Mississippi Center for Obesity Research

Obesity and Chronic Diseases

Over the past 20 years, research is showing that obesity is playing an ever-increasing role in diseases. Below are just a few diseases where obesity is proving to play a role.

Obesity and cancer

Excess body weight contributes in up to 20 percent of all cancer deaths, according to the American Cancer Society. Given that obesity is considerably more controllable than many types of cancer, it stands to reason that managing weight and staying fit are promising ways to cut the nation’s cancer rate and save lives.

However, science and medicine need to know more about the causes of obesity and why weight loss is so difficult for most people. What is certain though, is that as a person’s body mass increases, so do the risks for many types of cancer. Those include cancers of the colon, kidney, endometrium, esophagus, pancreas, gall bladder, thyroid, ovary, cervix, and prostate, as well as multiple myeloma and Hodgkin’s lymphoma. Overweight and obesity also raise the risk for breast cancer in post-menopausal women.

Scientists and clinicians worldwide continue to research the causes and controls for the many types of cancer. Given that obesity plays such a prominent role in cancer – even in largely preventable varieties like colon cancer – more investigation into the factors that link obesity with cancer holds the promise of further reducing cancer rates.

Obesity and diabetes

Diabetes in the past 20 years has risen to become one of America’s most prevalent chronic diseases. And its link to obesity is undeniable.

The good news is diabetes is largely controllable if obesity can be controlled. However, the obesity epidemic increasingly drives the rates of type 2 diabetes, the most common form of the disease. About 26 million people it the U.S. have diabetes, up from about 17 million a decade ago.

As obesity rates increase in children, it puts them at greater risk of developing type 2 diabetes as adults. Obese children and adolescents are more likely to have pre-diabetes, a condition in which blood glucose levels put the person at high risk for developing diabetes.

Left uncontrolled, diabetes can lead to severe kidney damage and failure, limb amputations associated with poor circulation, and death.

Treating diabetes and all of its fallout effects puts a tremendous extra financial burden on employers, insurers, care providers and individuals. Annually the direct cost of treating diabetes exceeds $116 billion and another nearly $60 billion is spent annually on indirect costs, according to the American Diabetes Association.

A healthy diet and daily exercise remain pillars of preventing and managing both obesity and type 2 diabetes. But given the rising rates of each, we clearly need more avenues.

Attacking obesity through science – learning how it functions, the hormones that influence it, what roles genetics play, how appetite can more accurately be controlled and why recidivism rates following weight loss are more than 80-90 percent – offers a twofold promise of combating both problems.

Obesity and heart disease

More people die from heart disease in the U.S. – one in three deaths in 2008 – than from any other cause of death. And the obesity epidemic threatens to increase that rate.

Obesity alone greatly increases a person’s risk of heart disease, even if that person doesn’t have other risk factors for heart disease. But the link goes deeper. For people with known risks for heart disease – including high blood pressure, high cholesterol, tobacco use and uncontrolled diabetes – the burden obesity adds makes heart disease all the more likely.

Maintaining a normal weight, as measured by a body mass index (BMI) below 25, helps a person to more efficiently circulate blood and manage fluid levels.  That means easier work and less stress for the heart, circulatory system and kidneys. But more weight makes the cardiovascular system work harder and adds stress.  Obesity is a major factor in raising one’s blood cholesterol levels. High cholesterol contributes to the buildup of plaque in the arteries, a major cause of heart attacks.

Though heart disease usually strikes in mid and late life, nearly 20 percent of today’s youth are obese – a figure that’s risen through the past two decades. Childhood obesity increases the risk for cardiovascular disease contributors such as high cholesterol and high blood pressure. In a population sample of  5- to 17-year-olds, 70 percent of obese youth had at least one risk factor for heart disease, according to the Centers for Disease Control.

The better job scientists, physicians and individuals do at curbing obesity in children and adults, the more we’ll see cardiovascular disease rates drop.

Obesity and neurological degeneration

Increasingly, scientific studies in the past 20 years are uncovering links between obesity and neurodegenerative diseases, in particular, Alzheimer’s. The brain depends on a supply of oxygen and nutrients to work correctly. That supply is provided through an increasingly fine system of blood vessels.

As we age our blood vessels stiffen and lose flexibility to expand and contract. Scientists believe those changes may affect the tiniest of vessels in the brain, as well as larger ones throughout the body, making delivery of oxygen and nutrients more difficult. That might contribute to changes in the brain during aging.

Long-term high blood pressure, which stresses the walls of our blood vessels, and high cholesterol, which contributes to the buildup of plaque in the arteries, are also major factors in causing atherosclerosis, the increasing inflexibility of blood vessels.

While some hardening of those blood vessels is thought to be a natural process of aging, there’s no doubt obesity contributes greatly to high blood pressure and high cholesterol, increasing the stress on the body’s circulatory system and causing damage to the brain.

More analysis of the wide-ranging effects of obesity will help researchers pinpoint the neurological implications and work to find ways to prevent obesity’s damage.

Obesity and stroke

Though stroke occurs almost exclusively in adults, the epidemic of obesity in children is decreasing the average age of victims and putting our next generation more at risk for this debilitating, often deadly event. Since obese children are more likely to become obese as adults, they are also at greater risk for health problems as adults, including high blood pressure and stroke.

High blood pressure is the leading cause of stroke and death rates due to stroke are nearly 45 percent, according to the American Heart Association. Excess weight and physical inactivity can both lead to high blood pressure. Therefore, to combat hypertension and limit stroke, diet and exercise remain paramount for individuals and as policy for schools, workplaces, insurers, states and the nation.

However, with more research into obesity, scientists could help cut short that progression from childhood to adult obesity. Obesity research holds the promise of findings that can lessen the rates and impact of hypertension, thereby limiting stroke before it strikes. Studies aimed at understanding the mechanics of obesity on chemical, cellular and system-wide levels, can also work to undercut hypertension and stroke.