By Steve Brown and Beth Taylor

Human nutrition and lifestyle studies prove there are ways to improve the odds that we will live long, healthy lives. It's simple: Eat a variety of fresh, minimally-processed foods, especially fruits and vegetables; stay lean; exercise often; and avoid toxins. Good nutrition is key. Dietary habits may be instrumental in about 60% of cancers in women and about 40% in men.¹

Good diets are just as important for dogs. Unfortunately, many of our dogs are eating diets composed exclusively of highly processed, grain-based foods with synthetic vitamins and minerals. Even the best of the "healthy" dry foods fall into this category. No wonder one in three dogs will die of cancer!

In our book, See Spot Live Longer, we discuss many easy things you can do to help your dog live longer. One easy step we can take is to add crushed Brazil nuts, a source of natural forms of selenium, to our dogs' food.

Selenium is an essential trace mineral of fundamental importance to human and canine health. Adequate selenium is necessary for the normal functioning of the immune system and thyroid gland. Selenium is receiving considerable attention for its possible role as an effective naturally occurring anti-carcinogenic agent.

Recently, the American Association for Cancer Research reported than high selenium consumption may protect humans from bladder cancer.² Animal studies have shown a beneficial effect of high selenium levels in the prevention of cancer.³ The form of the selenium is important: Natural, food-derived forms of selenium may have beneficial effects not shared by human-synthesized selenium compounds.⁴

Dogs evolved consuming two organic forms of selenium: selenomethionine (an essential amino acid found primarily in plants) and selenocysteine (an amino acid found mostly in organ meats). Most dry and canned dog foods today use an inorganic type of selenium, sodium selenite or sodium selenate. These forms of selenium are considered toxic by the National Toxicology Program of the US Department of Health and Human Services.⁵

The body reacts differently to the selenium in food as compared to food supplemented with sodium selenite. A 2003 study in The Journal of Nutrition stated that "the absorption, distribution, and excretion of selenium in food were ... distinctly different from sodium selenite."⁶ Natural forms of selenium are superior to human synthesized forms. Dr. John W Finley, supervisor of the Trace Element Absorption and Bioavailability Laboratory and the Grand Forks Human Nutrition Research Center, and one of the leading researchers on selenium stated:

"Something in the whole foods must boost selenium's anticancer property," and "These results are further evidence that broccoli may be an especially good source of selenium, and nutrition professionals may be wise to take this info into account when giving nutritional advice."⁷

Is selenium deficiency a contributing factor to canine hip dysplasia?

Insufficient selenium intake can cause serious health problems, including Kashin-Beck disease, which is characterized by the degeneration of the articular cartilage between joints⁸, thyroid disease and a variety of cancers. We've read unpublished, yet well researched, reports linking selenium deficiency with hip dysplasia.⁹ There is a wealth of data about farm animals which shows organic forms of selenium (selenomethionine) outperform sodium selenite. One of the reasons for this is that natural forms of selenium can be stored in the body for later use, while selenite cannot.¹⁰

Perhaps some dogs are not able to sufficiently use the inorganic forms of selenium found in most dry dog foods. Therefore if a bitch were unable to fully utilize sodium selenite, her puppies would be more likely to have joint problems. Pottenger's classic study with cats shows that problems due to nutrient deficiency get worse with each generation.¹¹ Is the source of the selenium used in most dry dog foods one of the reasons many dogs, purebred and mixed-breed, have hip problems? It may be one of the nutritional causes.

It's easy to correct this situation. Whether you're feeding dry, canned, or the best frozen raw diets, you can easily ensure that your dog is getting enough selenium by adding Brazil nuts. The selenium in broccoli and other vegetables will vary according to the amount of selenium in the soils. Brazil nuts, on the other hand, are a reliable source of selenium. Of course, the fresher the nut, the better. In our home tests with our dogs, freshly shelled Brazil nuts won over shelled nuts bought at natural food markets, in both flavor and fragrance.

We recommend that people add one-half of a crushed Brazil nut per day for every 50 pounds your dog weighs. Since natural forms of selenium are stored in the body, you can easily add one crushed nut every other day, or, for toy dogs, ten pounds or less, one crushed nut per week is great! Please remember, feed all foods in moderation. A meal of just Brazil nuts is not healthy for any dog or any human.

May your Spot live a long, healthy life.

References

1. Milner, John A. "Nonnutritive Components in Foods as Modifiers on of the Cancer Process" Preventive Nutrition: The Comprehensive Guide for Health Professionals, 2nd edition, p 131. 2001.

2. Mary E. Reid, Anna J. Duffield-Lillico, Linda Garland, Bruce W. Turnbull, Larry C. Clark, and James R. Marshall, "Selenium Supplementation and Lung Cancer Incidence: An Update of the Nutritional Prevention of Cancer Trial," Cancer Epidemiology Biomarkers & Prevention. November 2002; 11.

3. Patrick, Lyn, Selenium Biochemistry and Cancer; A Review of the Literature," Alternative Medicine Review, Volume 9, Number 3, 2004. 239 -- 258.

4. Schrauzer, G.N. "Selenomethionine: A Review of its Nutritional Significance, Metabolism and Toxicity," Journal of Nutrition, 130, 2000. 1653-1656

5. National Toxicology Program, http://ntp-server.niehs.nih.gov/ htdocs/ST-studies/TOX038.html

6. Hawkes, Alkan, and Oehler "Absorption, Distribution and Excretion of Selenium from Beef and Rice in Healthy North American Men," Jounral of Nutrition, November 2003. 3434.

7. Finley, J.W., Ip, C., Lisk, D.J., Davis, C.D., Hintze, K.J. and Whanger, "Cancer-protective properties of high-selenium broccoli" J Agricultural and Food Chemistry, Vol. 49, #5, 2679-2683, 2001.

8. Burk, R.F. & Levander, O.A. "Selenium," in Shils, M. et al. Eds. Nutrition in Health and Disease, 9th Edition. Baltimore: Williams & Wilkins, 1999. 265-276.

9. Parker, Jay, "Hip Dysplasia in Dogs: Why Seleniuim Deficiency Will Cause It." Unpublished manuscript.

10. Schrauzer, G.N. "Selenomethionine: A Review of its Nutritional Significance, Metabolism and Toxicity," Journal of Nutrition, 130, 2000. 1653-1656.

11. Pottenger, Francis. Pottenger's Cats A Study in Nutrition 1983. Dr. Pottenger compared four generations of cats fed cooked and four generations of cats fed the same diet, except raw. With the cooked diet, Dr. Pottenger found that each generation developed health problems at earlier ages than the preceding generation. The raw fed cats remained healthy. We now know that the cooked diets were deficient in taurine and thiamin.