Perilla oil is one of the richest sources of plant-based omega-3 fatty acids, in the form of alpha-linolenic acid. Omega-3 fatty acids are considered essential because they can’t be made in the body and must be consumed in the diet. What benefits could perilla oil have? Read on to find out.
What is Perilla Oil?
Perilla oil is obtained from the seeds of a species of plant in the mint family called Perilla frutescens. The perilla plant is native to Southeast Asia and India and has been used medicinally in China for thousands of years [1].
Perilla oil is popular because it is a plant source of essential omega-3 polyunsaturated fatty acids. Fatty acids are considered essential if they cannot be produced by the body and must be obtained via diet. The main omega-3 fatty acid in perilla oil is alpha-linolenic acid, which comprises 54 – 69% of the oil [1, 2].
The alpha-linolenic acid in perilla oil can be converted into longer chain omega-3 fatty acids such as EPA and DHA, the omega-3 fatty acids found in fish oil [3].
Components
Like many plants, perilla contains a wide variety of beneficial phytochemicals and compounds. The main compounds are [1]:
- Essential oils
- Fatty acids
- Flavonoids and triterpenes
- Phenolic compounds/polyphenols
- Policosanols
Essential Oils
Perilla seeds contain many essential oils, such as p-Cymene, beta-caryophyllene, and alpha-farnesene. The leaves and stems contain essential oils, as well, like limonene and eucalyptol, among others [1].
Fatty Acids
Perilla oil is mostly composed of fatty acids [1, 4]:
- Alpha-linolenic acid (omega-3 essential polyunsaturated fatty acid)
- Lauric acid (saturated fatty acid)
- Linoleic acid (omega-6 polyunsaturated essential fatty acid)
- Oleic acid (omega-9 monounsaturated fatty acid)
- Palmitic acid (saturated fatty acid)
- Stearic acid (saturated fatty acid)
Perilla oil is a good source of omega-3 polyunsaturated fatty acids since 54-64% of it is alpha-linolenic acid. alpha-linolenic acid is a plant-derived omega-3 fatty acid, similar to those found in fish oil, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) [1, 5].
Polyphenols
Extracts of the plant contain compounds like anthocyanins, triterpenes, and flavonoids [1, 6].
Health Benefits of Perilla Oil
Perilla oil supplements have not been approved by the FDA for medical use and generally lack solid clinical research. Regulations set manufacturing standards for them but don’t guarantee that they’re safe or effective. Speak with your doctor before supplementing.
Insufficient Evidence For
The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of perilla oil for any of the below-listed uses. Remember to speak with a doctor before using perilla oil, and never use it to replace anything your doctor recommends or prescribes.
1) Cholesterol
In a study with 86 people with high cholesterol, those supplemented with perilla oil had lower levels of total cholesterol, LDL, oxidized LDL, apolipoprotein B activity, and lipoprotein-associated phospholipase A2 (a marker for heart disease) activity [7].
In a study of 36 people with high cholesterol, perilla oil lowered total cholesterol levels. This effect was greater when combined with increased exercise [8].
In rabbits, perilla oil generated a similar reduction in total cholesterol, LDL, and triglyceride levels as Lovastatin treatment (a cholesterol medication), and both treatments reduced the accumulation of fat in the liver and kidneys [9].
In animal studies, perilla oil lowered total cholesterol and triglyceride levels. However, HDL cholesterol also decreased and LDL, free fatty acids, and body weight didn’t change [10, 2].
2) Heart Disease
A clinical trial with 605 people who had a heart attack compared the alpha-linolenic acid-rich Mediterranean diet with a typical diet recommended to heart attack patients. People on the Mediterranean diet had fewer second heart attacks and heart disease-related deaths [11].
Similarly, a study of over 43,000 men found that alpha-linolenic acid was correlated with a lower risk of developing heart disease [12].
However, a meta-analysis of 89 studies found no relationship between omega-3 fatty acid consumption and heart disease. The source of the omega-3 fatty acids did not matter [13].
No studies have yet determined whether there is a direct link between perilla and heart disease; only alpha-linoleic acid (abundant in perilla oil) has been studied.
3) Asthma
In a clinical trial of 14 people, those who consumed perilla oil had improved lung function. They also had decreased levels of the inflammatory compounds leukotriene B4 and C4 [14].
4) Osteoporosis
In a study of elderly adults, high consumption of alpha-linolenic acid was correlated with a reduced risk of hip fracture over the course of 16 years [15].
Rats fed a restricted, osteoporosis-inducing diet with perilla oil had increased bone strength and retained more calcium, which implies that perilla oil can benefit osteoporosis patients [16].
Animal & Cell Studies (Lacking Evidence)
No clinical evidence supports the use of perilla oil for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
5) Cognitive Function
Rats fed perilla oil performed better in a maze test than rats fed corn oil. Those that consumed perilla oil had changes in the protein levels in the brain [17].
Rats fed a diet rich in either perilla oil or fish oil had changes in gene activation in the brain. The genes affected may increase calcium signaling, stimulus responses, and neuron stability [18].
6) Weight Management
In a rat study, animals were fed a diet of perilla oil, safflower oil, olive oil, or beef fat. Rats fed a diet with perilla oil had less fat and lower cholesterol than the other groups [19].
Young guinea pigs that were fed diets with low levels of alpha-linolenic acid had increased weight gain compared to guinea pigs with normal levels of alpha-linolenic acid during development [20].
7) Atherosclerosis
While not as effective as Lovastatin (a cholesterol medication), perilla oil also reduced arterial plaque coverage by 60% in rabbits [9].
8) Liver Function
A high fat/high cholesterol diet with perilla oil helped reduce inflammation and fibrosis in the liver in rats. Liver fibrosis leads to the development of non-alcoholic fatty liver disease [21].
9) Blood Clots
In rabbits, perilla oil reduced platelet clumping (blood clots). High doses of perilla oil were comparable to aspirin in preventing clotting [22].
10) Colitis
In a rat model of Crohn’s disease, a diet with perilla oil reduced the severity of the ulcers and lowered levels of an inflammatory compound, plasma leukotriene B4 [23].
11) Inflammation
In a cell study, when activated white blood cells were exposed to perilla extracts, they migrated less and produced fewer reactive oxygen species [24].
12) Antimicrobial Activity
Perilla oil may be beneficial for fighting bacterial infections. When grown in the presence of perilla oil, antibiotic-resistant Staphylococcus aureus strains secreted fewer toxins. This effect was most pronounced for enterotoxins that harm the gut and cause food poisoning [25].
Cancer Research
A study of 121 women with breast cancer found that, aside from tumor size, low levels of alpha-linolenic acid in breast tissue was the only predictive indicator of metastasis, the spreading of cancer to other parts of the body [26].
In a rat study, perilla oil reduced the occurrence of colon, breast, and kidney tumors more than the omega-6-dense soybean and safflower oils. In another rat study, perilla oil was also associated with a reduced risk of colon cancer [27, 28].
However, some studies have found that alpha-linolenic acid may increase prostate cancer risk, so more studies are needed [29].
In a study of aging mice, the mice fed perilla oil had lower cholesterol and grew fewer tumors. However, they also had shorter lifespans, with an average decrease of nearly 70 days. The authors were not able to explain this apparent contradiction [30].
Limitations and Caveats
Most of the studies on perilla oil were conducted only on animal models and/or cell lines. Many more human studies need to be conducted.
Potential Adverse Effects
1) Diabetes
Very high levels of dietary perilla oil may actually contribute to insulin resistance. In a rat study, while a diet with 25% perilla oil decreased triglycerides and total cholesterol, it also reduced insulin sensitivity. More studies are needed to confirm this finding and determine the mechanisms [2].
2) Prostate Cancer
The literature on human studies of prostate cancer risk with alpha-linolenic acid is mixed, with some studies suggesting greater prostate cancer risk with high dietary alpha-linolenic acid while others demonstrate a lower risk. Ultimately, more studies are needed before this can be resolved [29].
Side Effects & Precautions
There are no known side effects to perilla oil consumption but more studies are needed. To avoid adverse effects or unexpected interactions, talk to your doctor before using perilla oil.
Drugs Interactions
Although there are limited data on the interactions between drugs and perilla oil, because of its effect on blood clotting, those taking medications such as blood thinners should consult with their doctors before consuming perilla oil.
Pregnant or Breastfeeding?
Please consult your doctor if you are pregnant or breastfeeding before taking any supplements.
Supplementation
Forms
Perilla oil is available as an oil for cooking or as an essential oil or as capsules.
The main active component of perilla oil, alpha-linolenic acid, is also available as a supplement, in the form of capsules.
Dosage
There is no safe and effective dose of perilla oil for any health purpose because no sufficiently powered study has been conducted to find one. In clinical studies, the range of dosages has been large, from 500-20,000 mg/day.
Perilla Oil vs Fish Oil
Fish oil is another good source of omega-3 fatty acids. However, unlike perilla oil, which is high in alpha-linolenic acid, fish oil contains longer-chain omega-3s, especially EPA and DHA [31].
In certain diseases, perilla oil and fish oil have similar effects. For example, in a study of rats with non-alcoholic fatty liver disease (NAFLD), both perilla oil and fish oil reduced inflammation and liver damage that arose from the consumption of a high-fat diet by decreasing harmful gut bacteria such as E. coli [32].
Perilla Oil vs. Other Vegetable Oils
Many vegetable oils are high in polyunsaturated fatty acids, yet they each have a unique distribution of fatty acids. Like perilla oil, flaxseed oil has high levels of alpha-linolenic acid, and both have shown heart-healthy effects of increased EPA and DHA levels [33].
Olive oil, by contrast, mainly consists of the monounsaturated fat oleic acid. Safflower oil and sunflower oil normally have high amounts of the omega-6 fatty acid linoleic acid so varieties with increased oleic acid and decreased linoleic acid have been cultivated [34, 35].
