Thursday, May 22, 2014

Almond Milk vs. Soy Milk

There are a lot of popular milk choices:  cow’s, soy, and almond. But are they nutritional equals?

Cow’s milk has a lot going for it. It’s naturally high in protein, calcium, phosphorus, potassium and selenium.  If you’re not a vegan vegetarian (no animal products!) and you’re not allergic to casein (milk protein), milk is a nutritious choice. If you’re lactose intolerant (you can’t digest the carbohydrate in milk), lactose reduced milk is a good and effective choice for most people.

A good alternative to milk if you’re allergic to milk protein or you are vegan vegetarian, is soy milk. Soy milk is also very high in protein (8 grams) and it’s a very high quality plant protein. It’s also naturally high in folate, magnesium, potassium, phosphorus and vitamin C. The

manufacturers add calcium, some B vitamins (B12 and riboflavin) and also vitamin D. I would say that soy and cow’s milk are the most nutritious milk choices. Both have a broad array of naturally occurring nutrients plus a few that are added for other benefits. Flavored soy milks have some sugar added so be sure to check out the sugars. Some have less, some have more than the natural sugar in milk (lactose).

A lot of people are drinking almond milk but it’s probably not as nutritious as you think. It only has one gram of protein compared to the eight grams in soy and cow’s milk. Nor does it have all the nutrition that almonds have – so don’t forgo your whole nuts for the milk. To make almond milk, the almonds are soaked in water and ground up and then more water is added. Then the mixture is strained – so much of the almond gets drained out.  When you look at the almond milk label, most of the nutrients in almond milk are added – not a natural part of the almond. The calcium, vitamin E, zinc, vitamin A, vitamin D, and the B-vitamins are all added synthetically. As with soy milk, the flavored versions can have quite a bit of sugar added. If you are vegan or allergic to cow’s milk, I definitely give a big nutritional edge to soy milk. One advantage to the plain almond milk (which is lightly sweetened) and the unsweetened is that they are low in calories – 30 and 60 respectively.  But light soy milk and skim milk are also pretty low in calories – 60 and 85 respectively. Now, if you love the way almond milk tastes, then it is fine to drink it – just make sure you’re getting your protein elsewhere. To me, taste always wins out! But if you’re just looking at which one packs the biggest nutritional punch, I’d have to give the edge to soy and cow’s milk over almond milk. 

Beth Kitchin, PhD, RDN
Assistant Professor, Nutrition Sciences
University of Alabama at Birmingham

Friday, May 16, 2014

Why I’m Not Surprised that Dietary Resveratrol may not be Associated with Living Longer

Headlines, supplements and nutrition fads often leap way ahead of the research. That’s why I’m not surprised at the results of the latest and best study done to date on dietary resveratrol. Resveratrol is a “phytochemical” – a naturally occurring chemical in plants – found in the skin of red grapes (and subsequently red wine), peanuts, and cocoa. This most recent study showed that resveratrol from foods and beverages did not correlate with a lower chance of dying, cancer risk, heart disease risk, or with markers of inflammation.
The study: Older adults in the Chianti region (a big red wine making area) were followed for 9 years. The participants reported on their dietary intake regularly during those years. The researchers and study geriatricians evaluated the participants’ dietary intake of resveratrol, their urinary resveratrol (which has been found to correlate with dietary intake), the diseases they had, and markers of inflammation over the course of the study. They found that the people who had the highest resveratrol intake were just as likely to suffer from heart disease and cancer and to die as the people with the lowest intake.  There were no differences in markers of inflammation between the groups.

Here’s why I am not surprised by the findings:

  • Many of the previous studies that have shown benefits from resveratrol have been done in rats. Rats are not humans – a fact often lost on those humans reporting on scientific studies and supplement makers.
  • Both the rat and the human studies have used large doses of resveratrol from supplements – far more than we can possibly get from foods and beverages.
  • Some human studies have shown benefits - and some have not. The ones that have shown benefits often look at “markers of inflammation” and show that resveratrol supplements lowered these markers. One study showed that resveratrol supplements lowered stiffness in the arteries of women. But, just lowering a marker of something bad does not necessarily translate into improved health or a lower chance of dying. I see this kind of data on markers of health all the time and they are useful but we shouldn’t base our recommendations off of them. These kinds of studies need to lead to studies that look at the outcomes that really matter – like disease, disability, and death.
  • Some human studies have shown no benefit and even harm from resveratrol supplements. One study showed that when older men were randomized to get either a 250 mg resveratrol supplement or a placebo for eight weeks during an intense exercise program, the men on the supplement did not experience the positive changes in cholesterol levels or in blood flow that the men on the placebo did. In other words, the supplements actually impaired some of the benefits of exercise rather than improving them as expected!

Keep in mind that this most recent study is also not the last word on resveratrol. While it was a strong, well-designed study, all studies have limitations. I also would not have been surprised if the study had shown that dietary resveratrol was beneficial because, again, the previous research had gone both ways. Neither outcome would have been surprising. 

Beth Kitchin, PhD, RDN
Assistant Professor, Nutrition Sciences
University of Alabama at Birmingham

Semba RD, Ferrucci L,  Bartali B, Urpi-Sarda M, Zamora-Ros R, Sun K, et al. Resveratrol levels and all-cause mortality in older community-dwelling adults. JAMA. 2014; published online May 12, 2014.

Tuesday, May 13, 2014

Think You’re Gluten Sensitive? Better Get a Diagnosis!

A new study shows that almost ¾ of people who say they are gluten sensitive have not had a proper diagnosis – and most have diagnosed themselves. But by self-diagnosing they may be missing an opportunity to find out first if they have the much more serious gluten problem called celiac disease. Gluten is the protein found in wheat and some other grains like barley and rye. If you’re gluten sensitive but don’t have celiac disease, eating gluten is not going to have an adverse effect on your intestines – you just don’t feel so good.  But in celiac disease the intestine responds to gluten by turning against itself in an autoimmune response, destroying the folds of the intestines and increasing your chances of getting osteoporosis, thyroid disease, type 1 diabetes, arthritis, and having a miscarriage. So knowing if you have celiac can help you properly treat it and to also be on the lookout for any serious complications. Celiac disease is genetic. So know if you are diagnosed, you can help you warn relatives to get tested. 

About 1 in 133 people (0.75%) have celiac disease but many of those are undiagnosed. The good news is that the damage to the intestines caused by celiac is reversible if people eliminate gluten from their diets. The symptoms vary from person to person and include other symptoms besides the telltale bloating and diarrhea:

Symptoms of celiac disease:
  • Digestive problems (abdominal bloating, pain, gas, diarrhea, pale stools, and weight loss) 
  • Severe skin rash 
  • Low iron in the blood 
  • Muscle cramps & joint pain 
  • Growth problems and failure to thrive in children 
  • Seizures
  • Tingling sensation in the legs 
  • Mouth Sores 
  • Missed menstrual periods
Now, you can probably imagine that many other disorders can cause these symptoms as well – which is why an accurate diagnosis is so important. You need to get treated properly for the disease you actually have. But if you self-diagnose yourself with gluten sensitivity and cut out grains, it makes it hard to diagnose celiac because the blood markers go away. Identifying these blood markers is the first step in diagnosing celiac disease. The second step is a biopsy of the intestines. This new study showed that 62% of the people who said they had gluten sensitivity had not been properly diagnosed - meaning they had not had celiac disease ruled out first among other things. An additional 24% still had symptoms despite getting rid of gluten in their diets. Most of the respondents were self-diagnosed or had been diagnosed by an alternative medicine practitioner. 

If you don’t have celiac disease but are still having symptoms that you think are linked to gluten, getting a diagnosis of gluten sensitivity is tricky because there are no tests for it and your symptoms could be a sign of many other disorders. If you think you have a problem, you need to see a doctor who specializes in digestive disorders – a gastroenterologist. Right now, the diagnosis is one of elimination of other possibilities.  The other problem with accurately diagnosing gluten sensitivity is that there is a strong link between your brain and your gut. If you’ve ever been nervous about a presentation or a performance and had to run to the bathroom, you’ve experienced this first hand. There are many studies that show a strong placebo effect with gut symptoms. So, you may eliminate gluten and your symptoms go away – but it could be because you were expecting them to go away. Of course, it could be because of the gluten, some other part of the wheat, or simply that you’re eating fewer calories. Researchers are working on developing a test for gluten sensitivity but until then, diagnosis will remain a bit of a guessing game.
Many people ask me if there are benefits to eliminating gluten from your diet if you don’t have celiac disease or gluten sensitivity. The answer is probably not – despite all of the popular books you may see about the dangers of gluten. The claims against gluten are largely unfounded and despite the gluten-haters claims, there are no good studies that show that gluten or grains are to blame for the wide variety of diseases they claim.
Beth Kitchin, PhD, RDN
Assistant Professor, Nutrition Sciences
University of Alabama at Birmingham
Source: Biesiekierski JR, Newnham ED, Shepherd SJ, Muir JG, Gibson PR. 2014. Characterization of adults with a self-diagnosis of nonceliac gluten sensitivity.  Nutrition in Clinical Practice; April 16, 2014.