Different types of fats
Almost all foods contain some fat. Fat provides a terrific source and depot of energy. Fat plays an important part of cell membranes, helping govern what gets into cells and what comes out. The body uses cholesterol as the starting point to make estrogen, testosterone, vitamin D, and other vital compounds. Fats are also biologically active molecules that can influence how muscles respond to insulin's "open up for sugar" signal; different types of fats can also fire up or cool down inflammation.
Fat & cholesterol can't dissolve in blood or water. This chemistry is solved by the body packaging fat & cholesterol into tiny, protein-covered particles called lipoproteins, which can mix easily with blood and flow with it. Some of these particles are big and fluffy, while others are small and dense.
3 types of lipoproteins
LDL (bad cholesterol): Low density lipoproteins carry cholesterol from the liver to the rest of the body. Cells latch onto these particles and extract required fat and cholesterol from them. When there is too much LDL cholesterol in the blood, these particles form deposits in the walls of our arteries. Such deposits, called plaque, narrow arteries and limit blood flow, eventually leading to a heart attack or a stroke. Because of this, LDL cholesterol is referred to as bad, or harmful, cholesterol
HDL (good cholesterol): High density lipoproteins scavenge cholesterol present in the bloodstream, in LDL and on artery walls and ferry it back to the liver for disposal. HDL cholesterol can be looked at as the garbage-truck of the bloodstream, collecting and getting rid of excess cholesterol. For this reasons, HDL is referred to as good, or healthy, cholesterol.
Triglycerides: most of the fat that we eat travels through the bloodstream in the form of triglycerides. While a certain amount of fat is required for the healthy functioning of cells (and thus a certain level of triglycerides is good for the body), an excess of triglycerides (or fat) has a number of adverse health effects.
The role of fat in diet and our health is often misunderstood. People mistakenly consider the total amount of fat in their diet, as an indicator of its health effects. However, what really matters is the type of fat (not so much quantity) consumed and the total calories in the diet. Bad fats (primarily trans and saturated fats) are bad for health – as they lead to a buildup of harmful LDL (low density lipoproteins) and triglycerides in the body. However, good fats (primarily mono and poly saturated fats) are good for health – as they lead to a buildup of healthy HDL (high density lipoproteins) in the body.
It is therefore important to focus on the types of fat being consumed in a diet (mono, poly, trans or saturated fats), rather than the overall levels of fat being consumed. Often, people opting for a low-fat diet, end up cutting back on fats that are good for the heart, along with the harmful fats.
Rather, than focusing on a low-fat diet, people need to focus on replacing foods with bad fats (trans & saturated fats) with good fats (mono & poly unsaturated fats). Most animal food products are associated with trans & saturated fats, while plant based foods have higher levels of mono & polysaturated fats. Replacing animal products for plant based foods in our diet, helps raise levels of good fats at the expense of bad fats, helping combat heart diseases, cancer and diabetes.
Impact of bad cholesterol
Higher than required levels of LDL and triglycerides in the blood stream, lead to a number of harmful health effects including
- Heart diseases: due to a choking of arteries, increasing cardiovascular risk
- Cancer: by impacting the hormonal balance of the body, increasing cancer risk
- Diabetes: by impacting the functioning of insulin in the body (insulin resistance) and preventing absorption of sugar in the bloodstream, increasing diabetes risk
Our diet & different types of fats
The types of fat in the diet determine the amount of total, HDL, and LDL cholesterol in the bloodstream. While mono & polysaturated fats (or good fats) help increase the levels of HDL, trans & saturated fats (or bad fats) increase the levels of LDL and triglycerides in the blood.
The Good Fats - Mono & Poly unsaturated fats: increase the levels of HDL (or good cholesetol) in the bloodstream that help regulate blood cholesterol levels, ease inflammation, stabalise heart rhythms amongst other positive health effects. Unsaturated fats are liquids at room temperatures, and are predominantly founds in foods from plants (such as vegetable oils, nuts and seeds).
Monounsaturated fats, are found in high concentrations in vegetable oils (olive, peanut ,canola oils), seeds (pumpkin, sesame), nuts (almonds, hazelnuts, pecans) and avocados. Polyunsaturated fats are found in high concentrations in vegetable oils (sunflower, corn, soybean, flaxseeds), flax seeds, walnuts and fish. Omega – 3, is an important type of polysaturated fat, that cannot be made in the body and therefore needs to be consumed through external sources. Due to other health issues relating to fish, the best sources of omega-3 oils include seeds (chia seeds, flax seeds), vegetable oils (flaxseed, canola, soybean) and walnuts.
The Bad Fats – Trans & Saturated fats: help increase the levels of LDL (or bad cholesterol) and triglycerides in the body. Higher levels of LDL and triglycerides in the blood is one of the leading causes of heart diseases, cancers and diabetes.
Saturated fats are derived primarily from animal products. Meat (both red meats & poultry) and Dairy products (milk, cheese, yogurts) are amongst the highest sources of saturated fats. While most plant based products have little or no saturated fats, certain vegetable oils (coconut, cottonseed, palm kernel) and prepared foods have high levels of saturated fats.
The primary source of trans fats is through partially hydrogenated vegetable oils – made by heating vegetable oil in the presence of hydrogen gas, causing the oil to become solid, more stable and less likely to spoil. These properties are highly appealing to the processed food industry, leading to most fried snacks & fried restaurant foods, being leading sources of trans fats. Trans fats are also found in smaller amounts in beef and dairy products.
Animal products (red meat, poultry and dairy products) are the prime sources of saturated fats (with the exception of a few vegetable oils and junk foods). By replacing animal products for plant based foods, saturated fats are replaced by unsaturated fats, with significant positive implications towards prevention of heart diseases, cancer and diabetes.
Recommendations to reduce or limit dietary intake of saturated fats are made by Health Canada, the US Department of Health and Human Services, the UK Food Standards Agency, the Australian Department of Health and Aging, the Singapore Government Health Promotion Board, the Indian Government Citizens Health Portal, the New Zealand Ministry of Health, the Food and Drugs Board Ghana, the Republic of Guyana Ministry of Health, and Hong Kong's Centre for Food Safety. (Source: Wikipedia)