The Great Fat Debate: Is Plant-Based Fat the Key to a Longer Life?

September 15, 2024

by Cathe Friedrich

Dietary fat – we need it in our diet for many reasons. It’s an energy source, for one. Even though you might not like the way it jiggles when you have too much of it, that insulative layer of fat helps protect your organs. Plus, it helps keep you warm, and consuming fat with a meal helps you absorb fat-soluble vitamins, like vitamins A, D, E, and K.

Yet there’s controversy about what type is best. A new study published in the Journal of American Medical Association (JAMA) Internal Medicine sheds new light on this issue. Is it best to add saturated fat to your diet or is it better to consume mostly unsaturated fats (monounsaturated and polyunsaturated)?

What the Study Shows: Animal Fats vs. Plant Fats

For the study, researchers followed the dietary habits of over 407,531 people for up to 24 years. (from 1995 to 2019) The subjects were all adults with an average age of sixty-one. Scientists wanted to see what impact their dietary choices, particularly fat sources, had on their health and mortality. They looked at fats from animal foods, which contain mostly saturated fat, and plant-based foods, consisting of mostly monounsaturated and polyunsaturated fats.

Saturated Fats: How Animal Sources Stack Up

Animal sources of fat include seafood, eggs, dairy foods, poultry, and red meat. All these foods, except for seafood, contain mostly saturated fat. Some seafood, particularly fatty fish from the ocean contain long-chain omega-3 fatty acids, a type of polyunsaturated fat. Plant sources of fat that they looked at include grains, legumes, nuts, seeds, and plant oils.

Plant-Based Fats: Are They the Healthier Choice?

What did they find? Study subjects who got their fat mostly from plant sources had a lower mortality than those who made animal fats a big part of their diet. They also were less likely to die of cardiovascular disease. But before filling your shopping cart with plant-based fat sources, the study has potential drawbacks that could have affected the results.

For one, the researchers questioned the participants about their diet only at the beginning of the study. They didn’t go back and ask whether the subjects changed how they ate over the two-decade study. As you know, people are changing their diets like they are changing their clothes these days.

There were certain differences between the two groups too. In the study, the participants who added more plant-based sources of fat to their plates were more likely to be overweight or obese, have diabetes, and consume alcohol. On the plus side, they also ate more fiber-rich foods, fruits, and vegetables. Plus, they were more physically active than the subjects who got their fat mainly from animal sources.

The Study Doesn’t Show Causation

Since this study isn’t a randomized controlled trial, you can’t say with certainty that the lower mortality came from eating more plant fats and less animal fat. Being an observational study, it can’t show cause and effect. Other lifestyle factors could explain the difference. Also, the researchers didn’t distinguish between the types of fat in each food. For example, coconut oil, which comes from a plant, contains saturated fat, a type of fat abundant in animal-based foods. The researchers tried to control these confounders.

Cardiovascular Health and Fat Intake: What Experts Recommend

What about cardiovascular health? The American Heart Association recommends reducing the amount of dietary saturated fat in your diet to less than 6% of total calories. This is based on the idea that saturated fat can raise blood lipids and increase the risk of cardiovascular disease. They recommend reducing the amount of meat on your plate and swapping it for plant-based sources of protein and fish, rich in omega-3 fatty acids, like wild-caught salmon. Other plant-based foods the American Heart Association recommends for heart health are whole grains, fruits, vegetables, seeds, avocados, and legumes.

The 5% Switch: The Impact of Replacing Animal Fats with Plant Fats

In the study, researchers found that switching 5% of calories from animal-based fats to plant fats was associated with a drop in mortality from cardiovascular disease of 5 to 30%. That’s significant! The benefits could be even more powerful if you have a history of cardiovascular disease, or if it runs in your family.

Practical Tips for Adding More Plant-Based Fats to Your Diet

There’s no need to give up all animal-based fat unless you want to go vegan, but based on these studies, it’s smart to diversify your fat sources. Need some tips for doing this?

Choose Healthy Oils

You might think so-called vegetable oils in plastic bottles at the grocery store are a good source. But these are processed seed oils. The golden liquid in the bottle is highly processed and exposed to hot temperatures during manufacturing. High heat alters fats in a way that could be harmful to health. A better choice is to choose a high-quality extra-virgin olive oil for lower-temperature cooking. Avocado oil is a smart option for higher-temperature cooking.

Snack on Nuts and Seeds

Nuts and seeds contain protein, fiber, and healthy plant-based fats, like monounsaturated and polyunsaturated fats. Plus, they’re not in a processed form, like seed oils. Skip the chips and grab a handful of walnuts or almonds as a snack. Add chia and hemp seeds to your morning porridge. Hemp seeds are rich in plant-based omega-3s. Chia seeds also contain omega-3s and are one of the best sources of fiber.

Add Avocados to Your Diet

Avocados are an excellent source of plant fats, primarily monounsaturated fats. According to the American Heart Association, monounsaturated fats lower LDL-cholesterol, the type linked with cardiovascular disease. They’re also rich in fiber and protein and contain more protein than almost any other fruit. Add avocados to smoothies in place of animal-based dairy or add slices of avocado to salads or wraps.

Incorporate Fatty Fish:

If you’re not going strictly plant-based add omega-3 rich fish to your diet in moderation. Use it as a replacement for red meat or poultry for some meals. While it’s not a true plant-based fat, the fats in fatty fish, like omega-3s, have anti-inflammatory benefits.

Conclusion

Although this study has limitations, being observational, there are a few downsides to adding more plant-based foods to your diet. A balanced and varied diet of minimally processed foods is the best way to meet your body’s nutritional needs and enjoy what you put on your plate. Time to try some new recipes?

References:

Eckert N. Eating the Right Fats May Help Patients Live Longer. Medscape. Published September 11, 2024. Accessed September 12, 2024. https://www.medscape.com/viewarticle/eating-right-fats-may-help-patients-live-longer-2024a1000ggd
‌ Zhao B, Gan L, Graubard BI, et al. Plant and Animal Fat Intake and Overall and Cardiovascular Disease Mortality. JAMA Intern Med. Published online August 12, 2024. doi:10.1001/jamainternmed.2024.3799.
“Saturated Fat | American Heart Association.” 23 Aug. 2024, https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/saturated-fats.
“Dietary Fats and Cardiovascular Disease: A Presidential Advisory from the American Heart Association | Circulation.” 2017. Circulation. https://doi.org/10.1161/CIR.0000000000000510.
“Monounsaturated Fats | American Heart Association.” 25 Oct. 2023, https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/monounsaturated-fats.
“Omega-3 Fatty Acids and Heart Health | Circulation | AHA/ASA Journals.” 01 Dec. 2015, https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.114.015176.
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