Plant-sourced food, vitamin intake associated with lower risk of endom

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Plant-sourced food, vitamin intake associated with lower risk of

endometrial cancer

 

A report published in the April 15, 2007 issue of the International

Journal of Cancer described the finding of a study funded by the

National Cancer Institute that a greater intake of calories,

attributable to a higher proportion of animal-sourced protein and fat,

is associated with an increased risk of endometrial (uterine) cancer,

and plant sources of these nutrients as well as vitamins A, C and E,

beta-carotene, fiber and vitamin supplements are associated with a

decreased risk.

 

Researchers in China and at Vanderbilt University in Nashville,

Tennessee compared 1,454 Chinese women with newly diagnosed endometrial

cancer to 1,212 age-matched women without the disease. Questionnaires

completed by the participants provided demographic information, health

history and data on macronutrient (protein, fat, carbohydrate, fiber)

and micronutrient (vitamin) intake, including the use of vitamin

supplements.

Greater consumption of calories, calories from animal food, increased

animal protein, and greater animal fat intake were associated with an

increased risk of endometrial cancer. Women whose dietary percentage of

animal derived food was in the top one-fifth of participants had a 90

percent greater risk of endometrial cancer than those whose percentage

was in the lowest fifth. Among women whose percentage of animal protein

was highest, the risk was double that of those in the lowest group, and

for those whose animal fat was highest, the risk was 50 percent greater.

In contrast, women whose percentage of calories from plants was in the

top fifth had half the risk of endometrial cancer compared to those in

the lowest fifth. Plant sourced protein and fat were also protective, as

were fiber, vitamin A, beta-carotene, vitamin C, and vitamin E.

 

When participants who reported having used vitamin supplements were

compared with those who had never used them, their risk of endometrial

cancer was found to be 30 percent lower. A similar effect was observed

for the use of single vitamin C and vitamin E supplements.

 

Supplementation with B vitamins was associated with a 70 percent

reduction in endometrial cancer risk, even though intake of vitamins B1

and B2 from diet had not been found to be related to risk of the

disease. Increased duration of any supplement use appeared to further

decrease risk.

 

The authors remark that the associations of dietary macronutrients with

endometrial cancer risk may depend on their sources. Micronutrients such

as those found to be protective in this study may inhibit tumor

development by their antioxidative effects. The authors note that

& ldquo;Inverse associations of vitamin supplement use with cancer risk

in our study provide additional evidence on the possible beneficial role

of vitamins in the development of the disease. & rdquo;

 

Health Concern

 

Uterine (endometrial) cancer

 

Obesity and a diet high in animal fats and low in fruits and vegetables

are associated with the development of uterine cancer (Hu FB 2003;

Schapira DV 1992). The relationship between unopposed estrogen exposure

and uterine cancer is well established (Berstein L et al 2002; Doherty

JA et al 2005; Persson I et al 1989). The incidence of uterine cancer

has increased in the past 50 years because of longer female life

expectancy and an increase in the use of unopposed estrogen therapy.

However, enhanced methods of diagnosis have improved detection rates

(Emons G et al 2004).

The rates of uterine cancer increase in first and second generation

Japanese women born in the United States (Liao CK et al 2003),

suggesting that the Western diet, high in animal fat, may be a risk

factor for uterine cancer (Potischman N et al 1993).

 

Various nutrients found in fruits and vegetables seem to have the

ability to detoxify certain carcinogens (cancer-causing agents)

(Steinmetz KA et al 1991). For example, the risk of uterine cancer is

inversely related to intake of beta-carotene and fiber (La Vecchia C et

al 1986). Fruits and vegetables that contain high amounts of vitamin A

(Schapira DV 1992), beta-carotene (Levi F et al 1993), and vitamin C

(Berstein L et al 2002) may decrease the risk of uterine cancer.

 

http://www.lef.org/protocols/cancer/uterine_cancer_01.htm