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13.1: Chapter Introduction

  • Page ID
    1924
  • Big Idea

    The human lifespan, the maximum number of years of human life, has remained unchanged and is around 130 years. Very few people have reached that age and the records show the oldest person lived 122 years and 164 days.  Good nutritional choices reduce the risk of chronic disease during the middle-aged and elderly years.

    Our diet has changed drastically as processed foods, which did not exist a century ago, and animal-based foods now account for a large percentage of our calories. Not only has what we eat changed, but the amount of it that we consume has greatly increased as well, as plates and portion size have grown much larger. All of these choices impact our health, with short- and long-term consequences as we age. Possible effects in the short-term include excess weight gain and constipation. The possible long-term effects, primarily related to obesity, include the risk of cardiovascular disease, Type 2 diabetes, hypertension, stroke, osteoarthritis, sleep apnea, respiratory problems, liver and gallbladder disease, and certain cancers (endometrial, breast, and colon) among middle-aged and elderly adults.Centers for Disease Control and Prevention. “Overweight and Obesity: Health Consequences.” Last updated March 3, 2011. http://www.cdc.gov/obesity/causes/health.html.

    It is best to start making healthy choices from a young age and maintain them as you mature. However, a recent report published in the American Journal of Clinical Nutrition, suggests that adopting good nutritional choices later in life, during the forties, fifties, and even the sixties, may still help to reduce the risk of chronic disease as you grow older.Rivlin, R. S. “Keeping the Young-Elderly Healthy: Is It Too Late to Improve Our Health through Nutrition?” Am J Clin Nutr 86, supplement (2007): 1572S–6S. Even if past nutritional and lifestyle choices were not aligned with dietary guidelines, older adults can still do a great deal to reduce their risk of disability and chronic disease. As we age, we tend to lose lean body mass. This loss of muscle and bone can have critical health implications. For example, a decrease in body strength can result in an increased risk for fractures because older adults with weakened muscles are more likely to fall and to sustain serious injuries when they do. However, improving your diet while increasing physical activity helps to control weight, reduce fat mass, and maintain muscle and bone mass.

    There are a number of changes middle-aged adults can implement, even after years of unhealthy choices. Choices include eating more dark, green, leafy vegetables, substituting high-fat proteins with lean meats, poultry, fish, beans, and nuts, and engaging in moderate physical activity for thirty minutes per day, several days per week. The resulting improvements in body composition will go a long way toward providing greater protection against falls and fractures and helping to ward off cardiovascular disease and hypertension, among other chronic conditions.Rivlin, R. S. “Keeping the Young-Elderly Healthy: Is It Too Late to Improve Our Health through Nutrition?” Am J Clin Nutr 86, supplement (2007): 1572S–6S.

    Life Expectancy

    Life expectancy has increased over time.  Now, in the USA, women can expect to live on average 81 years while the life expectancy for men on average is 71 years.  In the last few years, life expectancy has decreased due to the obesity epidemic.  For our forefathers, death was usually due to an infectious disease but the discovery of antibiotics, advances in medical treatment, improvement in nutrition and an abundant food supply has doubled life expectancy in the twentieth century.  

    Demographics have been changing.  In 1900, only one out of twenty-five people were 65 years or older.  Now, the number of people over the age of sixty-five has tripled and by 2060, the number will double again to 98 million people in the USA.  The fastest growing group are those over the age of 85 years.  This group has increased seven-fold since the 1950s.  Amazingly, in the last decade, the number of centurions has doubled.  Only 20-30% of the longevity is contributed to genes, most are due to health-related behaviors. Most of the elderly have chronic diseases that are related to nutrition.  These include heart disease, diabetes, hypertension, osteoporosis, and obesity.

    Causes of Aging

    Scientists have proposed a number of theories to explain why the human body ages but one single theory has not immerged.  The rate and manner in which humans age is influenced by genes, the environment, and lifestyle.  A complex interplay between each of these determines life expectancy.

    Characteristics of Longer Life Expectancy

    Why do some people live longer?  There are common characteristics among those that live longer.  They sleep regularly and adequately. They are physically active on a regular basis which is a powerful predictor of mobility. They don't smoke and they maintain a healthy body weight.  Their diets are charactered by well-balanced, regular meals, including breakfast.  They eat between 18-27% of their calories from fat.  Their meat consumption is low, and their fruit and vegetable intake is high.  They don't drink alcohol or they drink in moderation.

    You Decide:

    What is one nutritional choice that you can make today to reduce your risk of chronic disease tomorrow?

    Previously, we focused on the effects of dietary choices during pregnancy, infancy, and the toddler years. Our examination of nutrition through the human life cycle continues as we study the remainder of childhood into adulthood and the elderly years. Nutritional choices remain critical throughout a person’s life and influence overall health and wellness. The nutritional choices we make today affect not only our present health but also our future well-being.

    Video 13.1.1: Weight Gain and Body-Composition Changes, Midlife into Older Age

    This video focuses on the consequences of changing body composition from the middle-aged years into old age. (click to see video)