September 9, 2009April 9, 2015

Probiotic Confusion

Last week, I answered a question from a reader who had seen a study showing that probiotic supplements reduced cold and flu symptoms in children. He reasoned that eating yogurt every day might be a good step and wondered how much he’d have to eat to get a similar “dose” of probiotics. To answer his question, I compared the number of active cultures in a typical probiotic supplement to the number of active cultures in a typical yogurt.

But I missed an opportunity to clarify what I think is a widespread misunderstanding about probiotics. Many people think of all probiotic supplements and foods as being somewhat interchangeable. They’re not.

Probiotics: an umbrella term for thousands of different bacteria

In terms of labeling foods and supplements, the FAO/WHO defines probiotics as “Live microorganisms which when administered in adequate amounts confer a health benefit on the host.” That’s any health benefit.

There are hundreds of different strains of lactobacillus bacteria and they offer a variety of potential health benefits to humans. Some colonize the large intestine, others live in the lining of the stomach, still others have an affinity for the mucus membranes in the nose. Of the many strains likely to colonize the large intestine, for example, some may improve gut immune function, others digest complex sugars, others may benefit the host by producing vitamin K.

There are also lactobacillus bacteria that don’t do much of anything to improve or defend your health. These, while harmless, would technically not be classified as probiotics–although they might still be considered “live and active cultures.”

Foods versus supplements

Most probiotic foods contain a variety of bacterial strains–your average supermarket yogurt might contain six different bacterial strains. And the lactobacillus bacteria found in yogurt are not necessarily the same as those found in other fermented foods like kefir or kim-chi.

Many of the studies you read about use “boutique” strains that are not likely to be found in any traditionally-fermented foods. In the case of the study I mentioned above, for example, they used two trademarked strains called Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07.

Is there any point to consuming probiotic foods?

I still think there are general health benefits to eating traditionally-fermented foods like yogurt, kefir, kim-chi, kombucha, sauerkraut, and miso. Eating a variety of fermented foods, which provides a wider variety of bacterial strains, might offer a wider range of benefits.

But we need to be careful about assuming that the findings on a particular strain apply to all probiotics and probiotic foods. If you’re going for a specific therapeutic benefit, such as protecting against side effects while taking antibiotics or improving flu resistance, there’s no guarantee that yogurt or any other fermented food will contain the same bacteria as were used in a particular study.

Similarly, when shopping for probiotic supplements, pay attention to the individual strains in that supplement and how they compare with the strains used in various studies you might be responding to.

September 3, 2009April 9, 2015

Can yogurt protect you from the flu?

by Monica Reinagel, MS, LDN

Q. I recently read about a study showing that probiotics protected kids from getting the flu. It seemed like a pretty powerful study in favor of the health benefits of yogurt, at least in kids. Do you have any recommendations for a reasonable “dose” of yogurt would be for an adult?

A. Yes, I noted that study with interest as well. The kids (about 300 of them, aged 3 to 5) were taking probiotic supplements or placebo pills twice a day. The kids getting the probiotics had about half as many fevers, coughs, and runny noses, took fewer prescriptions and missed fewer days of school.

We should note that the study was funded by a company that makes probiotic products. That said, the results were published in a peer-reviewed journal (Pediatrics) so the study design apparently passed muster.

There’s no RDA for probiotics for kids or adults so it’s hard to say what a good”dose” might be. Most probiotic supplements contain 10 to 20 billion active cultures per dose at the time of manufacture. Yogurt that carries the “Live and Active Cultures” seal is certified to contain at least 100 million cultures per gram at the time of manufacture, which translates into about 22 billion live cultures in an eight ounce cup of yogurt.

So, I’m thinking that a single serving of yogurt every day would be a reasonable start for kids and adults. But the amount of sugar (often high fructose corn syrup) in sweetened yogurts is shocking. I’d advise you to steer clear of sweetened (and artificially-sweetened) yogurts and go for the plain yogurt. Sweeten (if you must) with fruit or a drizzle of honey.

Can yogurt protect you (or your kids) from getting the flu this season? Might help and can’t hurt (unless you’re lactose intolerant).

March 27, 2009December 7, 2011

Sodium and Potassium: What’s the Relationship?

by Monica Reinagel, MS, LDN

Q. Please comment on the relationship between potassium and sodium. How can I be sure that I’m not getting too much potassium as I continue to decrease the amount of sodium in my daily diet?

A. Decreasing the amount of sodium in your diet won’t necessarily affect the amount of potassium you’re getting but it will probably increase the ratio of potassium to sodium in your diet–and many believe that this is a good thing!

Sodium and potassium have complementary functions in the body, helping to regulate things like fluid balance and blood pressure. We need to maintain a precise balance of potassium and sodium in our cells but our intake of potassium and sodium may vary greatly from day to day. Therefore, the body has systems that tightly regulate this balance, excreting any excesses into the urine.

The potassium/sodium content of our modern diet is radically different than the diet our ancestors ate–and many believe that this contributes to a lot of our modern health problems. Potassium is found in fruits and vegetables; most of the sodium we eat comes from processed and packaged foods.

By some estimates, our ancestral (pre-industrial) diet had a potassium to sodium ratio of at least 3:1, meaning that it contained about three times as much potassium as sodium. However, as we’ve come to eat more and more processed foods and less fruits and vegetables, our intake of potassium has declined and our intake of sodium has skyrocketed. The typical potassium to sodium ratio today is 1:3 (three times as much sodium as potassium) or exactly the inverse of our ancestral diet.

Whether or not the potassium/sodium ratio theory is correct, reducing your intake of processed foods and increasing your intake of fruits and vegetables is a great health upgrade for your diet! I think its pretty unlikely that you will get too much potassium from foods. Most Americans get about 2500 to 3000 milligrams per day; the recommended intake is about twice that!

October 26, 2008September 26, 2013

The China Study: Does Dairy Cause Cancer

by Monica Reinagel, MS, LDN

Dear Monica, I enjoyed your post on diet and breast cancer. However, I cannot believe that you did not mention the direct relationship between the intake of casein (milk protein) and the growth of mammary tumors. T. Colin Campbell in his The China Study outlines how this protein turns on tumor growth and the lack of it in the diet turns off cancer growth. “

Before saying anything else, let me first say that I completely support anyone who does not care to consume dairy products, for whatever reason. Dairy is certainly not essential to a healthy diet. There are plenty of other ways to get calcium and vitamin D. (And those who do not consume dairy need to take care to be sure they do.) I recently did a podcast episode on the pros and cons of dairy. You can listen to it here.

Now, to Campbell’s book: Lots of people commenting on this blog over the years have referenced this book as a definitive scientific rationale for various dietary practices. Obviously, Campbell’s prose is compelling. But I have to be honest with you: The science behind his conclusions is less so.

You’re right: There are recent (2007) studies showing that milk increases the incidence of chemically-induced breast tumors in rats. Interestingly, I also found a 2007 study showing that soy milk does the same thing. And another (2006) showing that fermented milk (yogurt) prevented tumors; and another (2001) showing that soy protein was preventive.

It appears that studies on things that cause or prevent tumors in rats injected with carcinogens might not provide a definitive answer to the question: Do dairy products cause breast cancer in humans? For that, it makes sense to turn to studies that compare what people eat to their risk of breast cancer.

Do dairy products increase breast cancer risk in humans?

The so-called “China Study” was a nutritional analysis conducted in rural China in the 1980s. This study purportedly found a link between the intake of animal protein and an increased risk of cancer and other disease. In the intervening 20 years, many researchers have tested this conclusion, specifically with regards to dairy and breast cancer. Here’s a brief sampling:

2007 American Journal of Clinical Nutrition (5000 subjects in England and Scottland): Childhood dairy intake was not associated with breast cancer risk.

2007 Cancer Epidemiology (2000 subjects in U.S.): Reduced breast cancer risks were associated with increasing milk consumption from ages 10-29, probably because of the cancer-preventive effects of vitamin D.

2006 Cancer Causes and Controls (5000 subjects in Italy): Consumption of milk and diary products did not increase breast cancer risk (and, in fact, consumption of skim milk slightly reduced risk).

2005 Journal of the American College of Nutrition (meta-analysis of 52 different studies): Evidence does not support an association between diary product consumption and the risk of breast cancer.

2005 Nutrition and Cancer (study looking back 30 years and across 38 countries): No substantial effect of milk consumption on risk of breast (and other) cancers.

2004 American Journal of Clinical Nutrition (meta-analysis of 46 studies): No strong association between the consumption of milk or other dairy products and breast cancer risk.

2002 Journal of the National Cancer Institute (90,000 women followed for 16 years): “We found no association between intake of dairy products and breast cancer in postmenopausal women. Among premenopausal women, high intake of low-fat diary foods was associated with a reduced risk of breast cancer.”

2002 International Journal of Epidemiology (meta-analysis of 8 prospective studies involving 350,000 subjects in N. America and W. Europe): “We found no significant associations between intake of meat or dairy products and risk of breast cancer.”

Dairy is not essential to a healthy diet but it does not appear to cause breast cancer

Obviously, I would have had to have continued for quite a bit longer to work my way back to the China study. But there didn’t seem to be much reason to continue. (And I wasn’t cherry-picking, either…these are the studies that came up in response to my query!)

So, let me end this post the way I began: Dairy products are not essential to a healthy diet. Feel free to eliminate them. But I don’t actually see evidence to suggest that doing so will reduce your risk of breast cancer. And, in fact, because dairy products are one of the only sources of vitamin D in the American diet, eliminating them might well increase your risk if you’re not careful to get that nutrient from other food sources.

January 22, 2008June 10, 2015

On lard, pie crusts, and whether all saturated fats are the same

by Monica Reinagel, MS, LDN

Two related questions posted on the blog recently:

Q. I’ve been reading that lard is now considered a good fat, as long as it’s not hydrogenated. I realize that lard is still saturated fat, so it’s not ‘good’ like olive oil. And like all fats, it must be eaten in moderation. But I’m wondering what you think about going back to Gramma’s pie crust recipe. Crisco/butter just never did make the same good crust …

Crust-y Curious

Q. Like Crusty Curious, I’ve also been wondering about lard and pie crusts, as well as other saturated fats. If we limit our intake of saturated fats to recommended amounts, does it matter what TYPE of saturated fat we use? Are palm oil, coconut oil, butter, lard, and beef drippings (for homemade gravy) all equivalent, nutritionally? Or is there some good reason to avoid certain of these?

Judy

A. Pie crusts are a matter near and dear to my heart and I’ve been collecting pie crust recipes for years. My current favorite uses a mixture of butter (for flavor) and lard (for flakiness). But you will find equally ardent advocates for all-butter crusts and even some die-hard shortening devotees.

Epicurious.com’s Food Editor Sarah Kagen has long been a fan of this recipe, which uses part butter and part shortening. “But lately,” she says, “I’ve had several crusts made with part butter and part lard, and I have to say, I think I’ve been converted. The lard creates flakiness like shortening, but it adds a wonderful golden toastiness.”

Epicurious.com’s Associate Editor Lauren Salkeld (who is a graduate of the French Culinary Institute’s Classic Pastry Arts Program) says, “We made all butter dough in school, so that’s what I’m used to. I find it flaky and I prefer the flavor.”

Aside from the culinary debate, is there any difference nutritionally between butter, lard, and the naturally saturated fats found in palm kernel and coconut oil (used to make trans-fat free shortening)?

Here are a few facts that might surprise you :

1. Butter contains about 20% less fat and calories per ounce than lard or saturated vegetable fat, because it contains some water. (When substituting butter for other fats, adjust quantities accordingly.)

2. All of these products contain a mixure of saturated, monounsaturated, and polyunsaturated fats. Lard actually contains the least amount of saturated fat (11g per ounce) while coconut oil contains the most (24g per ounce).

3. Animal fats (lard and butter) contain more monounsaturated fat than palm kernel and coconut oil. In fact, lard contains more monounsaturated fats (13mg per ounce) than saturated fats (11g per ounce).

4. Butter contains twice as much cholesterol (60mg per ounce) as lard (27mg per ounce). Vegetable shortenings contain no cholesterol.

5. Lard contains 280mg of omega-3 fatty acids per ounce; butter has 88mg per ounce. (Palm kernel and coconut oil contain little or no omega-3s).

6. Butter contains a fair amount of vitamin A (700mg per ounce) whereas palm kernel oil contains a good helping of vitamin K (7mcg per ounce).

7. Both palm kernel and coconut oils contain natural phytosterols, which can help to reduce cholesterol levels by blocking the cellular uptake of cholesterol.

Regardless of what form of fat you’re trying to build a case for, you can find some support for it here. And of course there’s the argument that saturated fat isn’t really bad for you, anyway; it’s the carbs you eat with it that do the damage. (More comforting for bacon eaters than pie lovers.)

The only fat I can advise you to avoid completely are shortenings made with partially hydrogenated vegetable oil (old-style Crisco) or a mixture of fully hydrogenated and unhydrogenated vegetable oils (new-style Crisco). The former is full of trans fats and the latter, although it claims to be nearly trans fat free, is full of “interesterified fats,” which appear to be no better for you. (Also take care to select lard that has not been hydrogenated.)

No matter what form of fat you use, of course, pie crust is not a low-fat item. One slice of a double-crust pie will use up about a quarter of your daily allowance of fat and around 80% of your allowance for saturated fat (not counting the filling).

So, in answer to the questions above, as long as your overal intake of fat, calories, and saturated fat is not excessive, and you are avoiding all hydrogenated products, use whatever you like to make your pie crust. (And send me your recipe!)

March 16, 2007February 6, 2011

Will Taking Vitamins Improve Your Health?

by Monica Reinagel, MS, LDN

It’s a hotly debated question among health researchers. New studies come out every year but we don’t seem to be getting any closer to a definitive answer. About half the studies show that people who take vitamins are healthier and the other half find that taking vitamins makes no difference…or, in a few cases, actually make things worse. I have to admit that I’ve held, at various times in my career, different views on the question.

We know that the nutrients in food play important roles in keeping us healthy. Calcium helps prevent osteoporosis, folic acid helps prevent neural tube defects, antioxidants repair cellular damage, and so on down an ever expanding list of nutrients and co-factors. It seems like supplementing an (imperfect) diet with additional nutrients is a reasonable way to make sure we’ve got our bases covered.

If we’re talking about a 25¢ one-a-day multivitamin, I guess the vitamin as insurance policy makes sense. But it’s gotten way more complicated than that. For one thing, the list of “basic” nutrients gets longer and longer. A multivitamin used to involve 15 or so nutrients (A, B, C, D, E, and a few minerals.) Now, a typical multi boasts several dozen compounds, from astaxanthan to vanadium. But it’s still not truly complete. Next to it on the shelf you’ll find the anti-oxidant booster, the bone health formula, the immune booster, plus the the formulas for your eyes, skin, nails, hair, memory, joints, and prostate. Before you know it, you’re forking out a couple hundred bucks and month and swallowing a fistful of vitamins every day. But are you getting your money’s worth?

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