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Polyunsaturated Fat: The Healthy Fat that Supports the Heart, Brain & Eyes
November 21, 2018
With the emergence of popular diet plans that emphasize healthy sources of dietary fat, polyunsaturated fat has gathered a good amount of attention lately. Foods like nuts, seeds and seafood are all loaded with this heart-healthy type of fat, and it’s even found in supplements like fish oil, krill oil and cod liver oil as well.
Getting enough polyunsaturated fat in your diet is key to maintaining overall health. Not only can it reduce inflammation to aid in immune function and disease prevention, but it also boasts a long list of other impressive benefits for health. Keep reading for what you need to know about this powerful form of fat and how you can be sure to get enough in your diet.
What Is Polyunsaturated Fat?
Polyunsaturated fat, also known as PUFA, is a type of unsaturated fat that is found throughout the diet in both plant-based foods and animal sources. The polyunsaturated fat structure consists of one glycerol molecule and three fatty acids. It contains at least two or more double bonds. This distinct structure sets PUFAs apart from other types of fats, like monounsaturated fat and saturated fat.
There are two main types of polyunsaturated fat: omega-6 and omega-3 fatty acids. These differ in their chemical structure and the location of their double bonds, as well as the unique effects that they have on overall health.
Much like monounsaturated fats, polyunsaturated fats are considered a healthy type of fat that can promote heart health. They also play a role in many other aspects of health. In fact, some of the other potential polyunsaturated fat benefits include healthy bones and joints, better sleep, reduced menstrual pain, improved mental health, and more.
Is Polyunsaturated Fat Good for You? 7 PUFA Benefits
1. Keeps Your Heart Healthy
The heart-healthy benefits of polyunsaturated fatty acids have been extensively researched in recent years. (2) Omega-3 fatty acids, in particular, are linked to a number of benefits when it comes to heart health.
In fact, studies show that omega-3 fatty acids can help lower high triglycerides, decrease blood pressure, prevent blood clot formation and support healthy cholesterol levels. (3, 4, 5) Not only that, but omega-3 fatty acids are shown to lower markers of inflammation. Inflammation may contribute to chronic conditions, such as heart disease. (6, 7)
2. Enhances Mental Health
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the two most common types of polyunsaturated fats in the brain. They play a role in everything from cell membrane fluidity to gene expression and cell growth. (8) Not surprisingly, there’s a good amount of research recently indicating that polyunsaturated fats could have a powerful effect on mental health and brain function.
According to a review published in Oxidative Medicine and Cellular Longevity, regularly eating foods rich in polyunsaturated fat, such as oily fish, may be associated with a lower risk of depression and bipolar disorder. (9) Another study conducted by the Institute for Nutrition Research in Norway showed that women who consumed more very-long-chain omega-3 fatty acids during pregnancy and lactation had children with higher IQs and improved mental development. (10) Even more impressive, multiple studies have found that a higher intake of omega-3 fatty acids is linked to a reduced risk of cognitive decline in older adults. (11, 12)
3. Reduces Inflammation
Inflammation is an important part of the immune response. It is designed to help protect the body against foreign invaders and infection. However, long-term inflammation may actually negatively impact health. More and more mounting research suggests that inflammation is at the root of most diseases, including heart disease, cancer, diabetes and even obesity.
Certain types of polyunsaturated fats can help reduce inflammation to promote long-term health. Specifically, omega-3 fatty acids are shown to be effective at decreasing levels of multiple inflammatory markers. (13) Besides helping ward off chronic disease, this also may be beneficial in the treatment of inflammation-mediated disorders, such as rheumatoid arthritis, Crohn’s disease and lupus.
4. Supports Healthy Bones and Joints
Issues like arthritis and osteoporosis are incredibly painful conditions that become increasingly common with age. Arthritis is caused by inflammation of the joints. It results in symptoms like stiffness and pain. Meanwhile, osteoporosis is characterized by weak, brittle bones and an increased risk of fractures as a result of bone loss.
Some research shows that polyunsaturated fats may actually help support healthy bones and joints to reduce symptoms of these conditions and promote healthy aging. Essential fatty acids are shown to increase calcium absorption. This leads to increased bone mass and improved bone density. (14) Plus, omega-3 fatty acids can even soothe inflammation to protect joint health and relieve symptoms. (15)
5. Promotes Better Sleep
If you suffer from insomnia or have difficulty falling asleep, it may be time to ditch the sleeping pills and start evaluating your diet instead. Interestingly enough, studies show that low levels of polyunsaturated fats like omega-3 fatty acids are associated with a higher risk of sleep issues in children. (16) In adults, low levels also are tied to lower levels of melatonin and increased severity of obstructive sleep apnea. (17, 18) Although more research is still needed, these studies suggest that a higher intake of polyunsaturated fats — omega-3 fatty acids, in particular — could potentially help improve sleep quality.
6. Reduces Menstrual Pain
Menstrual pain can range in severity from mild and tolerable to completely unbearable. For some women, this type of pain can be so severe that it can actually interfere with overall quality of life.
According to one study published in the Caspian Journal of Internal Medicine, fish oil, a type of supplement made from PUFAs like omega-3 fatty acids, was significantly more effective than ibuprofen at relieving menstrual pain in women. (19) Several studies have also found that consuming a higher amount of polyunsaturated fatty acids is associated with more mild PMS symptoms. (20, 21)
7. Improves Vision
Polyunsaturated fatty acids are absolutely essential when it comes to eye health. DHA is a type of polyunsaturated fat that regulates the function of the photoreceptor cells in the retina and helps support healthy vision. (22) Studies show that getting enough polyunsaturated fats in your diet is tied to a reduced risk of age-related macular degeneration. Macular degeneration is a common eye disease that is considered the leading cause of vision loss. (23)
Related: Is Peanut Oil Good or Bad for Health? Separating Fact vs. Fiction
Top 10 PUFA Foods
Looking to up your intake of polyunsaturated fats? Here are a few of the top sources to consider adding to your diet: (24)
- Walnuts — 1 ounce: 13.2 grams
- Sunflower seeds — 1 ounce: 10.5 grams
- Pine nuts — 1 ounce: 10 grams
- Flaxseed oil — 1 tablespoon: 8.9 grams
- Flaxseed — 1 ounce: 8 grams
- Pecans — 1 ounce: 6 grams
- Salmon — 3 ounces: 3.8 grams
- Mackerel fish — 3 ounces: 3.7 grams
- Almonds — 1 ounce: 3.4 grams
- Tuna fish, canned in oil — 3 ounces: 2.5 grams
Polyunsaturated vs. Monounsaturated vs. Saturated vs. Trans Fat
Polyunsaturated fats are just one type of fat. Other types include monounsaturated fats, saturated fats and trans fats. How do these fats all compare?
The main difference between polyunsaturated fat vs. monounsaturated fat is their respective chemical structures. Both polyunsaturated fat and monounsaturated fat contain a double bond. This is what classifies them as “unsaturated fats.” However, while polyunsaturated fats have two or more double bonds, monounsaturated fats have just one. Both are considered “good fats.” They are associated with a wide array of health benefits. Monounsaturated fats are also found in several types of nuts, as well as other healthy fats like olive oil, avocados and certain types of vegetable oil.
So what sets apart polyunsaturated fat vs. saturated fat? The difference is in the unique chemical structure of saturated v.s unsaturated fatty acids. Unsaturated fats contain a double bond while saturated fatty acids do not. Although once demonized and classified as unhealthy, more recent research reveals that saturated fat could help increase HDL cholesterol, improve brain function and even reduce the risk of stroke. (25, 26, 27) Saturated fat is found primarily in sources like meat, full-fat dairy products and coconut oil.
However, while both saturated and unsaturated fats are linked to plenty of powerful health benefits, trans fats are an unhealthy type of fat that should be avoided altogether. Found mostly in processed products like store-bought pastries, crackers, cookies and doughnuts, trans fats are associated with a higher risk of coronary heart disease along with a slew of other adverse effects on health. (28)
PUFAs in Ayurveda, TCM and Traditional Medicine
Many foods rich in polyunsaturated fats are loaded with health-promoting properties and have been used in holistic forms of medicine for centuries.
Fish, for example, is classified as highly nutritive according to Ayurveda. It is considered sattvic compared to other animal products like red meat. This means that it promotes clarity and awareness without being overly heavy or difficult to digest. In Traditional Chinese Medicine (TCM), on the other hand, fish is thought to strengthen the spleen, increase energy levels and remove dampness.
Meanwhile, high-fat nuts like walnuts are used in Ayurvedic medicine to build stamina, support satiety and stop diarrhea. Meanwhile, in TCM, walnuts are said to reduce fatigue, correct kidney deficiencies, and relieve issues like chronic coughing or urinary tract infections.
Where to Find and How to Use
Foods rich in polyunsaturated fatty acids are easy to find at most major grocery stores. They can easily be incorporated into a healthy diet. Fatty fish varieties like salmon, tuna fish and mackerel, for example, can take center stage as a nutrient-rich main course for lunch or dinner. Meanwhile, nuts and seeds can be enjoyed as is for healthy snacks. They can be combined into homemade trail mix or even sprinkled over top of salads, smoothies, cereals or yogurt.
When buying fish, it’s important to look for wild-caught varieties over farm-raised fish and keep intake in moderation to avoid mercury poisoning. If buying canned, be sure to opt for BPA-free cans and rinse thoroughly before consuming to remove excess sodium.
Nuts and seeds are common sources of polyunsaturated fats. They make for delicious and versatile additions to the diet. Selecting unsalted nuts with minimal extra ingredients and no added sugar is the best way to reap the nutritional rewards that this tasty ingredient has to offer.
There are plenty of delicious and nutritious ways to increase your intake of polyunsaturated fatty acids. Here are a few simple recipes to get you started:
- Raw Walnut Tacos
- Sautéed Spinach with Toasted Pine Nuts
- Grilled Honey Glazed Salmon
- Flaxseed Wraps
- Salted Paleo Sunbutter Cups
Although polyunsaturated fat is associated with a number of powerful health benefits, there are a few drawbacks that need to be considered as well.
First of all, there are two different types of polyunsaturated fats: omega-3 and omega-6 fatty acids. Both are considered essential fatty acids. That means your body is unable to produce them on its own and needs to obtain them through food sources. Additionally, both are incredibly important to health and are involved in a number of different functions within the body.
It’s believed that humans evolved consuming a ratio of omega-6 to omega-3 fatty acids of about 1:1. Studies show that maintaining a ratio between 1–5:1 can be therapeutic for many conditions, including asthma, heart disease and cancer prevention. Unfortunately, most people get way too many omega-6 fatty acids in their diets. Scientists estimate that the typical Western diet today comprises a ratio of omega-6 to omega-3 fatty acids closer to about 15:1. (29)
This could have many negative implications on health. Some researchers point out that this increase in omega-6 fatty acid intake may coincide with the increased prevalence of chronic inflammatory diseases like obesity, heart disease, inflammatory bowel disease and rheumatoid arthritis. (30)
Furthermore, not all sources of polyunsaturated fatty acids are healthy. Vegetable oils, for example, are typically highly refined and heavily processed. They also often are derived from genetically modified crops. For this reason, these forms of polyunsaturated fatty acids should be limited in the diet and replaced with other healthier sources of fat, such as nuts, seeds or fatty fish.
Although researchers today are well-aware of the massive impact that dietary fats have on health, the importance of fat only really came to light within the last century. In fact, up until the 1900s, fat was viewed as a way to increase caloric intake and promote weight gain rather than a key macronutrient that is integral to health.
In 1929, scientists George and Mildred Burr conducted a series of animal studies that began to unearth the importance of fat in the diet. Through their research, they found that feeding rats a specialized diet that was lacking fatty acids produced several severe side effects, including death.
The term “essential fatty acid” was soon introduced and used to describe any fatty acids that the body needs but is unable to produce on its own. The Burrs noted that linoleic acid, a type of polyunsaturated fatty acid, was especially important. A deficiency was found to cause issues like scaly skin and water loss in rats. (31)
While there is now no doubt that dietary fat is crucial to the body, researchers continue to learn more about the multitude of roles that certain types of fat play in health.
Risks and Side Effects
Polyunsaturated fats are essential to health, but not all sources are created equal. For example, foods like nuts, seeds and fish are all sources of polyunsaturated fat that are loaded with important nutrients and health-promoting properties. Meanwhile, highly processed and heavily refined foods like vegetable oils are high in polyunsaturated fat but do not carry the same health benefits.
Additionally, it’s important to keep your intake of omega-6 and omega-3 fatty acids in balance. While your body needs both to function and thrive, most of us get far more omega-6 fatty acids than we actually need. Try incorporating more omega-3 foods, such as fatty fish, nuts, seeds, natto and egg yolks, into your daily diet to be sure you get enough of this vital form of polyunsaturated fat.
- Polyunsaturated fat is a type of unsaturated fat that plays a central role in many different aspects of health.
- Some of the potential polyunsaturated fat benefits include improved heart health, better sleep, reduced inflammation, enhanced mental health, decreased menstrual pain, reduced bone and joint pain, and improved vision.
- Nuts, seeds, flaxseed oil and fatty fish are just a few of the ingredients that make the healthy polyunsaturated fat foods list. Other sources of polyunsaturated fats, like vegetable oils, are typically highly refined, heavily processed and derived from genetically modified crops.
- Omega-6 and omega-3 fatty acids are both types of polyunsaturated fat. However, most of us get far too much omega-6 and not enough omega-3 in our diets. That may negatively impact health and contribute to inflammation.
- For best results, be sure to include a good variety of polyunsaturated fats and omega-3 fatty acids in your diet alongside a good mix of other heart-healthy fats and nutritious whole foods.