By Rishipal Bansode, PhD, NCA&T Center for Excellence in Post-Harvest Technologies, for Bioactive Monthly newsletter.
Recent findings from the NCA&T laboratory at the NC Research Campus that were published in the journal Food Chemistry demonstrated in an animal model that peanut skin polyphenols, specifically A-type procyanidin, can lower lipid levels. The findings are part of the process to develop a heart-healthy ingredient made from the peanut skin extract that can be added to other foods to enhance their nutritional value.
When people hear about scientific findings like these, words like polyphenols and lipids may not be familiar. Polyphenols are a class of phytonutrients found plants that are linked to many health benefits like preventing cardiovascular disease, some types of cancers, neurodegenerative disorders, osteoporosis and diabetes.
Lipids are something quite different and an area of nutrition and health that are beneficial to know. Understanding how lipids impact human health can help people find ways to prevent heart disease and other chronic health conditions. Lipids are actually a variety of compounds that are non-soluble in water and include fats, oil, waxes, phospholipids and steroids that are easily stored in the body. Because some lipids are fats, they often get a bad rap. Actually, they are involved in very important body functions. For example, they insulate and protect the body. They facilitate communication between cell membranes, are part of the digestive process and absorb and transport nutrients.
Types of Lipids
Fatty acids are acids produced when fats are broken down. They may be saturated, monounsaturated or polyunsaturated. Saturated fats are found in meats, dairy products and palm oil, palm kernel oil and coconut oil. The American Heart Association recommends limiting saturated fats to no more than seven percent of daily caloric intake.
Health experts encourage people to eat unsaturated monounsaturated or polyunsaturated fats found in foods like nuts, seeds, many unhydrogenated vegetable oils and fatty, coldwater fish like salmon. Essential unsaturated fats are the omega-3’s. They are a main structural component of cell walls and have important roles in visual and neurological development. Several studies show eating omega-3’s lowers the risk of coronary heart disease.
Cholesterol is a waxy substance synthesized by the liver. It is also derived from animal-based foods. It is an important part of cell membranes and a precursor to steroid hormones, which perform essential functions in the human body. Cholesterol is recognized as either low density lipoprotein (LDL) or high density lipoprotein (HDL). LDL is thought of as “bad” cholesterol because it carries cholesterol from the liver to the cells for storage. If there is too much in the body, it is the culprit that builds up in the blood and increases the risk factor for heart disease. HDL or “good” cholesterol takes cholesterol from the cells to the liver where it is broken down to be used by the body or excreted as waste.
Triglycerides are formed by combining glycerol with three molecules of fatty acids. Triglycerides are derived from the fat in the food we eat. When calories are not used immediately, the body converts them into triglycerides that are stored in fat cells. The body can draw on these stores when it needs energy. When triglyceride levels are too high, they accumulate in the blood and contribute to heart disease.
Trans fats, otherwise known as partially hydrogenated vegetable oils and spreads, are created by adding an extra hydrogen molecule to vegetable oil in the manufacturing process. The extra hydrogen makes the oils last longer on the shelf. In the human body, the oils are digested as saturated fats and are known to raise the LDL levels and lower HDL. The US Food and Drug Administration recently passed a preliminary determination that declared partially hydrogenated oils as generally unsafe and may ban their use completely.
Keep Lipid Levels in Check
A diet that is too high in fats, especially saturated, can lead to weight gain and hyperlipidemia, which is elevated levels of cholesterol and triglycerides that substantially raise the risk for developing heart disease, metabolic syndrome, diabetes and stroke. To keep lipid levels in check and help increase HDL levels while reducing the risk of disease, focus on eating more monounsaturated and polyunsaturated fats like those found in olive, peanut and canola oils. Eat nuts, fish and other omega-3 rich foods as well as lots of fruits, vegetables and whole grains. Doctors also recommend little to no alcohol, no smoking and an active lifestyle with regular exercise that will help achieve or maintain a normal body weight.