Effects of increased consumption of fluid milk on energy and nutrient intake, body weight, and cardiovascular risk factors in healthy older adults

Abstract

Objective: To assess the impact of increased consumption of milk, without other dietary advice, on older adults' energy and nutrient intakes, weight, cardiovascular risk factors (blood pressure, plasma lipid levels), and quality of life.

Subjects/setting: Two hundred four healthy men and women, aged 55 to 85 years, who consumed fewer than 1.5 dairy servings per day were chosen from six US academic health centers.

Design: Randomized, controlled open trial.

Intervention: Advice to increase skim or 1% milk intake by 3 cups per day (n = 101) or to maintain usual diet (n = 103) for 12 weeks after a 4-week baseline period.

Main outcome measures: Changes in energy and nutrient intake assessed from 3-day food records, body weight, blood pressure, and plasma lipid levels.

Statistical analyses performed: Group-by-time analysis of variance with repeated-measures, chi 2 test.

Results: Compliance with the intervention was good. Compared with controls, participants in the milk-supplemented group significantly increased energy, protein, cholesterol, vitamins A, D, and B-12, riboflavin, pantothenate, calcium, phosphorus, magnesium, zinc, and potassium intakes. Prevalence of nutrient inadequacy, assessed for nutrients with Estimated Average Requirements, decreased among women in the milk group for magnesium (40% at baseline vs 13% at 12 weeks, P < .001) and vitamin B-12 (6% vs 0%, P < .05) and tended to decrease (P < .10) for protein and thiamin (women) and magnesium and vitamin B-6 (men). The milk group gained 0.6 kg more than control group (P < .01); however, weight gain was less than predicted, which suggests some compensation for the added energy from milk. Blood pressure decreased similarly over time in both groups. Total and low-density lipoprotein cholesterol levels, and the ratio of total cholesterol to high-density lipoprotein cholesterol, were unchanged. Triglyceride levels increased within the normal range in the milk group (P = .002). Quality of life scores were high at baseline and remained high throughout.

Applications/conclusions: Older adults can successfully increase milk intake, thereby meaningfully improving their nutrient intakes. Dietitians can play a key role in disseminating this advice.