Cholesterol, heart disease, obesity…everyone is concerned about these scary buzz words that have permeated doctor’s visits for the last few decades. When it comes to heart health, it seems like there is no other way but banning eggs and other high-cholesterol foods from our diet and sticking to “low-fat” products. However, research shows that there is more to the cholesterol story than fatty foods and eggs.
Carbs & Cholesterol
The logic seems simple: cholesterol in the diet = high blood cholesterol levels. Unfortunately, our physiology is not that straightforward. Only 20% of our total cholesterol comes from our food, while the remaining 80% is manufactured by our liver. This means that reducing the number of eggs that we eat per day will not necessarily significantly reduce our cholesterol problem. A more important consideration is the types and amounts of simple processed carbohydrates that we eat.
Simple carbohydrates, foods like sweets, pastries, white bread, white pasta and sodas, are made up of many sugar molecules connected to each other to form long chains. During digestion, these chains are quickly broken down into individual sugar molecules that are absorbed in the bloodstream. As a result, blood sugar rises. To counteract this sudden increase in our blood sugar levels, our bodies produce the well-known hormone, insulin. This allows our cells to take up as much sugar as needed to meet our energy requirements. Once our cells are satisfied, the liver takes up the remaining sugar and puts it into storage for later use (about 400g of sugar are stored in our liver and muscles). If there are still high levels of glucose in the blood, insulin orders the liver to turn it into fat molecules and cholesterol. The newly made fat and cholesterol molecules are then shuttled to specialized fat-storing cells via the bloodstream – this leads to the characteristic abdominal “tire”, love handles and high cholesterol! Storing extra sugar as fat made sense in prehistoric times when times of famine were common. Today, this extra fat and cholesterol paves the way to obesity, diabetes and cardiovascular disease.
Oxidation & Cholesterol
Research has elucidated that the problem is not necessarily cholesterol per say, but oxidized cholesterol – that is, cholesterol that has been damaged by free radicals. One theory is that the oxidized molecules are structurally altered, such that our fat-storing cells no longer recognize them and thus cannot absorb them. As a result, instead of penetrating the tissues to be utilized, oxidized cholesterol remains in our blood vessels, leading to hardening of arteries, plaque formation and finally heart problems. Reducing the free radical load introduced into the body and eating a diet rich in antioxidant foods are therefore important strategies in lowering cholesterol levels and preserving our cardiovascular health.
HDL vs LDL Cholesterol
After the results of our blood test come back from the lab, we know to interpret LDL as “bad” cholesterol and HDL as “good”. This is because LDL is the cholesterol that is leaving our liver to potentially stay stuck in our arteries, while the HDL is the cholesterol that is shuttled back from the body to the liver to be processed (and maybe even eliminated!). Studies have shown that total levels of cholesterol may be less important than the ratio of HDL to LDL cholesterol, as HDL has protective effects on cardiovascular health. The best way to maintain high HDL levels is to obtain enough essential fatty acids in one’s diet, especially the now popular omega-3s.
Practical Strategies to Reduce Cholesterol Levels
- Reduce your intake of simple processed carbohydrates like white refined starches (rice, pasta, breads…), sodas or sweets. Sodas in particular, are essentially “liquid sugar” and enter the bloodstream at record speed, leading to a corresponding high increase in insulin levels (and ultimately fat & cholesterol!).
- Soluble fibers have been intensely researched in the last few years, and found to significantly reduce cholesterol levels. This is because they bind cholesterol in the digestive system and prevent its absorption. In addition, they also bind glucose and slow down its absorption into the bloodstream, preventing a steep rise in insulin. Good sources of soluble fiber are eggplants, oats, okra (ie: ladyfingers) and psyllium.
- Make sure vegetables make up at least 1/3rd of your plate for every meal. Coloured vegetables such as carrots, yellow squash, beets and peppers are especially high in antioxidant molecules that protect cholesterol from being oxidized in the long term.
- Reduce the free-radical load introduced in your body. Some of the worst offenders are toxins from cigarette smoking and those from deep fried foods. Quitting smoking and making deep-fried foods as an occasional treat can greatly lower oxidative stress in your body.
- Make omega-3s part of your diet to boost your HDL (good) while lowering LDL (bad). Add ground flaxseeds to your breakfasts and salads, and consume cold-water fish (salmon, mackerel, anchovies, herring, sardines) twice a week.