TABLE 3.
Odds ratios (ORs) (95% confidence intervals) of individual domains of healthy aging assessed in 2014/2016 according to intake of protein in 1984/1986 among 48,762 participants in the Nurses’ Health Study (ORs >1 denote greater odds of healthy aging)
| ORs (95% CI) for 3%-energy increment |
||||
|---|---|---|---|---|
| Absence of chronic diseases (n = 15,131)5 | No impairment in memory (n = 23,215)6 | No physical function limitations (n = 7303)7 | Good mental status (n = 18,211)8 | |
| Total protein | ||||
| Age-adjusted model1 | 0.97 (0.95, 0.99) | 1.02 (1.00, 1.04) | 1.04 (1.01, 1.07) | 1.03 (1.01, 1.05) |
| Multivariate model 12 | 0.91 (0.89, 0.93) | 0.97 (0.95, 0.99) | 0.95 (0.92, 0.98) | 0.97 (0.95, 0.996) |
| Multivariate model 23 | 0.95 (0.93, 0.97) | 0.99 (0.96, 1.01) | 1.03 (0.999, 1.07) | 1.01 (0.98, 1.03) |
| Animal protein | ||||
| Age-adjusted model1 | 0.94 (0.92, 0.96) | 0.99 (0.97, 1.01) | 0.98 (0.95, 1.01) | 0.99 (0.97, 1.01) |
| Multivariate model 12 | 0.91 (0.89, 0.93) | 0.97 (0.94, 0.99) | 0.93 (0.90, 0.95) | 0.96 (0.94, 0.98) |
| Multivariate model 23 | 0.95 (0.93, 0.97) | 0.98 (0.96, 1.00) | 1.00 (0.97, 1.03) | 0.99 (0.97, 1.02) |
| Multivariate model 34 | 0.95 (0.93, 0.98) | 0.99 (0.97, 1.01) | 1.05 (1.02, 1.09) | 1.01 (0.99, 1.04) |
| Dairy protein | ||||
| Age-adjusted model1 | 1.11 (1.07, 1.15) | 1.06 (1.02, 1.09) | 1.09 (1.04, 1.14) | 1.08 (1.04, 1.12) |
| Multivariate model 12 | 1.03 (0.99, 1.07) | 0.97 (0.93, 1.00) | 1.00 (0.95, 1.06) | 0.98 (0.94, 1.02) |
| Multivariate model 23 | 1.04 (1.00, 1.08) | 0.97 (0.93, 1.01) | 1.02 (0.96, 1.07) | 0.98 (0.95, 1.03) |
| Multivariate model 34 | 1.02 (0.98, 1.06) | 0.97 (0.94, 1.02) | 1.08 (1.02, 1.15) | 1.01 (0.97, 1.06) |
| Plant protein | ||||
| Age-adjusted model1 | 1.46 (1.37, 1.56) | 1.42 (1.34, 1.51) | 1.85 (1.70, 2.01) | 1.54 (1.44, 1.64) |
| Multivariate model 12 | 1.17 (1.09, 1.26) | 1.12 (1.05, 1.20) | 1.47 (1.37, 1.61) | 1.20 (1.11, 1.28) |
| Multivariate model 23 | 1.09 (1.01, 1.17) | 1.09 (1.02, 1.17) | 1.32 (1.20, 1.45) | 1.14 (1.06, 1.22) |
| Multivariate model 34 | 1.02 (0.94, 1.10) | 1.08 (0.998, 1.16) | 1.41 (1.27, 1.57) | 1.16 (1.07, 1.26) |
BMI, body mass index; CI, confidence interval; MET, metabolic equivalent; OR, odds ratio; SSB, sugar-sweetened beverage.
Logistic model adjusted for baseline age.
Multivariate logistic model 1 was adjusted for baseline age (continuous), race (White, other), education (registered nurse, bachelor, or graduate), marital status (married, other), postmenopausal hormone use (premenopausal; never, past user, current user), smoking status (never smoked; former smoker, 0.1–14.9, 15.0–29.9, >30 pack-y), alcohol intake (0, 0.1–4.9, 5.0–14.9, >15.0 g/d), physical activity (<3, 3–8.9, 9–17.9, 18–26.9, >27 MET/wk), baseline history of hypertension or hypercholesterolemia (yes, no), aspirin use (never, past, current), multivitamin use (yes, no), SSB intake, and total energy intake (kcal/d, quintiles).
Multivariate model 2 included the covariates in multivariate model 1 and was additionally adjusted for BMI (averaged 1984 and 1986; <22.5, 22.5–24.9, 25.0–27.5, 27.5–30.0, 30.0–34.9, >35.0).
Multivariate model 3 included covariates in multivariate model 2 with additional mutual adjustment of animal and plant protein. The models for dairy protein were adjusted for plant protein and other animal protein (nondairy protein).
Absence of chronic disease was defined as not being diagnosed with a history of 11 chronic diseases (cancer, type-2 diabetes, myocardial infarction, coronary artery bypass graft surgery or percutaneous transluminal coronary angioplasty, congestive heart failure, stroke, kidney failure, chronic obstructive pulmonary disease, Parkinson disease, multiple sclerosis, and amyotrophic lateral sclerosis) by the end of follow-up (2016).
No impairment in memory was defined as having 1 memory complaint at most on the basis of 7 regarding self-reported memory complaints about the change in the ability to remember things and trouble in remembering recent events, short lists, 1 s to the next, spoken instructions, following conversations or plot, and finding the way on familiar streets.
No physical function limitations were defined as having no limitations in moderate activities (e.g., walking a few blocks, bathing) and no more than moderate limitations on vigorous activities (e.g., running, lifting heavy objects, strenuous sports from the Medical Outcomes Study Short-Form Health Survey.
Good mental status was defined as a Geriatric Depression Scale-15 score ≤1.