Diet and Cancer: Aimee’s Q & A

QI have heard that sugar feeds cancer.  If I have a cancer diagnosis, should I cut all sugar out of my diet?

Aimee:  There’s a lot of confusion out there about the connection between sugar and cancer.  The idea that sugar feeds cancer is misleading because sugar feeds ALL cells in the body.  Glucose, or sugar, is your primary source of energy.  And, even if you cut all sugar out of your diet, your body will still make sugar from other sources, like protein and fat.

The real problem with a lot of simple sugar is that it causes the body to produce excess insulin.  Insulin is a hormone that causes cells to grow and divide.  For healthy cells, growth is a good thing.  For cancer cells, it is definitely not a good thing.  In general, keeping insulin in balance is very important for your health.

If you have a cancer diagnosis, the recommendations are to follow a plant-based diet that includes a wide variety of healthy foods.  Here are some tips to improve your nutrition:

  • To satisfy your sweet tooth, choose naturally occurring sources of sugar – a.k.a. fruit.  It’s best to limit foods that are very high in refined or processed sugar because they don’t have a lot of nutritional value.  Such foods include sodas or sweetened beverages, cakes, cookies, candy, etc.
  • Choose complex carbohydrates like vegetables, fruits, whole grains, and legumes (beans) instead of simple carbohydrates like candy, soda, or desserts.  Coincidentally, these complex carbohydrates are the very foods that contain lots of cancer-fighting nutrients!
  • Combine foods to balance your insulin response.  In general, combining carbohydrates with protein, fat or fiber can help the body produce less insulin.  So, instead of having a piece of fruit by itself for a snack, combine the fruit with a handful of nuts (nuts contain protein, fat and fiber).  Or, instead of drinking fruit juice, choose whole fruit (it contains fiber, which helps slow down the release of sugar into the bloodstream).

Q:  I have heard that having an “acid environment” in the body can encourage cancer cells to grow and that I should avoid acidic foods.  Is this true?

Aimee:  This is a very common question among patients dealing with cancer.  Cancer cells can produce acid, but an acid environment does not encourage their growth.

Your body keeps acid-base balance under very tight control.  If your body were to suddenly become significantly more or less acidic, serious side effects and illness would occur.  Even though you can’t significantly change the acidity of your body, certain foods can promote a slightly less acidic environment.

Luckily, the same foods that can help fight cancer can also help make the body less acidic.  These include plant-based foods, such as vegetables, fruits and legumes.  You don’t have to be a vegetarian, but eating more plants will help keep you healthy.  A general rule is to try to have two-thirds or more of your plate covered by plant foods (vegetables, fruit, whole grains and beans) and one-third or less covered by animal foods (meat, chicken, fish, dairy, eggs).

Q:  Are soy foods dangerous for women with breast cancer?

Aimee:  This is a great question that unfortunately creates a lot of anxiety for individuals who have been diagnosed with breast or other hormone-related cancers.

Originally, the medical community thought that soy foods contained estrogen and thus should be avoided by women with a history of breast cancer.  This idea comes from the fact that soy foods contain a group of nutrients known as phytoestrogens (a.k.a. plant estrogens).  While these nutrients look chemically similar to human estrogen, they are not the same as naturally occurring human estrogens.  In other words, they do not act like human estrogen and thus do not promote tumor growth.

Researchers have noted that women who regularly consume soy food as part of their normal diet, such as Japanese women living in Japan, have much lower breast cancer rates than women who do not eat soy foods regularly.  Of course, this data may or may not apply to women of other ethnic backgrounds living in other countries, but overall research indicates that soy foods are safe.  In fact, a recent consensus among soy experts, as published in the December 2010 supplement of the Journal of Nutrition, indicates that soy foods “appear to be protective” against breast cancer and are “associated with a lower risk of recurrence for women who have consumed soy throughout most of their lives.”

The current consensus in the oncology nutrition world is that 2-3 servings of whole soy foods per day are safe for women with breast cancer.  Whole soy foods include edamame, tofu, tempeh, miso, and soy milk.  Highly-processed soy-based foods, such as soy protein powder or processed soy “meats”, are not as beneficial as whole soy foods and should be avoided until further research has been conducted on their safety.

Q:  Should I switch to organic foods?  If so, what about the high cost of eating organic?

Aimee:  Research tells us that organic fruits and vegetables are often higher in vitamins, minerals, antioxidants and other healthy nutrients than conventionally-grown foods.  Choosing organic foods can also decrease your exposure to pesticides.  That being said, current research has not shown a link between cancer and exposure to trace amounts of pesticides found on conventionally-grown fruit and vegetables.

Unfortunately, organic foods can be more expensive.  However, by making smart choices when buying organic, you can balance your health and your budget.

The Environmental Working Group recommends that you choose organic when buying the following fruits and vegetables – often called “The Dirty Dozen”:

  • Peaches
  • Apples
  • Sweet Bell Peppers
  • Celery
  • Nectarines
  • Strawberries
  • Cherries
  • Pears
  • Grapes (imported)
  • Spinach
  • Lettuce
  • Potatoes

At the same time, they found that certain fruits and vegetables are minimally contaminated with pesticides – thus choosing organic may not be necessary.  The “Clean Fifteen” includes:

  • Onions
  • Avocado
  • Sweet Corn (Frozen)
  • Pineapples
  • Mango
  • Asparagus
  • Sweet Peas (Frozen)
  • Kiwi Fruit
  • Bananas
  • Cabbage
  • Broccoli
  • Papaya

Hopefully, these lists can help you prioritize your spending.  Remember, eating fruits and vegetables, even if they aren’t organic, is always better than avoiding them – countless studies have shown their protective effects in reducing cancer risk and promoting overall health.

Q:  Where can I find reliable information about diet and cancer on the internet?

This is a great question!  While the internet can be a wonderful source of information, there is also a lot of mis-information out there that is not supported by solid science.  Here are two credible web sites that I find helpful:

The American Institute for Cancer Research

For more on foods that fight cancer, check this site.

For more on eating a plant-based diet, check this site.

Caring 4 Cancer

For more on sugar and cancer, check this site.

For more on acid balance and cancer, check this site.

For more on soy and breast cancer, check this site.

For more on choosing organic, check this site.

The information found here is not intended to provide nor should it be interpreted to provide professional medical, legal or financial advice. You should consult a trained professional for more information.

Category: Experts Speak

Tags: acid environment, Breast Cancer, cancer, Caregivers, complex carbohydrates, diet, hormone-related cancers, oncology nutrtition, organic foods, plant-based diet, soy food, sugar