For many older adults, breakfast is a carbohydrate-dominated lower-protein meal and represents an opportunity to improve and more evenly distribute daily protein intake.

Although both animal and plant-based proteins can provide the required essential amino acids for health, animal proteins generally have a higher proportion of the amino acid leucine. Leucine plays a key role in stimulating translation initiation and muscle protein anabolism and is the focus of ongoing research.

Protein requirements should be assessed in the light of habitual physical activity. An evenly distributed protein diet provides a framework that allows older adults to benefit from the synergistic anabolic effect of protein and physical activity.

People who eat or are considering vegetarian or vegan diets may be concerned about getting enough protein from their food. In this article, we look at…. My podcast changed me Can 'biological race' explain disparities in health?

Why Parkinson's research is zooming in on the gut Tools General Health Drugs A-Z Health Hubs Health Tools Find a Doctor BMI Calculators and Charts Blood Pressure Chart: Ranges and Guide Breast Cancer: Self-Examination Guide Sleep Calculator Quizzes RA Myths vs Facts Type 2 Diabetes: Managing Blood Sugar Ankylosing Spondylitis Pain: Fact or Fiction Connect About Medical News Today Who We Are Our Editorial Process Content Integrity Conscious Language Newsletters Sign Up Follow Us.

Medical News Today. Health Conditions Health Products Discover Tools Connect. Plant protein linked to healthy aging in women, study finds. By Katharine Lang on January 18, — Fact checked by Jill Seladi-Schulman, Ph. Share on Pinterest A new study shows women who eat more plant protein are likely to age healthily and lower their risk of chronic conditions.

Assessing diet and chronic condition risk. Plant protein linked to healthier aging. Plant foods provide protein, other nutrients. Which plant-based foods are best for health? Share this article.

Latest news Ovarian tissue freezing may help delay, and even prevent menopause. RSV vaccine errors in babies, pregnant people: Should you be worried? Scientists discover biological mechanism of hearing loss caused by loud noise — and find a way to prevent it.

How gastric bypass surgery can help with type 2 diabetes remission. Atlantic diet may help prevent metabolic syndrome.

Related Coverage. Aging: Could a moderate protein diet be the key to youth? READ MORE. Vegan diet may promote healthy aging New research adds to the mounting evidence that following a vegan diet can help promote healthy aging and prevent age-related disease.

What is the difference between animal and plant proteins? Medically reviewed by Natalie Olsen, R. Everything you need to know about plant based diets. Medically reviewed by Natalie Butler, R.

In mice, a diet low in protein resulted in the development of fatty liver , and middle-aged mice exhibited higher levels of lipids, or fats, in their systems than younger mice. The moderate-protein diets also lowered lipid and blood sugar levels in the mice.

Conner Middlemann , the nutritionist behind Modern Mediterranean, said she felt the study nonetheless had value. This is significantly more than the average American currently consumes.

Some people need even more protein. Of special note are people practicing resistance training. To maximize lean mass, the average required amount, Conner said, is about 1.

For people wishing to burn fat while still retaining muscle, 1. Middlemann explained to MNT that older people require more protein than younger individuals. Basically, every tissue requires protein to grow. Body protein turnover happens during our entire lives.

In the United States, the required daily amount RDA of 0. She clarified that the figure represents only the required amount of protein to avoid malnutrition , not the amount to promote good health. Middlemann noted that the RDA is a holdover from a time when nitrogen-balance studies that are no longer considered valid formed the foundation of such recommendations.

She said one could get a more accurate understanding of nutritional needs using the Indicator Amino Acid Oxidation IAAO technique.

The IAAO technique, said Middlemann, provides a more reasonable daily recommendation. It suggests 1. The difference between the two recommendations is significant. The RDA for a pound person is 54 g of protein daily, while according to IAAO measurement, it would rise to 81 g of protein.

In this Honest Nutrition feature, we look at how much protein a person needs to build muscle mass, what the best protein sources are, and what risks…. The answers to both questions become a bit more complicated as the years pass. The Recommended Dietary Allowance is 0. You can get about 50 grams in 5.

But older adults who hit these recommendations may still have a protein shortfall. According to Lonnie, although you might consume the same amount of protein you did in your younger years, your body might not be able to use it as well.

Another factor is inflammation from infections and other medical problems, which hikes protein needs. You probably have more comorbidities, injuries, chronic diseases, or surgery in older age, Lonnie says. Some medications, like steroids, may also ramp up protein needs.

That can lead to further loss of muscle and strength. Because of the factors above, research supports increasing the recommended intake of protein for older adults by up to 50 percent. That means people over age 65 should strive for 0. Older adults with chronic diseases should get even more protein—0.

Your muscles prefer that you spread your protein out over the day. And note that while most older adults should be able to tolerate adding protein to their diets, this could exacerbate chronic kidney disease, Marian says.

Meat, poultry, seafood, and dairy provide protein, as you probably know. But you can also get plenty from plant sources such as beans, lentils, nuts, seeds, soy, and whole grains.

The main difference between animal and plant proteins is the variety of amino acids they contain. Some plant foods, including quinoa and soy, are also considered complete. Certain others, such as grains and legumes, form complete proteins when eaten in the same meal say, rice and beans or peanut butter on whole-wheat toast or on the same day.

We've updated our Privacy Policy to make it clearer how we use your personal data. We use cookies to provide you with a better experience. You can read our Cookie Policy here. We all know having a balanced diet is important to stay healthy.

New research from Waseda University has started to unpick the optimum proportion of macronutrients for a diet that supports metabolic health as we age — starting with protein. The study is published in GeroScience.

Over our lifespans, our nutrition needs change. Various diet-related interventions — such as caloric restriction and intermittent fasting — have been shown to alter the life- and healthspans of rodents in animal studies, with further research linking lifespan and metabolic health to the consumption of dietary macronutrients.

Macronutrients are the nutrients that provide calories and energy necessary for growth and metabolism. Carbohydrates, proteins and fats are all macronutrients.

Previous studies show the possibility of minimizing age-specific mortality throughout life by changing the ratio of dietary protein to carbohydrates. The new study aimed to identify the ideal amount of protein needed in a diet that improves metabolic health in the approach to old age.

In their new investigation, the team fed young and middle-aged mice diets with the same number of calories, but varying protein contents. The mice were fed the diet for two months before various health measures, including skeletal muscle weight and liver and plasma lipid profiles, were recorded.

The researchers also analyzed the plasma amino acid concentrations of the mice, finding that the concentrations of individual amino acids in plasma vary with age and the protein content of the diet.

The Recommended Dietary Allowance is 0. You can get about 50 grams in 5. But older adults who hit these recommendations may still have a protein shortfall. According to Lonnie, although you might consume the same amount of protein you did in your younger years, your body might not be able to use it as well.

Another factor is inflammation from infections and other medical problems, which hikes protein needs. You probably have more comorbidities, injuries, chronic diseases, or surgery in older age, Lonnie says.

Some medications, like steroids, may also ramp up protein needs. That can lead to further loss of muscle and strength. Because of the factors above, research supports increasing the recommended intake of protein for older adults by up to 50 percent.

That means people over age 65 should strive for 0. Older adults with chronic diseases should get even more protein—0. Your muscles prefer that you spread your protein out over the day. And note that while most older adults should be able to tolerate adding protein to their diets, this could exacerbate chronic kidney disease, Marian says.

Meat, poultry, seafood, and dairy provide protein, as you probably know. But you can also get plenty from plant sources such as beans, lentils, nuts, seeds, soy, and whole grains. The main difference between animal and plant proteins is the variety of amino acids they contain.

Some plant foods, including quinoa and soy, are also considered complete. Certain others, such as grains and legumes, form complete proteins when eaten in the same meal say, rice and beans or peanut butter on whole-wheat toast or on the same day.

A potential drawback to getting protein solely from plants is that you may have to eat a larger volume of food to get the amount of protein you would from animal sources. Am J Clin Nutr ;88 5 — Campbell, WW, Trappe, TA, Wolfe, RR, Evans, WJ. The recommended dietary allowance for protein may not be adequate for older people to maintain skeletal muscle.

J Gerontol A Biol Sci Med Sci ;56 6 :M— Millward, DJ, Fereday, A, Gibson, N, Pacy, PJ. Aging, protein requirements, and protein turnover. Am J Clin Nutr ;66 4 — Courtney—Martin, G, Ball, RO, Pencharz, PB, Elango, R. Protein Requirements during Aging.

Nutrients ;8 8 : E Burd, NA, Gorissen, SH, van Loon, LJ. Anabolic resistance of muscle protein synthesis with aging. Exerc Sport Sci Rev ;41 3 — Article PubMed Google Scholar.

Ilich, JZ, Kelly, OJ, Inglis, JE. Osteosarcopenic Obesity Syndrome: What Is It and How Can It Be Identified and Diagnosed? Curr Gerontol Geriatr Res ; Google Scholar. USDA Food and Nutrient Database for Dietary Studies — Bowman SACJ, Friday, JE, Lynch, KL, and Moshfegh, AJ.

Food Patterns Equivalents Database — Methodology and User Guide [Online]. Beltsville, Maryland, Institute of Medicine U. Subcommittee on Interpretation and Uses of Dietary Reference Intakes. Subcommittee on Upper Reference Levels of Nutrients.

Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary reference intakes. Applications in dietary assessment: a report of the Subcommittees on Interpretation and Uses of Dietary Reference Intakes and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine.

National Academy Press, Washington, D. Krebs—Smith, SM, Pannucci, TE, Subar, AF, Kirkpatrick, SI, Lerman, JL, Tooze, JA, Wilson, MM, Reedy, J. Update of the Healthy Eating Index: HEI— J Acad Nutr Diet ; 9 — United States. Department of Health and Human Services.

Department of Agriculture. Dietary Guidelines Advisory Committee. Dietary guidelines for Americans, — Eighth edition. Department of Health and Human Services and U. Department of Agriculture, Washington, D. C Wischmeyer, PE. Tailoring nutrition therapy to illness and recovery.

Crit Care ;21 Suppl 3 Berryman, CE, Lieberman, HR, Fulgoni, VL, 3rd, Pasiakos, SM. Protein intake trends and conformity with the Dietary Reference Intakes in the United States: analysis of the National Health and Nutrition Examination Survey, — Am J Clin Nutr ; 2 — Cruz—Jentoft, AJ, Landi, F, Schneider, SM, Zuniga, C, Arai, H, Boirie, Y, Chen, LK, Fielding, RA, Martin, FC, Michel, JP, Sieber, C, Stout, JR, Studenski, SA, Vellas, B, Woo, J, Zamboni, M, Cederholm, T.

Prevalence of and interventions for sarcopenia in ageing adults: a systematic review. Report of the International Sarcopenia Initiative EWGSOP and IWGS. Age Ageing ;43 6 — PubMed PubMed Central Google Scholar. Hiza, HA, Casavale, KO, Guenther, PM, Davis, CA.

J Acad Nutr Diet ; 2 — Engel, JH, Siewerdt, F, Jackson, R, Akobundu, U, Wait, C, Sahyoun, N. Hardiness, Depression, and Emotional Well—Being and Their Association with Appetite in Older Adults. Journal of the American Geriatrics Society ;59 3 — Lee, JS, Kritchevsky, SB, Tylavsky, F, Harris, TB, Ayonayon, HN, Newman, AB.

Factors associated with impaired appetite in well—functioning community—dwelling older adults. J Nutr Elder ;26 1—2 — Nieuwenhuizen, WF, Weenen, H, Rigby, P, Hetherington, MM.

Older adults and patients in need of nutritional support: review of current treatment options and factors influencing nutritional intake.

Clin Nutr ;29 2 — Schiffman, SS. Taste and smell losses in normal aging and disease. JAMA ; 16 — Solemdal, K, Sandvik, L, Willumsen, T, Mowe, M, Hummel, T. The impact of oral health on taste ability in acutely hospitalized elderly.

PLoS One ;7 5 :e Morley, JE. Aging successfully needs lifelong prevention strategies. European Geriatric Medicine ;7 4 — Pilgrim, AL, Robinson, SM, Sayer, AA, Roberts, HC. An overview of appetite decline in older people. Nurs Older People ;27 5 — Netz, Y, Wu, MJ, Becker, BJ, Tenenbaum, G.

Physical activity and psychological wellbeing in advanced age: a meta—analysis of intervention studies. Psychol Aging ;20 2 — Lattimer, JM, Haub, MD. Effects of dietary fiber and its components on metabolic health.

Nutrients ;2 12 — Montgomery, SC, Streit, SM, Beebe, ML, Maxwell PJt. Micronutrient Needs of the Elderly. Nutr Clin Pract ;29 4 — Prasad AS Zinc in human health: effect of zinc on immune cells. Mol Med 14 5—6 — Rehm, CD, Monsivais, P, Drewnowski, A.

Relation between diet cost and Healthy Eating Index scores among adults in the United States — Prev Med ;— Rehm CD, Penalvo JL, Afshin A, Mozaffarian D, Dietary Intake Among US Adults, — JAMA ; 23 — Eicher—Miller, HA, Boushey, CJ, How Often and How Much?

Differences in Dietary Intake by Frequency and Energy Contribution Vary among, U. Adults in NHANES — Nutrients ;9 1 Article PubMed Central Google Scholar. Ervin, RB. Healthy Eating Index scores among adults, 60 years of age and over, by sociodemographic and health characteristics: United States, — Advance data from vital and health statistics; no National Center for Health Statistics, Hyattsville, MD, Shlisky, J, Bloom, DE, Beaudreault, AR, Tucker, KL, Keller, HH, Freund—Levi, Y, Fielding, RA, Cheng, FW, Jensen, GL, Wu, D, Meydani, SN.

Nutritional Considerations for Healthy Aging and Reduction in Age—Related Chronic Disease. Adv Nutr ;8 1 — Ogden, CL, Carroll, MD, Kit, BK, Flegal, KM.

Prevalence of childhood and adult obesity in the United States, — JAMA ; 8 — Ward, BW. Barriers to health care for adults with multiple chronic conditions: United States, — NCHS data brief, no Hyattsville, MD, Ward, BW, Schiller, JS, Goodman, RA. Multiple chronic conditions among US adults: a update.

Prev Chronic Dis ;E Mustafa, J, Ellison, RC, Singer, MR, Bradlee, ML, Kalesan, B, Holick, MF, Moore, LL. Dietary Protein and Preservation of Physical Functioning Among Middle—Aged and Older Adults in the Framingham Offspring Study.

Am J Epidemiol ; 7 — Mishra, S, Goldman, JD, Sahyoun, NR, Moshfegh, AJ. Association between dietary protein intake and grip strength among adults aged 51 years and over: What We Eat in America, National Health and Nutrition Examination Survey — Plos One ;13 1 :e doi:ARTN e Kranz, S, Brauchla, M, Campbell, WW, Mattes, RD, Schwichtenberg, AJ.

High—Protein and High—Dietary Fiber Breakfasts Result in Equal Feelings of Fullness and Better Diet Quality in Low—Income Preschoolers Compared with Their Usual Breakfast. The Journal of Nutrition ; 3 — Gregorio, L, Brindisi, J, Kleppinger, A, Sullivan, R, Mangano, KM, Bihuniak, JD, Kenny, AM, Kerstetter, JE, Insogna, KL.

Adequate Dietary Protein Is Associated with Better Physical Performance among Post—Menopausal Women 60—90 Years. doi:DOI Article CAS Google Scholar.

Bauer, J, Biolo, G, Cederholm, T, Cesari, M, Cruz—Jentoft, AJ, Morley, JE, Phillips, S, Sieber, C, Stehle, P, Teta, D, Visvanathan, R, Volpi, E, Boirie, Y.

Evidence—based recommendations for optimal dietary protein intake in older people: a position paper from the PROT—AGE Study Group.

J Am Med Dir Assoc ;14 8 — Baum, JI, Kim, IY, Wolfe, RR. Protein Consumption and the Elderly: What Is the Optimal Level of Intake? Too much dietary protein can put stress on the kidneys as they work to get rid of the excess, and while adequate dietary intake of protein is important for growth and maintenance of bone throughout life, too much protein can weaken bones.

To counteract the acid, the body releases calcium ions from bones, potentially weakening them. Even acidic fruits like citrus and tomatoes reduce acid load once digested and metabolized.

Although most U. adults get plenty of protein, older adults who get too little could be at increased risk for frailty and illness.

Some studies suggest older adults may be able to stave off loss of muscle and function by consuming somewhat more than the Recommended Dietary Allowance RDA of 0. This works out to about 58 grams for someone weighing pounds and 68 grams for someone weighing pounds. While most adults in the U.

have overall protein intake well above the RDA consuming about grams of protein a day when all sources are taken into consideration , some older adults for example those with low appetite or dental problems or those following diets that restrict the categories of foods they consume may not be eating enough in general.

average of grams of protein a day. Dietary protein comes from both animal sources meats, poultry, fish, eggs, and dairy and plant sources like beans, lentils, and nuts.

The best way to get protein is to choose sources low in saturated fat and rich in nutrients and use them to replace starches and refined carbohydrate foods. Plant foods particularly beans and legumes, but also nuts contain protein that adds to your daily total, and plant proteins are a good choice.

People who report consuming more plant protein tend to eat less animal protein, making it difficult for researchers to determine exactly which factors contribute the most benefit, but including more plant protein in place of animal protein could result in a less inflammatory dietary pattern overall and support a healthier planet as well.

Timing of protein is emerging as an important consideration. Emerging evidence suggests spreading protein intake out throughout the day may be as important as getting enough.

adults have a low-protein breakfast, a little protein at lunch, and consume most of their protein at the evening meal.

To preserve muscle and bone, minimize inflammation, and maintain physical function, get enough healthy protein choices…but not too much. White fish is not low in protein. I think researchers just listed some populate sources of protein. Want to cut way back on refined carbs and increase healthy protein in my diet as well as regular exercise.

Hi, Women generally weigh less than men. Can you please offer estimates of grams per kilo pounds for women say lbs to lbs range as offered above for those weighing lbs and lbs??

Thanks, Tanja. So, not too much and not too little, just right. But, wonder if we could have some hints of what is just right? Or a link, which takes in to account some variables, to help us find the approximate just right, please? Agreed that the linked page considers appropriate factors presented clearly, but I wonder about their recommendations.

Overall, this is an excellent article regarding the necessity of good and adequate protein. If you work out, you will get more tissue breakdown, so not a bad number is to bump up to about.

At age 76, since I do intense powerwalking 3 to 4 times a week average 5 miles, 16 min miles and weight lifting twice a week, I try to get a minimum of.

Make sure you adequately hydrate 60ish oz all fluids or very slightly yellow urine ;That way there will not be issues with your kidneys. For some reason, nutritionists appear to think that we weigh our food all of the time—and even do it only in grams, etc. Talk about being caught between a rock and a hard place.

Salmon and asparagus are my go to meals.

Combined with a tendency to become more sedentary, this puts them at risk of deteriorating muscles, compromised mobility, slower recovery from bouts of illness and the loss of independence. Impact on functioning. In a study that followed more than 2, seniors over 23 years, researchers found that those who ate the most protein were 30 percent less likely to become functionally impaired than those who ate the least amount.

In another study, which was published in and followed nearly 2, older adults over six years, people who consumed the least amount of protein were almost twice as likely to have difficulty walking or climbing steps as those who ate the most, after adjusting for health behaviors, chronic conditions and other factors.

Recommended intake. So, how much protein should seniors eat? The most commonly cited standard is the Recommended Dietary Allowance RDA : 0. For a pound woman, that translates into eating 55 grams of protein a day; for a pound man, it calls for eating 65 grams.

To put that into perspective, a 6-ounce serving of Greek yogurt has 18 grams; a half-cup of cottage cheese, 14 grams; a 3-ounce serving of skinless chicken, 28 grams; a half-cup of lentils, 9 grams; and a cup of milk, 8 grams. To check the protein content of other common foods, click here.

Older adults were rarely included in studies used to establish the RDAs, however, and experts caution that this standard might not adequately address health needs in the older population. After reviewing additional evidence, an international group of physicians and nutrition experts in recommended that healthy older adults consume 1 to 1.

Its recommendations were subsequently embraced by the European Society for Clinical Nutrition and Metabolism. When illness is an issue. For seniors with acute or chronic diseases, the group suggested protein intake of 1. At the 1. However, an important limitation is that there was no adjustment for relevant confounders, including age, sex and physical activity.

Several intervention studies have assessed the effect of different protein sources alone or with exercise on HRQoL and measures of muscle strength and function [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. In addition, this study found that changes in lower leg muscle strength were positively associated with changes in HRQoL.

It is possible that the lack of any improvements in HRQoL in many of these studies relates to the lack of or modest improvements in muscle strength or function with the provision of additional protein, or the HRQoL tools used not being sensitive enough to detect changes over the intervention period.

Collectively, evidence examining the effects of increased dietary protein, irrespective of source, on HRQoL remains mixed. Prospective epidemiological cohort studies provide an opportunity to examine the relationship of habitual total protein intake and different protein sources with changes in HRQoL over time.

Participants were from the Australian Diabetes, Obesity and Lifestyle AusDiab study [ 33 ]. Details of recruitment methods and baseline response rates have been described previously [ 33 ]. Recruitment was based on 42 randomly selected clusters using census collector districts and stratified by Australian states and territories.

Participants with incomplete data were excluded. A flowchart of the final sample analysed is shown in Fig. The AusDiab study was approved by the International Diabetes Institute ethics committee and Alfred Health ethics committees. All AusDiab participants provided written informed consent.

The current analysis was approved by Deakin University Human Research Ethics Committee Project number — Habitual dietary intake was assessed via self-administration of a item food frequency questionnaire FFQ.

The FFQ was developed in Australia to assess the habitual dietary intakes of an ethnically diverse cohort aged 40—years [ 34 ]. Plant protein was calculated by combining soy and vegetable.

Dairy protein was calculated by combining full-fat dairy and low-fat dairy. Animal protein was calculated by combining red meat, dairy, fish steamed, grilled, baked, fried, tinned , chicken, butter, eggs, flavoured milk and ice-cream.

Total protein intake was calculated by combining protein from all foods. Health-related quality of life HRQoL was collected via the self-administered SF Version 1 questionnaire used with permission from the Medical Outcomes Trust Boston, MA, USA [ 38 ].

Based on the answers from this question survey, the two summary scores of PCS and MCS were calculated using published guidelines [ 39 , 40 ]. Summary scores were then normalised to have a mean of 50 and standard deviation of 10 across the Australian general population [ 39 , 40 ].

Higher scores indicate better HRQoL. Positive results indicate improved HRQoL. The SF has demonstrated good construct validity, test-retest reliability and internal consistency, and has been validated for use in older adults [ 41 , 42 , 43 ].

Prior history of cardiovascular disease CVD; angina, coronary heart disease, or stroke was obtained by self-reported medical history [ 44 ].

Diet quality was assessed using the Dietary Guideline Index DGI [ 45 ] based on food intakes collected from the item FFQ. The DGI is a food-based dietary index which assesses dietary intake against the Australian Dietary Guidelines [ 46 ].

Indicators of each dietary guideline were identified, with age and sex specific cut-offs developed. Two items usually included in the DGI fluid intake and limiting intake of salty food were not included, as the FFQ did not collect this data.

Adherence was scored from 0 not meeting recommendation to 10 fully meeting recommendation. Total scores ranged from 0 to , with higher scores indicating greater diet quality. Height was measured without shoes to the nearest 0. Weight was measured to the nearest 0.

Body mass index BMI was calculated as weight in kilograms divided by height in meters squared. Physical activity level was assessed using the validated Active Australia survey [ 48 , 49 ]. Time spent performing leisure time physical activity duration and frequency was reported over the preceding week.

Because vigorous-intensity activity is commonly considered to contribute additional health benefits, double the time spent in vigorous physical activity is used when creating insufficient and sufficient categories of physical activity.

Data for all potential confounders were collected at baseline, except household type which was collected at the year follow-up. Differences between included and excluded participants were assessed using independent sample t —tests for continuous variables and chi-squared tests for categorical variables.

Changes in HRQoL from baseline to the year follow-up were assessed using paired t -tests. The interaction of the relationship between protein intakes and HRQoL by sex was assessed using linear regression. Protein intake cut-points were chosen based on the recommendation from the PROT-AGE study group that adults aged over years consume dietary protein of at least 1.

Directed acyclic graphs [ 51 ] were used to assist with the identification of key confounders based on assumed directions of associations between covariates, the exposure and the outcome Supplemental Fig. Model 2 included all confounders included in model 1 plus BMI the direction of the relationship between protein intake and BMI is unclear i.

protein intake may influence BMI or BMI may influence protein intake. Based on the literature, the presence of diabetes [ 52 ] and CVD [ 53 ] were considered to be on the causal pathway between intakes of dietary protein total protein and different sources of protein and HRQoL, as was diet quality as protein intake and protein source are components of diet quality [ 45 ] and therefore not included as confounding factors in the main model [ 54 ].

However, sensitivity analysis was performed including diet quality and the presence of diabetes and CVD. To adjust for possible over and under reporting of energy intake, the model also included EI:EE. The possibility of non-linear relationships between protein intakes and year changes in HRQoL was assessed using squared protein intakes.

No evidence of non-linearity was found. Residuals from regression models were assessed for normality and heteroscedasticity using P-P plots and plots of residuals against fitted values, respectively. To determine the robustness of our findings, the following sensitivity analyses were performed.

In the second sensitivity analysis, baseline HRQoL was included in the model as a covariate. In the third sensitivity analysis, participants baseline CVD and diabetes status, together with diet quality, were included in the model as confounders. Statistical analysis was performed using SPSS Software version 25, , IBM Corp.

Baseline characteristics and nutrient intakes of the participants are shown in Table 1. The mean ±SD age of participants was Compared to the participants included in this study, the excluded were older, had a higher BMI, were more likely to be from a rural location, had a higher prevalence of CVD and diabetes, had lower PCS and MCS scores, had lower levels of education, had a higher proportion of current smokers and had lower levels of physical activity Supplemental Table 1.

Analysis of the interaction between sex, protein intake and HRQoL found limited interactions significant in only two of the 20 relationships assessed data not shown. Therefore, data for males and females were pooled. In the fully adjusted model, higher intakes of animal protein, red meat protein and processed animal protein were associated with detrimental changes in PCS scores.

Higher intakes of red meat protein were also associated with detrimental changes in MCS in the fully adjusted model. Sensitivity analysis supported results from the main analysis. In all sensitivity analyses, detrimental associations between animal and red meat proteins and PCS were confirmed.

The detrimental association between red meat protein and MCS was confirmed in two of the three sensitivity analyses Supplemental Table 2. There were no other changes in results between total protein and HRQoL results not shown.

Total dietary protein, dairy protein and plant protein were not associated with changes in HRQoL. Moreover, there was no difference in changes in HRQoL between participants who exceeded the total recommended protein intake compared with those who met the recommendation and those consuming below the recommended intake.

In this year longitudinal study we found that total dietary protein was not associated with changes in HRQoL. To our knowledge, our study is the first to investigate the long-term association between habitual dietary protein intake with changes in HRQoL.

For instance, Ten Haaf et al. This is of relevance to our study as there is evidence to support a strong association between depression and HRQoL [ 57 ]. A novel finding from our study was that meat-based proteins red meat protein and processed animal protein were associated with detrimental changes in PCS.

Recent evidence suggests several detrimental health outcomes associated with higher meat-based protein intakes. Consumption of processed meat has also been associated with numerous chronic health conditions, including colorectal cancer, coronary heart disease and diabetes [ 59 , 60 , 61 ].

Thus, the presence of chronic conditions could explain, at least in part, the relationships observed between meat-based proteins and the deterioration in PCS in the current study. Another possible explanation for the associations detected between meat-based proteins and detrimental changes in PCS is that the saturated fat associated with meat-based proteins has caused the detrimental effect on PCS.

Diets high in saturated fat produce a less diverse and more inflammatory gut microbiome [ 62 ], and increased systemic inflammation which has been linked to many age-related diseases such as rheumatoid arthritis, sarcopenia muscle loss and osteoporosis [ 63 ].

Thus, it could be hypothesized that higher consumption of saturated fat by consuming higher meat-based proteins may have increased rates of these age-related diseases. The association between higher saturated fat intake and lower PCS has been observed in previous observational studies [ 64 , 65 ].

The inability to control for saturated fat is a limitation of the findings. Nevertheless, it is worth noting that despite the significant adverse relationships between increased meat-based protein intake and changes in HRQoL, the associations were modest.

In our study, we found that changes in HRQoL in participants with total protein intakes below recommendations did not differ from those with protein intakes at or above recommendations. A number of limitations must be considered when interpreting these findings. Firstly, a limitation of this study, as well as previous observational studies on this topic [ 19 , 20 , 21 , 22 ], is the modest sample size of Secondly, although this study included a range of confounders, it is possible residual confounding remained because of unmeasured confounders.

Thirdly, associations were only assessed using baseline protein intakes and confounders. Fourthly, only community-dwelling adults were eligible to participate in the AusDiab study, and thus the results cannot be generalised to other populations.

Fifthly, the study was exploratory in its analysis of a range of protein sources and therefore correction for multiple comparisons was not employed. Caution should be used when interpreting the results of this study due to the number of associations assessed with no adjustments made for multiple comparisons, which may increase the likelihood of a type I error.

The results of this study provide a hypothesis of associations which need to be corroborated by future research. This suggests our results may only be generalizable to healthier participants.

However, it should also be noted that sensitivity analysis revealed only a marginal decrease in the association between protein intake and HRQoL when baseline HRQoL was included in the model. Despite the low number of participants available for our analysis, there are a number of strengths to the original AusDiab study which is why it was used for our secondary analysis.

In addition, the AusDiab study used validated tools to measure dietary data and HRQoL. We found that meeting recommended daily total protein intakes when expressed as grams per kg did not influence year HRQoL. Our results suggest that clinical advice, to potentially minimise long-term detrimental effects to HRQoL, include recommendations on avoiding animal protein, red meat protein and processed animal protein when choosing proteins to consume.

Dietary guidelines for older adults should consider protein source when advising older adults on protein consumption. The data that support the findings of this study are available from the Australian Diabetes, Obesity and Lifestyle study, contact Prof.

Jonathan Shaw Baker Heart and Diabetes Institute , but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. United Nations Department of Economics and Social Affairs. World Population Prospects: The Revision [Internet].

Geneva: United Nations; [updated Jun 21; cited Aug 2]. Accessed 11 July Beard JR, Officer A, de Carvalho IA, Sadana R, Pot AM, Michel JP, et al. The world report on ageing and health: a policy framework for healthy ageing.

Article PubMed Google Scholar. Australian Bureau of Statistics. Canberra: ABS; [updated Oct 18; cited Aug 30]. Australian Institute of Health and Welfare. Australian burden of disease study impact and causes of illness and death in Australia Canberra: AIHW; Google Scholar.

Fuchs J, Scheidt-Nave C, Hinrichs T, Mergenthaler A, Stein J, Riedel-Heller SG, et al. Indicators for healthy ageing - a debate. Int J Environ Res Public Health. Article PubMed PubMed Central Google Scholar. Inaba Y, Obuchi S, Arai T, Satake K, Takahira N.

The long-term effects of progressive resistance training on health-related quality in older adults. J Physiol Anthropol. Borowiak E, Kostka T. Predictors of quality of life in older people living at home and in institutions.

Aging Clin Exp Res. Li CC, Matthews AK, Dong X, Simon M. The influence of smoking status on the health profiles of older Chinese American men.

J Am Geriatr Soc. Kostka T, Bogus K. Z Gerontol Geriatr. Article CAS PubMed Google Scholar. Milte CM, Thorpe MG, Crawford D, Ball K, McNaughton SA. Associations of diet quality with health-related quality of life in older Australian men and women.

Exp Gerontol. Xu F, Cohen SA, Lofgren IE, Greene GW, Delmonico MJ, Greaney ML. Relationship between diet quality, physical activity and health-related quality of life in older adults: findings from National Health and nutrition examination survey. J Nutr Health Aging.

Article Google Scholar. Govindaraju T, Sahle BW, McCaffrey TA, McNeil JJ, Owen AJ. Dietary patterns and quality of life in older adults: a systematic review. Bauer J, Biolo G, Cederholm T, Cesari M, Cruz-Jentoft AJ, Morley JE, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE study group.

J Am Med Dir Assoc. Trombetti A, Reid KF, Hars M, Herrmann FR, Pasha E, Phillips EM, et al. Age-associated declines in muscle mass, strength, power, and physical performance: impact on fear of falling and quality of life.

Osteoporos Int. Geirsdottir OG, Arnarson A, Briem K, Ramel A, Tomasson K, Jonsson PV, et al. Protein requirements should be assessed in the light of habitual physical activity.

An evenly distributed protein diet provides a framework that allows older adults to benefit from the synergistic anabolic effect of protein and physical activity.

To fully understand the role of dietary protein intake in healthy aging, greater efforts are needed to coordinate and integrate research design and data acquisition and interpretation from a variety of disciplines.