Healthy Fats Improve Heart Health (For Some People)
But knowing which fats are best is a challenge. New research brings clarity.
Cindy Cao and Brent R. Stockwell co-authored this article
New research has revealed which fats are best, and why. Fish fats such as EPA (short for eicosapentaenoic acid) prevent heart disease. An important new study published in the scientific journal Nature Metabolism finds that EPA activates the protein S1PR1 (sphingosine-1-phosphate receptor 1), explaining why some people respond better than others to health-promoting fats such as EPA — people have different versions of S1PR1 that can affect how they respond to EPA.
People respond differently to what they eat, including when it comes to consuming fats. That’s because there are a variety of fats — some help and some hurt health, and what they do can be different in different people.
Pop star Jennifer Lopez and Princess of Wales Kate Middleton both followed a diet low in fat to lose weight. Former Spice Girl Victoria Beckham, on the other hand, eats a diet rich in fish and healthy fats. Who is right?
In a separate study, researchers in Canada reported in the medical journal The Lancet that people who eat a low fat diet die sooner than those who don’t, suggesting that some fat is crucial for health.
In diet culture, fat has been posed as something harmful. The low-fat diet created by American physician Dean Ornish, M.D., for example, seeks to minimize fat consumption. With the keto diet and low fat diet gaining in popularity, it’s difficult to know what kind of fat to eat, and how much.
Why you need fat
“I love to eat everything and you pretty much can,” said Jennifer Lopez, “A little piece of something fattening is not going to kill you”. That’s a reasonable way of thinking about it, but knowing which fats to eat is key to good health, since not all fats are equal in nutritional and health-promoting value.
Dietary fats help build cells, provide energy, protect organs, absorb vitamins from food, and make hormones. There are saturated and unsaturated fats: Saturated fats are solid at room temperature, while unsaturated fats are liquid.
Essential fats called polyunsaturated fatty acids (PUFAs) protect from diseases like cancer, bone problems, autoimmune disorders, and heart damage. The two main classes of PUFAs, omega-3 and omega-6, are both essential, since your body cannot make them in sufficient amounts. You need to get them from your diet.
The fat EPA relaxes blood vessels
Omega-3 fats are essential for people, as much as water and oxygen are. One of these key fats is EPA, found in fish. Some people respond to EPA while others don’t.
While these benefits have been known for some time, the way EPA affects the body to promote health hasn’t been clear. The study in Nature Metabolism found that EPA works by interacting with the protein S1PR1 in the cells that line blood vessels. This protein causes the gas nitric oxide to be produced, relaxing blood vessels and preventing blockages in arteries that can damage the heart.
Mice lacking S1PR1 don’t benefit from EPA the way other mice do. People lacking S1PR1 might also not benefit, and could explain the variable effect of EPA in people.
The authors of this study suggest that drugs could be designed to activate S1PR1 more effectively than EPA, further benefiting many people.
Understanding how food affects the body may help address diseases related to diet. Since the beginning of the Agricultural Revolution, and over the last 10,000 years, diets have changed substantially, while genes have not. Especially in the last 100 years, rapid changes to what we eat — particularly in Western countries — has increased obesity, diabetes, and heart disease, as well as different types of cancers.
Westerners now consume more omega-6 fatty acids than omega-3 fatty acids, and these two classes of PUFAs have opposing effects on many functions in the body.
The right fat for your diet
Diets high in omega-6 PUFAs are associated with inflammation, constriction of blood vessels, and platelet aggregation, whereas diets high in omega−3 PUFAs, including EPA, reduce inflammation and the risk of cancer and heart disease. A balanced ratio of these PUFAs is important for health.
There are dietary sources that supplement the Western diet to allow for a better ratio of these two types of essential fats. Research published in the journal eLife showed that adults with higher blood levels of omega-3 fatty acids have lower mortality risks compared to those with lower levels of omega-3 in blood.
There are three main omega-3 fatty acids:
- alpha-linolenic acid (ALA)
- eicosapentaenoic acid (EPA)
- docosahexaenoic acid (DHA)
ALA is found in plant oils, such as flaxseed, soy, and canola. DHA and EPA are found in seafood, including fatty fish.
The human body can convert a little ALA into EPA, then EPA to DHA, but in such small amounts that getting EPA and DHA directly from food is crucial to maintain levels of these critical omega-3 fatty acids in your body.
There is no widely agreed-upon recommendation for the minimum amount of EPA humans should consume. It is often suggested that the daily intake of EPA for adults should be at least 220 mg per day. In the diet, this would be 2 or 3 servings of fatty fish each week.
Adults should eat two servings of fish, including cold-water fatty fish, such as salmon, mackerel, tuna, herring, or sardines, per week. The National Institutes of Health suggests a combined daily PUFA intake of 1.1 grams for adult women and 1.6 grams for adult men, which would be even more daily consumption of fish. However, deep sea fish such as swordfish and tuna have high levels of mercury, so intake of those should be limited.
For those on vegetarian and vegan diets, alternative sources of dietary omega-3s are found in flaxseed, walnut, and algal oil.
Nuts and seeds are generally a good source of omega-3s. A handful of walnuts (about 30 grams or 10 walnuts) contains 1.9 g of the omega-3 ALA, which meets the daily recommendation of ALA to prevent heart disease.
Other vegetarian sources of omega-3s (ALA specific) are (keeping in mind the daily recommended intake of ALA in adults ranges from 1100 mg-1600 mg):
- Chia seeds (15g serving = 2,685 mg ALA)
- Walnuts (30g serving = 1,884 mg ALA)
- Canola oil (1 tbs serving = 1,820 mg ALA)
- Soybean oil (1 tbs serving = 1,434 mg ALA)
- Flaxseeds (1 tsp serving = 922 mg ALA)
The bottom is that not all fats are detrimental, and some such as EPA are essential for good health. Finding sources of these good fats are critical for a long and healthy life. Eating EPA-rich foods in particular, such as salmon, on a weekly basis is important for heart health for most people.
As the great Roman poet Virgil said, “The greatest wealth is health.” Eating foods that provide the right fats such as EPA each day is the key to good health and wealth.
Cindy Cao graduated from Barnard College, double majoring in Cellular Biology and English.
Brent R. Stockwell is Chair of the Department of Biological Sciences at Columbia University.
