Eat Less Or Exercise More? Either Way Leads To More Youthful Hearts

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" By the end of the yearlong study, both the calorie restriction and

exercise groups of volunteers lost 12 percent of their weight and 12

percent of their body mass index (BMI), a measurement considered to be

a fairly reliable indicator of the amount of body fat. In both groups,

participants' hearts responded to this weight loss by gaining the

ability to relax more quickly, recovering some of the elasticity

characteristic of younger heart tissue. Those in the calorie

restriction group achieved slightly more reduction of heart stiffness. "

Don't CRON'er exercise too? maybe not as much but generally most do

engage in some right? So, doesn't this really say that exercise is

very good, and that the addition of CRON to exercise only slightly

better for the aspects of heart function recorded in this study?

Eat Less Or Exercise More? Either Way Leads To More Youthful Hearts

ScienceDaily (Jan. 11, 2008) — Overweight people who lose a moderate

amount of weight get an immediate benefit in the form of better heart

health, according to a study conducted at Washington University School

of Medicine in St. Louis. And the heart improvements happen whether

that weight is shed by eating less or exercising more.

" If individuals want to do something that's good for their heart, then

my message to them is lose weight by the method they find most

tolerable, " says the study's senior author Sándor J. Kovács, Ph.D,

M.D., director of the Cardiovascular Biophysics Laboratory and

professor of medicine. " They're virtually guaranteed that it will have

a salutary effect on their cardiovascular system. "

Studying a group of healthy, overweight but not obese, middle-aged men

and women, the researchers found that a yearlong regimen of either

calorie restriction or exercise increase had positive effects on heart

function. Their analysis revealed that heart function was restored to

a more youthful state so that during the heart's filling phase (called

diastole) it took less time for participants' hearts to relax and fill

with blood.

" As we get older, our tissues become more fibrotic as collagen fibers

accumulate, " says study co-author O. Holloszy, M.D., professor of

medicine in the Division of Geriatrics and Nutritional Science. " So

the arteries and heart muscle stiffen, and the heart doesn't relax as

well after contracting. Similar studies that we've conducted with

members of the Caloric Restriction with Optimal Nutrition Society

(CRONies) show they have heart function resembling much younger

people. " CRONies voluntarily consume about 25 percent fewer calories

than the average American while still maintaining good nutrition.

The scientists used ultrasound imaging (echocardiography) to measure

the diastolic or filling phase of the cardiac cycle because it is a

crucial indicator of heart health. " During filling, the left ventricle

is a suction pump, " Kovács explains. " Think of the rubber bulb of an

old-fashioned bicycle horn -- you squeeze it (the analog of the

ejection phase of the cardiac cycle), then let go (the analog of the

filling or diastolic phase) and the rubber bulb springs back to its

original shape, sucking air back in. Similarly, the heart's muscle and

connective tissue are elastic, and after ejecting blood to the body

during contraction (systole), the left ventricle springs back to draw

in new blood (diastole). It's during this filling phase of the cardiac

cycle that subtle changes in heart health can be most readily detected. "

By the end of the yearlong study, both the calorie restriction and

exercise groups of volunteers lost 12 percent of their weight and 12

percent of their body mass index (BMI), a measurement considered to be

a fairly reliable indicator of the amount of body fat. In both groups,

participants' hearts responded to this weight loss by gaining the

ability to relax more quickly, recovering some of the elasticity

characteristic of younger heart tissue. Those in the calorie

restriction group achieved slightly more reduction of heart stiffness.

Cardiologists can measure delicate alterations in diastolic function

because of the work of Kovács, also professor of cell biology and

physiology and adjunct professor of physics and of biomedical

engineering, who developed a methodology called parameterized

diastolic filling (PDF) formalism, which analyzes the filling of the

heart according to physical laws and determines the chamber's

elasticity and stiffness. Previous studies in humans using the PDF

formalism have shown that it's a more sensitive and specific predictor

of cardiovascular health than conventional indexes of heart function

determined by echocardiography.

Although previous studies also have indicated that the heart benefits

from weight loss, those studies were performed on morbidly obese

people, few focused on diastolic function and none used the

sophisticated PDF formalism. By looking at filling function in

healthy, non-obese people using PDF formalism, the researchers in the

current study were able to understand in more detail how normal hearts

react to moderate weight loss.

The detailed analysis showed that in both groups, the left ventricle

gained an increased capacity to expand to accommodate blood entering

during diastole. In the calorie restriction group, the global

stiffness of the left ventricle decreased, suggesting that the muscle

and connective tissue of the heart more readily sprang back after the

contraction phase. This group also experienced a decrease in the

internal pressure gradient, indicating that their left ventricles had

better suction ability.

The study participants were nonsmokers between ages 50 and 60 and had

BMIs between 23.5 and 30, making them high normal to overweight. None

of the participants had diabetes, coronary artery disease, stroke,

hypertension, cancer or lung disease. Before enrolling in the study,

all were relatively sedentary -- they exercised less than 20 minutes a

day or twice a week.

Twelve participants (four men and eight women) were in the calorie

restriction group, in which volunteers reduced the amount of calories

they ate between 12 percent and 15 percent. Their physical activity

did not change. Thirteen participants (six men and seven women) were

in the exercise group and increased their exercise to burn the caloric

equivalent of the other group's caloric reduction. The exercise group

exercised about six days a week for an hour each session walking,

running, cycling or doing elliptical training. Their caloric intake

did not change.

Kovács said he feels the study offers encouragement for those who are

overweight. " One reason that it's hard to get people to change their

behavior and lose weight is that we warn them about consequences of

being overweight that might occur sometime in the future -- we say if

your BMI is too high, eventually you'll develop heart disease,

diabetes or hypertension, " Kovács says. " But now we can tell them,

lose weight and right away you can have better cardiovascular health. "

This study was part of a larger trial, CALERIE (Comprehensive

Assessment of Long-term Effects of Reducing Intake of Energy),

designed to investigate the feasibility of long-term calorie

restriction in humans. CALERIE investigators have begun a second phase

of their study in which they will determine the effect of calorie

restriction in younger people, age 25 to 45.

Journal reference: Riordan MM, Weiss EP, Meyer TE, Ehsani AA, Racette

SB, Villareal DT, Fontana L, Holloszy JO, Kovács SJ. The effects of

caloric restriction- and exercise-induced weight loss on left

ventricular diastolic function. American Journal of Physiology. Heart

and Circulatory Physiology. 2007 Dec 27; advance online publication.

Funding from the National Institutes of Health, the Whitaker

Foundation, the Alan A. and Edith L. Wolff Charitable Trust and the

-Jewish Hospital Foundation supported this research.

[Guest guest]

Hi All, The pdf is availed. http://tinyurl.com/37xju8 Riordan MM, Weiss EP, Meyer TE, Ehsani AA, Racette SB, Villareal DT, Fontana L, Holloszy JO, Kovacs SJ. The Effects of Caloric Restriction- and Exercise-Induced Weight Loss on Left Ventricular Diastolic Function.Am J Physiol Heart Circ Physiol. 2007 Dec 27; [Epub ahead of print] PMID: 18162561 http://tinyurl.com/3827kr

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Hi folks:

One way to interpret this, I suggest, may be as follows:

When people exercise, greater amounts of nutrients are required by

many muscles all around the body. The heart responds to this by

beating faster to circulate more blood. So the heart is put to work

and, in response to what is sometimes called 'training effect',

unsurprisingly perhaps, becomes better at doing its job. Most

muscles improve their performance over time when a training load is

applied.

However, it could be considered quite surprising if not remarkable,

that simply eating less can have even better effects on the heart's

effectiveness even without its having to exert itself. Were it not

for the evidence of the benefits of CRON with which we are all

familiar, that is not something I would have expected.

So, 'BRAVO to CRON' is my response to this.

Of course there are many other aspects of heart health that this

paper did not attempt to address - clogged arteries for example. In

people established on CRON carotid IMT measurements indicate little

if any carotid artery plaque. Whether exercise would have effects

on these other factors as beneficial as those of CRON remains to be

demonstrated, as far as I know.

I wonder whether the benefits found in the exercisers were a

consequence of the weight loss or the training effect.

Rodney.

--- In , Al Pater <old542000@...>

wrote:

>

> Hi All,

>

> The pdf is availed.

>

> http://tinyurl.com/37xju8

>

> Riordan MM, Weiss EP, Meyer TE, Ehsani AA, Racette SB, Villareal

DT, Fontana L, Holloszy JO, Kovacs SJ.

> The Effects of Caloric Restriction- and Exercise-Induced Weight

Loss on Left Ventricular Diastolic Function.

> Am J Physiol Heart Circ Physiol. 2007 Dec 27; [Epub ahead of

print]

> PMID: 18162561 http://tinyurl.com/3827kr

>

>

>

>

> ---------------------------------

> Never miss a thing. Make your homepage.

>

[Guest guest]

I noticed Luigi Fontana was an author on a paper linked to the one

Rodney discusses below, but in the other paper they compared the

effect of CR and exercise on bone mineral density:

http://snipurl.com/1x7u5

They concluded by recommending that CRONers should be exercising to

preserve BMD.

-Diane

> >

> > Hi All,

> >

> > The pdf is availed.

> >

> > http://tinyurl.com/37xju8

> >

> > Riordan MM, Weiss EP, Meyer TE, Ehsani AA, Racette SB, Villareal

> DT, Fontana L, Holloszy JO, Kovacs SJ.

> > The Effects of Caloric Restriction- and Exercise-Induced Weight

> Loss on Left Ventricular Diastolic Function.

> > Am J Physiol Heart Circ Physiol. 2007 Dec 27; [Epub ahead of

> print]

> > PMID: 18162561 http://tinyurl.com/3827kr

> >

> >

> >

> >

> > ---------------------------------

> > Never miss a thing. Make your homepage.

> >

>