It is difficult to avoid the advice to exercise more if you want to look slimmer and maintain a healthy weight. But many of us simply have no desire or ability to run, or join a gym. But did you know that walking can help to prevent all manner of conditions including depression, Alzheimer’s disease, cancer, diabetes and memory loss? One doctor even prescribes walking to his cancer patients.
Size matters – at least in your brain
As we age, our brains shrink in size, with a resulting reduction in function. Hence it becomes harder to remember things and it takes us longer to do things. In patients with Alzheimer’s disease, this reduction in brain size is accelerated well beyond the normal shrinkage seen with age.
Researchers have found evidence that declines in a substance called brain-derived neurotrophic factor (BDNF) could also be important in memory loss, depression and shrinkage of the hippocampus.
Walking maintains the hippocampus
The good news is that research has shown that moderate intensity aerobic exercise (and brisk walking is an excellent choice) is not only associated with the maintenance of BDNF levels and hippocampal size, but could also reverse shrinkage. It was found that in the walkers the size of the hippocampus increased by 2% - making it equivalent in size to those in people 1 to 2 years younger.
The research team also found that those in the control group (who didn’t do the exercise) who were fitter at the start of the study had less hippocampal shrinkage than those who were less fit. This showed that even previous exercise had a protective effect on brain size.
Other studies have also shown a protective effect of exercise in warding off Alzheimer’s Disease. The earlier in life people develop Alzheimer’s, the worse the disease and outcomes tend to be. This research shows that at any age, walking as a form of exercise can help put off or possibly avoid a decline in memory and even the onset of Alzheimer’s.
Depression
It has also been found that depression is also associated with reduced levels of BDNF and shrinkage of the hippocampus. This may help to explain the known link between depression and Alzheimer’s disease. But since depression can occur at any age, this is worrying as it would seem to predispose people with depression to early onset of Alzheimer’s.
Other researchers have found significant improvements in people with depression who walked, and some concluded that walking had a similar effect to other forms of exercise — in some cases, antidepressants are not even needed, and exercise alone can be enough to lift depression.
Walking Improves Cancer Outcomes
Two studies have shown better outcomes in cancer treatment for people who exercise more. Both studies specifically investigated people who developed colon cancer and found that the outcomes were greatly improved in people who exercised both before and after their cancer diagnosis.
Walking prescribed for cancer patients
As a result, Dr John L Marshall MD, a cancer specialist at Georgetown University Hospital, Washington DC prescribes walking for his cancer patients. He advises patients to get a dog in order to make sure they walk regularly. He said the research showed that the reduction in patients’ risk of dying from colon cancer was greater than could be obtained by chemotherapy. He added that exercise both before and after diagnosis produced the greatest benefit, but even taking up exercise after being diagnosed with cancer proved to be very beneficial, showing again, that it’s never too late to start. He says he tells patients:
‘Now is the time for intensive physical activity. You always said you wanted to get in shape. Well, now is a good time to do it, and with good reason, because the magnitude of benefit of the physical activity may be, in fact, greater than the magnitude of chemotherapy.’
Walking protects against other cancers too
Other research studies have found that walking delayed progression of disease in men diagnosed with localized (not spread) prostate cancer. Of particular interest was the finding that brisk, as opposed to leisurely, walking produced the greatest health benefits. There was a 57% lower rate of progression in the men who walked briskly for 3 hours a week or more, compared with those who walked at a leisurely pace for less than 3 hours a week.
Another study found that brisk walking reduced a person's chances of developing breast cancer after the menopause (the most common time to develop the disease). They also found that stepping up the level of activity after the menopause, to more than half an hour every day, was more protective than continuance at a lower intensity.
Ward off diabetes by walking
Prediabetes is a condition often seen in overweight and obese people, where there is raised blood glucose and resistance to the effects of insulin. If the effects seen in prediabetes are not reversed, it will inevitably progress to type 2 diabetes, and the negative impact on health which that disease brings.
So whether you are currently healthy or battling diseases like cancer or Alzheimer’s, the message is clear, get a dog and start walking!
Sources & Links
- Erickson KI, et al. Exercise training increases size of hippocampus and improves memory.Proc Natl Acad Sci USA. 2011, 108(7),3017-22
- www.sciencedirect.com/science/article/pii/S1755296612000099
- cancerres.aacrjournals.org/content/71/11/3889.abstract?sid=7e535c9f-b340-4172-af30-0babb3be6d31
- Eliassen AH, et al. Physical activity and risk of breast cancer among postmenopausal women. Arch Intern Med.2010, 170(19), 1758-64
- Photo courtesy of Ted Eytan by Flickr : www.flickr.com/photos/taedc/7889236652/
- Photo courtesy of Philip Squires by Flickr : www.flickr.com/photos/philsquires/4810811506/
- www.ncbi.nlm.nih.gov/pmc/articles/PMC3575139/
- www.ncbi.nlm.nih.gov/pubmed/20975025?dopt=Abstract