The older population is about to "boom" much as they did
when entering the world as “babies” some six decades ago. The
first of the “baby boomers” will turn 65 years old in 2011, with
the last group turning the same age in 2029. This means that
by 2030, the 65 years and older population is expected to double to
71 million according to the Centers for Disease Control and
Prevention. In just over two decades, one in every five Americans
will officially be “elderly,” making the challenge to defend
against their susceptibility to illness even more difficult.
Many debilitating conditions are directly attributed to their
age-vulnerability, but one of the most prevalent conditions may
also be the most preventable. Amazingly, it may also be one
that you’ve never heard of.
This article, which focuses on protein and sarcopenia, is the
second in a series of articles examining an expanded role for
protein and health.
What is
Sarcopenia?
Sarcopenia is the progressive decline in muscle mass and strength
that occurs as an effect of natural aging. More specifically,
it is defined as a three to eight percent reduction in lean muscle
mass per decade after the age of 30.
Scope of
Sarcopenia
Sarcopenia is widespread among the elderly, yet surprisingly
remains in relative obscurity. It is thought to affect 30
percent of those age 60 years and over, and greater than 50 percent
of those older than 80 years of age. Advanced sarcopenia is
synonymous with physical frailty and associated with increased
likelihood of falls, disability, and the impairment of activities
of daily living. With such a high prevalence and potential risk, it
comes as no surprise that sarcopenia significantly contributes to
the cost of healthcare. In 2000, the estimated direct
healthcare cost of sarcopenia in the United States was $18.5
billion, or about 1.5 percent of total healthcare expenditures for
that year. With an increasingly aging population, the cost of
providing healthcare to older individuals is sure to become even
more challenging for public health officials.
Reduce
Risk
Although the onset of sarcopenia may be inevitable for some, it
may be avoidable and reversible for others. Researchers have
identified two measures that can play a role in the fight against
sarcopenia: diet and exercise. The benefits of consuming a
well-balanced diet and getting regular physical activity are
widespread and diverse. Although difficulties implementing diet and
exercise interventions with the elderly are well documented, there
is no denying the positive impact both have on sarcopenia. Older
people can offset the progression of sarcopenia through regular
resistance exercise. Furthermore, the benefits of this type
of exercise, including increasing muscle strength and size, may be
supported by consuming moderately more than the current daily
recommendation for protein.
Increase
Intake in Older Individuals
Protein is recognized as the key macronutrient responsible for
safeguarding against sarcopenia, but there is some debate over the
exact amount required. Presently, the daily recommended
dietary intake (RDI) for protein is 0.8 grams per kilogram of body
weight for adults ages 19 and older, but recent arguments claim
this amount may not promote optimal health or protect the elderly
population from sarcopenic muscle loss. Unfortunately, many older
persons may not be meeting the current RDI standards for protein,
with approximately 35 percent consuming less than what is
recommended, and about 15 percent consuming less than 75 percent of
recommended amounts. Even greater cause for concern is that
emerging research points to the need for moderately
higher protein
recommendations (1-1.3 grams per kilogram of body weight per
day) than already exist to reduce the risk of sarcopenia. In
other words, although many older individuals lack a
sufficient amount of protein in their diet, the true protein
deficiency may be even larger than we realize.
Divide
and Conquer
As we grow older, the body becomes less efficient in converting
amino acids into muscle tissue. However, higher doses of amino
acids may be capable of stimulating muscle building to a similar
extent as that of the young. In addition to meeting daily protein
requirements, research indicates that reaching a specific threshold
of protein at each meal may generate a maximum muscle building
effect. Thus, assuming adequate total energy intake and
normal renal function, placing importance on the distribution of
protein across meals is paramount and may be a useful strategy for
muscle mass maintenance.
Build
Strong Bones
In addition to aiding muscle development, protein also benefits
bone health. Similar to many other body tissues, bones
undergo protein turnover and require a steady stream of dietary
protein for maintenance. However, just as the current DRI for
protein for muscle maintenance may be too low for older
individuals; it may also be too low for optimal bone health. In
fact, research with this population has identified a positive
association between protein intake and change in bone mass density
in those with the highest intake of protein that were supplemented
with calcium and vitamin D. So, while the role of protein and bone
health is important, it should also be complemented with calcium
and Vitamin D.
Defending against the onset of sarcopenia is a daunting task,
particularly when it comes to getting a person to comply with new
or unfamiliar lifestyle modifications. Individuals may be
challenged to find ways to incorporate more exercise and consume
the recommended amounts of protein every day. Advice about how to
reduce risk of sarcopenia should take into consideration the many
barriers that might prevent someone from taking steps to build
strong muscles and bones while improving their quality of life in
later years.
Centers for Disease Control and Prevention. Department of Health
and Human Services. “Healthy Aging for Older Adults.”
http://www.cdc.gov/aging/.