activity even at a moderate level of intensity can have a large impact on one’s risk of developing breast cancer risk and overall health.

1. Friedenreich, CM. The role of physical activity in breast cancer etiology. Semin Oncol. 2010 Jun;37(3):297-302.

2. Hildebrand, J. S. et al. Recreational Physical Activity and Leisure-Time Sitting in Relation to Postmenopausal Breast Cancer Risk. Cancer Epidemiol Biomarkers Prev. 2013 Oct;22(10):1906-12

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