Responsible Health

Predicting Healthy Aging - Dr. Mark Miller

Western societies are facing a series of major challenges that represent a potential healthcare tsunami in the next few decades. They are the combined forces of the population demographic group known as the Baby Boomers (those born between 1946 - 1964) and consequences of altered diet and lifestyle resulting in obesity. Thus, the elderly population is growing in stature - both physically and numerically.

Given the expanding numbers of the older population and the burden that their numbers and poor health have on healthcare resources, it is timely to evaluate the determinants of healthy aging. If we could direct efforts early so this population bubble was in better health as they age, it would have dramatic effects on the costs to society. So what are the predictors of healthy aging?

A recent publication out of Harvard in the British Medical Journal (Sun et al., 2009) shed some important insight. Using data from the Nurses Health study they determined that weight gain at middle age was a strong predictor for health at age 70. This was a prospective study where over 17,000 nurses were evaluated from 1976 (at a mean age of 50) to 2000. Being healthy was defined as being free of cognitive, mental health or physical health deficits as well as free of 11 major chronic illnesses. The latter were diseases like cancer, cardiovascular disease, diabetes, Parkinson's disease, Multiple sclerosis and chronic obstructive pulmonary disease etc.

Stunningly only 9.9% on nurses that enrolled in the study in 1976 were healthy at age 70! In other words over more than 9 out 10 were unhealthy as they aged. After adjustments for lifestyles and dietary variables a major determinant of healthy aging was weight at middles age. Indeed it was linearly related, so that for every 2.2 pounds of weight put on between the ages of 18 and 50, the chances of being healthy at 70 went down by 5%. So if you gained 22 pounds your chances were reduced by 50%. Do your own personal math and calculate your risk. Frightening and this is for the population that lived to age 70. The focus was on healthy aging not longevity.

The lowest odds for healthy aging were those that were overweight at age 18 and gained more weight with age. Indeed, in this study 37% of the participants had both a chronic disease and at least one limitation (physical, mental or cognitive) and 55% had more than one limitation. In contrast if you maintained a healthy and stable body weight your chances for healthy aging improved dramatically.

The study pointed out some of the attributes that were associated with those that aged in a healthy manner versus those that did not. These include:

• More physically active
• Lower dietary intake of saturated fatty acids, trans fats and red meat
• Higher dietary intake of PUFA /Saturated fats, alcohol intake, cereal fiber and fruits & vegetables.
• Less likely to be a smoker
• Better educated

It appears that choices are major determinants of healthy aging, especially choices related to obesity and weight gain. Those individuals that maintain a stable healthy weight over their lifetime are far more likely to enjoy a healthy status as elderly citizens. This has a massive bearing on societal issues as noted at the beginning given the population bubble of Baby Boomers and the costs associated with managing poor health and aging.

Apparently size matters, and healthy aging is certainly determined by weight gain in adulthood.

Mark JS Miller, PhD, MBA, FACN

1) Sun Q et al. 2009. Adiposity and weight gain in mid-life in relation to healthy survival after age 70 in women: prospective cohort study. BMJ 339: b3796 doi: 10.1136/bmj.b3796