Estrogen levels are highest in fatty dairy products, compared to low-fat dairy.
The investigators analyzed a group of women who were diagnosed with early-stage, invasive breast cancer between 1997 and 2000. Most of the them (83 percent) were from Kaiser Permanente’s Northern California region. High fat dairy products include:
- Mature and/or hard cheese
- Evaporated milk
- Ice cream
- Whole milk
- Yogurt (made from full fat milk)
The investigators found that a high-fat dairy diet was linked to a greater breast cancer death rate – no association was found in low-fat dairy products though.
Dr. Kutner concluded:
“Women have been clamoring for this type of information. They’re asking us, ‘Tell me what I should eat?’ With this information, we can be more specific about recommending low-fat dairy products.”
People mostly think that How much do I have to eat to reduce my risk of cancer:
Although it is difficult to specifically state how much of a particular fruit or vegetable a is needed to reduce risk of developing cancer a sample of the data from studies can provide some guidelines.
In a large cohort study, the Nurses’ Health Study, researchers reported a 17% lower rate of breast cancer among women who consumed at least 2 servings per day of fruits and vegetables as compared to those who consumed less than 1 serving per day. In another recent study, the consumption of more than 5 servings per day of vegetables versus less than 3 servings per day was associated with a 54% reduction in the breast cancer rate.
The health benefits of eating fruits and vegetables have prompted the National Cancer Institute and the Produce for Better Health Foundation to co-sponsor the National “5 a Day for Better Health” program. This program is designed to encourage and provide practical ways for people to consume at least 5 servings per day of fruits and vegetables. Also, the USDA food guide pyramid suggests that people consume 5 to 9 servings per day of fruits and vegetables. A serving is:
- 1 piece of fresh fruit
- 6 oz. (3/4 cup) 100% fruit juice
- 1/2 cup of cooked vegetables or canned fruit
- 1 cup of leafy vegetables or salad
- 1 handful (1/4 cup) of dried fruit
- 1/2 cup of dried peas or beans
fruits and vegetables contain that may influence the risk of cancer:
Researchers have identified and isolated many natural chemicals in fruits and vegetables that may prevent or help combat breast cancer. Remember, many of these nutrients may be changed or destroyed by heat and cooking. These include:
Carotenoids– Carotenoids are chemicals found in yellow and orange vegetables and fruits, and in dark-green leafy vegetables. Certain fruits and vegetables contain particularly high amounts of specific carotenoids. Sweet potatoes and carrots are especially high in beta-carotene. Kale, spinach, parsley and mustard greens contain high amounts of lutein. Lycopene is a carotenoid found in high amounts in tomatoes. Some (but not all) carotenoids can be converted to vitamin A in the body. Foods that are particularly high in the pro-vitamin Acarotenoids include cantaloupe, carrots and sweet potatoes.
Vitamin C or Ascorbic acid. Vitamin C is found in citrus fruits and juices, such as grapefruits and oranges. Other good sources of vitamin C are green peppers, cauliflower, broccoli, tomatoes, strawberries, melons, cabbage and leafy green vegetables.
Vitamin E. Foods high in vitamin E include broccoli, kohlrabi, cilantro, turnip greens, spinach, avocados, blueberries, mangos, ripe olives, and especially nuts. Other plant sources of vitamin E include vegetable oils and whole grains.
Folic acid. Folic acid is a vitamin found in relatively high concentrations in green leafy vegetables, asparagus, lima beans, broccoli, beets and several types of beans. It is found in moderate amounts in oranges and orange juice.
Selenium. Selenium is a mineral which plants obtain from the soil and the higher the concentration of selenium in the soil, the higher the concentration of selenium in plants. Many animal studies have demonstrated anti-carcinogenic effects of selenium in the form of supplements to diets or in selenium-enriched foods such as garlic grown in selenium-rich soil.
Dietary fiber. Dietary fiber includes both cereal and vegetable fiber. Most fruits and vegetables contain fiber. Fruits and vegetables that contain high amounts of fiber are apples, blackberries, grapefruits, oranges, raspberries, and broccoli.
Dithiolthiones and glucosinolates. These natural chemicals are found exclusively in cruciferous vegetables, such as brussels sprouts, cauliflower, cabbage, broccoli, rutabaga and turnips.
Phytoestrogens. These are substances found in plants that act like weak versions of the hormone estrogen. When consumed, phytoestrogens may decrease the level of estrogen circulating in the body. Women who have high levels of circulating estrogen throughout their childbearing years may have an increased risk of breast cancer. See BCERF fact sheet #1 for more information about phytoestrogens and breast cancer risk. Foods high in phytoestrogens include soybeans, dried beans and peas, and bean sprouts.
There are many other natural chemicals in fruits and vegetables that researchers are currently studying. Information on these potential cancer preventing chemicals is preliminary. These chemicals include isothiocyanates and thiocyanates (in brussels sprouts), flavonoids (in berries), coumarins (in citrus fruits), phenols (in almost all fruits and vegetables), protease inhibitors (in legumes), plant sterols (in vegetables), isoflavones,saponins, and inositolhexaphosphate (in soybeans), allium compounds (in garlic), limonene (in citrus fruit oils), and resveratrol (in grapes).
vegetarian diet and reduce cancer risk:
Two studies were unable to show an association between eating a vegetarian diet, either during adolescence or as an adult, and a reduced risk of developing breast cancer. A few studies report lower levels of hormones, such as estrogen, in the bodies of vegetarian versus non-vegetarian women. Also, studies that compare the risk of breast cancer between different cultures, such as American versus Asian, have reported a decrease in the risk of breast cancer among women who consume a plant-based diet. However, scientifically there is not enough information to establish a solid conclusion that a vegetarian diet reduces the risk of breast cancer. However, use your common sense – if some studies indicate that fruits and vegetables reduce the risk of cancer, plus other studies show that there are known carcinogens formed by cooking animal products (see my article on Toxins Created by Cooking), then it isn’t hard to conclude that a diet consisting of whole fruits and vegetables will significantly reduce the intake of carcinogens while increasing the consumption of nutrients known to prevent cancer.
The best way to add more fruits and vegetables to my diet:
There are many ways for women to easily and conveniently add more fruits and vegetables to their diets:
- Keep prepared vegetables in the refrigerator for snacks
- Substitute spinach or another dark green leafy vegetable for iceberg lettuce in a salad
- Eat a sweet potato instead of a white potato
- Eat fruit as a snack
- Drink real fruit or vegetable juice instead of a soda
- rate a carrot or pepper and add it to spaghetti sauce
- If you have children, ask them to help make fruit or vegetable salads. This will help establish good habits.
Adapted from article by Julie A. Naieralski, PhD. and Carol Devine, PhD, RD, BCERF, Program on Breast Cancer and Environmental Risk Factors, New York State.