Sugar and Soy

I mentioned in an earlier post that I already know, even though I am a vegetarian, I eat too much sugar.  So I googled on “does sugar feed tumors” and found this fascinating roadmap article from The University of Colorado Cancer Center. It mentions that Indole-3-Carbinol (found in cruciferous vegetables) that I ordered this morning.  It also brings up a new food to watch out for:  Soy. 

As a vegetarian, I get a lot of protein from soy and generally speaking, that’s a good thing.  But in the case of estrogen-sensitive tumors, it says to be cautious about soy, so that will become another homework item.

http://www.uccc.info/cancercenter/content/breast/default.asp?index=BreastCancer&title=Buddy%20Check9%20November%202005

Fighting Breast Cancer with a Fork, Part 2 of 2

Colleen Gill, MS, RD, University of Colorado Cancer Center

As we discussed in the first part of “Fighting Breast Cancer with a Fork,” what we eat can influence our risk for developing some types of cancers, including breast cancer. For this reason we need to incorporate healthy eating habits into our everyday life. In addition to managing your weight, eating fruits and vegetables and incorporating a limited amount of healthy fats in your diet, here are other things to consider.

Does Sugar Feed the Tumor Feed the Tumor?

The consumption of sweets and other carbohydrates that raise blood sugars and, thus, insulin levels in the blood has been tied to an increased risk of breast cancer, where there was insulin resistance. When this is present, you are not able to clear sugar from your blood stream efficiently, causing your pancreas to produce more insulin.  Insulin, as a marker of “feast” or excess calories, stimulates growth and cancer cells may have many more receptors that can pick up this signal:

• If you are active and lean, the risk of insulin resistance is almost eliminated!Weight loss and exercise is the best prevention.

• Generally, foods that are more processed or refined will raise blood sugars and insulin levels to a greater degree. Limiting these foods may be helpful.

• Including fiber, protein and/or healthy fats with carbohydrate sources will slow the release of carbohydrate from the stomach and keep blood sugars under better control. 

Modifying Estrogen Balance

Research has found that estrogen exposure increases breast cancer risk through its stimulation of breast cell growth.    Genetic variations in estrogen production may contribute to some of the variation in risk for breast cancer, but estrogen metabolism also is influenced by diet. The following recommendations can optimize estrogen balance and are consistent with other recommendations that limit cancer risk:

 

Moving estrogen production to the “good” 2-OH path - women with more 2-OH form had 30% less breast cancer

• Indole-3-carbinol in cruciferous veggies. Goal: 5-7 servings a week

• Exercise, green tea

• Soy also influences estrogen production but is controversial in breast cancer

Increasing sex hormone binding globulin: keeps estrogen bound in the blood

• Moderate carbohydrate diet, lower insulin levels increase SHBG

• Low fat diet, high fiber

• Soy also influences estrogen production but is controversial in breast cancer

Limit beta-glucuronidase enzyme activity, to limit reabsorption of estrogen in the gut

• Low animal fat diet, since high fat increases enzyme levels

• High fiber, 30-35 g/day: achieved with 7-10 servings of fruits/vegetables a day and use of whole grains

• Calcium-d-glucarate, found in cruciferous vegetables such as broccoli, broccoli sprouts, cauliflower, cabbage, watercress, kale, Brussels sprouts

• Probiotics, changing the acidity in the gut and limiting the enzyme activity

Remove sources of artificial estrogens

• Avoid hormone replacement therapy, metabolized to the 4-OH and 16-OH forms.

The Soy Controversy

Soy has multiple cancer protective properties and is actively encouraged for those with many cancer diagnoses. But for those with estrogen sensitive tumors, soy remains controversial. Isoflavones in soy are phytoestrogens, looking enough like estrogen that they can interact with estrogen receptors. Still, current research indicates that soy in the diet during adolescence is actually quite protective against later risk of breast cancer. We are less certain about the effect of soy when it is added later in life, and we know even less about its impact in women who already have been diagnosed with breast cancer. Most experts feel that there is little risk involved with consuming soy at the levels in the normal Asian diet, or roughly one serving a day containing 40-50 mg of isoflavones. Work continues to clarify this critical question.

 

What is the Bottom Line?

2/3 of your plate should be plant-based

• 50% vegetables and legumes

• 5-7 servings/week of cruciferous vegetables for detoxification support

• 7-10 servings of fruits/vegetables, 1 of legumes/beans and 2 whole grains achieves the goal for 25-35 g of fiber each day

Eat small, frequent, mixed meals

• Avoid diets that drastically reduce or eliminate one source of calories

• Choose foods as close to their “natural form” as possible, using fewer refined and processed options

• Include more fish, olive oil and other healthy fats

Limit the “bad stuff”

• Choose low fat meats and dairy products

• Avoid trans fats in processed and deep fried foods

• Limit excess sugar and high glycemic index carbohydrates

• Alcohol should be limited to less than 1 drink/day: Risk increased ~10%/drink/day related to higher estrogen levels and detoxification issues.    Increased folate intake through food or multiple vitamins was protective

Drink lots of fluid

• Water, green/black tea and vegetable juices are good choices

Take a multiple vitamin with folate and vitamin D

• Avoid vitamins containing iron, unless you are premenopausal.

Get regular exercise

• Start with at least 15 minutes a day for weight and blood sugar control

Heart disease kills more women than all cancers combined

• Know your cholesterol level, and follow your doctor’s advice - LDL < 130; HDL > 40; Triglycerides < 150; CRP < 4

Make Recipes Healthier

• Make healthy substitutions - Use olive/canola for oil, substitutes for large quantities of animal protein

• Add healthier ingredients to the mix - Include fruits/vegetables in recipes

• Serve smaller portions of less healthy foods\Save some foods for special occasions

• Check www.aicr.org for many free cancer prevention recipes and materials

Additional Resources

• Read Colleen’s bottom line when it comes to nutrition and cancer prevention.

• 101 Ways to Cut 100 (or more) Calories

• Find a dietitian in your area.

• Free cancer prevention recipes and materials from the American Institute for Cancer Research.

• Free nutritional seminars at University of Colorado Cancer Center.

• American Cancer Society’s guidelines for eating well and being active.

• American Heart Association

About the Author

Colleen Gill, MS, RD, has worked with patients at the University of Colorado Cancer Center (UCCC) and the University of Colorado Hospital Center for Integrative Medicine for the past 15 years. In addition, Colleen provides nutritional counseling at Nutrition Foundations. To address patients’ questions effectively, she stays current with nutrition information through continuing education, attending conferences, reading list serves, newsletters and medical literature, and listening to patients.