By Ashley Huser, RD, LDN, Block Center for Integrative Cancer Treatment
The Concern:
As a Registered Dietitian working in an integrative oncology setting, I often hear patients sharing concerns that acidic foods may increase cancer risk or decrease the chance of successfully beating cancer.
This theory has been spurred on by many different Internet sources suggesting cancer cells thrive in an acidic environment. From my experience, this may lead patients to severely restricting their diets (and eliminating fantastic phyto-nutrient packed foods, such as lemons, oranges, and tomatoes!)
But before you kick the citrus and vinegars, let’s discuss the whole story.
While, there is research to suggest tumor cells create an acidic micro-environment1, our bodies have ways of keeping the entire body at a very steady pH, which is the standard for how acidic our bodies are, a number higher than 7 indicating a basic, or less acidic environment, and a number less than 7 indicating an acidic environment.2
Buffers and how our body maintains our pH:
Maintaining a pH in our bodies around 7.4 is crucial for many bodily functions. Our kidneys, lungs, and other regulatory systems help to keep our pH as steady as possible (fluctuating slightly between 7.35 and 7.45). We get acid from our metabolism and the foods we eat, all of which need to be “buffered” or evened out. If our pH is not maintained, severe health consequences can occur.2
Foods that bring acid into our body and favor a lower pH include foods with sulfur-containing amino acids3. Metabolism and exercise can also create acid in our bodies. When these things occur, certain reactions occur at a cellular level to balance out the heavy acid content in our blood or our kidneys excrete acid-forming atoms and our lungs can alter the amount of carbon dioxide we exhale. Between these processes, our bodies do a miraculous job in maintaining our blood pH so all of our bodily functions can operate at an optimal level.2
Can we still get health benefits from less acidic foods?
Yes we can! Some research suggests that healthier bones and more stable muscle mass maybe related to eating less acidic foods4. Greater bone and muscle health may translate into the ability to be more active and involved within your community, which may translate into greater physical and emotional health! What is most important to remember is the majority of basic, or non-acidic, foods in the diet are our fruits and vegetables!3 These foods are related to a cornucopia of health benefits and disease prevention.
So if my citrus fruits and vinegars aren’t acidic, what foods are?
Citrus, tomatoes, vinegars, and other acidic fruits and veggies do not contribute to the acid load in our diet because they get broken down into basic, or alkaline, compounds in our bodies.3
Grains, dairy and proteins are the foods that contribute the greatest amount of acid to our diet. This is because grains, dairy, animal and plant proteins all contain proteins made up of amino acids. If the amino acids in the proteins contain sulfur, they will bring acid into the body.3 As far as proteins go, the worst “acid-offenders” are cheese and animal meats, and avoiding these foods may help to decease the acid you are bringing into your body. Beans tend to be alkaline, while soy, veggie burgers, and the more heavily processed products are acidic.5 When looking at grains, rye, some pastas, and oats tend to be acidic, while cooked brown rice is not very acidic and quinoa is alkaline. For a more comprehensive review of foods which contribute acid to the diet, check out a website GoutPal.com at http://www.goutpal.com/gout-food-to-avoid.html. At this site, you can find a wide variety of foods, ranked from alkaline to acidic.
The Bottom Line:
Since grains and protein are essential parts of our diet and should not be taken out of the diet, focusing on increasing our fruit and vegetable intake can help to neutralize our acid load by providing many basic compounds. Thus, a high fruit and vegetable intake can “cancel-out” the acid we get from proteins and grains. According to Bess Dawson-Hughes, a professor of medicine at Tufts University School of Medicine in Boston, a combined intake of 11 servings of fruits and vegetables daily provides the optimal method to neutralize excess acid in the diet and promote health.3
Sources:
- Gatenby, R.A., & Gillies, R.J. (2004). Why do cancers have high aerobic glycolysis. Nature Reviews, 4, 891-899.
- Mahan, L.K., & Escott-Stump, S. (2008). Acid-Base Balance. (2008). Krause's food and nutrition therapy. St. Louis, Missouri: Saunders.
- Liebman, B. (2010, November). Bad for bones? the latest of food and fractures. Nutrition Action, 3-7.
- Jajoo, R, Song, L, Rasmussen, H, Harris, S, & Dawson-Hughes, B. (2006). Dietary acid-base balance, bone resorption, and calcium excretion. Journal of the American College of Nutrition, 25(3), 224-230.
- Taylor, Keith. (2005). Gout foods to avoid, makes you acid. Retrieved from http://www.goutpal.com/gout-food-to-avoid.html
What about drinking alkaline water to reduce the acidity the body has to regulate?
Posted by: Lara | 07/23/2011 at 10:01 AM