Edited by Kate Findley, The Great Courses Daily
Fat is vital for the functioning of your body, down to your cells and DNA. Michael Ormsbee, Ph.D., breaks down the different types of fat and explains how fat maintains cellular health.
Fats and Cell Membranes
To understand how fat maintains cellular health, there’s one thing you need to realize first. The structures of your cells are made up of fats, proteins, carbohydrates, vitamins, and minerals, and so are the foods we eat every single day.
This is not a coincidence. The foods you eat have a major influence on your cellular function because they ultimately become your cells.
There are some specific nutrients that can impact your internal cellular functioning, starting with unsaturated fats. Unsaturated fats are necessary for strong cell membranes.
The membrane is semi-permeable thanks to the fluid structure of the fats. However, saturated and trans fats are much more rigid than unsaturated fats. They don’t function the same way as the unsaturated fats, and they cause membranes to be much more rigid than is optimal, potentially limiting the functionality of the cells.
Diets that are too high in one type of fat—for example, trans fats—might lead to rigid, brittle cell membranes that cannot communicate as well as they would if they were composed of a better mix of fat types.
Thus, many nutritionists recommend eating all types of fats so that one type doesn’t predominate in the diet and end up altering the optimal functioning of those cells. In general, diets high in unsaturated fats will promote healthy cell membranes.
Omega-6 and Omega-3 Fatty Acids
Two categories of the unsaturated fats to take particular note of are the omega-6 fatty acids and the omega-3 fatty acids. Omega-6 fatty acids are highly concentrated in foods like walnuts, almonds, and various types of vegetable oils, including corn, soybean, safflower, cottonseed, sunflower seed, and peanut oil. These are all types of oils that are in the majority of any processed, boxed, pre-packaged foods that you probably have in your kitchen pantry.
Rich sources of omega-3 fatty acids include fatty fish such as salmon, tuna, cod, and trout. Some seeds and nuts also contain omega-3s, like flaxseed, but to a much lesser extent. Both omega-6 and omega-3 fatty acids are essential for good health; however, they play very different roles.
Omega-3s have an anti-inflammatory effect in the body; whereas, the omega-6s have a pro-inflammatory effect. The pro-inflammatory effect of omega-6 fatty acids may sound bad; however, some inflammation is actually necessary to some extent.
Some amount of inflammation can help protect the body from infection and from injury. For example, if you roll your ankle, inflammation sets in to immobilize your ankle so you can begin to heal. Same thing goes for a cut—the inflammation shows that an immune response is underway to help fight off any pathogens that might make you sick.
However, too much inflammation can lead to other things like heart disease, metabolic syndrome, diabetes, Alzheimer’s disease, arthritis, and many types of cancer. Conversely, omega-3s are known to lower the risk of these diseases by decreasing the amount of inflammation within the body.
In the current Western diet, the omega-6 to omega-3 ratio has skyrocketed because of the high intake of vegetable oils rich in omega-6 fatty acids. In order to protect the cells from damage, this ratio needs to be decreased.
To lower this ratio, you need to decrease your intake of processed vegetable oils that are high in omega-6 fatty acids, as well as increase your intake of fatty fish, flaxseeds, chia seeds, and fish oil, which are all rich in omega-3 fats.
Other nutrients required to maintain healthy cell membranes include high quality proteins, fat-soluble vitamins like A, D, E, and K, and vitamin C. Whole grains, vegetables, fruits, and lean poultry and fish will all provide you with these nutrients to keep your cell membranes in top shape.
DNA and Fats
What about the cell nucleus and your DNA? Unfortunately, despite the barrier provided by the nucleus, DNA can be damaged from any excess potentially harmful substances, often called toxins, circulating around in the body.
Toxins is a term that is far too widely used by so-called nutrition experts, but you can produce molecules that damage your DNA. These molecules can come from excess trans fats and high amounts of omega-6 fatty acids, compared to omega-3 fatty acids in your diet.
Additionally, damage to DNA can occur from reactive oxygen species or excessive oxidative stress, which can be produced as a by-product from the energy, or ATP, we produce from food or even from excessive exercise. If reactive oxygen species make their way into the nuclear membrane, they can potentially alter normal DNA functioning.
If this occurs, the proteins that the particular DNA strand produced will no longer be available to your body. This will lead to poor functioning in your body, and in the worst case scenario, could lead to various disease states.
Eating polyunsaturated fats from quality sources prevents this from happening. These fats can be found in sources like fatty fish, flaxseeds, walnuts, and even soybeans.
Other nutrients that are needed to protect DNA include high-quality protein, antioxidants, and vitamins like vitamin E and C, the carotenoids, folate, and vitamin B12. The easiest way to get all of these nutrients into your diet is to consume foods like lean meats, eggs, dairy, colorful vegetables, whole grains, and fruits. If you do this, you will have the best chance at protecting your DNA from excessive damage.
Dr. Michael Ormsbee is an Associate Professor in the Department of Nutrition, Food, and Exercise Sciences and Interim Director of the Institute of Sports Sciences and Medicine in the College of Human Sciences at Florida State University. He received his M.S. in Exercise Physiology from South Dakota State University and his Ph.D. in Bioenergetics from East Carolina University.