2.32 Unsaturated Fats and Omega 3 Fatty Acids
Unsaturated fats include monounsaturated and polyunsaturated fats. These fats are liquid at room temperature. These types of fats are considered good for your heart health in appropriate, very small amounts. They have been shown to reduce cholesterol levels, decrease inflammation and even in some studies help with heart rhythm disorders. These types of fats are mostly found in foods that are plant derived like avocado, seeds and nuts.
Monounsaturated fats chemically have one pair of carbon atoms connected with a “double bond”. These are more liquid at room temperature and are found in these foods:
- Olives
- Nuts (almonds, pecans)
- Avocados
- Seeds (sunflower, pumpkin, sesame)
Polyunsaturated fats chemically have at least two pairs of carbon atoms connected. These are a little more solid at room temperature, but still liquid and are found in these foods:
- Sunflower, corn, soybean and flax seed oils
- Pine nuts, walnuts, brazil nuts
Omega-3 Fatty Acids
Omega-3 fatty acids are a type of polyunsaturated fat that is very important for many reasons, including for heart and brain health. They reduce inflammation in the body which is crucial for heart disease prevention. It is important to know that the body is not able to make omega-3 fatty acids on its own so it relies on you getting them from your diet. Omega-3 fatty acids are therefore referred to as “essential fatty acids” since it is essential that you get them from food. All omega-3 fatty acids originate from plants. While people frequently associate fish and fish oil with omega-3 fatty acids, the fish actually get it by eating algae.
You can easily get all the omega-3 fatty acids that you need from whole plant foods. Good plant sources of omega-3 fatty acids include:
- Flax seeds (better absorbed if ground), chia seeds, hemp seeds, sesame seeds, pumpkin seeds
- Walnuts and other nuts
- Green leafy vegetables (i.e. spinach, kale, brussel sprouts, brocolli, collard/mustard greens)
- Seaweed
- Squash
- Fruit – especially berries, mangoes, honeydew
- Herbs/spices
- Wild rice
While these are the plant foods higher in omega-3 fatty acids, essentially all plant foods have some omega-3 fatty acids. Even though these omega 3 fatty acids are “essential”, a dietary deficiency of omega-3s does not occur if you eat a variety of whole plant foods. Do not worry about whether you are getting enough omega-3 fatty acids on a whole food plant based diet.
Lastly, it is important to know that there are three types of omega-3 fatty acids. They are ALA (alpha-linolenic acid), DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). The good news is that your body can convert the “short-chain” ALA to both “long-chain” DHA and EPA in sufficient amounts, so ALA is really all that you need to get in your diet. The omega-3s found in plants are predominately ALA while in fish and animal foods EPA and DHA are present. It is actually preferred to get your omega-3 fatty acids from plants for 2 reasons. First, you are avoiding the harmful cholesterol and saturated fats that come in animal based foods and second, too much EPA and DHA may be harmful. If you consume only ALA, your body can regulate how much EPA and DHA to produce and thus you will not get too much.
There is one catch though. Research shows that as we age our ability to convert ALA to EPA and DHA decreases. While a specific age to start taking supplements of EPA and DHA is not clear, many experts recommend taking an algae based omega-3 supplement specifically to preserve brain health. The effects of this on heart health is not clear. There are many algae based omega-3 supplements on the market.
Omega-6 Fatty Acids
The second type of essential fatty acid (also polyunsaturated) is omega-6 fatty acids. Even though these are “essential” meaning we must get them from our diet, they are quite plentiful and thus getting an adequate amount is rarely a concern. Omega-6 fatty acids are higher in animal based foods such as beef, poultry and eggs. In fact, grain fed beef can have 17 times more omega-6 than omega-3 which creates a problem as we will soon found out below. Omega-6 fatty acids are pro-inflammatory which is not good, especially in regards to heart disease. The most common omega-6 is linoleic acid (LA).
Omega-3 to Omega-6 Ratio
The most important factor about omega-3 and omega-6 intake in your diet is not how much you are getting, but it is the ratio of omega-3 to omega-6 fatty acids. The typical American diet includes a large amount of omega-6 with little omega-3. This results in a ratio of omega-6/omega-3 ratio of 12:1 to 25:1. Thus Americans are getting large amounts of omega-6 and not enough omega-3 fatty acids. These omega-6 fatty acids frequently come from oils. It makes sense that to solve this problem we should eat less processed oils and less foods that contain high levels of omega-6 fatty acids. Unfortunately the supplement industry has a different idea. Just get Americans to increase their omega-3s by taking fish oil or flax oil supplements and the ratio will improve! Eating an unhealthy diet and then correcting the deficiency that it created with a supplement is never a good idea. This ratio should be balanced naturally with the proper foods. This concept has been confirmed by multiple clinical trials showing that fish oil supplements do not reduce the rate of cardiovascular disease, heart attack, stroke or death and thus they are not recommended for use by any major medical society.
As mentioned above, humans have an enzyme that can convert ALA into DHA and EPA at a sufficient rate. The problem is that the same enzyme also processes omega-6 fatty acids, thus omega-6s compete with omega-3s for use of this enzyme. Thus if you have too many omega-6 fatty acids, the enzyme is not able to be efficient converting the omega-3 fatty acid ALA to DHA and EPA. So having the correct, healthy ratio of omega-6 to omega-3 is important.
The consensus among nutrition experts is that we do indeed need more omega-6 than omega-3, but only by a little. Many studies show humans evolved with an omega-6 to omega-3 ratio of 1:1, meaning we ate about the same amount of omega-6 as we did omega-3. Certainly not the 25 times more omega-6 that many Americans currently get compared to omega-3. Nutrition experts also agree with the goal that we should strive for a ratio of at least 4:1 or less. That would mean that for every 4 mg of omega-6 fatty acids we should get 1 mg of omega-3 or more. A lower ratio would be even better.
Summary and Conclusions
- Fats in the diet need to be kept to a minimum, as low as 10% of calories when trying to reverse heart disease
- Unsaturated fats are the healthy type of fats
- Two important “essential” unsaturated fats are omega-3 and omega-6 fatty acids
- All omega-3 and omega-6 fatty acids originate from plants
- The three types of omega-3 fatty acids are ALA, DHA and EPA
- Your body can efficiently convert ALA to DHA and EPA when the omega-6 to omega-3 ratio is favorable, thus dietary sources of DHA and EPA are not needed
- Keep the omega-6 to omega-3 ratio to 4:1 or less – ideally 1:1
- A whole food plant based diet without added oils and limited nuts/seeds/avacado and with good sources of omega-3 is the healthiest way to get the right fat
- Use ground flax, chia seeds, and green leafy vegetables to get your omega-3s
- Algae based omega-3 supplements are available and may be reasonable to preserve brain function since conversion of ALA to DHA and EPA decreases as you age