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Meal Skipping Helps
Rodents Resist Diabetes, Brain Damage
A new mouse study suggests fasting every other day can help fend off
diabetes and protect brain neurons as well as or better than either vigorous
exercise or caloric restriction. The findings also suggest that reduced meal
frequency can produce these beneficial effects even if the animals gorged
when they did eat, according the investigators at the National Institute on
Aging (NIA).
“The implication of the new findings on the beneficial effects of regular
fasting in laboratory animals is that their health may actually improve if
the frequency of their meals is reduced,” says Mark Mattson, Ph.D., chief of
the NIA’s Laboratory of Neurosciences. “However, this finding, while
intriguing, will need to be explored further. Clearly, more research is
needed before we can determine the full impact that meal-skipping may have
on health.”
In the study*, published in the Proceedings of the National Academy of
Sciences Online Early Edition the week of April 28, 2003, Dr. Mattson
and his colleagues found mice that were fasted every other day but were
allowed to eat unlimited amounts on intervening days had lower blood glucose
and insulin levels than either a control group, which was allowed to feed
freely, or a calorically restricted group, which was fed 30 percent fewer
calories daily than the control group. Despite fasting, the meal-skipping
mice tended to gorge when provided food so they did not eat fewer calories
than the control group. This finding in mice suggests that meal-skipping
improves glucose metabolism and may provide protection against diabetes, Dr.
Mattson says.
In the same study, mice on these three diets were given a neurotoxin called
kainate, which damages nerve cells in a brain region called the hippocampus
that is critical for learning and memory. (In humans, nerve cells in the
hippocampus are destroyed by Alzheimer’s disease). Dr. Mattson’s team found
that nerve cells of the meal-skipping mice were more resistant to neurotoxin
injury or death than nerve cells of the mice on either of the other diets.
Previous studies by Dr. Mattson and his colleagues suggested that nerve
cells in the brains of rodents on a meal-skipping diet are more resistant to
dysfunction and death in experimental models of stroke and other
neurological disorders including Parkinson’s, Alzheimer’s and Huntington’s
diseases. Dr. Mattson also has found that meal-skipping diets can stimulate
brain cells in mice to produce a protein called brain-derived neurotrophic
factor (BDNF) that promotes the survival and growth of nerve cells.
Dr. Mattson and his colleagues are currently studying the effects of
meal-skipping on the cardiovascular system in laboratory rats. The findings
of this study, which compares the resting blood pressures and heart rates of
rats that were fasted every other day for six months with rats allowed to
eat unlimited amounts of food daily, should be available soon.
The NIA leads the Federal effort supporting and conducting biomedical,
clinical, social, and behavioral research on aging. This effort includes
research into the causes and treatment of Alzheimer’s disease, Parkinson’s
disease, stroke and other neurodegenerative disorders associated with age.
Press releases, fact sheets, and other materials about aging and aging
research can be viewed at the NIA’s general information Web site,
www.nia.nih.gov.
*RM Anson, Z Guo, R de Cabo, T Iyun, M Rios, A Hagepanos, DK Ingram, MA
Lane, MP Mattson, “Intermittent fasting dissociates beneficial effects of
dietary restriction on glucose metabolism and neuronal resistance to injury
from caloric intake,” Proceedings of the National Academy of Sciences
Online Early Edition the week of April 28, 2003 |
