Juice bad, fat good?

orangejuice3Never get your food and nutrition information from headlines.

Juice Bad?

The headline screams: “Does drinking fruit juice give you high blood pressure?  New study finds a regular morning glass of orange juice significantly raises health risk

Oh really? The study went like this:

  • 160 adults were given a questionnaire, asking them to document the foods they ate for the past 12 months.  Quick, can you remember all the foods you ate for the past 12 months?
  • Frequency of fruit “juice” consumption was noted.  However, definition of “juice” was not noted.  Were the subjects drinking only 100% juice?  Or did they use “juice” to refer to any fruity-flavored beverage that looked like juice. Were they only drinking orange juice, as the headline implies?  The actual study does not mention orange juice specifically.
  • Blood pressure was measured for the subjects.  People who said they drank juice daily tended to have higher blood pressure than people who drank juice infrequently.  That’s higher blood pressure.  Not necessarily high.

Are there problems with the headline?  Oh, many.  The biggest problem is expecting 160 people (not a large number) to accurately remember and accurately/truthfully report their juice consumption.  If you’re answering questions for health researchers, are you going to paint a pretty picture of your food choices?  Juice has a health halo, so reporting daily juice consumption makes you look like a good, health conscious person.  Even if you rarely drink any juice.

Another major problem: define juice.  If the researchers define juice as 100% from fruit, but the subjects include all kinds of juice-like beverages, including Kool Aid (hey, it’s the right color), then the data has a serious problem.

Another problem: what is “daily” consumption of juice?  Once a day?  3-4 times/day?  And how big are portions?  Certainly no one recommends that a person guzzle quarts of juice all day.  Eating whole fruit is better, but a single 8 oz glass of OJ with breakfast isn’t likely to send blood pressure skyrocketing.  Especially since OJ is loaded with potassium, and higher potassium intake is linked to lower blood pressure.  That headline above just makes no nutritional sense whatsoever.

Another major problem: people who drink more juice probably make other characteristic food choices.  They probably drink less milk, for example.  Maybe more sweetened beverages of all types.  Maybe less whole fruit, since they may believe they don’t need to eat actual fruit because they’re drinking juice.  And on and on.  The possibilities for different diet choices are endless.  The study doesn’t clarify any of this.

This study, and the ensuing headlines, are the perfect example of the pitfalls of ignoring the Prime Rule of Interpreting Nutrition Research:

Association DOES NOT EQUAL Causation.  

 By the way, a multi-country study of fruit and juice consumption reported last year came to the exact opposite conclusion: no association of fruit or juice with blood pressure.

Fat Good?

Here’s another headline: “Should people be eating more fat?” At least it doesn’t try to answer that question, although the implied answer is “Yes.”

What’s behind that headline?  It starts with a discussion of a study, published several months ago, that seemed to contradict the conventional wisdom that saturated fats cause heart disease.  These sorts of results are always welcomed by people who believe saturated fats — from meats and dairy foods — are at least harmless, if not actually healthy.  The study results seemed to support that belief.  Not so fast.  In fact, as one of the study authors notes, only some specific saturated fats might be linked to less risk, not all saturated fats in general.  In this, it’s a certain saturated fat from dairy foods.  And another study linked intake of high fat dairy foods to lower abdominal obesity.  Did dairy fat prevent abdominal obesity?  Or are higher fat dairy foods so satisfying that people are less inclined to eat high calorie junk food, leading to abdominal obesity?  In another study — discussed previously on Walk Talk Nutrition — the Mediterranean diet was compared to the standard low fat diet.  The people the higher fat Mediterranean diet were much more likely to stick to the regimen than those on the low fat diet.

So should people be eating more fat?  Well, not if you’d rather avoid eating too many calories.  Healthy or not, all fat is high calorie.  Too much of it leads to weight gain.  The author of this article (a doctor by the way) didn’t actually answer Yes or No.  But he did admit he was eating butter, Greek yogurt and milk with some fat, as well as nuts, fish and vegetables.  In other words, a Mediterranean-style diet.

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