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Aging News for Seniors
Low Calorie Diet Wins over Exercise in Extending
Life Up to 50 Percent
Diet and exercise prevent of age-related disease,
but reducing calories needed to slow aging
May 31, 2006 If you prefer dieting to exercise,
you may be in luck, assuming you, like most senior citizens, are seeking
ways to live longer. A new study found that only calorie restriction
not exercise increases the maximum lifespan up to 50 percent.
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Related Stories |
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Cutting a Few Calories, Taking Short Walks May
Reverse Aging Damage
Study shows it can
even reverse aging cell and organ damage
May 8, 2006 - A lifelong habit of trimming just a
few calories from the daily diet can do more than slim the waistline - a
new study shows it may help lessen the effects of aging. Scientists from
the University of Florida's Institute on Aging have found that eating a
little less food and exercising a little more over a lifespan can reduce
or even reverse aging-related cell and organ damage in rats.
Read more...
Inability of Elderly to Walk Quarter-Mile is
Predictor of Death, Poor Health
May 2, 2006 Elderly people, who cannot walk 400
meters, or about a quarter mile, may not be here to try it six years
from now and may suffer considerable illness and disability during that
time, according to a study of senior citizens ages 70 through 79.
Walking fitness makes a significant difference in predicting the
likelihood of future disability in the elderly, according to a study
published today in the Journal of the American Medical Association.
Read more...
Older Women Who Sleep Least Gain Most Weight
Appetite and diet not accounting for weight gain in
women who sleep less
May 23, 2006 - Women who sleep 5 hours or less per
night weigh more on average than those who sleep 7 hours, according to a
study of middle-aged women to be presented at the American Thoracic
Society International Conference today.
Read more...
Elderly May Need Extra Pounds to Live Longer Lives
Body Mass Index may need to be adjusted for those
over 80
May 16, 2006 - If youre more than 80 years old,
carrying a few extra pounds might not be such a bad idea. In fact, it
may be beneficial. Thats one of the findings from a joint UC Irvine and
University of Southern California analysis of body mass index (BMI) and
mortality rates from participants of a large-scale study based in a
Southern California retirement community.
Read
more...
Two Studies Indicate We Can Live Longer,
Better With Proper
Diets
Reducing calories
worked in one, DASH diet with exercise in the second
April 5, 2006 Two studies released this week
indicates that diets one reducing calories and the other using the
DASH diet can make a significant contribution to longer life. Reducing
calories, even without more physical activity, over six months resulted
in a decrease in fasting insulin levels and body temperature, two
biomarkers of longevity. The DASH study was of people with elevated
blood pressure who increased physical activity while eating on the DASH
plan, resulting in much lower hypertension and less risk of the major
killers heart disease and stroke.
Read
more...
Read more
on
Aging News |
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Previous research on mice and rats has shown that
both calorie restriction (CR) and endurance exercise protect them
against many chronic diseases including obesity, diabetes,
cardiovascular disease and some types of cancer. However, this new
research has shown that only CR increases the lifespan.
These animal studies suggest that leanness is a key
factor in the prevention of age-associated disease, but reducing caloric
intake is needed to slow down aging.
Investigators at Washington University School of
Medicine in St. Louis have found that eating a low-calorie yet
nutritionally balanced diet lowers concentrations of a thyroid hormone
called triiodothyronine (T3), which controls the body's energy balance
and cellular metabolism.
The researchers also found that calorie restriction
decreases the circulating concentration of a powerful inflammatory
molecule called tumor necrosis factor alpha (TNF). They say the
combination of lower T3 levels and reduced inflammation may slow the
aging process by reducing the body's metabolic rate as well as oxidative
damage to cells and tissues.
For the new study, researchers examined 28 members
of the Calorie Restriction Society who had been eating a CR diet for an
average of six years. Although the CR group consumed fewer calories --
averaging only about 1,800 per day -- they consumed at least 100 percent
of the recommended daily amounts of protein and micronutrients.
A second group of 28 study subjects was sedentary,
and they ate a standard Western diet.
A third group in the study ate a standard Western
diet -- approximately 2,700 calories per day -- but also did endurance
training. The researchers found reduced T3 levels -- similar to those
seen in animals whose rate of aging is reduced by CR -- only in the
people on CR diets.
But their serum concentrations of two other
hormones -- thyroxin (T4) and thyroid stimulating hormone (TSH) -- were
normal, indicating that those on CR were not suffering from the thyroid
disease of clinical hypothyroidism. The findings are published online in
the Journal of Clinical Endocrinology and Metabolism.
Interestingly, body fat levels did not affect serum
T3 concentrations. The people in the CR group and the endurance athletes
had similar amounts and composition of body fat. But although the CR
group had lower T3 levels, the exercise group had T3 levels closer to
those seen in the sedentary people who ate a standard Western diet.
"The difference in T3 levels between the CR group
and the exercise group is exciting because it suggests that CR has some
specific anti-aging effects that are due to lower energy intake, rather
than to leanness," says first author Luigi Fontana, M.D., Ph.D.,
assistant professor of medicine at Washington University in St. Louis
and an investigator at the Istituto Superiore di Sanita, Rome, Italy.
"These findings suggest that although exercise
helps prevent problems that can cut life short -- such as obesity,
diabetes and cardiovascular disease -- only CR appears also to have an
impact on primary aging."
Primary aging determines maximal length of life.
Secondary aging, on the other hand, refers to diseases that can keep a
person or an animal from reaching that expected lifespan. Eliminating
factors related to secondary aging allows more people to reach their
projected length of life. By slowing primary aging, CR may increase
maximal lifespan.
In a related study in 1997, co-investigator John O.
Holloszy, M.D., professor of medicine at Washington University School of
Medicine, reported in the Journal of Applied Physiology that in rats, CR
extended life longer than exercise.
"Sedentary rats who ate a standard diet had the
shortest average life-spans," Holloszy says. "Those who exercised by
running on a wheel lived longer, but animals on calorie restriction
lived even longer."
Earlier this year, Fontana's group reported that CR
seemed to prevent or delay primary aging in the heart. Ultrasound
examinations showed that the hearts of people on calorie restriction
were more elastic than those of age- and gender-matched control
subjects. Their hearts were able to relax between beats in a way similar
to the hearts of younger people.
This latest study targeted another marker of
primary aging. The thyroid gland produces critical hormones that play an
indispensable role in cell growth and development as well as in lipid
and carbohydrate metabolism.
T4 is the main product secreted by the cells of the
thyroid gland, but most actions of thyroid hormone are initiated by T3.
Fontana says T3 controls body temperature, cellular metabolism and to
some extent, it also appears to be involved with production of free
radicals, unstable molecules that can damage cells. All are important
aspects of aging and longevity.
In fact, a 2002 study in Science magazine from
researchers at the National Institute on Aging observed that men with
lower body temperatures tended to live longer those with higher body
temperatures.
Fontana says lower levels of T3, cholesterol and
the inflammatory molecules TNF and C-reactive protein, combined with
evidence of "younger" hearts in people on calorie restriction, suggest
that humans on CR have the same adaptive responses as did animals whose
rates of aging were slowed by CR.
Holloszy and Fontana are getting ready to launch a
2-year study to look at the effects of calorie restriction. Later this
year, they will begin recruiting volunteers between the ages of 25 and
45 who are willing to go on a CR diet for 24 months.
Called the Comprehensive Assessment of the Long
Term effects of Reducing Intake of Energy (CALERIE) study, the goal is
to get some clues about whether putting a normal weight person on
calorie restriction will lower their levels of inflammation and their
serum concentrations of T3, improve their heart function and change
other markers of aging, as Fontana and Holloszy have observed in members
of the Calorie Restriction Society.
"We want to learn whether calorie restriction can
reverse some of these markers of aging in healthy people," Holloszy
says. "It's going to be many years before we know whether calorie
restriction really lengthens life, but if we can demonstrate that it
changes these markers of aging, such as oxidative damage and
inflammation, we'll have a pretty good idea that it's influencing aging
in the same way that CR slows aging in experimental animals."
About study:
Fontana L, Keline S, Holloszy JO,
Premachandra BN. Effect of long-term calorie restriction with adequate
protein and micronutrients on thyroid hormones. Journal of Clinical
Endocrinology and Metabolism, first published ahead of print May 23,
2006 as doi: 10.1210/jc 2006-0328.
This research was supported by the
National Institutes of Health.
Related
articles:
Fontana L. Excessive adiposity, calorie
restriction and aging in humans. Journal of the American Medical
Association, vol. 293:13, April 5, 2006.
Meyer TE, Kovacs SJ, Ehsani AA, Klein S,
Holloszy JO, Fontana L. Long-term caloric restriction ameliorates the
decline in diastolic function in humans. Journal of the American College
of Cardiology, vol. 47:2, pp. 398-402, Jan. 17, 2006.
Holloszy JO. Mortality rate and
longevity of food-restricted exercising male rats: a reevaluation.
Journal of Applied Physiology, vol. 82, pp. 399-403, Feb. 1997.
Roth GS, Lane MA, Ingram DK, Mattison
JA, Elahi D, Tobin JD, Muller D, Metter EJ. Biomarkers of caloric
restriction may predict longevity in humans. Science, vol. 297, p. 811,
Aug. 2, 2002.
Washington University School of
Medicine's full-time and volunteer faculty physicians also are the
medical staff of Barnes-Jewish and St. Louis Children's hospitals. The
School of Medicine is one of the leading medical research, teaching and
patient care institutions in the nation, currently ranked fourth in the
nation by U.S. News & World Report. Through its affiliations with
Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine
is linked to BJC HealthCare.
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