Innovative studies
look at diet and
cancer prevention

How does fish oil, walnuts, or a mother's diet affect your cancer risk? These are a few of the questions that scientists from institutions around the country are working to find out, with AICR support. In no particular order, here are the researchers and the studies they are starting this year.

Heather J. Baer, ScD
Harvard Medical School

Childhood body fatness and breast cancer risk

Many people have seen that greater body fatness at young ages is associated with decreased breast cancer risk in adulthood, says Baer. "But no one really understands why that is."

Baer is looking at data from girls to see whether body fatness in childhood and adolescence has effects on breast density or on levels of an ovarian hormone called MIS (Mullerian inhibiting substance) later in life, during young adulthood. Other studies have associated both MIS and body fatness to breast cancer risk. "If we can figure out this pathway, we may be able to intervene on those steps in the future."

Jimmy W. Crott, PhD
Tufts University

Does maternal vitamin B influence cancer risk in offspring? 

In prior animal studies, Crott found that diets deficient in B vitamins promoted intestinal tumors in offspring and diets supplemented with B vitamins were protective.

Now, Crott will use mice predisposed to colon cancer who consume varying amounts of B vitamins to determine if changes in a specific gene – commonly mutated in colorectal cancer responsible for the different tumor incidence seen in offspring.

According to Crott, once we know more about the effects of the maternal diet and the mechanism involved, “we can begin thinking about optimizing a mother’s nutrient requirements, not only to protect against diseases such as neural tube defects at birth, but also to protect against cancers that may occur later in a child’s life.”

Iris Edwards, PhD
Wake Forest University

Fish oil and breast cancer

Cell studies have found that omega-3 fatty acids, which are abundant in fish oil, prevent cancer cell growth.

By studying women who were recently diagnosed with invasive breast cancer, Edwards hopes to determine whether fish oil is protective against breast cancer and if so, how it does so.

“We propose that omega-3 fatty acids are potentially a safe and inexpensive tool in the arsenal of agents to combat breast cancer, but physicians need more data to guide their recommendations.”

David Feldman, MD
Stanford University

Obesity, breast cancer and vitamin D

For those who are overweight or obese, vitamin D may play an important role in preventing breast cancer, Feldman suggests.“Women who are overweight or obese have an increased risk of breast cancer and they also have increased risk of vitamin D deficiency.

There’s a potential link there and [our] study is looking at the ways that obesity increases the risk and how vitamin D might reduce those risk factors,” he says

Using a mouse model of breast cancer, Feldman hopes “to develop vitamin D as a therapy to protect against fatness-enhanced breast cancer…and investigate whether vitamin D added to the diet protects against the negative effects of fatness.”

Bryan Fuchs, PhD
Massachusetts General Hospital

Green tea's EGCG may protect against liver cancer

In previous animal studies, Fuchs found that a gene called epidermal growth factor (EGF), promoted liver cancer growth.

Other studies have suggested that EGCG, a phytochemical rich in green tea, may inhibit EGF signaling. Putting those two findings together, Fuchs is using an animal model of chronic liver disease to determine whether EGCG inhibits the development of liver cancer by inhibiting cirrhosis. He is testing EGCG alone and in combination with erlotinib, a common treatment for the disease, to determine if it slows tumor progression.

"If EGCG is successful and we can prevent [liver cancer] from occurring in the first place, then the implications are huge,” says Fuchs.

Timothy Gershon, MD, PhD
University of North Carolina at Chapel Hill

Treating pediatric brain tumors with the ketogenic diet

Medulloblastoma is the most common brain tumor in children. In earlier animal studies, Gershon observed that medulloblastoma cells use far more glucose than normal brain cells.  

With this new animal study, he hopes to target the unusual way medulloblastoma cells use glucose to see if a ketogenic diet – high fat, low-carb – will have an anti-tumor effect by forcing the tumor cells to burn fat rather then glucose from carbohydrates.

Normal brain cells can adapt to a ketogenic diet, but tumor cells appear less able to, says Gershon. “The hope is that if cancer cells have a different metabolism than the rest of the body, then targeting cancer metabolism may be the magic bullet we’ve been looking for.”

Dominic Smiraglia, PhD
Roswell Park Cancer Institute

Dietary folate levels and prostate cancer risk

We need folate for healthy DNA, and prostate tissue is especially dependent on the pathways central to folate, says Smiraglia. In Smiraglia's new study, he is comparing the development of prostate cancer in mice fed a folate-restricted diet to mice that are fed a diet that is supplemented with folate.

"We expect that dietary folate restriction, when combined with androgen deprivation therapy, will result in reduced ability of the cancer to recur," he says.

"The relationship between folate and prostate cancer is complex and will require significant effort to understand how dietary levels of folate impact cancer risk, cancer progression and therapeutic outcomes.”

Robin T. Wilson, PhD
Pennsylvania State University

Genetic differences in metabolizing vitamin D and its health implications

There is no conclusive evidence linking vitamin D to cancer prevention yet. But the inconsistent results may be due to how individuals metabolize vitamin D, says Wilson. For example, studies consistently show that serum vitamin D levels are lower among African Americans than Caucasians.

Wilson's study is investigating whether there are different rates of vitamin D metabolism according to a person's genetic ancestery and genetic differences in vitamin D metabolizing.

This study will help us "understand the genetic as well as the environmental influences on serum vitamin D levels and hopefully avoid some of the issues of overdosing and some of the adverse side effects," says Wilson.

Christos Mantzoros, MD, DSc
Harvard Medical School

Walnuts and colon cancer

Mantzoros recently found that walnut consumption decreased the growth of colon cancer in mice. However, the mechanisms involved in this effect are still poorly understood.

By looking at how habitual walnut consumption effects microRNA, small molecules that regulate gene expression, he hopes to gain a more advanced understanding of how walnuts are able to decrease the risk of cancer and use this knowledge to improve colon cancer prevention and therapies.

Sabrina Trudo, PhD, RD
University of Minnesota

Effect of vegetables on meat compounds

A diet high in red meat increases colon cancer risk, possibly due to the meat compounds called heterocyclic amines (HCAs). Earlier lab research has found that carrots, broccoli and other plant foods may reduce or "deactivate" the levels of HCAs and other carcinogens.

Trudo is honing in on the effect of these foods in people by measuring HCA levels after people eat a grilled burger with foods in the broccoli family, the carrot family or both. "Studies of plant foods and cancer have fed the same single food item for prolonged periods then looked for a benefit.  As a next logical step, we hope that this study will shed light on whether combinations of plant foods consumed in a single meal will improve metabolism of carcinogens," said Trudo.

More on Research in Cancer Prevention

Keep checking back for more information on the outcomes of these studies and the overall research in the field. To read more about the research related to diet, activity, weight and cancer prevention, visit:

Foods that Fight Cancer

Learn More about Cancer: By Site

Making Sense of the Science