Yesterday the results of a study were published in the on line version of research journal BMJ. The research involved the Nurses Health Study that began in 1976. (BMJ 2009;339:b3796) The average age of the all female nurses when they entered the study was 50. The women have been followed over time while lifestyle factors and disease conditions were measured. Most recently, scientists at Harvard analyzed the data to determine if being overweight in middle age would have an impact on disease status as well as functionality in older age. Their study doesn’t answer all questions but it certainly should give us pause and motivate the country to work to prevent overweight and obesity.
The scientists looked at weight and disease status not weight and disease causality, we already know that weight and disease are related. Here the scientists learned that for every two (plus) pounds of weight gained since age 18 the odds of healthy survival beyond age 70 were reduced five percent. (the study was on women but previous studies have told us the same type of information for men)
If you weighed 120 at age 18 and at age 50 you weigh 160 that is 20 pounds. The data was calculated with kilograms, so that is really 2.2 pounds. So divide that 20 pounds by 2.2 and get 9 and 9 times 5 = 40% The persons chances of living past age 70 disease free just dropped 40 percent.
If a person was already overweight at age 18, saying they weighed 160 then (they aren’t tall or athletic!) and gained 22 pounds as they aged, there odds of reaching 70 in good health were quite slim.
The scientists also tracked outcomes by BMI http://yourhealtheducator.blogspot.com/2009/05/obesity-meaning-and-measurement.html numbers. For every point that the subjects BMIs increased they lowered their chance of a healthy older age by 12 percent. That is substantial. The researchers define this “health” as being free of chronic disease and ALSO having the ability to live independently doing ones own activities of daily living which includes physical and mental function.
The end of the study found only about 10% reached age 70 disease free where as 90 percent had at least one chronic disease condition, some had two and others three. Thirty seven percent had chronic disease as well as physical and mental declines.
The research does not answer the question about weight gain and weight loss (they did see an improvement but the amount of women who lost weight was so SMALL that the results are not considered statistically significant), but certainly other studies have demonstrated the effects of weight loss on disease conditions and thus life expectancy. Beyond that, we also know that we have treatments for diseases that keep people alive longer and we have the concept of “compressed morbidity” that we would like to make a reality. We do not want to die longer but to LIVE longer.
I feel this is important to drive home because when the weight control experts or pundits get passionate, the “accept your body” activists get louder. This is NOT about aesthetics… this is about disease and disability. Do you know what the study listed as the most common diseases associated with the weight gain? I will tell you – in this order; cancer, heart disease and diabetes. I understand that food can be comforting, believe me I DO understand, but living well as I live longer is the comfort I aspire to.
Maybe think of it this way. Anything could happen, but most of us are given strong odds to live into our eighties or even nineties. In other words, medicine may give you an extra ten years but what are you getting for that? Will you be able to live those extra years?
It is like your boss saying that everyone gets two more weeks of vacation - but no one can take time off. It is a useless benefit.
I read an article about this study and then read the study. The article had a few things wrong - so always keep that in mind.