Benefits of plant-based fats
Featured author: Dr. Matthew Nagra
Hi everyone, I am Dr. Matthew Nagra, a Naturopathic doctor based in Vancouver, BC. I spend my time researching and sharing the latest in evidence-based nutrition across social media platforms to help everyone better understand the ins and outs of this confusing world we call nutrition. In addition to my online work, I’m a public speaker and have worked with medical professionals to help integrate nutrition counselling into their practices.
Today, for the Vancouver Humane Society’s PlantUniversity Platform, I’m going to talk about fats, particularly which plant-based fat sources are beneficial for overall health and whether or not we should be limiting our overall consumption of added fats in the form of nuts, seeds, avocados, and oils.
Within the plant-based nutrition community, there is a common misbelief that we should avoid all added fats, including nuts and oils, and promote a very low-fat diet for cardiovascular disease prevention and treatment, as well as other chronic diseases. In fact, I myself used to be very much in the camp that believes that all oils are detrimental to health, including olive oil! However, the best available research on the topic may suggest otherwise.
Of course, plant-based diets are consistently associated with good health outcomes, including a lower risk of heart disease, the world’s number 1 killer. In fact, the 2020 Dietary Guidelines Advisory Committee conducted the most comprehensive review of dietary patterns ever done, which included 153 studies and over 6.5 million participants across 28 countries, and they determined that the healthiest dietary patterns were all dominated by plants with a focus on whole foods. Click the link below to read more about this review. No doubt, there are many benefits to choosing more plant-based foods, including an increase in fibre intake, but I want to hone in on the fats in particular.
There are 4 main groups of fats that we need to discuss: trans fats, saturated fats, monounsaturated fats, and polyunsaturated fats.
1. Trans Fats
There is very little controversy around the detrimental impact of trans fats on our health, including increasing risk of cardiovascular diseases. In fact, Health Canada has banned the inclusion of partially hydrogenated oils, which are the primary sources of trans fats, in food products due to how dangerous they can be.
2. Saturated Fats
Saturated fat, which is predominantly found in meat, dairy, coconut oil, and palm oil, can also raise risk of cardiovascular disease if not limited in the diet. That’s because saturated fat can increase our LDL (or “bad”) cholesterol, which can end up in our artery walls, lead to the development of a plaque, and can eventually cause a heart attack. In fact, as saturated fat intake is reduced, we also see a reduction in risk of heart attacks or other cardiac events. Of course, there is some nuance within this topic and differences amongst different types of saturated fats, but as a general rule, they increase risk of cardiovascular disease.
I also want to quickly mention that dietary cholesterol, which eggs contain a lot of, can also raise LDL-cholesterol levels and contribute to cardiovascular disease risk, but to a lesser degree than saturated fat.
3. Monounsaturated Fats
Next up are the unsaturated fats. There are 2 main types, monounsaturated fats and polyunsaturated fats. Monounsaturated fats can be found in both animal foods, such as meat and dairy, and plant foods, such as olive oil, avocados, and almonds; however, where you get your monounsaturated fats from matters. One study with over half a million participants and 16 years of follow-up found that, compared to carbohydrates, increasing animal-based monounsaturated fat intake increased risk of dying during the study period by 5%, while plant-based monounsaturated fat sources lowered risk by 2%! You can find this study in the blog post below.
4. Polyunsaturated Fats
Polyunsaturated fats, which includes omega-3 and omega-6 fats, are largely found in nuts, seeds, their oils, and fish, and may be the most beneficial of all the different categories of fats I’ve discussed so far. They have the most potent LDL-cholesterol lowering properties, and unsurprisingly can result in substantial reductions in cardiovascular disease risk, especially when replacing saturated fat. In fact, a 2016 study comparing different types of fats found that replacing just 5% of calories from saturated fat with polyunsaturated fats can reduce risk of total mortality by an astonishing 27%!
With that overview out of the way, it’s time to talk about the impact that higher fat plant foods can have on our health! After all, we don’t typically eat nutrients in isolation. Food is a package deal.
Starting with avocados, they’re rich in monounsaturated fat and have been shown to markedly improve cardiovascular risk factors. Plus, they can be a delicious source of fibre, B vitamins, and potassium.
Studies comparing various food groups find that nuts may be the best overall food group for lowering LDL-cholesterol, and studies on different types of nuts have shown that almonds may be of particular benefit in this case. With nuts and seeds, you can’t really go wrong with whichever ones you choose to eat, but in addition to almonds, I would also highlight omega-3 rich nuts and seeds. The type of omega-3 fat found in plants is called alpha-linolenic acid, or ALA for short, and it is recommended that adult women consume at least 1.1g per day and men consume at least 1.6g per day, which is more than covered with a tablespoon of ground flaxseeds or chia seeds, or an ounce of walnuts. In fact, each gram of ALA consumed per day has been associated with a 5% lower risk of death from cardiovascular disease and from all causes combined. One of the most astonishing and very well conducted studies I’ve seen recently found that those consuming at least 5 servings of walnuts per week had a 14% lower risk of dying from all causes compared to those who didn’t or rarely consumed them! Since that study came out, I’ve been making an effort to eat some walnuts everyday.
Regarding omega-3s, there are other types called eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) that are predominantly found in fish, although we do convert some of the ALA from plants into those forms. Some individuals believe the conversion isn’t adequate and that non-fish eaters ought to supplement, and there is some evidence suggesting benefit in certain cases, such as during pregnancy; however, there is a lack of convincing evidence for otherwise healthy adults. Regardless, supplementing can be considered a precautionary measure, and vegan options do exist in the form of algae-based supplements, so please discuss your options and individual needs with your healthcare provider.
Oils themselves are a hot button topic with a lot of the concerns stemming from the fact that many vegetable oils contain a fair amount of omega-6 fats. One of the beliefs is that the main omega-6 fat in plant-based oils can be converted into an inflammatory fat and wreak havoc on the body. Well, it’s a nice theory, but when we look at studies that feed omega-6-rich oils to people and measure markers of inflammation, there is no increase in inflammation. Not only are they not harmful, but their intake is associated with a lower risk of total, cardiovascular, and cancer deaths.
To add to the discussion on oil, a 2021 study on different types of cooking oils, which included over half a million people found that each Tbsp of canola oil consumption was associated with a 2% lower risk of total mortality and olive oil was associated with a 3% lower risk. When replacing 1 Tbsp of butter or margarine, canola and olive oil lowered risk of total mortality by anywhere from 5 to 7%, and a similar trend was seen for deaths due to cardiovascular disease. As you may have noted, I mentioned that the study was on cooking oils, and you may have been told that cooking with oils like olive oil, which has a relatively low burning point, is not a healthy choice because cooking can produce “dangerous” compounds. Well, the research consistently shows an overall benefit, even when cooking with these oils, with the only concerns I would possibly raise being over continuously reheating the same oil at high temperatures, as is done in many fast food restaurants.
Speaking of olive oil, some of those in the plant-based community also advise against consuming it. These concerns stem primarily from 2 studies (study a, study b) that fed roughly ¼ cup of olive oil to participants and measured their artery function. In these particular studies, olive oil did lead to a temporary decrease in their arteries’ ability to dilate, but one of those very studies also suggested that certain foods like fruits, vegetables, and vinegar can mitigate the impact of the oil on our arteries, so adding olive oil to a salad would be no issue at all! Furthermore, if we review the bulk of the studies on the topic instead of just picking 1 or 2 studies, we actually see an overall beneficial effect of olive oil on artery function! Not to mention the research I discussed earlier that found that olive oil consumption is associated with a lower risk of dying from cardiovascular disease, which is what really matters.
Since I didn’t know this when I started out on my plant-based journey, I used to avoid oils at all costs, and not only did that deprive me of a key ingredient for many great recipes, but significantly limited my options at restaurants as well. Of course, now knowing that these low saturated fat oils are associated with a lower risk of disease, there was clearly little reason to worry, and even some reason to include them. However, due to their ability to raise LDL-cholesterol, it may be best to limit high saturated fat oils like coconut and palm oil (study a, study b).
In addition to research on individual foods, we also have data on an overall low carb, higher fat vegan diet called the Eco-Atkins diet. One randomized controlled trial found that 6 months on an Eco-Atkins diet, where the primary sources of fats were nuts, oils, and soy, resulted in lower LDL-cholesterol compared to a high carb, lower fat vegetarian diet. These findings are quite contrary to the dangerous rises in LDL-C we can see with animal-based low carb or keto-style diets. Given that information, it’s no surprise that the data we do have on various types of low carb diets suggest a higher risk of cardiovascular disease if consuming a lot of animal fats, whereas we see a lower risk with the more plant-based approach.
At the end of the day, some people may feel better on a lower fat diet, while others may prefer a higher fat diet. Both can be healthy ways to eat if you’re focusing your diet on plant-based foods, and choosing low saturated fat options. There’s no good reason to be like I once was, worried about those added fats, so I hope this has helped you understand a little more about how some high fat plant foods may actually be very beneficial.
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