Beth Kitchin PhD RD blogs twice a week on health and nutrition topics. Beth's blogs are refreshingly fact-based and offer a common sense approach to a healthier life. She's a food lover so don't expect her to tell you what not to eat! Beth is a registered dietitian, an Assistant Professor in the University of Alabama at Birmingham's Nutrition Sciences Department, and the patient educator at UAB's Osteoporosis Prevention and Treatment Clinic.
Friday, March 22, 2013
The Myth of Sugar-Loving Tumors
I went out to dinner
with a friend of mine last night who asked me if sugar feeds tumors. He had
seen some sort of presentation where someone showed sugar being taken up by tumors.
I see these kinds of things on Facebook
posts all the time and scroll by. But
when friends pose these questions to me over a plate of pasta, I take the
concern a little more seriously.
So what are the facts here?
Well, cancer cells and tumors need calories and nutrients just like the healthy
cells in our bodies. While cancer cells
do feed off sugar, healthy cells do too. So yes, if you give a tumor sugar in a
petri dish it will surely be taken up by the cancer cells – but so will all the
other cells of your body. It also makes
for some nice scary pictures to post on Facebook and for an overly simplistic
message about how cancer cells operate.
Research shows that eating sugar
doesn’t speed up cancer growth. If you
want to shut off what feeds cancer, you have to shut off what feeds all of your
cells. You would starve and kill the cancer cells but you would also starve and
kill healthy cells and die. Some
research shows that there may be some sort of link between high insulin levels
and growth of some cancers. Some people
pump out too much insulin when they eat too many carbohydrates. But many of us have normal insulin levels.
We do know that obesity may be a
risk factor some cancers. So eating too much sugar and other calorie dense
foods could be an indirect factor in some cancers. In fact, one of the first recommendations
by the American Institute for Cancer Research for cancer prevention is to
be as thin as possible without being underweight. They also recommend eating fewer calorie
dense foods – including sugar sweetened beverages. These foods can increase
weight. It’s the weight gain that can
lead to many problems – including too much insulin – and that increases the
risk of some cancers.
But notice I said some cancers. And this is another area of misconception
about cancer. Cancer is not just one disease. While there are common themes to
all cancers – such as all cancers start with some sort damage to genes – risk factors and causes of each of the
cancers are not always the same. For instance, the human papilloma virus is a
cause of cervical cancer and possibly some oral cancers but not of other types
of cancers. Weight gain seems to be a
risk factor for cancers in the esophagus, pancreas, colon/rectum, endometrium,
kidney, gallbladder, and postmenopausal breast cancers. It may not be much of a
risk factor for cancers in the lung, ovaries, or stomach.
The bottom line is that we
should all be moderate with sugar. But it is the not the tumor-feeding fiend a
lot of people make it out to be. You can
also check out this excellent explanation
of this myth on the Mayo Clinic website.
Beth Kitchin PhD RD
Assistant Professor, Nutrition Sciences
University of Alabama at Birmingham