We hear it all the time...lose weight for your health. Few people however, realize the extent to which this is critical to their physical well-being and ultimately their life expectancy.
In January 2003, the Journal of the American Medical Association featured a study finding that obesity appears to lessen life expectancy, especially among young adults. The researchers compared Body-Mass Index (BMI) to longevity and found a correlation between premature death and higher BMIs. For example, a 20-year-old white male, 5'10" weighing 288 pounds with a BMI of greater than 40 was estimated to lose 13 years of his life as a result of obesity.
Jamie McManus, M.D., F.A.A.F.P. and author of "Your Personal Guide to Wellness" notes that while this study referenced extreme levels of obesity, there are still millions of overweight people in developed countries with a life expectancy rate that is three to five years less than their healthy-weight counterparts. Australia is following the US trends where an alarming 600,000 obesity related deaths occur each year.
Just how does obesity shorten our lifespan? The answer to this question is complex, yet there is a clear link between obesity and the development of cancer. An extensive study conducted by the American Cancer Institute involving 750,000 people showed that obesity significantly increased the risk of cancer developing in the following organs: breast, colon, ovaries, uterus, pancreas, kidneys and gallbladder.
Michael Thun, MD, vice-president of epidemiology and surveillance research for the American Cancer Society (ACS) says one reason obesity may raise cancer risk is because fat cells produce a form of estrogen called estradiol that promotes rapid division of cells, increasing chances of a random genetic error while cells are replicating, which can lead to cancer. In addition, fat centered around the abdomen may increase insulin and insulin-like growth factors in the blood, which may increase cancer risk. "Women who are obese after menopause have a 50% higher relative risk of breast cancer," notes Thun, "and obese men have a 40% higher relative risk of colon cancer.... Gallbladder and endometrial cancer risks are five times higher for obese individuals".
There is evidence that cancer rates in developed countries are increasing at 5 to 15 times faster than developing countries. A major contributor to this alarming reality has proven to be diet. In populations where the diet consists mostly of fresh fruit and vegetables and whole grains - in contrast to the typical Western diet of fatty meats, refined flours, oils and sugars - the risk of cancer is much lower.
The interaction of diet and the development of cancer is an active field of research and Dr David Heber, M.D., Ph.D. and author of "What Color is Your Diet", says "It appears that diet has its most significant effects after the cancer has already formed, acting to inhibit or stimulate the growth of that cancer". At the risk of oversimplifying a complex set of interactions, the typical Western diet that leads to obesity may actually act to stimulate the growth of cancer cells.
It is never too late to improve your health through healthful eating and adopting a more health-giving lifestyle.
