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How to Design a Misleading Study

August 14, 2014 by Michael Greger M.D. in News with 13 Comments

How the Meat Industry Designed a Highly Misleading Study

Imagine working for the now defunct Twinkie division of Hostess and wanting to take the tobacco industry tact of not just downplaying the risk of your product, but actually promoting it as healthy. How would we do that?

Our first problem is that each Twinkie has 2.5 grams of saturated fat, which raises cholesterol, the #1 risk factor of our #1 killer, heart disease. How are we going to get around that?

Well, what if we designed a study in which we took a bunch of people eating our arch-rival, Little Debbie cloud cakes. Now they only have one gram each, so what if we took a group eating five cloud cakes a day — five grams of saturated fat — and then cut that saturated fat intake in half by switching them to eating one Twinkie a day. What would happen to their cholesterol levels? Their cholesterol would go down due to their decreased saturated fat consumption. So even though they went from eating five cakes down to one, technically, they went from zero Twinkies a day to one Twinkie a day, and their cholesterol went down (we wouldn’t mention the five to one thing).

We publish it and crank out a press release, “New research shows that eating a Twinkie a day can be good for heart health by improving cholesterol levels.” The media takes our press release and runs with it: “Consumers can eat a Twinkie every day if they choose, and feel confident that science supports Twinkies’ healthy benefits, which now include cholesterol-lowering effects!” Twinkies, we just proved with science, have cholesterol-lowering effects. Too outlandish a scenario? Amazingly, that’s exactly what the beef industry did (those above quotes are actual quotes–just replace the word beef for Twinkie).

In a study bought and paid for by the beef industry, beef was added to people’s diets. At the same time, the subjects removed so much poultry, pork, fish, and cheese from their diet that they halved their saturated fat intake from 12 percent of their diet, down to 6 percent of their diet, causing their cholesterol levels to go down. If our diet goes from 12 percent saturated fat down to 6 percent saturated fat, it doesn’t matter if that 6 percent comes from beef, chicken, lard, or Twinkies. If we cut our total saturated fat in half, our cholesterol will follow, especially if we eat more fiber and vegetable protein as they did in the study.

The researchers conclude: “The results of the BOLD study [standing for Beef in an Optimal Lean Diet] provide convincing evidence that lean beef can be included in a heart-healthy diet that meets current dietary recommendations and reduces cardiovascular disease risk.” Crisco could be included. Krispy Crème could be included, as long as we cut our total saturated fat intake. What the researchers fail to mention is that our risk would drop even lower if we dropped the beef, as was pointed out by the chair of nutrition at Harvard in a response to the study.

The subjects in this study went from a high risk of dying from heart disease to… a high risk of dying from heart disease. We need to get our LDL (bad) cholesterol down to 50, 60, or 70 to become essentially heart attack proof (see Eliminating the #1 Cause of Death). For most people, that means eliminating saturated animal fat and cholesterol intake completely.

This study is really just showing how bad saturated fat is from any animal source. Yes, based on saturated fat levels, lean beef is often better than chicken (and Twinkies), but that’s like touting the health benefits of Coca Cola because it has less sugar than Pepsi. It does—15 spoonfuls of sugar per bottle instead of 16—but that doesn’t mean we wouldn’t be better not consuming soda at all. Reminds me of this study: “Cheese Intake Lowers LDL-Cholesterol Compared With Butter Intake….” [emphasis added]

In my video, Bold Indeed: Beef Lowers Cholesterol? you can see the beef industry’s release. and how they ended up with the “cholesterol-lowering effects of beef.” If we cut out enough poultry, pork, fish, and cheese from our diet, we could replace this with almost anything (bacon grease, candy, frosting, deep-fried snickers bars, sewer sludge, etc.), and still reduce cholesterol levels.

How are Americans exposed to saturated fat? Burgers actually fall well below chicken. See Trans Fat, Saturated Fat, and Cholesterol: Tolerable Upper Intake of Zero.

The beef industry is by no means alone in having a corrupting influence on the scientific method. See, for example:

-Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Seth Tisue / Flickr

How Grapefruit Affects Prescription Drugs

August 12, 2014 by Michael Greger M.D. in News with 10 Comments

How Grapefruit Affects Prescription Drugs

Does grapefruit in particular help people lose weight?

If someone eats half of a grapefruit three times a day before each meal for a couple months, they may lose about two pounds — but that’s no more than if they ate three apples or pears a day. In one study, the grapefruit eaters not only saw their weight go down, but their waist got slimmer, and their body fat melted away. If, however, we repeat the experiment and instead ask people to drink a half cup of water before each meal, we get the same result. So this belief that grapefruit has some special fat-burning quality appears to be just a long-held myth.

The researchers reported that grapefruit consumers had a drop in weight, a significant drop in cholesterol, and a significant drop in blood pressure. They concluded that consumption of grapefruit daily for six weeks does not significantly decrease body weight, cholesterol, or blood pressure, though. That made me do a little double take, but again, it’s because the grapefruit didn’t do any better than placebo.

Other studies have found a legitimate cholesterol-lowering benefit of grapefruit, and even a little dip in triglycerides, especially eating red as opposed to white . For example, one study showed a decrease in cholesterol, but only from one life-threatening cholesterol level to another life-threatening cholesterol level. To prevent heart disease, we really have to get down to a total cholesterol of around 150, which is the average cholesterol of those eating diets composed exclusively of plant foods, not just grapefruits (See, for example, One in a Thousand: Ending the Heart Disease Epidemic).

Even though grapefruits alone don’t do much, the researchers suggest that people might be more likely to stick with them than cholesterol lowering drugs, noting that most people with heart disease stop taking their statin drugs within a couple years because of the adverse side effects (see Statin Muscle Toxicity). While grapefruits alone don’t have any side effects, ironically, combining grapefruits and drugs can make drug side effects even worse.

If we eat lots of fruits and vegetables, we hopefully won’t need a lot of drugs (Say No to Drugs by Saying Yes to More Plants), but certain phytochemicals in plants can affect the metabolism of drugs in the body. Grapefruit is the poster child, described as a “pharmacologist’s nightmare.” Natural phytochemicals in grapefruit suppress the enzymes that help clear more than half of commonly prescribed drugs, and less drug clearance means higher drug levels in the body. This may actually be good if we want a better caffeine buzz from our morning coffee, or our doctors want to help us save thousands of dollars by boosting the effects of expensive drugs instead of just peeing them away.

But higher drug levels may mean higher risk of side effects. Women taking the Pill are normally at a higher risk of blood clots, but even more so, perhaps, if they have been consuming grapefruit. Taking the Pill with grapefruit juice may increase blood drug concentrations by 137 percent.

If suppressing our drug clearance enzymes with grapefruit juice elevates levels of ingested estrogen, what might it be doing to our own estrogen levels? A study associating grapefruit consumption with breast cancer freaked out the medical community, but subsequent studies on even larger groups of women found no evidence of a link. The Harvard Nurses’ Study even found a decreased risk of the scariest breast cancer type, so it doesn’t look like we have to worry about grapefruit affecting our natural chemistry.

For those prescribed unnatural chemistries, it may be a good idea to discontinue grapefruit consumption for 72 hours before use of a drug that may interact with it. If you don’t want to give up your grapefruit, you can ask your doctor about switching from a grapefruit-affected drug like Lipitor to one of the citrus-proof alternatives (the replacement drug chart can be seen in my video, Tell Your Doctor If You Eat Grapefruit).

Other videos on citrus include:

And another video on the risks associated with taking estrogens: Plant-Based Bioidentical Hormones.

Can’t eat grapefruit without sprinkling sugar on top? Try erythritol instead to avoid so many empty calories: Erythritol May Be a Sweet Antioxidant.

-Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Liz West / Flickr

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