9 replies to this topic

[InquilineKea]

http://www.nih.gov/n...2015/nia-01.htm

 

The study was designed to test the effects of calorie restriction on resting metabolic rate (after adjusting for weight loss) and body temperature, which are diminished in many laboratory animal studies and have been proposed to contribute to its effects on longevity. The study found a temporary effect on resting metabolic rate, which was not significant at the end of the study, and no effect on body temperature.

Although the expected metabolic effects were not found, calorie restriction significantly lowered several predictors of cardiovascular disease compared to the control group, decreasing average blood pressure by 4 percent and total cholesterol by 6 percent. Levels of HDL (“good”) cholesterol were increased. Calorie restriction caused a 47-percent reduction in levels of C-reactive protein, an inflammatory factor linked to cardiovascular disease. It also markedly decreased insulin resistance, which is an indicator of diabetes risk. T3, a marker of thyroid hormone activity, decreased in the calorie restriction group by more than 20 percent, while remaining within the normal range. This is of interest since some studies suggest that lower thyroid activity may be associated with longer life span.

 

 

Hmm.. Thoughts?

[scottknl]

No real surprise there.   All those changes jive with what I experienced when going onto a CRON diet (5 yrs) and the tests I took before and after. An example would be my blood pressure dropped from 118/83 to 106/64 before/after CRON.  Total Cholesterol dropped from 232 (on meds, no CRON) to 138 (no meds, CRON diet).  And I could go on...etc.  Just like in all the animal studies CR is great for cardiovascular health and cancer avoidance.  

[ta5]

No real surprise there.   All those changes jive with what I experienced when going onto a CRON diet (5 yrs) and the tests I took before and after. An example would be my blood pressure dropped from 118/83 to 106/64 before/after CRON. 

 

106 systolic is lower than optimal, and your pulse pressure worsened, from 35 up to 42. It's not bad, but not really an improvement. 

[scottknl]

 

No real surprise there.   All those changes jive with what I experienced when going onto a CRON diet (5 yrs) and the tests I took before and after. An example would be my blood pressure dropped from 118/83 to 106/64 before/after CRON. 

 

106 systolic is lower than optimal, and your pulse pressure worsened, from 35 up to 42. It's not bad, but not really an improvement. 

 

Yeah, but it matches what the OP said "decreasing average blood pressure...".  And as for 106 being below optimal, I don't experience any bad effects from my blood pressure at this level.  I just ran 27 miles in the last 3 days with no problems, so it my body seems to work for me.

 

Do you know of any resources that link lower pulse pressure to increased longevity?

[Brett Black]

 

No real surprise there.   All those changes jive with what I experienced when going onto a CRON diet (5 yrs) and the tests I took before and after. An example would be my blood pressure dropped from 118/83 to 106/64 before/after CRON. 

 

106 systolic is lower than optimal, and your pulse pressure worsened, from 35 up to 42. It's not bad, but not really an improvement. 

 

 

Why is 106 systolic lower than optimal? Do you have any studies/evidence that support that?
 

[Darryl]

Prospective Studies Collaboration. 2002. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. The Lancet, 360(9349), 1903-1913.

 

 

Throughout middle and old age, usual blood pressure is strongly and directly related to vascular (and overall) mortality, without any evidence of a threshold down to at least 115/75 mm Hg

 

Looking for mortality studies with populations that offer adequate tests of the lower range of blood pressures, I found:

 

Neaton JD & Wentworth D. 1992. Serum cholesterol, blood pressure, cigarette smoking, and death from coronary heart disease overall findings and differences by age for 316099 white men. Archives of internal medicine,152(1), 56-64.

 

Age adjusted CHD death rate (per 10000 person years) was lowest for:

 

 

systolic

 91-100   9.6

101-110   8.9

111-120  10.5

121-130  13.3

 

diastolic  

60-65    12.8

66-70    10.4

71-75    11.8

76-80    13.6

 

Suggesting its perfectly healthy to lower blood pressure all the way down to 100 / 65

 

Most of the studies suggesting a risk with hypotension focus on orthostatic hypotension: large drops in blood pressure between measurements in supine and standing positions (commonly systolic >20 mm Hg, diastolic > 10 mm Hg), but that's more a marker of frailty in the elderly. I doubt a person running 27 miles in 3 days suffers from that, but note that exercise level is also pushing into the realm of adverse cardiovascular remodelling, patchy myocardial fibrosis and arrhythmia 

[Darryl]

Note, there is a U-shaped risk profile for blood pressure in hemodialysis patients, myocardial infarction survivors, and acute stroke admissions:

 

Zager PG et al. 1998. “U” curve association of blood pressure and mortality in hemodialysis patients. Kidney international, 54(2), 561-569.

Flack JM et al. 1995. Blood pressure and mortality among men with prior myocardial infarction. Circulation, 92(9), 2437-2445.

Vemmos KN  et al. 2004. U‐shaped relationship between mortality and admission blood pressure in patients with acute stroke. Journal of internal medicine, 255(2), 257-265.

 

This of course says nothing about optimal BP for minimizing all-cause mortality in healthy people.

 

This study suggests that 10 year mortality risk increases with diastolic pressure below 65 mm Hg in ambulatory elderly Japanese villagers, in accord with the Neaton paper.

 

Kikuya M et al. 2005. Ambulatory blood pressure and 10-year risk of cardiovascular and noncardiovascular mortality the Ohasama study.Hypertension, 45(2), 240-245. 

[scottknl]

Prospective Studies Collaboration. 2002. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. The Lancet, 360(9349), 1903-1913.

 

 

Throughout middle and old age, usual blood pressure is strongly and directly related to vascular (and overall) mortality, without any evidence of a threshold down to at least 115/75 mm Hg

 

Looking for mortality studies with populations that offer adequate tests of the lower range of blood pressures, I found:

 

Neaton JD & Wentworth D. 1992. Serum cholesterol, blood pressure, cigarette smoking, and death from coronary heart disease overall findings and differences by age for 316099 white men. Archives of internal medicine,152(1), 56-64.

 

Age adjusted CHD death rate (per 10000 person years) was lowest for:

 

 

systolic

 91-100   9.6

101-110   8.9

111-120  10.5

121-130  13.3

 

diastolic  

60-65    12.8

66-70    10.4

71-75    11.8

76-80    13.6

 

Suggesting its perfectly healthy to lower blood pressure all the way down to 100 / 65

 

Most of the studies suggesting a risk with hypotension focus on orthostatic hypotension: large drops in blood pressure between measurements in supine and standing positions (commonly systolic >20 mm Hg, diastolic > 10 mm Hg), but that's more a marker of frailty in the elderly. I doubt a person running 27 miles in 3 days suffers from that, but note that exercise level is also pushing into the realm of adverse cardiovascular remodelling, patchy myocardial fibrosis and arrhythmia 

Thanks, Darryl.  That study is a good refutation of ta5's post.  That study is getting a little bit old and in the meantime people have decreased their transfats intake greatly, so I'd expect all the mortality levels to have decreased across the board.  I'm 50, and very healthy, so those U shaped risks will not likely apply.  If you take the above study on blood pressure and allow for my low cholesterol and the 58 HDL score, and CRON diet my risk for CHD is very low(as it is for everyone doing a CRON diet).  The exercise regimen is temporary as it's a challenge to myself to do 50 miles running in 5 days this year.  I'll go back to my regular ~15 miles per week once the challenge is finished because I believe that it's the optimal amount of exercise for my longevity.

[ta5]

Do you know of any resources that link lower pulse pressure to increased longevity?

 

Articles with pulse pressure and mortality in the title.

[ta5]

Why is 106 systolic lower than optimal? Do you have any studies/evidence that support that?

 

Darryl posted studies showing the U-shaped curve in certain conditions, but I shouldn't have said 106 is lower than optimal in general or in healthy people.