Although ketogenic diets have caused a number of “serious potentially-life-threatening complications,” perhaps the greatest danger of the Atkins Diet, according to the American Medical Association, lies in the heart.
Atkins claimed a worsening of cholesterol levels typically only occurs “when carbohydrates are a large part of the diet.” We’ve known this to be false since 1929 when the Institute of American Meatpackers paid to see what would happen if people lived on an all-meat diet. The blood plasma of the unfortunate subjects was so filled with fat it “showed a milkiness” and one of the subjects’ cholesterol shot up to 800!
In the head-to-head comparisons of the four popular weight-loss diets, Ornish’s vegetarian diet was the only one that showed a significant decrease in LDL levels–the so-called “bad” cholesterol. Even researchers paid by Atkins concede that high saturated fat diets like Atkins’ tend to increase LDL cholesterol. These researchers have to concede the truth since they publish their work in peer-reviewed scientific journals. Dr. Atkins, though, died without ever publishing a single paper in any scientific journal about anything, and thus had more freedom to bend the truth.
“The truth,” Atkins wrote, “is that every one of a score of studies on [very low carb diets] showed a significant improvement in cholesterol.” He accused those who say otherwise of simply not doing their homework. Any claim that cholesterol doesn’t significantly improve in “every one of scores of studies” is, he wrote in the last edition, “one of the many examples of untruths being perpetrated because the accusers don’t bother to read the scientific literature.” He then goes on to recommend no less than 17 supplements for the “prevention of cholesterol elevations” on his diet.
But what about his claim that “every one of a score of studies showed a significant improvement in cholesterol.” When the AMA and the American Heart Association question this “fact,” is it just because they “don’t bother to read the scientific literature?” That statement of his, in the latest edition of his book and in essence repeated to this day on the Atkins website,, presents a clear opportunity to test the veracity of his claims. And the actual truth is almost the exact opposite.
Unfortunately, Dr. Atkins didn’t include citations to back up his “score of studies” statement. In fact, when pressed for a list of citations in general, Dr. Atkins told an interviewer that “It and the papers I quoted were in a briefcase I lost some time ago.” Researchers have located about a dozen studies, though, that measured the effects of low carb diets on cholesterol levels. Did they all “show a significant improvement in cholesterol?” No. In fact, with only one exception, every single controlled study showed just the opposite–LDL cholesterol either stagnated or was elevated by a low carb diet, even in those that showed weight loss.[325-338]
During active weight loss–any kind of weight loss (whether from chemotherapy, cocaine use, tuberculosis or the Atkins Diet)–cholesterol synthesis temporarily decreases and LDL cholesterol levels should go down. Yet, all the saturated animal fat in the Atkins Diet tends to instead push levels up, and in most studies the bad cholesterol doesn’t fall as it should with weight loss. The saturated fat in effect cancelled the benefit one would expect while losing weight and cutting out trans fats. And what happens when people on the Atkins Diet stop losing weight? People can’t lose weight forever (Stephen King novels aside). The fear is that their LDL cholesterol level might then shoot through the roof.[341-342]
“There is no doubt that you lose weight initially,” Dr Jim Mann, an endocrinology specialist from the University of Otago, New Zealand, told the 2003 meeting of the European Society of Cardiology, “but there is a grave risk of a dramatic rise in cholesterol levels during the maintenance phase [of the Atkins Diet]. “When weight loss is maintained–or as often happens, there is weight gain [on the Atkins Diet],” Mann continued, “we have observed that a lot of people experience a rise in cholesterol to levels greater than when they started the diet.”
Sometimes even during the active weight loss, however, LDL cholesterol levels became elevated on the Atkins Diet. One study of women, for example, showed that just two weeks on the Atkins Diet significantly elevated average LDL levels over 15%. In a trial of men on the Atkins Diet, even though they lost an average of 17 pounds after 3 months, their LDL cholesterol jumped almost 20%.
The May 2004 Annals of Internal Medicine study showed that a third of Atkins dieters suffered a significant increase in LDL cholesterol. The goal is to have a double digit LDL–an LDL under 100 (mg/dl). In the study, one person’s LDL shot from an unhealthy 184 to a positively frightening 283 (which means their total cholesterol was probably somewhere over 350). With so many people on these diets, that could mean Atkins is endangering the health of millions of Americans. LDL cholesterol is, after all, the single most important diet related risk factor for heart disease, the number one killer in the United States for both men and women.
In another clinical trial, despite statistically significant weight loss reported in the Atkins group, every single cardiac risk factor measured had worsened after a year on the Atkins Diet. The investigator concludes “Those following high fat [Atkins]diets may have lost weight, but at the price of increased cardiovascular risk factors, including increased LDL cholesterol, increased triglycerides, increased total cholesterol, decreased HDL cholesterol, increased total/HDL cholesterol ratios, and increased homocysteine, Lp(a), and fibrinogen levels. These increased risk factors not only increase the risk of heart disease, but also the risk of strokes, peripheral vascular disease, and blood clots.”
While the LDL in the Atkins group increased 6%, the LDL cholesterol levels in the whole-foods vegetarian group was cut in half–dropping 52%. This kind of drop would theoretically make your average American almost heart-attack proof.
When the pro-Atkins journalist who wrote the misleading New York Times Magazine piece was confronted as to why he didn’t include the results of this landmark study, which directly contradicted what he wrote in the article, all he could do was to accuse the researchers of just making the data up.
It’s interesting to note that the one exception –a published study of the Atkins Diet showing a statistically significant reduction in LDL–had no control group, put subjects on cholesterol-lowering supplements and was funded by the Atkins Corporation itself. Even in that study though, the drop was modest–only a 7% drop (compared, for example, to the 52% drop on the vegetarian diet)–and didn’t include two subjects who quit because their cholesterol levels went out of control.
Yet studies like this have been heralded as a vindication of the Atkins Diet by the mainstream media. As journalist Michael Fumento, co-author of Fat of the Land, pointed out, “How peculiar when the most you can say for the best-selling fad-diet book of all time is that it probably doesn’t kill people.” To which I might add, “in the short-term.” Based on an analysis of the Atkins Diet, long-term use of the Atkins Diet is expected to raise coronary heart disease risk by over 50%. “The late Dr. A,” Fumento quips, “still gets an F.”
Less often reported in the media is the fact that one of the research subjects placed on the Atkins Diet in the 2003 “vindication” study was hospitalized with chest pain and another died. Similarly, in the widely publicized May 2004 study, less widely publicized was the fact that two people in the low carb-diet arm of the study couldn’t complete the study because they died. One slipped into a coma; the other dropped dead from heart disease. As the Director of Nutrition at the Harvard School of Medicine has written, “there is still much danger in the widespread fad enthusiasm for these diets.”
The Atkins Corporation boasts about the supposed ability of the Atkins Diet to significantly raise the level of HDL, or “good” cholesterol on a consistent basis. HDL transports cholesterol out of one’s arteries to the liver for disposal or recycling. Though it is actually only a minority of controlled studies on Atkins-like diets that have shown such an effect,[358-371] it is important to note that the type of HDL increase sometimes seen on these diets is not necessarily healthful. When one eats more garbage (saturated fat and cholesterol) one may need more metabolic garbage trucks (like HDL) to get rid of it. Eating a stick of butter may raise one’s HDL, but that doesn’t mean chewing one down is good for one’s heart. In any case, significantly lowering one’s LDL seems more important than significantly raising one’s HDL, though the studies done on low carb diets typically show neither.
Because of these “well-known hazards,” when Atkins’ book was originally published the Chair of the Nutrition Department at Harvard warned physicians that recommending the Atkins Diet “borders on malpractice.”