As a dietitian, I’m often asked questions about the latest trends on social media. One of the most prominent ones lately is that seed oils are “toxic” and should be avoided at all costs. But is this good advice, or not?
Seed Oils 101
Seed oils are produced from whole seeds, including sunflower seeds, sesame seeds, flaxseeds, and chia seeds. Other seed oils include canola, corn, grapeseed, rice bran, and soybean oil.
For the most part, seed oils are inexpensive, accessible, and versatile to use in most dishes. They also have a high smoke point, making them useful for baking or frying.
Unfortunately, the majority of ultra-processed foods, including biscuits, cakes, chips, cookies, granola bars, muffins, deep-fried food, margarine, salad dressings, and sauces, contain many of the seed oils listed above.
These foods should be enjoyed on occasion, but consumption is not recommended as part of a healthy diet. Many ultra-processed foods also contain higher amounts of other unwanted ingredients such as sugar, sodium, and artificial colors or flavors.
Seed Oils and Inflammation
Inflammation is a broad term to describe pain, swelling, or tissue damage in the body. Chronic inflammation is linked with arthritis, heart disease, dementia, and cancer. Inflammation in the gut is associated with IBS, ulcerative colitis, and colon cancer. Some people claim that seed oils are inflammatory. However, the research begs to differ.
Omega fatty acids have been at the center of the controversy. These essential fatty acids include both omega 6 and omega 3 fats because our bodies can’t make them. Omega-6 fatty acids are found in foods such as seeds, nuts, and vegetable oils. We need a balance of these fats to maintain good health, but the American diet often lacks omega-3 fats.
Flaxseed oil is a source of omega-3 fatty acids, which have been shown to reduce the risk of heart disease. 1 This type of fat is also found in walnuts, salmon, and canola oil. Despite what influencers say about canola oil, it is safe and healthy to cook with!
Studies on omega-6 fats and the risk for disease have thus far not indicated a problem. A meta-analysis of randomized controlled studies from 2022 failed to find a connection between consumption of omega-6 fatty acids and a higher risk of cardiovascular disease. More studies are needed. 2
A recent animal study found that sesame oil combined with MSM (Methylsulfonylmethane), which is often used for joint pain, improved dyslipidemia in mice with type 1 and type diabetes. This is an example of the potential benefit of seed oils. 3
Seed Oils and Colorectal Cancer
Results of a large study by the Barcelona Institute for Global Health (ISGlobal) using questionnaires about food behaviors of nearly 8,000 individuals in Spain found that intake of ultra-processed foods and drinks may raise the risk of colorectal cancer. While no link was seen with prostate cancer, a higher risk was observed for breast cancer in a subgroup of former and current smokers who reported consuming more ultra-processed foods.4
The link between ultra-processed food and colorectal cancer has been established in other studies. Research from the University of South Florida and Tampa General Hospital Cancer Institute have discovered a potential link between the Western diet (high in ultra-processed food and oils) and chronic inflammation, which may increase the risk of colorectal cancer. Colorectal cancer is the second leading cause of cancer death in the US. 5
Through a five-year, $3.1 million grant from the NIH, researchers have made big strides in understanding colorectal cancer. An initial study evaluated how processed foods may slow the body’s natural healing process.
A Western diet is often high in added sugars, saturated fat, ultra-processed foods, and artificial chemicals. Past studies by the USF Health Heart Institute have linked an imbalanced diet with Alzheimer’s disease, diabetes, and cardiovascular conditions in addition to colorectal cancer.
Ganesh Halade, associate professor at the USF Health Heart Institute and a member of the Cancer Biology Program at TGH Cancer Institute states, "Our bodies are designed to actively resolve inflammation through bioactive lipid compounds derived from the healthy fats, like avocados, that we consume. “
He continues on to say, “Bioactive lipids are very small molecules derived from the foods that we eat and, if the molecules are coming from processed food products, they directly imbalance the immune system and drive chronic inflammation."
While ultra-processed foods often contain seed oils, the oils themselves are not to blame here.
How to Tame Inflammation
No one will argue that reducing ultra-processed foods will help decrease inflammation and the chronic conditions that go with it. But if you’re like me, you also want to know what to eat.
Research suggests that foods high in antioxidants, fiber, and healthy fats help to reduce inflammation and the risk of chronic disease. 4 Most of these foods are part of a Mediterranean diet, which has been found to cut the risk of obesity, diabetes, cancer, and heart disease. 5
A Mediterranean diet is also beneficial for mental health. One study in over 150 adults with depression found that individuals attending a 3-month Med-diet cooking class along with the use of fish oil supplements had better fruit, vegetable, legume, nuts, whole grain intake, and reduced intake of red meat and unhealthy snacks. Depressive symptoms were kept at bay for 6 months after the intervention. 6
The most beneficial foods include:
· Fresh or frozen fruits and vegetables (without added sugars or sauces). Focus on cabbage-family vegetables such as broccoli, Brussels sprouts, cabbage, cauliflower, and kale. 7
· Healthy fat from avocados, walnuts, olives, peanuts, pistachios, pumpkin, and sunflower seeds
· Beans and lentils
· Whole grains such as barley, brown rice, bulgur, farro, rolled oats, whole wheat or bran cereal, whole grain pasta, and quinoa
· Low-fat dairy products 8
· Lean, unprocessed meats such as skinless poultry, lean beef, and pork.
· Fatty fish such as halibut, mackerel and salmon
· Fermented foods and beverages like kefir, kimchi, kombucha, sauerkraut, and yogurt
· Frozen meals and snack foods such as pizza rolls
· Ultra-processed snacks such as chips, cookies, crackers, and pastries
· Alcoholic beverages
· Full-fat dairy products like ice cream, cheese, and sour cream
· Candy and other high-sugar treats
Lisa Andrews, MEd, RD, LD
References:
1. Tian M, Bai Y, Tian H, Zhao X. The Chemical Composition and Health-Promoting Benefits of Vegetable Oils-A Review. Molecules. 2023 Sep 1;28(17):6393. doi: 10.3390/molecules28176393. PMID: 37687222; PMCID: PMC10489903.
2. Mazidi M, Shekoohi N, Katsiki N, Banach M. Omega-6 fatty acids and the risk of cardiovascular disease: insights from a systematic review and meta-analysis of randomized controlled trials and a Mendelian randomization study. Arch Med Sci. 2021 Apr 24;18(2):466-479. doi: 10.5114/aoms/136070. PMID: 35316920; PMCID: PMC8924827
3. Fili CV, Lin L, Chapman J, Hamilton D, Yates CR. Methylsulfonylmethane and Sesame Seed Oil Improve Dyslipidemia and Modulate Polyunsaturated Fatty Acid Metabolism in Two Mouse Models of Diabetes. J Med Food. 2022 Jun;25(6):607-617. doi: 10.1089/jmf.2021.0196. PMID: 35708633; PMCID: PMC9247677.
4. Dora Romaguera, Sílvia Fernández-Barrés, Esther Gracia-Lavedán, Eva Vendrell, Mikel Azpiri, Emma Ruiz-Moreno, Vicente Martín, Inés Gómez-Acebo, Mireia Obón, Amaia Molinuevo, Ujué Fresán, Ana Molina-Barceló, Rocío Olmedo-Requena, Adonina Tardón, Juan Alguacil, Marta Solans, Jose M. Huerta, José Manuel Ruiz-Dominguez, Nuria Aragonés, Tania Fernández-Villa, Trinidad Dierssen-Sotos, Victor Moreno, Marcela Guevara, Mercedes Vanaclocha-Espi, Macarena Lozano-Lorca, Guillermo Fernández-Tardón, Gemma Castaño-Vinyals, Beatriz Pérez-Gómez, Antonio J. Molina, Javier Llorca, Leire Gil, Jesús Castilla, Marina Pollán, Manolis Kogevinas, Pilar Amiano. Consumption of ultra-processed foods and drinks and colorectal, breast, and prostate cáncer. Clinical Nutrition, March 2021.
5. Nani A, Murtaza B, Sayed Khan A, Khan NA, Hichami A. Antioxidant and Anti-Inflammatory Potential of Polyphenols Contained in Mediterranean Diet in Obesity: Molecular Mechanisms. Molecules. 2021 Feb 12;26(4):985. doi: 10.3390/molecules26040985. PMID: 33673390; PMCID: PMC7918790.
6. Parletta N, Zarnowiecki D, Cho J, Wilson A, Bogomolova S, Villani A, Itsiopoulos C, Niyonsenga T, Blunden S, Meyer B, Segal L, Baune BT, O'Dea K. A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED). Nutr Neurosci. 2019 Jul;22(7):474-487. doi: 10.1080/1028415X.2017.1411320. Epub 2017 Dec 7. PMID: 29215971
7. Amarakoon D, Lee WJ, Tamia G, Lee SH. Indole-3-Carbinol: Occurrence, Health-Beneficial Properties, and Cellular/Molecular Mechanisms. Annu Rev Food Sci Technol. 2023 Mar 27;14:347-366. doi: 10.1146/annurev-food-060721-025531. PMID: 36972159.
8. Nieman KM, Anderson BD, Cifelli CJ. The Effects of Dairy Product and Dairy Protein Intake on Inflammation: A Systematic Review of the Literature. J Am Coll Nutr. 2021 Aug;40(6):571-582. doi: 10.1080/07315724.2020.1800532. Epub 2020 Sep 1. PMID: 32870744.
Lisa Andrews, MEd, RD, LD, is a registered dietitian and owner of Sound Bites Nutrition in Cincinnati. She shares her clinical, culinary, and community nutrition knowledge through cooking demos, teaching, and freelance writing. Lisa is a regular contributor to Food and Health Communications and Today’s Dietitian and is the author of the Healing Gout Cookbook, Complete Thyroid Cookbook, and Heart Healthy Meal Prep Cookbook. Her line of food pun merchandise, Lettuce beet hunger, supports those suffering food insecurity in Cincinnati. For more information,
The Scoop on Seed Oils and Health
As a dietitian, I’m often asked questions about the latest trends on social media. One of the most prominent ones lately is that seed oils are “toxic” and should be avoided at all costs. But is this good advice, or not?
Seed Oils 101
Seed oils are produced from whole seeds, including sunflower seeds, sesame seeds, flaxseeds, and chia seeds. Other seed oils include canola, corn, grapeseed, rice bran, and soybean oil.
For the most part, seed oils are inexpensive, accessible, and versatile to use in most dishes. They also have a high smoke point, making them useful for baking or frying.
Unfortunately, the majority of ultra-processed foods, including biscuits, cakes, chips, cookies, granola bars, muffins, deep-fried food, margarine, salad dressings, and sauces, contain many of the seed oils listed above.
These foods should be enjoyed on occasion, but consumption is not recommended as part of a healthy diet. Many ultra-processed foods also contain higher amounts of other unwanted ingredients such as sugar, sodium, and artificial colors or flavors.
Seed Oils and Inflammation
Inflammation is a broad term to describe pain, swelling, or tissue damage in the body. Chronic inflammation is linked with arthritis, heart disease, dementia, and cancer. Inflammation in the gut is associated with IBS, ulcerative colitis, and colon cancer. Some people claim that seed oils are inflammatory. However, the research begs to differ.
Omega fatty acids have been at the center of the controversy. These essential fatty acids include both omega 6 and omega 3 fats because our bodies can’t make them. Omega-6 fatty acids are found in foods such as seeds, nuts, and vegetable oils. We need a balance of these fats to maintain good health, but the American diet often lacks omega-3 fats.
Flaxseed oil is a source of omega-3 fatty acids, which have been shown to reduce the risk of heart disease. 1 This type of fat is also found in walnuts, salmon, and canola oil. Despite what influencers say about canola oil, it is safe and healthy to cook with!
Studies on omega-6 fats and the risk for disease have thus far not indicated a problem. A meta-analysis of randomized controlled studies from 2022 failed to find a connection between consumption of omega-6 fatty acids and a higher risk of cardiovascular disease. More studies are needed. 2
A recent animal study found that sesame oil combined with MSM (Methylsulfonylmethane), which is often used for joint pain, improved dyslipidemia in mice with type 1 and type diabetes. This is an example of the potential benefit of seed oils. 3
Seed Oils and Colorectal Cancer
Results of a large study by the Barcelona Institute for Global Health (ISGlobal) using questionnaires about food behaviors of nearly 8,000 individuals in Spain found that intake of ultra-processed foods and drinks may raise the risk of colorectal cancer. While no link was seen with prostate cancer, a higher risk was observed for breast cancer in a subgroup of former and current smokers who reported consuming more ultra-processed foods.4
The link between ultra-processed food and colorectal cancer has been established in other studies. Research from the University of South Florida and Tampa General Hospital Cancer Institute have discovered a potential link between the Western diet (high in ultra-processed food and oils) and chronic inflammation, which may increase the risk of colorectal cancer. Colorectal cancer is the second leading cause of cancer death in the US. 5
Through a five-year, $3.1 million grant from the NIH, researchers have made big strides in understanding colorectal cancer. An initial study evaluated how processed foods may slow the body’s natural healing process.
A Western diet is often high in added sugars, saturated fat, ultra-processed foods, and artificial chemicals. Past studies by the USF Health Heart Institute have linked an imbalanced diet with Alzheimer’s disease, diabetes, and cardiovascular conditions in addition to colorectal cancer.
Ganesh Halade, associate professor at the USF Health Heart Institute and a member of the Cancer Biology Program at TGH Cancer Institute states, "Our bodies are designed to actively resolve inflammation through bioactive lipid compounds derived from the healthy fats, like avocados, that we consume. “
He continues on to say, “Bioactive lipids are very small molecules derived from the foods that we eat and, if the molecules are coming from processed food products, they directly imbalance the immune system and drive chronic inflammation."
While ultra-processed foods often contain seed oils, the oils themselves are not to blame here.
How to Tame Inflammation
No one will argue that reducing ultra-processed foods will help decrease inflammation and the chronic conditions that go with it. But if you’re like me, you also want to know what to eat.
Research suggests that foods high in antioxidants, fiber, and healthy fats help to reduce inflammation and the risk of chronic disease. 4 Most of these foods are part of a Mediterranean diet, which has been found to cut the risk of obesity, diabetes, cancer, and heart disease. 5
A Mediterranean diet is also beneficial for mental health. One study in over 150 adults with depression found that individuals attending a 3-month Med-diet cooking class along with the use of fish oil supplements had better fruit, vegetable, legume, nuts, whole grain intake, and reduced intake of red meat and unhealthy snacks. Depressive symptoms were kept at bay for 6 months after the intervention. 6
The most beneficial foods include:
· Fresh or frozen fruits and vegetables (without added sugars or sauces). Focus on cabbage-family vegetables such as broccoli, Brussels sprouts, cabbage, cauliflower, and kale. 7
· Healthy fat from avocados, walnuts, olives, peanuts, pistachios, pumpkin, and sunflower seeds
· Beans and lentils
· Whole grains such as barley, brown rice, bulgur, farro, rolled oats, whole wheat or bran cereal, whole grain pasta, and quinoa
· Low-fat dairy products 8
· Lean, unprocessed meats such as skinless poultry, lean beef, and pork.
· Fatty fish such as halibut, mackerel and salmon
· Fermented foods and beverages like kefir, kimchi, kombucha, sauerkraut, and yogurt
Foods and beverages to consume less of:
· Sugar-sweetened beverages (soft drinks, sports drinks, sweetened tea)
· Fast food
· Frozen meals and snack foods such as pizza rolls
· Ultra-processed snacks such as chips, cookies, crackers, and pastries
· Alcoholic beverages
· Full-fat dairy products like ice cream, cheese, and sour cream
· Candy and other high-sugar treats
Lisa Andrews, MEd, RD, LD
References:
1. Tian M, Bai Y, Tian H, Zhao X. The Chemical Composition and Health-Promoting Benefits of Vegetable Oils-A Review. Molecules. 2023 Sep 1;28(17):6393. doi: 10.3390/molecules28176393. PMID: 37687222; PMCID: PMC10489903.
2. Mazidi M, Shekoohi N, Katsiki N, Banach M. Omega-6 fatty acids and the risk of cardiovascular disease: insights from a systematic review and meta-analysis of randomized controlled trials and a Mendelian randomization study. Arch Med Sci. 2021 Apr 24;18(2):466-479. doi: 10.5114/aoms/136070. PMID: 35316920; PMCID: PMC8924827
3. Fili CV, Lin L, Chapman J, Hamilton D, Yates CR. Methylsulfonylmethane and Sesame Seed Oil Improve Dyslipidemia and Modulate Polyunsaturated Fatty Acid Metabolism in Two Mouse Models of Diabetes. J Med Food. 2022 Jun;25(6):607-617. doi: 10.1089/jmf.2021.0196. PMID: 35708633; PMCID: PMC9247677.
4. Dora Romaguera, Sílvia Fernández-Barrés, Esther Gracia-Lavedán, Eva Vendrell, Mikel Azpiri, Emma Ruiz-Moreno, Vicente Martín, Inés Gómez-Acebo, Mireia Obón, Amaia Molinuevo, Ujué Fresán, Ana Molina-Barceló, Rocío Olmedo-Requena, Adonina Tardón, Juan Alguacil, Marta Solans, Jose M. Huerta, José Manuel Ruiz-Dominguez, Nuria Aragonés, Tania Fernández-Villa, Trinidad Dierssen-Sotos, Victor Moreno, Marcela Guevara, Mercedes Vanaclocha-Espi, Macarena Lozano-Lorca, Guillermo Fernández-Tardón, Gemma Castaño-Vinyals, Beatriz Pérez-Gómez, Antonio J. Molina, Javier Llorca, Leire Gil, Jesús Castilla, Marina Pollán, Manolis Kogevinas, Pilar Amiano. Consumption of ultra-processed foods and drinks and colorectal, breast, and prostate cáncer. Clinical Nutrition, March 2021.
5. Nani A, Murtaza B, Sayed Khan A, Khan NA, Hichami A. Antioxidant and Anti-Inflammatory Potential of Polyphenols Contained in Mediterranean Diet in Obesity: Molecular Mechanisms. Molecules. 2021 Feb 12;26(4):985. doi: 10.3390/molecules26040985. PMID: 33673390; PMCID: PMC7918790.
6. Parletta N, Zarnowiecki D, Cho J, Wilson A, Bogomolova S, Villani A, Itsiopoulos C, Niyonsenga T, Blunden S, Meyer B, Segal L, Baune BT, O'Dea K. A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED). Nutr Neurosci. 2019 Jul;22(7):474-487. doi: 10.1080/1028415X.2017.1411320. Epub 2017 Dec 7. PMID: 29215971
7. Amarakoon D, Lee WJ, Tamia G, Lee SH. Indole-3-Carbinol: Occurrence, Health-Beneficial Properties, and Cellular/Molecular Mechanisms. Annu Rev Food Sci Technol. 2023 Mar 27;14:347-366. doi: 10.1146/annurev-food-060721-025531. PMID: 36972159.
8. Nieman KM, Anderson BD, Cifelli CJ. The Effects of Dairy Product and Dairy Protein Intake on Inflammation: A Systematic Review of the Literature. J Am Coll Nutr. 2021 Aug;40(6):571-582. doi: 10.1080/07315724.2020.1800532. Epub 2020 Sep 1. PMID: 32870744.
Lisa Andrews, MEd, RD, LD, is a registered dietitian and owner of Sound Bites Nutrition in Cincinnati. She shares her clinical, culinary, and community nutrition knowledge through cooking demos, teaching, and freelance writing. Lisa is a regular contributor to Food and Health Communications and Today’s Dietitian and is the author of the Healing Gout Cookbook, Complete Thyroid Cookbook, and Heart Healthy Meal Prep Cookbook. Her line of food pun merchandise, Lettuce beet hunger, supports those suffering food insecurity in Cincinnati. For more information,
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