In recent years, dietary information has gotten so mixed up to the point almost every medical, health and fitness professionals have different recommendation. Although basic human body is about the same from one another, how come the information varies and changes almost every year has been my question.
After reading number studies from early 1900s to the recent years, I have learned that information has gotten confusing because some people forced the fixed information to go out in the public, for the money and fame, made so many people suffer in the consequence leading to obesity, diabetes, coronary heart disease and so on. Although the information was inappropriate, now, nobody is willing to admit it. Because of that information including right and wrong has been mixed up to make the population confuse because nobody in the authority clarified it.
This article will be covering how cholesterol and fat information has been misguided and some important data were hidden to mask the important information. As you read, you may come across the information that you may not agree, which is ok and there should be some conflict with what you know. So I will be providing references for you to look into to make an educated conclusion on the information I'm sharing.
Understanding Lipid Profile
When you go to your doctor for annual physical, in your results, you will come across a section of cholesterol or often called lipids. We've all learned that the cholesterol level should be below 200mg/dL to be in normal or healthy range. Some may know already that that is not the entire picture. Even when your total cholesterol is relatively higher, you can still be healthy.
When you look at your results under lipids, you will most likely see sub-categories, LDL, HDL, Triglyceride. If you have extended lipid profile, you may also see another sub-categories, VLDL.
The question is what are they? In 1950s, Doctor John Gofman (1), "father of clinical lipidology" submitted the studies that differentiate the lipids in to sub-categories. Study illustrated that as the density of lipid lowers, triglyceride concentration increases.
In other words, HDL has lower concentration of triglyceride compared with LDL or VLDL. VLDL or very low density lipoprotein, has the higher concentration of triglycerides among the three. HDL also has higher concentration of protein and VLDL has the lowest concentration of protein. Therefore, if you are consuming more protein and less with triglyceride, then HDL level gets higher and when the reverse happens, then your VLDL would be higher.
However, if you don't have extended test VLDL may categorized in LDL and may not distinguish between the two. LDL has highest concentration of cholesterol compared with VLDL, however, higher in protein concentration and much lower in triglyceride concentration.
Therefore, if you are consuming low carbohydrate and higher fat and protein you may have high HDL, relatively high LDL but low in VLDL because of carbohydrate converts into triglycerides in the blood.
Strong evidence of low carb diet reducing risk of heart disease.
In 1960, Dr. Gofman published a book titled Dietary Prevention and Treatment of Heart Disease and he wrote, "In many individuals, the coronary heart disease comes primarily from the high concentration of VLDL. For such individuals, the preventative effort would have to be directed towards lowering the carbohydrate intake, which will on the average, lower the triglyceride concentration which leads to lowering of VLDL"(p.124).
In 1958 article (2), Dr. Gofman took a patient of heart attack survivor and monitor what effect the low carbohydrate diet (<100mg/d) have on this patient. Before changing the diet, VLDL level was significantly high and once the carbohydrate intake were reduced VLDL level was reduced in 30 days and maintained lower VLDL from there. Interesting thing is cholesterol level did not change during the trial, and Atherogenic index, or measurement for atherosclerosis risk, was lowered.
In 1967 article, Dr. Peter Kuo wrote "The role of this variable cellular response to carbohydrate in human atherosclerosis, and directed by a rise of very low density lipoprotein and triglyceride level, deserves further and more intensive investigation." (3) Although, these finding existed with request for more funding to investigate, the focus has shifted to "cholesterol" and the role of dietary fat being the cause of atherosclerosis.
Ancel Key's 7 Countries Study
In 1950s, government has announced that they are funding huge amount of money in heart research. Obviously, there was a race for who gets the money. First person in line for leading the study was Dr. John Gofman for his work, studies and qualification. Another person who came forward was Dr. Ancel Keys. Dr. Keys had no qualification, physiologist but not cardiologist, then but came up with the way to match with Dr. Gofman.
Dr. Ancel Keys took Diet-heart theory and Lipid Hypothesis from Dr. Gofman and announced that the high fat diet causes atherosclerosis, and carbohydrate and sugar are safe. In his work, Dr. Key indicated that what you eat will elevate the cholesterol level. Therefore 1.) eating high saturated fat cause elevation of total cholesterol concentration 2.) which will cause the artery to clog, 3.) which leads to all kinds of medical issues. Therefore, he concluded that 4.) 1.)and 3.) must be true. However, Dr. Keys did shortcut in his study and only did association study between eating saturate fat and heart diseases, which is a theory that we all are familiar with.
Dr. Key's famous study is "Seven Country Studies" where he looked at diet and heart disease relation in 7 different countries (Figure 1). The charts to the right is from the Dr. Key's study. Left side of the column is number of death per 1000 and the bottom number is amount of fat in percentage of calories that were consumed. You will see Japan is at the bottom of the chart and USA at the top.
He actually did not perform the study but adapted a data in WHO annual epidemiological document where there were 22 countries data available and selected 7 countries.
Figure 2 is the original 22 countries data. When you look at it you can see how 7 countries was selected at the convenience because there are countries with high saturated fat consumption that has lower death rates. Which indicates there are other factors that cause of mortality rather than saturated fat consumption leading to coronary heart disease, however, the 7 countries data by Dr. Keys was more widely accepted.
Association study can be done on any categories and may have significant finding but that cannot be the find of what actually the cause. Interesting thing is although Japan's mortality rate is significantly low from coronary heart disease, however, stroke rate is higher and U.S death rate from stroke is lower.
Failure of the 7 Country Study
Dr. Ancel Key used Japan as proof of lower death rate from coronary heart disease and proposed that lower saturated fat consumption will lower the death rate from coronary heart disease. However, what Dr. Keys did not know was that Japan's saturated fat intake has increased as the consumption of fish, egg and meat has increased and lowered the heart disease occurrence, which was also visible in Italy and Spain.
In 1996, Japanese study (7) has investigated the trend in food consumption in Japan from 1946 to 1993. Figure 3 shows that amount of grain and rice consumption decreased and meat, fish and egg consumption has elevated. Despite this elevation, death rate from heart diseases still remained lower than any other countries which contradict with what Dr. Keys has suggested. Which also means that he's hypothesis were wrong but still published his study proposing that we should be consuming more carbohydrate, vegetable oils, and reduce saturated fat intake.
Battle of Two Opposite Theories
So there were two theories that were battling in late 1950s. One was high carbohydrate diet that causing an elevation in triglycerides concentration, which is leading to coronary heart disease. Second was consumption of high cholesterol and saturated fat leading coronary atherosclerosis and coronary heart disease.
At the time, they were viewed equally, however, U.S. government threw out the first theory and ran with Dr. Key's theory. So what happened? In 1977, one of the senate committee got together to figure out how they can keep the committee going since they were about to be disbanded. So they have came up with an idea to create dietary guideline for all Americans. And once the guideline was created by the government, the debate of those two theories was ended even when there were so much more needed to be discussed. Even the dietary guideline in 2020, it is evident that the government has not look into all the evidence.
In part two of the article I will share some information on how our diet changed and how American health has gotten worsen for following the guideline.
Kota Shimada
Reference:
https://jamanetwork.com/journals/jama/article-abstract/333986
https://www.truehealthinitiative.org/wp-content/uploads/2017/07/SCS-White-Paper.THI_.8-1-17.pdf
http://library.crossfit.com/free/pdf/1957_Yerushalmy_Hilleboe_Fat_Diet_Mortality_Heart_Disease.pdf
https://www.jstage.jst.go.jp/article/jea1991/6/3sup/6_3sup_189/_article
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