JustGetMeIntoSpace,
I am going to retract this one, even though I really believe a flexitarain, high fiber diet is the optimal way to go personally. But I actually pulled up the full study and looked at it (instead of sound bites), and as far as I can figure out, there is a 2 gram difference in fiber between the high and low groups! Maybe I'm missing something, but it looks like this study is nonsense:
http://biomedgeronto...ona.glw091.full
If anyone finds out something different, i.e. that there really was a significant difference in fiber between high and low groups, I'd love to hear about it.
Don't give up so easily!
You are right - the deltas in fiber intake between the "healthy aging" group, the "suboptimal aging" group, and the "folks who died" group in the study in question [1] was small. Here are the figures: "healthy agers" (29g/day of fiber), "suboptimal agers" (27.7g/day of fiber) and people who died (26.4g/day of fiber). Nevertheless the associations between fiber intake and likelihood of successful aging were highly statistically significant (P < 0.0002). In fact you don't see P-values that significant in many nutrition studies.
The same was true in [2], a study of diet vs. mortality in the Baltimore Longitudinal Study of Aging (BLSA) cohort. The researchers in [3] measured the baseline diet of BLSA participants over a 7-day period and then followed them for 18 years to see which of them died, and what they'd be eating. From the free full text, here is what they found:
Survivors had significantly greater intakes of [fruits and vegetables], dietary fiber, magnesium, and vitamin C, and lower intakes of saturated fat than those who died from CHD or other causes, and higher intake of folate than those who died from CHD.
Even more astonishing, they found that:
In fully adjusted models ... dietary fiber [showed] a 6% reduction [in mortality risk] / g (P < 0.05).
In other words, each extra gram per day of fiber someone in the BLSA cohort ate during the 7-day baseline period was associated with a 6% lower likelihood of dying during the 18y follow-up period. Further, the beneficial fiber effect was largely associated with the kind of fiber we eat most around here - the fiber in fruits and veggies. Once again, the absolute amount of fiber these BLSA men were eating was small (long-lived = 21.8g fiber / day vs short-lived = 16.8g fiber / day). But again the correlation between fiber intake and reduced mortality was highly significant.
But perhaps the best evidence in favor of high fiber comes from the vegan Adventists studied in [3]. They eat twice as much fiber as all the folks in [1] and [2] (46g/day) and live the longest of all on average (men ~87 years). Even comparing within different Adventist subpopulations, there is a nice correlation between fiber intake and reduced mortality over a significant range of fiber consumption. Specifically, the vegan Adventists eat 50% more fiber than the omnivorous Adventists (46g vs. 30g), and had a 15% reduced mortality rate over about 6 years of follow-up in [3].
So while many of us whole-food, plant-based folks (and doubless the flexitarians as well) eat a lot more fiber than even the vegan Adventists, it looks like on whole fiber does appear to have strong health and longevity boosting effects.
--Dean
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[1] J Gerontol A Biol Sci Med Sci. 2016 Jun 1. pii: glw091. [Epub ahead of print]
Association Between Carbohydrate Nutrition and Successful Aging Over 10 Years.
Gopinath B(1), Flood VM(2), Kifley A(3), Louie JC(4), Mitchell P(3).
BACKGROUND: We prospectively examined the relationship between dietary glycemic
index (GI) and glycemic load (GL), carbohydrate, sugars, and fiber intake
(including fruits, vegetable of breads/cereals fiber) with successful aging
(determined through a multidomain approach).
METHODS: A total of 1,609 adults aged 49 years and older who were free of cancer,
coronary artery disease, and stroke at baseline were followed for 10 years.
Dietary data were collected using a semiquantitative Food Frequency
Questionnaire. Successful aging status was determined through
interviewer-administered questionnaire at each visit and was defined as the
absence of disability, depressive symptoms, cognitive impairment, respiratory
symptoms, and chronic diseases (eg, cancer and coronary artery disease).
RESULTS: In all, 249 (15.5%) participants had aged successfully 10 years later.
Dietary GI, GL, and carbohydrate intake were not significantly associated with
successful aging. However, participants in the highest versus lowest (reference
group) quartile of total fiber intake had greater odds of aging successfully than
suboptimal aging, multivariable-adjusted odds ratio (OR), 1.79 (95% confidence
interval [CI] 1.13-2.84). Those who remained consistently below the median in
consumption of fiber from breads/cereal and fruit compared with the rest of
cohort were less likely to age successfully, OR 0.53 (95% CI 0.34-0.84) and OR
0.64 (95% CI 0.44-0.95), respectively.
CONCLUSIONS: Consumption of dietary fiber from breads/cereals and fruits
independently influenced the likelihood of aging successfully over 10 years.
These findings suggest that increasing intake of fiber-rich foods could be a
successful strategy in reaching old age disease free and fully functional.
PMID: 27252308
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[2] J Nutr. 2005 Mar;135(3):556-61.
The combination of high fruit and vegetable and low saturated fat intakes is more
protective against mortality in aging men than is either alone: the Baltimore
Longitudinal Study of Aging.
Tucker KL(1), Hallfrisch J, Qiao N, Muller D, Andres R, Fleg JL; Baltimore
Longitudinal Study of Aging.
Author information:
(1)Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University,
Boston, MA, USA. katharine.tucker@tufts.edu
Saturated fat (SF) intake contributes to the risk of coronary heart disease (CHD)
mortality. Recently, the protective effects of fruit and vegetable (FV) intake on
both CHD and all-cause mortality were documented. However, individuals consuming
more FV may be displacing higher-fat foods. Therefore, we investigated the
individual and combined effects of FV and SF consumption on total and CHD
mortality among 501 initially healthy men in the Baltimore Longitudinal Study of
Aging (BLSA). Over a mean 18 y of follow-up, 7-d diet records were taken at 1-7
visits. Cause of death was ascertained from death certificates, hospital records,
and autopsy data. After adjustment for age, total energy intake, BMI, smoking,
alcohol use, dietary supplements, and physical activity score, FV and SF intakes
were individually associated with lower all-cause and CHD mortality (P < 0.05).
When both FV and SF were included in the same model, associations of each were
attenuated with CHD mortality, and no longer significant for all-cause mortality.
Men consuming the combination of > or =5 servings of FV/d and < or =12% energy
from SF were 31% less likely to die of any cause (P < 0.05), and 76% less likely
to die from CHD (P < 0.001), relative to those consuming < 5 FV and >12% SF. Men
consuming either low SF or high FV, but not both, did not have a significantly
lower risk of total mortality; but did have 64-67% lower risk of CHD mortality (P
< 0.05) relative to those doing neither. These results confirm the protective
effects of low SF and high FV intake against CHD mortality. In addition, they
extend these findings by demonstrating that the combination of both behaviors is
more protective than either alone, suggesting that their beneficial effects are
mediated by different mechanisms.
PMID: 15735093
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[3] JAMA Intern Med.. 2013 Jul 8;173(13):1230-8.. doi: 10.1001/jamainternmed.2013.6473.
Vegetarian dietary patterns and mortality in Adventist Health Study 2.
Orlich MJ(1), Singh PN, Sabaté J, Jaceldo-Siegl K, Fan J, Knutsen S, Beeson WL,
Fraser GE.
Author information:
(1)School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA.
morlich@llu.edu
Comment in
JAMA Intern Med.. 2014 Jan;174(1):168-9.
JAMA Intern Med.. 2014 Jan;174(1):169.
JAMA Intern Med.. 2013 Jul 8;173(13):1238-9.
Dtsch Med Wochenschr.. 2013 Sep;138(39):1930.
IMPORTANCE: Some evidence suggests vegetarian dietary patterns may be associated
with reduced mortality, but the relationship is not well established.
OBJECTIVE: To evaluate the association between vegetarian dietary patterns and
mortality.
DESIGN: Prospective cohort study; mortality analysis by Cox proportional hazards
regression, controlling for important demographic and lifestyle confounders.
SETTING: Adventist Health Study 2 (AHS-2), a large North American cohort.
PARTICIPANTS: A total of 96,469 Seventh-day Adventist men and women recruited
between 2002 and 2007, from which an analytic sample of 73,308 participants
remained after exclusions.
EXPOSURES: Diet was assessed at baseline by a quantitative food frequency
questionnaire and categorized into 5 dietary patterns: nonvegetarian,
semi-vegetarian, pesco-vegetarian, lacto-ovo-vegetarian, and vegan.
MAIN OUTCOME AND MEASURE: The relationship between vegetarian dietary patterns
and all-cause and cause-specific mortality; deaths through 2009 were identified
from the National Death Index.
RESULTS: There were 2570 deaths among 73,308 participants during a mean follow-up
time of 5.79 years.. The mortality rate was 6.05 (95% CI, 5.82-6.29) deaths per
1000 person-years.. The adjusted hazard ratio (HR) for all-cause mortality in all
vegetarians combined vs nonvegetarians was 0.88 (95% CI, 0.80-0.97).. The adjusted
HR for all-cause mortality in vegans was 0.85 (95% CI, 0.73-1.01); in
lacto-ovo-vegetarians, 0.91 (95% CI, 0.82-1.00); in pesco-vegetarians, 0.81 (95%
CI, 0.69-0.94); and in semi-vegetarians, 0.92 (95% CI, 0.75-1.13) compared with
nonvegetarians.. Significant associations with vegetarian diets were detected for
cardiovascular mortality, noncardiovascular noncancer mortality, renal mortality,
and endocrine mortality.. Associations in men were larger and more often
significant than were those in women.
CONCLUSIONS AND RELEVANCE: Vegetarian diets are associated with lower all-cause
mortality and with some reductions in cause-specific mortality.. Results appeared
to be more robust in males.. These favorable associations should be considered
carefully by those offering dietary guidance.
PMCID: PMC4191896
PMID: 23836264
Edited by deanp, 13 June 2016 - 10:17 PM.