Omega-3 fatty acids are essential fatty acid compounds found primarily in fish oils, flaxseed oil, walnuts and other plant sources. They have been shown to reduce inflammation and protect against heart disease, cancer and diabetes.    Omega-3s have also been associated with improved cognitive function. However, some studies suggest that they may increase the risk of developing Alzheimer’s Disease. 
The omega-6 fatty acids (found mainly in animal products) include linoleic acid (LA), arachidonic acid (ARA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Studies show that these fats have been linked to increased risk of cardiovascular disease, type 2 diabetes, depression, obesity and certain types of cancers.  
Omega-3s are found in oily fish such as salmon, herring, sardines and mackerel. They’re also present in many vegetables and nuts. Some fruits contain high levels of omega-3s including blueberries, apricots, peaches and plums. However, the best sources are algae (spirulina, chlorella, klamath algae) and hemp seeds.
Omega-6s are found in most nuts, seeds, certain vegetable oils (soybean oil, sunflower oil, cottonseed oil, corn oil), meat and animal fat. The main omega-6 fatty acid is linoleic acid (LA – 18:2w6), although certain variations (allo- LA, gamma-LA) are also found in some vegetable oils.
Omega-9s are found in various types of nuts and seeds. They are also present in small quantities in vegetable oils, especially olive oil. The main omega-9 fatty acid is oleic acid (18:1w9).
Omega-3 vs. Omega-6
The omega 3 and 6 fats are ‘essential’ fatty acids, meaning they play an important role in the body’s functioning and development and can’t be synthesized within the body. The problem is that most people consume too many omega-6 fatty acids and not enough omega-3. This has led to an imbalance that contributes to various diseases and disorders. It is therefore recommended that the ratio between omega-6 and omega-3 should be around 2:1.
The best way to achieve this ratio is to eat foods rich in omega-3 and to limit the intake of foods high in omega-6. The problem is that most of the oils that are commonly used for cooking, such as sunflower oil and corn oil, are very rich in omega-6. Olive oil, which is a monounsaturated fat, also has a high ratio of omega-6 to -3 (approx. 10:1).
Therefore, it would be preferable to use a polyunsaturated fat with a lower ratio of omega-6 to -3, such as flax oil (approx. 5:1) or hemp seed oil (approx. 1:1) when cooking.
However, there is no need to avoid the oils high in omega-6 altogether. The problem isn’t just high levels of omega-6, the problem is an imbalanced ratio of omega-3 to -6. Even olive oil and most nuts and seeds (high in omega-6) can be incorporated into a healthy diet. The key is not to exclude them, but to limit their use and replace them with foods rich in omega-3.
Foods High in Omega-3
Foods high in omega-3 include sea bass, salmon, herring, sardines, trout, mackerel, anchovies, tofu, pumpkin seeds and walnuts. Flaxseed oil is also a very good source of omega-3.
Why Are Omega-3s So Important?
Omega-3s are vital for normal brain and eye function, and they help reduce the risk of heart disease. They also play a vital role in genetic activity, immunity, inflammation and allergies, and they even help prevent depression.
A lack of omega-3s has been linked to various types of arthritis and autoimmune disease.
Deficiency is also common in people who have a diet high in processed food, as it is often lacking in omega-3s and other essential nutrients.
As the human body can’t produce omega-3 on its own, it is vital to get an adequate supply from your diet.
How Much Omega-3 Do You Need?
The recommended daily amount of omega-3 for adults is 1 gram.
To put this in perspective, one ounce of walnuts (a half cup) contains 3.5 grams of omega-3, and two tablespoons of flaxseed oil contain 2.1 grams of omega-3.
If you don’t get enough omega-3, your body cannot function normally and disease and disorder will inevitably occur.
It is important to get your omega-3s from natural sources such as nuts, seeds, eggs and fish, rather than taking supplements. Although you may be able to consume more using supplements, your body will not be able to process them as efficiently.
The most common types of omega-3 supplement are fish oil capsules and liquids or triglyceride (TG) extracts from fish.
What About Fish?
Fish is a great source of protein and omega-3, but it also contains mercury, dioxins and other toxic substances. If you’re going to eat fish, it is important to choose the right types and limit the amount you consume.
The best sources of omega-3 are oily fish such as mackerel, sardines, herring, lake trout, salmon, albacore tuna, and Atlantic and Pacific oysters.
Other fish that are good sources of omega-3 include bluefish, sea bass, halibut, and cod.
Fish that are lower in mercury and safe to eat include shrimp, lobster, canned light tuna, crab, and haddock.
Farmed fish are also a healthy option as they contain less toxic than wild-caught fish.
As a general rule, try to eat fish with a high fat content, as this will increase the amount of omega-3 you consume.
Toxic vs. Beneficial Oils
There are many different types of oils, and some have very different effects on the human body.
While it may seem that oils are oils and they’re all fairly similar, this is not the case. Some are good for you, and some should be strictly avoided.
For example, canola oil is often thought of as a healthy oil, but it is in fact seriously detrimental to our health.
Most oils that are high in omega-3s are also high in omega-6 and should be avoided.
These oils include: corn oil, cottonseed oil, peanut oil, soybean oil and sunflower oil.
Other oils to avoid include: safflower oil, grape seed oil, coconut oil and rice bran oil.
The only oils that you should include in your diet are the following: flaxseed oil, cod liver oil, hempseed oil, and sesame oil.
Most oils are easy to differentiate between, but it can get a bit more confusing when it comes to animal products.
Dairy products, for example, often contain high levels of omega-6 oils.
This includes cheese and milk.
While it is fine to consume these on rare occasions, it should not be a regular part of your diet.
Other animal products like eggs and meat may also contain high levels of these oils, so you will need to be careful when selecting your food.
It is important to stick with lean meats like turkey, chicken, and fish rather than red meats like beef.
Meats that are higher in saturated fats like lamb and duck are better than those that are low in fat like chicken.
Foods to Eat:
Foods to Avoid:
Foods with High Levels of Oils:
Foods with Low Levels of Oils:
Oily Fish and Seafood
Seafood is an excellent source of protein and many other nutrients, but only some species are good for you.
As was previously mentioned, fatty varieties like salmon, tuna, and sardines are packed with essential nutrients, while leaner varieties like cod or halibut are not.
If you’re looking to get some healthy fats into your diet, shellfish is an excellent choice.
Oysters in particular are rich in zinc, omega-3s, vitamin B12, and vitamin D.
Clams, crab, and lobster are also healthy choices.
It is always preferable to eat your seafood fresh, but if you do need to pick something up from a store, be sure it is either canned or packed in water, rather than oil.
While there are many misconceptions about oily fish being dangerous due to their high levels of mercury, as long as you do not over-consume them, they can be a very nutritious and healthy choice.
Oily fish includes varieties like anchovies, bluefish, salmon, sardines, and trout.
In general, any fish you’re able to eat the whole thing is a good choice.
Avoid fish that have a lot of different parts, such as smoked salmon.
Also try to avoid fish like catfish or carp that tend to have a lot of smaller bones.
While they are still nutritious, they can be a bit of a pain to eat.
If you’re looking for something different, try some shellfish.
There is a very wide variety and they are all packed with nutrients.
Oysters have long been considered nature’s multivitamin because they contain so many important nutrients.
Like fish, the key when selecting shellfish is avoiding those that have been bread in oil.
The Best Meats
Beef, veal, lamb, and pork are all good sources of protein, but only if they’re prepared properly.
This means they should either be roasted, grilled, or fried in a pan.
Avoid any meat that has been prepared with a lot of extra fat and served in a sauce.
Also avoid pre-packaged deli meats.
While these meats may be high in protein, they are also very high in sodium and other preservatives.
When selecting meat to eat, always choose the most natural product you can find with the fewest additives.
This means the meat should not be smoked, dyed, or preserved in any way.
The Most Nutritious Vegetables
Some vegetables are better for you than others.
When selecting your vegetables, try to go for those that are fresh and have brightly colored leaves.
Green leafy vegetables are the most nutritious.
These include spinach, lettuce, cabbage, kale, collard greens, and many others.
Green vegetables are good sources of iron and fiber.
Most fruits are high in natural sugars, so it’s important to consume them in moderation.
With that being said, dried fruits are excellent sources of nutrients and can make an excellent snack if you’re looking for a little something extra added to your lunch.
Fruits like cranberries, blueberries, cherries, and apricots contain valuable antioxidants and fiber.
When selecting fruit, make an effort to choose those that still have the stem attached.
Stemmed fruits are typically fresher and the stem can be used to prevent the fruit from spoiling as quickly.
How to Store Fruits and Vegetables
It is highly recommended that you store your fruits and vegetables away from other foods.
Storing them with other foods can cause them to spoil faster or lose their nutritional value.
The refrigerator is an ideal place to store fruits, but it can make some vegetables, like lettuce or tomatoes, a little limp.
If you’re storing any vegetables in the fridge, make sure to keep them away from other foods and wrap them in either plastic or paper so that they don’t come in contact with anything else.
Keeping fruits in the fridge is fine, but many fruits, like bananas and avocados, actually stay ripe longer when stored away from the cold.
Some fruits should be kept on the counter such as citrus fruits.
You can store them in paper bags or wooden crates away from other foods.
Some fruits such as apples and pears should be kept in wooden crates or paper bags in a cool, dry place.
It is best to wash your fruits and vegetables just before you eat them.
Washing fruits and vegetables is an important step in making sure that the food you’re putting into your body is free of pesticides and harmful chemicals.
The Environmental Working Group is an independent research group that monitors the dangers of pesticides and other chemicals found on foods.
If you’re really concerned about the foods you eat, many grocery stores now offer organic options.
These are usually priced higher than their non-organic counterparts, so if budget is a concern, then sticking with the regular produce aisle should take care of you.
To wash fruits and vegetables, gently scrub them under running water using your hands or a soft brush.
You can also use a produce wash to help remove any stubborn pesticides.
Most stores offer these washes next to the produce, or they can be found in the laundry aisle of your favorite store.
These washes typically come in liquid or powder form and can be used for all types of fruits and vegetables.
If you’re concerned about the freshness of your fruits and vegetables, you can use a paper towel to check for spoilage.
Most fruits and vegetables give off a distinct smell when they are spoiling.
You can check your fruits and veggies this way without getting them wet.
If you’re still not sure about the ripeness of your produce, you can use a knife to cut it open.
Sometimes the color of the inside tells you whether or not it’s ripe.
You can typically find these at the grocery store or your local market.
They’re easy to use and they eliminate the need for a knife or cutting board.
If you’re concerned about eating healthy, then you may want to consider choosing organic food options whenever possible.
The difference between organic and regular food usually affects the quality of the food you’re eating.
Organic fruits and vegetables contain higher levels of nutrients and offer lower toxicity when consumed.
Research shows that people who eat organic food have lower chances of developing health concerns.
This includes cancer and other diseases linked to the food you eat.
If you’re looking for organic fruits and vegetables, then the best way to shop is by season.
Knowing what fruits and vegetables are in-season can help you find the best options without breaking the bank.
Most grocery stores will have weekly advertisements showing which fruits and vegetables are in-season.
Sources & references used in this article:
Health effects of omega-3,6,9 fatty acids: Perilla frutescens is a good example of plant oils by M Asif – Oriental Pharmacy & Experimental Medicine, 2011 – Springer
Essential fatty acids for dry eye: a review by M Roncone, H Bartlett, F Eperjesi – Contact Lens and Anterior Eye, 2010 – Elsevier
The effects of addition of omega-3, 6, 9 fatty acids on the quality of bovine chilled and frozen-thawed sperm by R Robertson – Pridobljeno, 2017
Long chain omega-3 dietary supplements: a review of the National Library of Medicine Herbal Supplement Database by MAS Kandelousi, J Arshami, AA Naserian… – Open veterinary …, 2013 – ajol.info
Omega-3 fatty acids–A review of existing and innovative delivery methods by A Zargar, MK Ito – Metabolic syndrome and related disorders, 2011 – liebertpub.com