Cholesterol: What causes high cholesterol ? Is diet the real cause?

Do you have high cholesterol ? Should you blame your diet ? Almost everyone blames the fats or carbs or the combination of both for increased cholesterol levels. But almost no one is paying attention to the effects of stress on blood cholesterol and the mechanisms by which stress affects our blood lipids.

Biochemistry textbooks claim that only 20% of the cholesterol in our bodies comes from food food, the other 80% the body produce itself. Stress, however, is never mentioned.

In a Russian study, scientists measured the cholesterol levels of a group of accountants at the end of the accounting year, when they were preparing all the reports and were under great stress because of approaching deadlines. They found out that everyone of the group had drastically high cholesterol levels.

Again, cholesterol was measured just two months after the deadlines. During those two months nothing was changed in the lifestyle of the group – they ate the same foods they normally do, played sports at the same level they did before, but now the cholesterol levels were in normal ranges :

To all students – if you decide to have blood tests and measure your cholesterol – choose any other time , exept before an exam. “Agarwal” and colleagues found out that the greater the stress before an exam, higher the recorded total cholesterol and triglycerides. As we can assume – all indicators returned to normal after the stress of the exam passed. Scientists theorize that the increase is due to hormonal change as a consequence of stress , as well as from the peripheral lipolysis . ( 1 )

Similar to this study, “Westlake” et al. found that in apparently healthy individuals serum cholesterol may increase by 11 % in the presence of a strong mental or emotional stress. ( 2 )

Sane and Kukreti were investigating the effect of pre-operative stress on serum cholesterol levels of 65 patients who were yet to be operated . Cholesterol levels were compared directly with the those when the patient is discharged from the hospital. The figures show that total cholesterol pre-operatively was between 39% and 57 % higher than post-operatively . Sane and Kukreti concluded that these results confirm there is a link between mental stress and blood lipid levels .

You may be thinking – “So what? When I’m stressed, my cholesterol goes up, and when the stress goes away – blood cholesterol decreases. Big deal.”

Seen from this perspective – yes, that’s right. High cholesterol does not automatically mean that something is wrong and you should limit certain foods and start taking medications. Prior to something radical, first make a short record about the way of life you live. Studies show a link between mental and emotional stress and cholesterol levels. Is this true, however, about physical stress?

Smoak et al. investigated the effects of intensive military training on blood lipids of 44 Marines . Research has two formats :

5 weeks of physical training;
5 days long , high intensity physical and psychological stress.

The marines weight did not change significantly, and their food had high caloric value as well as high levels of saturated fat and cholesterol. What happened after five weeks of physical training ? The levels of HDL ( the so-called . “Good cholesterol” ) increased by 31% , and all other blood lipids (total cholesterol , LDL, triglycerides) remained unchanged. On the other hand after a cycle of five days, high-intensity physical and mental load than the levels of HDL, which increased by 12% , total cholesterol fell by 17.2 and LDL ( the so-called . “Bad “) cholesterol fell by 30%. Scientists concluded that changes in lipoprotein profile occur not only after prolonged exercise, but after a short super-intensive workload , although rich in calories, saturated fat and cholesterol diet.

The conclusions that we can take out from the study are that while the mental stress increases cholesterol levels shortly, the physical stress ( when there is enough food) apparently influenced them positively. Even with the simultaneous presence of mental stress. Anyone doing sports in one form or another, felt the physical load balancing (or should we say decreasing) the mental load.

On the other hand – food also plays a role here. First, from the books we know that saturated fats raise the levels of HDL. Second, if the food quantity a person consumes is not enough, and the physical load is high , the results are not pretty.

Karl et al. studied American rangers in an environment exposed to multiple stressors , constant load , insufficient sleep and increased heat for 8 weeks. Their daily food allowance amounts between 1000 and 1200 kcal. After 8 weeks, not only they decreased their levels of body fat , the amounts of thyroid hormones were below the normal range, their levels of testosterone were very low , and insulin-like growth factor I (IGF -I) was reduced 1.5 times. Meanwhile the cholesterol of the Rangers had jumped from 158 to 217 mg / dl or 37%. ( 3 ) The findings – when stress levels are high for prolonged time, and recovery capabilities in the form of sleep and food are few, everything goes wrong.

Scientists assume that the possible reason for this may be the fact that stress stimulates the body to produce more energy as the main fuel for metabolism – the free fatty acids and glycogen. Such substances require the liver to produce and secrete LDL, which is the major transporter of cholesterol in the blood.

Another reason is that stress prevents the elimination of lipids from the blood , and a third possible reason is that stress increases the production of a large number of inflammatory processes such as interleukin 6 , tumor necrosis factor and C-reactive protein , which also increase production of lipids.

Dr. Steptoe said: ” Although increases in lipids caused by stress is not so great, survey data allows us to know whose cholesterol levels may increase as a result of stress (long term) and this way to predict who is at greater risk of developing cardiovascular diseases. ”

If we summarize the research to date , we can subtract the following conclusions:

– mental and emotional stress can lead to a spike in blood lipid levels ;
– exercise (at a reasonable dose intensity and duration ) can be beneficial for cholesterol levels ;
– long-term exposure to multiple stressors and insufficient recovery had a devastating effect on the whole body ;
– bodies of different people react differently to stress;


Take care of yourself! If you are currently undergoing a lot of stress , but is likely to end soon – that’s great, your body can tolerate periods of increased stress, you just have to give it a chance to recover . If stress is not likely to end soon, it is advisable to find a way to, at least, slightly reduce the stress or rest. Take care of your health and body – it’s the only place you HAVE to live.