ResearchCategory Archives

Dietary fats and atherosclerosis

The following is a review of the study, Dietary fats, carbohydrate, and progression of coronary atherosclerosis in postmenopausal women, published in The American Journal of Clinical Nutrition. It’s one of those studies that can make your blood boil because it would indicate that we’ve been given some really bad information over the years about what to eat to prevent heart disease.  This summary of it got me interested in checking out the details:

“A 2004 study from Brigham and Women’s Hospital and Harvard School of Public Health showed that in postmenopausal women, the more PUFA [polyunsaturated fatty acids such as from vegetable oil] they ate, and to a much lesser extent the more carbohydrate they ate, the worse their atherosclerosis became over time. The more saturated fat they ate, the less their atherosclerosis progressed; in the highest intake of saturated fat, the atherosclerosis reversed over time.”

They chose for their study postmenopausal women who’d already had a heart attack and who had measurable atherosclerosis in their arteries. This study is important because it shows that the advice we have been given by the USDA and major medical organizations for preventing cardiovascular disease is the opposite of what actually works. The fact that some of these women were able to reverse the progression of their atherosclerosis is significant as well. We don’t often hear of that happening. The participants eating the most saturated fat were also eating more total fat. In general, the ones eating the most saturated fat had the best lipid profiles. Those eating the most saturated fat were eating more protein and less carbohydrate than other groups. Those eating the most carbohydrate had the greatest decline in coronary artery size. To a lesser extent, those eating the least total fat had the greater decline in coronary artery size. Among types of fat, polyunsaturated fat was associated with the greater progression of atherosclerosis. Particularly noteworthy were actual improvements seen when monounsaturated fat displaced saturated fat and when protein displaced polyunsaturated fat. Stearic acid, most often found in animal fats, was associated with lesser progression (better outcome) than other saturated fats. Oddly, smoking was inversely associated with progression of atherosclerosis. I would say that the summary I read the other day held up under closer review.

This was an observational study. There were no interventions done. In the discussion section of the study, they presented a chart of intervention studies. Many of them studied an intervention to increase the ratio of polyunsaturated fat to saturated fat. Most of these showed improved outcomes for the intervention group. I have to wonder, though, if intervention groups were eating better in other ways as well. Perhaps they were eating less processed foods, too, which could have a tremendous impact on the results of the study. After all, in this study that I just read, carbohydrate intake was highly correlated to progression of atherosclerosis. Considering that grain desserts and pizza are the largest identified sources of saturated fat in the American diet according to the USDA, this could well be the case. Intervention studies in the chart where they increased consumption of certain whole foods generally showed a strong trend in improved outcomes. Only an examination of the other individual studies could determine if change in consumption of processed foods was properly accounted for and analyzed for confounding. Did these studies have only two groups, a single intervention group and a control group? It would be more interesting to see a single study with multiple intervention types and compare those outcomes since an intervention group is more likely to be conscientious, and conscientiousness is likely a confounding factor when comparisons are made to controls. An observational study such as the one I just read would be less impacted by conscientiousness. As for a multiple intervention study, I wonder if scientists would be brave enough to create an intervention group where saturated fats from grain desserts and pizza were replaced by higher quality sources of saturated fat that did not come with a boatload of refined carbohydrates, thus retaining the level of consumption of saturated fat but eliminating the junk. Comparing that intervention group to an intervention group increasing the ratio of polyunsaturated fat might yield different results entirely. It remains to be seen. Interestingly, studies where the ratio of monounsaturated fats was increased were not listed. Have they not been done?

The diabetes, heart disease, and the lipid hypothesis

It boggles my mind that high-carbohydrate diets are recommended to diabetics even though the carbohydrates will increase their insulin needs. The recommendations come out of a faulty belief in the lipid hypothesis. The intent is to prevent the heart disease that often accompanies diabetes. Those on the lipid hypothesis bandwagon like to cite Ancel Keys, but his study fell apart when confounding factors such as accuracy of the reporting of cause of death country to country were looked at. High- carbohydrate diets do lower cholesterol. I can even attest to that from my own experience with the vegan diet. But more recent studies are showing that there is no clear relationship between cholesterol and heart disease. T. Colin Campbell could not find one in his extensive study of the Chinese, and he very much would have liked to since it would have supported his assertion that a vegan diet is healthier. Never mind that the vegans were dying of infectious diseases and malnutrition at a higher rate.

Have you noticed that guidelines relating to cholesterol have been changing? It used to be that they told us that all cholesterol was bad. Then they told us that HDL was a good cholesterol and needed to be high and LDL was the bad cholesterol. Now they’re telling us that not all LDL is bad. It’s only the small dense LDL that’s bad. Such a change over the years! By the way, a high-carbohydrate diet increases the harmful small dense LDL. Some studies do show that heart disease improves when cholesterol is lowered by cholesterol drugs. But there may be another effect at work. The American Heart Association published a study showing that statins decrease inflammation, and this effect may actually be the beneficial action of the drugs.

With the lipid hypothesis falling apart, the rationale for recommending a low-fat/high-carbohydrate diet to diabetics falls by the wayside, or at least it should. Doctors who have suggested anything else have lost their jobs even though their results have proved their recommendations to be valid. So there’s a disincentive in the industry for jumping off the high-carbohydrate bandwagon even if it might actually be wrong. Many doctors are frustrated by the lack of improvement in their diabetic patients, but they’re also afraid to stray from the standard recommendations. A high-carbohydrate diet increases the need for insulin, which is a dangerous situation for a diabetic. Plus, as mentioned, it increases the worst kind of cholesterol. It’s far better to pursue a diet that decreases the need for insulin, I think.

Triglycerides have been shown to be more strongly linked to heart disease than cholesterol is. A high-carbohydrate diet increases triglycerides, too. If you are trying to prevent heart disease and diabetes, a closer look is definitely warranted. The standard protocol may not be the best one.

The positive correlation of wheat to heart disease proved to be interesting. Wheat has a correlation of 0.67 with heart disease—which is the strongest association between any food and heart disease found in the China Study. This is of particular concern given that the recommended high-carbohydrate diet often contains a lot of wheat. I picked the correlation out of a table from a post on animal protein, but apparently I was not the only one to notice. The blogger, Denise Minger, did an entire post on that correlation elsewhere in the blog. She took the data from China Study II and attempted to determine if the wheat/heart disease correlation was confounded by any other factors. With every combination she tried, the wheat/heart disease correlation held up. T. Colin Campbell, an author of China Study II, wrote a paper on the link back in 1996. The theory is that the correlation has something to do with the insulin index of wheat compared to rice. The insulin index of the rice is quite low compared to its glycemic index while the insulin index of wheat is high. In other words, wheat stimulates a higher output of insulin than rice does. I took a look at a chart listing the insulin scores of foods compared with their glucose scores. Rice did indeed have an insulin score much lower than its glucose score, both for brown rice and for white rice, which made it rather unique among carbohydrate sources on the list.

Denise Minger looked through the literature to see if there were any research studies relating to wheat and heart disease. Apparently, there were very few. It isn’t something researchers are looking at. Most wheat related research looked at things like whole grain vs. processed grain. She did find an old rabbit study that looked at wheat germ vs. various oils and atherosclerosis and a human study that looked at wheat bran vs. flaxseed and insulin sensitivity and C-reactive protein. In both studies, the wheat group fared worst. The wheat connection is definitely something that deserves a closer look. Hopefully, other scientists picked up on it and will do some studies.

It would not surprise me if the link held up under closer scrutiny. Gluten, a protein in wheat, has already been found to cause problems in relation to other disorders. I am at present trying to get my daughter to try a gluten free diet to see if it will help improve her neuropathy. The doctors think now that the neuropathy is a rare autoimmune reaction related to her cancer. Supposedly, gluten-free diets have improved neuropathy. Gluten-free diets have been shown to help other autoimmune disorders as well.

References:
T. Colin Campbell. The China Study: The Most Comprehensive Study of Nutrition Ever Conducted And the Startling Implications for Diet, Weight Loss, And Long-term Health. BenBella Books (May 11, 2006).
Denise Minger. “Forks Over Knives”: Is the Science Legit? (A Review and Critique), Raw Food SOS.
Denise Minger. The Truth About Ancel Keys: We’ve All Got It Wrong, Raw Food SOS.
Denise Minger. The China Study: My Response to Campbell, Raw Food SOS.
Denise Minger. Heart Disease and the China Study, Post #1.5, Raw Food SOS.
David J. Lefer, PhD. Statins as Potent Antiinflammatory Drugs, Circulation 2002; 106: 2041-2042, American Heart Association.

Looking at the USDA Dietary Guidelines

Today’s reading included a blog post by Denise Minger looking at USDA recommendations. The USDA recommends reducing saturated fat in the diet as well as reducing overall fat content. In their library of supporting documents, only one of the 12 studies cited actually supports these recommendations. The one study that does, a meta-analysis of studies, is later contradicted by a larger meta-analysis that shows no improvements. The first study is apparently confounded by publication bias. To further confound such studies, the USDA presented a pie chart showing where saturated fat in the American diet comes from. Grain-based desserts and pizza provide the largest portions of saturated fat in the American diet. But I just learned from the “Forks over Knives” post that China Study II positively correlates wheat with heart disease death and deaths from all medical causes. In fact, wheat correlates with heart disease better than any other food. Those grain-based desserts and pizza that we’re getting our saturated fat from have a lot of wheat in them. Meanwhile, animal protein and animal fat were negatively correlated in that study, meaning that death rates were lower. That’s an interesting finding from a scientist who promotes a vegan diet. So anything showing that saturated fat is harmful is likely confounded by the junkie carbohydrate and wheat intake that often accompanies the saturated fat. Furthermore, studies supporting increased intake of polyunsaturated vegetable oils are confounded by the overall healthier habits of those consuming those oils. When the data are corrected for these healthy habits, the benefit of the vegetable oils disappears.

By the way, the cited USDA studies and also Dr. Caldwell Esselstyn’s results cited in “Forks over Knives” blog post would support my modifications to the NutriSystem diet for attempting to keep my cholesterol levels healthy. This further increases my optimism that I have made the right modifications. We’ll see when I get the results back from this coming Thursday’s blood draw.

As an interesting aside, the USDA was unable to be conclusive as to whether fruits and vegetables are actually good for you. They say further study is needed. Very interesting indeed! Results from China Study II would support the inclusion of green vegetables, at least, since they are negatively correlated to deaths from all medical causes. Fruit is positively correlated with deaths from heart disease, stroke, and diabetes in that same study, though. Have I not said before that fruit poses problems due to the sugar content? That’s why I decided to eliminate fruit from my modified diet. There are better sources for the micronutrients fruits provide among the vegetables, and I do make sure to include those.

References:
U.S. Department of Agriculture, U.S. Department of Health and Human Services. Dietary Guidelines for Americans 2010.
Denise Minger. The New USDA Dietary Guidelines: Total Hogwash, and Here’s Why, Raw Food SOS.
Denise Minger. “Forks Over Knives”: Is the Science Legit? (A Review and Critique), Raw Food SOS.

MSG and obesity

I’ve been reading blogs. A post mentioned that MSG is given to lab rats when they are first born to damage their hypothalamus and make them fat. If allowed, these rats will eat more than normal control rats. These rats will get fat even if their food intake is controlled to be the same as a normal control rat. This means that the altered rats are hungrier because their adipose [fat] tissue is gobbling up a disproportionate amount of the energy from their diets. They’re hungrier because they’re getting fat and not the other way around. If you need a reason to avoid processed food, MSG is a good one. A little more digging on that topic revealed that MSG has been included in vaccinations since 1982. Could that be why we’ve seen a jump in childhood obesity since then? We’re doing the same thing to our kids that the scientists do to their rats! What I’d like to know is if MSG damage can be undone. I haven’t found any indication yet that it can.

References:
Carol Hoernlein, P.E. MSG and Obesity, MSGTruth.org.
Gong SL, Xia FQ, Wei J, Li XY, Sun TH, Lu Z, Liu SZ. Harmful effects of MSG on function of hypothalamus-pituitary-target gland system. Biomed Environ Sci. 1995 Dec;8(4):310-7.

Critiques of the science behind plant-based diets

I’ve been reading a lot of blogs about dietary studies. A blog of particular interest is Raw Food SOS by Denise Minger. One of her posts tore apart Ancel Keys’ 22 country data. That data is often cited as proof that dietary fat causes heart disease. By the time Denise Minger got done with it, the data from the 22 countries more likely proved only that richer countries that could afford better medical care were better able to determine cause of death. In other words, the Keys study and data were rendered meaningless.

And another post dissects the movie Forks over Knives and critiques the science in that movie. So far, it isn’t looking good for the movie. Forks over Knives promotes a plant-based or vegan diet. I tried a vegan diet for about three months not so long ago. I ran into problems with it. I began developing a physical form of depression. Fortunately, my mood was still generally good. I had my blood checked, and my cholesterol had dropped too low. The total was 147. My psychiatrist was concerned. He wants to see the total be at least 160. Low cholesterol is associated with depression and other mental disorders. So I stopped being vegan and eventually recovered. As you can tell, I am not a fan of veganism. For me, at least, veganism is a dangerous diet. Generally, though, depression is more common among vegans, so it isn’t just me. One of my lowest total cholesterol readings, 125, coincided with my first round of NutriSystem back in 1990 or so. It also coincided with my diagnosis of bipolar disorder. And that, folks, is why I have adjusted my diet. I’m trying to keep my cholesterol levels from falling. I’ll have blood drawn to test cholesterol on Thursday to see if my strategy is working. I’m optimistic. My mood has been good so far this round.

References:
Denise Minger. The Truth About Ancel Keys: We’ve All Got It Wrong, Raw Food SOS.
Denise Minger. “Forks Over Knives”: Is the Science Legit? (A Review and Critique), Raw Food SOS.
Chris Masterjohn. My Experience With Vegetarianism, cholesterol-and-health.com.
Shin JY, Suls J, Martin R. Are cholesterol and depression inversely related? A meta-analysis of the association between two cardiac risk factors. Ann Behav Med. 2008 Aug;36(1):33-43. Epub 2008 Sep 12.
Michael Pekker. Could Eating A Vegan Diet Cause Depression? Clinical Depression: Symptoms and Treatment.

Challenging the current diet advice paradigm

I am currently rereading “Why We Get Fat and What To Do About It” by Gary Taubes. I saw Gary Taube’s lecture online in Dr. Mercola’s article, “These Vilified Foods Help Build Hormones and Tame Your Appetite,” and wanted to review his book. Gary reported on how the low-fat advice for heart health became a government recommendation. Back in 1984, the National Heart, Lung, and Blood Institute launched a massive health campaign. “At the time, the NHLBI experts lacked confidence in the fat/heart-disease connection, for good reason: the institute had spent $115 million on a huge, decade-long clinical trial to test the idea that eating less saturated fat would curb heart disease, but not a single heart attack had been prevented. This could have been taken as reason to abandon the idea entirely, but the institute had also spent $150 million testing the benefits of a cholesterol-lowering drug, and this second trial had succeeded. So the institute’s administrators took a leap of faith, as one of them, Basil Rifkind, later described it: They had spent twenty years and an inordinate amount of money trying to demonstrate that cholesterol-lowering, low-fat diets would prevent heart disease, Rifkind explained, and they had, up until then, failed. Trying again would be too expensive and would take at least another decade, even if the institute could afford it. But once they had compelling evidence that lowering cholesterol with a drug would save lives, it seemed like a good bet that a low-fat, cholesterol-lowering diet would as well. ‘It’s an imperfect world,’ Rifkind had said. ‘The data that would be definitive are ungettable, so you do your best with what is available.’” They declared the diet study to be flawed and went ahead with their health campaign.

But here’s the thing: the effect of a drug is not limited to the purpose it was developed for. When the cholesterol lowering drug trial succeeded, it was assumed that the cause of the success was the lowering of the cholesterol, but that may not actually be the case. In 2003, the American Heart Association reported this: “Statins Promote Potent Systemic Antioxidant Effects Through Specific Inflammatory Pathways.” In the conclusion, they state, “Statins promote potent systemic antioxidant effects through suppression of distinct oxidation pathways. The major pathways inhibited include formation of myeloperoxidase-derived and nitric oxide–derived oxidants, species implicated in atherogenesis. The present results suggest potential mechanisms that may contribute to the beneficial actions of statins.” So now we have a major health organization reporting a cause of benefit for statins other than its cholesterol lowering effects. Given that multiple studies have not shown a heart health benefit for following a cholesterol-lowering low-fat diet, perhaps the original NHLBI study on low-fat diets was not flawed after all. In other words, following a low-fat diet may not actually be heart-healthy as we’ve been led to believe for the past nearly 30 years.

A closer look at the effects of a low-fat diet reveal that the opposite may be the case. A low-fat high-carbohydrate diet will:

  • decrease HDL cholesterol
  • increase triglycerides
  • increase the harmful small dense LDL cholesterol while decreasing the large fluffy healthy LDL cholesterol
  • increase insulin in the blood, thereby increasing the risk of insulin insensitivity and metabolic syndrome

The A TO Z Weight Loss Study published in The Journal of the American Medical Association in 2007, gives an indication of what may actually be the best diet for losing weight and improving heart health. The winner in the study surprised even the researchers. This study compared four diets: the Atkins diet, a traditional low-fat diet, the Ornish diet, and the Zone diet. Those on the Atkins diet lost the most weight, and they had the best results for heart disease risk factors. Keep in mind that the Atkins dieters did this while eating as much food as they wanted while those on the other diets were restricting their calories. “The point man on this trial was Christopher Gardner, director of Nutrition Studies at the Stanford Prevention Research Center. Gardner presented the results of the trial in a lecture that’s now viewable on YouTube—“The Battle of Weight Loss Diets: Is Anyone Winning (at Losing)?” He begins the lecture by acknowledging that he’s been a vegetarian for twenty-five years. He did the study, he explains, because he was concerned that a diet like the Atkins diet, rich in meat and saturated fat, could be dangerous. When he described the triumph of the very low-carbohydrate, meat-rich Atkins diet, he called it ‘a bitter pill to swallow.’”

Video: Gary Taubes—Why We Get Fat and What To Do About It

Video: Christopher Gardner—The Battle of Weight Loss Diets: Is Anyone Winning (at Losing)?

Your doctor’s advice may not be so great

While reading Trick And Treat by Barry Groves, I found information about an important study of heart disease interventions done in Finland. This study is important because the intervention group in this study was given the current standard of care for the prevention of heart attacks. One group was given the standard heart disease interventions: blood pressure medications, cholesterol medications, advice about diet and exercise. The other group was given no interventions. The study shows that while risk factors were improved, the number of deaths including from heart disease was actually higher in the intervention group. In other words, the standard interventions ultimately had the reverse effect of what was intended. Something in the standard treatments isn’t right.

From the book:

One [study] that did seem to support the “healthy” recommendations was a Finnish trial involving 1,222 men published in 1985. Men in the intervention group were seen regularly and advised about diet, physical activity and smoking. Those with high blood pressure or high cholesterol levels were treated with drugs. The men in this group did as they were advised and, as a result, the “predicted risks” for CHD were halved during the trial. It was hailed as a great success because: “The program markedly improved risk factor status.” In other words, they succeeded in changing their subjects’ diets, and so on. In December 1991, the results of a 15-year follow-up to that trial were published. During this period the intervention group had continued to be instructed on diet, smoking and exercise and treated for high blood pressure and cholesterol when present. Were they healthier? Did they live longer? The results are show in the table:

Deaths during 15-year follow-up
Intervention group Control group
Total deaths 67 46
Heart disease deaths 34 14

These figures show that not only did those who continued to follow the carefully controlled, cholesterol-lowering diet had more deaths in total, they were also more than twice as likely to die of heart disease as those who didn’t – some success!

Dr Michael Oliver, Professor of Cardiology at Edinburgh University’s Cardiovascular Research Unit, commenting on these results in the British Medical Journal, wrote that:

This runs counter to the recommendations of many national and international advisory bodies which must now take the recent findings from Finland into consideration. Not to do so may be ethically unacceptable. We must now face the fact that the evidence from large, well conducted trials gives little support to hopes that altering the lifestyle of the community at large, when started in middle age, will reduce cardiac deaths or total mortality.

References:
Barry Groves. Trick And Treat – how ‘healthy eating’ is making us ill. 2008.
Barry Groves’ site: http://www.second-opinions.co.uk/
Miettinen TA et al. Multifactorial Primary Prevention of Cardiovascular Diseases in Middle-aged Men, JAMA. 1985;254(15):2097-2102.
Strandberg TE, et al. Long-term Mortality After 5-Year Multifactorial Primary Prevention of Cardiovascular Diseases in Middle-aged Men, JAMA. 1991;266(9):1225-1229.
Oliver MF. Doubts about preventing coronary heart disease. BMJ 1992; 304: 393-4.

Stroke reduction in Japan

Cholesterol and animal fat are actually protective against strokes. That’s why Japan has such a high stroke rate. They don’t eat as much animal fat as we do. But they do eat a fair amount of rice, and that can cause damage from the carbohydrates. After the second world war, the Japanese were influenced to eat more like us with more meat and dairy. Their stroke rate went down by 85%.

One of these Japanese studies showed that the benefit came from the animal fat and cholesterol consumed. Those with the highest intake had the lowest incidence of stroke. Animal protein was not significant—just the fat and cholesterol.

The Okinawans, the Japanese people with the longer lifespans, eat more meat and less rice than other Japanese people, and they’re healthier for it.

References:
Barry Groves. Trick And Treat – how ‘healthy eating’ is making us ill. 2008.
Barry Groves. The Dangers of Low Blood Cholesterol, Second Opinions.
Shimamoto T, et al. Trends for Coronary Heart Disease and Stroke and Their Risk Factors in Japan. Circulation. 1989; 3: 503-15.
Adachi H, Hino A. Trends in nutritional intake and serum cholesterol levels over 40 years in Tanushimaru, Japanese men. J Epidemiol 2005; 15:85-89.
Liu L, et al. Changes in stroke mortality rates for 1950 to 1997. A great slowdown of decline trend in Japan. Stroke 2001; 32:1745.
Iso H, et al. Trends of cardiovascular risk factors and diseases in Japan: implications for primordial prevention. Prev Med 1999; 29: S102-S105.
Sauvaget C, et al. Animal protein, animal fat, and cholesterol intakes and risk of cerebral infarction mortality in the Adult Health Study. Stroke 2004; 35: 1351.
Gillman MW, et al. Inverse association of dietary fat with development of ischemic stroke in men. JAMA 1997; 278: 2145-2150.
Atkins D, et al. Cholesterol reduction and the risk of stroke in men. A meta-analysis of randomized, controlled trials. Ann Int Med 1993; 119: 136-145.
Dyker AG, et al. Influence of cholesterol on survival after stroke: retrospective study. BMJ 1997; 314: 1584.

An interesting dietary study from 1931

There was an interesting dietary study done in 1931. They conducted a controlled dietary trial using a large variety of diets, ranging from 800 to 2,700 calories. Before they did that, they put all patients on a 1,000 calorie diet of varying types. Here are the stats for the average daily losses for the 1,000 calorie diets:

High-carbohydrate/low-fat – 49 grams
High-carbohydrate/low-protein – 122 grams
Low-carbohydrate/high-protein – 183 grams
Low-carbohydrate/high-fat – 205 grams

In other words, the patients on the low-carbohydrate/high-fat diet lost 4 times what those on the high-carbohydrate/low-fat diet lost. In another commentary on this diet, Barry Groves said that some patients actually gained weight on the high-carbohydrate/low-fat diet.

It was expected that on the 1,700 and 2,700 calorie diets, patients would not lose weight. In fact, all but three did lose weight.

In their conclusion, Lyon and Dunlop said: “The most striking feature … is that the losses appear to be inversely proportionate to the carbohydrate content of the food. Where the carbohydrate intake is low the rate of loss in weight is greater and conversely.”

Barry Groves says in Trick and Treat that the high-fat diet is preferable over the high-protein diet because excess protein creates waste products that stress the organs such as the kidneys. Fat burns cleaner in the body.

References:
Lyon DM, Dunlop DM. The treatment of obesity: a comparison of the effects of diet and of thyroid extract. Quart J Med 1932; 1: 331.
Barry Groves. Trick And Treat – how ‘healthy eating’ is making us ill. 2008.
Barry Groves’ site: http://www.second-opinions.co.uk/

Why we must be carnivores

I’m reading the chapter in my book, Trick And Treat – how ‘healthy eating’ is making us ill by Barry Groves about why we must be carnivores.  Basically, we have small digestive systems and large brains.  We are designed for an energy dense diet such as is found in fatty meats.  Fossil evidence indicates that our prehistoric ancestors ate very little if any vegetable matter.  They analyzed fossil poop to determine that.  Vegetarians like to compare us to other primates, but our digestive systems are very different from theirs.  Our digestive systems are more like those of carnivorous species.