Notably, protein intake was quite high in this cohort: Median intake was 1. As mentioned, within subsets of the present study population, we previously observed beneficial associations of protein intake and quadriceps strength 2 , as well as 6-year change in grip strength 5.

A recent study in 1, community-dwelling older Quebecois adults age 67—84 years observed beneficial associations between total protein intake and 3-year changes in physical performance as assessed by a composite score of muscle strength in both men and women Mean protein intake was approximately 1.

However, these associations were not significant after controlling for fat mass and were generally more evident in women without sarcopenia, suggesting fat mass may be playing a mediating role between protein intake and some aspects of function.

Interestingly, although our results in the total population were statistically significant, stratified analyses indicated that these results were driven by associations in women, rather than in men, despite few differences in baseline FIS or protein intake.

However, a differential association by sex was observed in the Health ABC study 23 and in a prior Framingham Offspring report 26 discussed earlier.

In both cases, the authors have suggested that such differences may be explained in part by differences in body composition either fat-free mass or skeletal muscle mass between men and women.

Health ABC investigators have observed that lean mass adjusted for adiposity better predicted physical functioning deficits and incident disability than lean mass alone 39 , whereas Framingham investigators have observed that skeletal muscle mass may be a mediator of protein-function relationships These and other phenomena 25 , 40 potentially underlying observed differences are also supported by prior studies indicating that protein intake in men may have weaker associations with frailty 19 , disability 25 , 26 , and health-related quality of life, fatigue, or well-being Furthermore, there is mixed evidence on the effects of protein or high-protein food intake on strength and lean mass in men alone or when compared with women 6 , 25 , With regard to frailty, in the present study, we validated our score of functional integrity against a commonly used measure of frailty, the Fried frailty phenotype Although the concept of function captures related but distinct aspects of well-being, including mobility and independence, that are not part of the typical frailty phenotype, the relationship between protein intake and frailty merits at least brief discussion in the present context.

A systematic review reported that three out of five studies examining protein intake and frailty in older adults found a beneficial association with higher intake Notably, only one of these five studies was longitudinal The remaining cross-sectional study conducted in community-dwelling older participants reported that although total protein intake was not significantly associated with frailty, its mealtime distribution was a factor Furthermore, these data highlight the need to identify and target nutrition and exercise therapies within and potentially before the fifth decade of life to optimize healthy aging.

Our study has several strengths. First, we used repeated measures of both dietary intake and self-reported assessments of function across several decades of follow-up, thereby informing a life-course picture of dietary protein in relation to function into mid- and late-old age.

To our knowledge, our results represent one of the most comprehensive, repeated self-reported assessments of dietary protein intake and function over time. The present study also has several limitations.

Dietary data were derived from self-report by FFQs, thus come with inherent self-report biases and other limitations. However, no cost-effective or feasible alternative to measuring diet over this time period in this size of a population has been identified.

We also could not assess the potential impact of mealtime distribution of protein, given our dietary assessment instrument, and mealtime distribution of protein may be relevant to frailty and related functional measures The primary outcome of functional integrity was based on self-reported measures, which are subject to misreporting.

However, previous studies support that such self-reports have a physiologic basis and can accurately predict preclinical disability and related impairment In addition, it would have been interesting to assess the mediating impact of both body mass compartments eg, lean vs fat mass and muscle strength on the association between protein intake and functional measures because relationships between protein intake and strength and function may be partially, but not entirely mediated through muscle mass 44 and may help explain the differential associations by sex.

However, such measures were available either at limited time points or in limited subsamples of the cohort, precluding a meaningful analysis across the entire population in the timeframe of interest. Women remain an understudied population within aging literature, and these results further underscore the need to include women as part of intervention studies related to diet, physical function, and aging.

Finally, as with all observational studies, we cannot infer a causal relationship between protein intake and functional integrity and residual confounding is possible.

In conclusion, we observed favorable associations between protein intake and functional integrity over a greater than year timeframe, notably in women. Our approach was one that relied on function-related questions, such as the ability to pull, lift, and do housework, asked repeatedly, and validated against objective physical performance as well as a well-characterized frailty phenotype.

This study was supported in part by the North American Branch of the International Life Sciences Institute ILSI N. and P.

ILSI N. is a public, nonprofit foundation that provides a forum to advance understanding of scientific issues related to the nutritional quality and safety of the food supply by sponsoring research programs, educational seminars and workshops, and publications.

receives support primarily from its industry membership. This study was also supported by the U. Department of Agriculture—Agricultural Research Service ARS , Agreement No.

The Framingham Heart Study of the National Heart, Lung, and Blood Institute of the National Institutes of Health and Boston University School of Medicine is supported by Contract No. The views expressed in this article are of those of the authors. The sponsors had no role in the conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication.

is a member of the Danone North America Essential Dairy and Plant-Based Advisory Board. has received institutional grants from the Dairy Management and is also a member of the Nutrition Research Scientific Advisory Committee, National Dairy Council.

is an employee of Danone North America. The authors declare no conflicts of interest. The authors wish to thank the participants of the Framingham Heart Study for their tireless volunteerism and, by extension, their immense contributions to public health.

designed the research. analyzed the data and wrote the manuscript. and D. provided subject matter expertise. All authors contributed to interpreting the data and edited, reviewed, approved the manuscript. and A. are responsible for the final content of the manuscript.

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High protein intake is associated with low prevalence of frailty among old Japanese women: a multicenter cross-sectional study.

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Macronutrients, diet quality, and frailty in older men. Beasley JM , Wertheim BC , LaCroix AZ , et al. Associations of dietary protein intake on subsequent decline in muscle mass and physical functions over four years in ambulant older Chinese people. Isanejad M , Mursu J , Sirola J , et al.

Dietary protein intake is associated with better physical function and muscle strength among elderly women. Houston DK , Tooze JA , Garcia K , et al. Protein intake and mobility limitation in community-dwelling older adults: the Health ABC Study. Farsijani S , Payette H , Morais JA , Shatenstein B , Gaudreau P , Chevalier S.

Even mealtime distribution of protein intake is associated with greater muscle strength, but not with 3-y physical function decline, in free-living older adults: the Quebec longitudinal study on Nutrition as a Determinant of Successful Aging NuAge study.

Bradlee ML , Mustafa J , Singer MR , Moore LL. High-protein foods and physical activity protect against age-related muscle loss and functional decline.

Mustafa J , Ellison RC , Singer MR , et al. Dietary protein and preservation of physical functioning among middle-aged and older adults in the Framingham Offspring Study. Ageing is accepted as the biggest risk factor for disease and death, and more than three quarters of elderly Australians have a chronic disease, according to the Australian Institute of Health and Welfare.

Globally, the World Health Organization estimates that chronic diseases such as cardiovascular disease and diabetes account for about 70 percent of deaths.

The research findings paint a clearer picture of the role of a little-known hormone called Fibroblast Growth Factor 21 FGF21 — a hormone produced primarily in the liver. The research shows that diets high in carbohydrate and low in protein are the best for boosting levels of FGF21 in mice. The high-carb element does not mean gorging processed cakes and cookies, however.

Dr Solon-Biet and Professor Simpson rely on the expertise of University mathematicians to crunch the numbers that support this geometric approach, and interrogate research from every possible angle.

On any given day she collaborates with researchers across biochemistry, microbiology, public health, medicine, business and pharmacology. The researchers analyzed plasma — the cell-free, fluid fraction of blood — from 4, people ages Those three points, occurring on average at ages 34, 60 and 78, stand out as distinct times when the number of different blood-borne proteins that are exhibiting noticeable changes in abundance rises to a crest.

This happens because instead of simply increasing or decreasing steadily or staying the same throughout life, the levels of many proteins remain constant for a while and then at one point or another undergo sudden upward or downward shifts.

The investigators built their clock by looking at composite levels of proteins within groups of people rather than in individuals. The researchers obtained their samples from two large studies.

One of them, known as the LonGenity study, has assembled a registry of exceptionally long-lived Ashkenazi Jews. It was able to provide many blood samples from people as old as The study also strengthened the case that men and women, who were about equally represented in the study, age differently.

Of the proteins the analysis found to change with age, — nearly two-thirds — were significantly more predictive for one sex than for the other. Any clinical applications of the technique are a good five to 10 years off, he said.