Heavy Mettle

Obesity comes with a plethora of terrible conditions. This is old news. Yet, an onslaught of recent discoveries among the overweight and elderly population has brought new concerns to light. Studies show that mortality and other serious risks apply to aging patients with high BMI scores, despite the common belief that people over 65 years of age face no increased consequences for extra pounds.

Nearly 30 years have passed since the obesity epidemic in the U.S. became a well-recognized concern. Physicians have fought to stymie the growing list of comorbidities: diabetes, heart disease, metabolic syndrome, hypertension, stroke, and more. But until recently, many experts believed in a so-called “obesity paradox” that claimed overweight and obese individuals will live just as long, if not longer, than healthy-weight individuals after retirement age. Battling the bulge after a certain age was often considered pointless. New research on elderly obese individuals has disproven this theory and revealed some surprising additions to the list of correlated diseases.

Cognitive Functioning

Many studies have focused on obesity and mental cognition in an aging population, but lacked the long-term data to prove the relationship. Kaiser Permanente decided to exercise its considerable patient database to elucidate this topic, and the results were damning. The 27-year longitudinal study, which was recently published in the British Medical Journal (BMJ), found a 74% increased risk of dementia among individuals with a BMI >30 (defined as obese) in comparison to healthyweight individuals. Overweight participants — defined as a BMI between 25 and 29.9 — also had a 35% elevated risk of dementia.

The data included over 10,000 individuals, who participated in thorough health evaluations from 1964 to 1973 when they were between the ages of 40 and 45 years old, and who were still enrolled in the health plan in 1994. The patients in Kaiser’s study were born prior to the baby boom following World War II, meaning that the next generation of elderly will be significantly larger in both population and, quite likely, weight. Genuine concerns over the costs of caring for baby boomers in old age continue to burden the public and policymakers, and these worries are compounded by the effects of obesity.

The authors concluded that, “With the aging of the population, it is expected that the incidence of dementia will increase 400% in the next 20 years.” The worldwide cost of dementia already exceeds $600 billion per year according to the World Health Organization (WHO). On a global scale, WHO estimates this population will double by 2030 to 65.7 million, and more than triple by 2050 to 115.4 million. In combination with obesity, the price of these two conditions could be crippling to the world’s economy.

Although the exact connection between weight and cognitive functioning remains unknown, the scientific evidence is clear: Overweight and obese adults are more likely to develop dementia and Alzheimer’s disease. Some researchers theorize that proteins released into the bloodstream by adipose tissue have a damaging effect on the brain, but consensus among experts has not been reached. Other issues among the obese elderly have proven easier to dissect.

Handle with Care

The condition of obesity seems to affect nearly all bodily systems in mid to old age — even bones. Increased weight generally leads to increased muscle and bone mass due to the extra exertion of gravity and movement. However, studies have also shown obesity to be a major indicator of fracture risk.

“Those patients with obesity in midlife have five times higher risk of developing frailty during the next two decades compared to those who were normal weight at midlife,” says Sari Stenholm, PhD, senior researcher at the Academy of Finland and National Institute for Health and Welfare. He discovered these statistics as a part of his recent 22-year, follow-up study of the relationship between obesity and frailty in midlife to old age in the male and female Finnish population.

Once an individual has reached old age, treatment for obesity and its comorbidities becomes more difficult. In addition to cognitive decline, Stenholm’s research has shown a significant risk of osteoarthritis in obese elderly patients, and thus a greater possibility of disability. Patients that do manage to lose weight in old age are probably too late to reverse these effects, as they are likely losing muscle mass and bone density along with fat loss. Intervention in midlife might offer the only solution.

“I believe we really should start thinking about aging from the ‘life course’ perspective. It is hard to do major lifestyle changes in your seventies, but by avoiding excess weight and other unhealthy manners in midlife, you can really make a difference in terms of health and functioning in old age,” Stenholm explains.

The obese participants in his study that maintained physical activity fared better than obese individuals who lived a sedentary lifestyle. Stenholm notes that muscle strength is a sizeable factor in a patient’s likelihood of becoming frail.

The fear of muscle loss and frailty partially contributed to the past theory that weight loss has no benefits over 65 years of age. This puzzling conclusion does not factor in the positive effects of physical activity and good nutrition, which has led many experts to call its validity into question. Weight loss and exercise might be more difficult and dangerous over a certain age, but can actually increase one’s life expectancy.

Risk of Death

The outdated belief that obesity past a certain age proves no additional mortality risk originates from one central flaw in the National Health Interview Service (NHIS). According to Ryan Masters, PhD, a scholar at Columbia University’s Mailman School of Public Health, “Obesity wreaks so much havoc on one’s long-term survival capacity that obese adults either don’t live long enough to be included in the survey or they are institutionalized and, therefore, also excluded.”

Obese individuals in nursing homes were left out of the original NHIS research, which thus ignored crucial overweight populations and skewed obesity in the elderly toward an innocuous status. Patients with dementia, fractures, stroke, and other obesity-related conditions did not make the cut due to placement in an assistedliving facility. This inspired Masters and his colleagues to take a new approach, and their work recently found its way into theAmerican Journal of Epidemiology.

Masters reevaluated the NHIS survey by comparing it to 800,000 records from the National Death Index (NDI) for adults surveyed between 1986 and 2006. He found that obesity correlates to a higher risk of death with age — reversing old conclusions. “This study should put to rest the notion that it’s possible to ‘age out’ of obesity risk and provides a powerful counterfactual against those who say concern over obesity is overhyped,” Bruce Link, PhD, professor of Epidemiology and Sociomedical Sciences at the Columbia University and co-author on the study, toldScience magazine.

Using the same data, Masters was able to prove that obesity causes far more deaths in the general population than previously thought. The reigning mortality statistic for obesity has been 5%. His new research shows a death toll of 18% for black and white Americans aged 40 to 85. Black women showed the highest rate of weight-related mortality at 27%, followed by white women at 21%.

Link believes that we are yet to see the worst effects of extra weight. He believes that the current generation of obese children will likely display more frightening symptoms when they reach adulthood, and especially if they make it to old age. Only time will tell if he is correct, but the additions of cognitive functioning and frailty to the list of obesity concerns do not bode well for the future.

— Mapes is a freelance writer in Washington, D.C. She wrote about how to set up an in-house laboratory in the January issue.

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