Shiso (Perilla Leaves)

Digestive health and gut comfort This is where the strongest human evidence sits. In a randomized, double-blind, placebo-controlled pilot trial (the gold standard for clinical research design) involving 50 adults aged 30–70 with functional gastrointestinal discomfort, participants taking a standardized perilla leaf extract for 4 weeks reported significantly less bloating, gas, rumbling, fullness, and abdominal discomfort compared to those taking a placebo. Stool frequency and consistency also improved, suggesting the extract positively influenced gut motility (how efficiently food moves through the digestive tract). A separate review of perilla's traditional use highlights its long history as a digestive herb in East Asia, with preparations traditionally used for nausea, stomach fullness, and gut spasm. Shiso leaves are not spicy or harsh, making them easy to add to meals even for people with sensitive stomachs. Important caveat: The trial used a concentrated extract, not fresh leaves. Benefits from everyday culinary amounts are plausible given the shared compounds, but have not been directly tested. Inflammation and recovery Shiso's anti-inflammatory reputation is backed by solid laboratory evidence. Studies show that perilla leaf extracts and isolated compounds — particularly rosmarinic acid and luteolin — reduce the activity of pro-inflammatory molecules including TNF-α, IL-1β, IL-6, IL-8, COX-2, and iNOS. These are key signaling proteins involved in the body's inflammatory response. In human terms: a randomized controlled trial in adults with mild knee pain found that 8 weeks of perilla leaf extract improved pain scores and physical function more than placebo. Interestingly, standard blood inflammation markers (like hs-CRP, a protein that rises during inflammation) didn't change significantly between groups, which suggests the benefit may come through pathways not captured by those markers. Overall, the anti-inflammatory evidence is best described as emerging in humans. The lab science is robust; human trials are fewer, shorter, and rely on extracts. As part of a regular diet, shiso contributes anti-inflammatory plant compounds alongside other foods — which is exactly how dietary patterns work. Antioxidant capacity and immune support Shiso's polyphenol profile, especially rosmarinic acid, luteolin, and anthocyanins, makes it one of the more antioxidant-dense culinary herbs available. Antioxidants help neutralize free radicals (unstable molecules that can damage cells) and support the immune system's ability to respond appropriately to threats. Research also suggests that luteolin from perilla leaves may inhibit the overactivation of mast cells — immune cells involved in allergic reactions and histamine release — which could be relevant for people dealing with seasonal allergies or skin sensitivity. These effects are well-characterized in cell studies; human trials for immune and allergy support specifically remain limited. Shiso leaves for perilla immune support align with broader evidence on polyphenol-rich diets and immune health, even where perilla-specific human trials are sparse. Heart and circulation Most cardiovascular research on perilla focuses on perilla seed oil (rich in ALA omega-3) rather than the leaves. Small human studies suggest potential effects on lipid profiles, but evidence is inconsistent. The leaves themselves provide a modest amount of ALA and a range of antioxidant compounds that, as part of a plant-rich diet, may support vascular health. In short: shiso leaves contribute positively to a heart-healthy diet, but should not be singled out as a heart remedy. The benefit here is dietary context, not a specific perilla effect. Blood sugar and metabolism Evidence is currently limited. Animal and cell studies suggest perilla compounds may influence glucose metabolism and insulin sensitivity (how efficiently cells respond to the blood sugar–regulating hormone insulin), but human trials have not shown meaningful effects on blood sugar or HbA1c (a 3-month average blood sugar marker). Culinary shiso contributes fiber and low-glycemic carbohydrates, which fit naturally within a blood-sugar-friendly eating pattern. Brain health and cognition This is an exciting and early area. A 12-week randomized, double-blind, placebo-controlled trial in 100 older adults with cognitive impairment found that 500 mg/day of a standardized purple perilla leaf extract significantly improved scores on validated cognitive tests (K-MMSE-2 and ADAS-Cog) compared to placebo. Tolerability was good, with no major safety concerns reported. This study is promising but preliminary. It used a highly concentrated extract, not dietary shiso. Larger, longer trials and independent replication are needed before any clinical recommendation can be made. For now, shiso as a brain-supportive herb is an intriguing area to watch.

Buying guide: fresh vs. dried vs. tea vs. extract Fresh shiso leaves are the most versatile form for everyday use and retain the full spectrum of vitamins (especially heat-sensitive vitamin C), fiber, and volatile aromatic compounds. Look for vibrant, unblemished leaves without yellowing or dark spots. Green shiso (also called ao-jiso) is milder; purple shiso (red shiso or aka-jiso) has a slightly more bitter, earthy flavor and higher anthocyanin content. Both are excellent. Label tip: At Asian grocery stores, shiso is often sold in small plastic-wrapped bunches of 10–20 leaves. Use within 3–5 days; store stems-down in a glass of water in the fridge, loosely covered. Dried shiso leaves and furikake (seasoning blends containing dried shiso) concentrate polyphenols and aroma compounds but lose some vitamin C and delicate volatiles. Great as a shelf-stable seasoning over rice, eggs, or avocado toast. Shiso or perilla herbal tea is a traditional preparation with limited human trial data. It may deliver some polyphenols in a gentler form — useful for digestive comfort. Standardized leaf extracts (capsules/tablets) are the forms used in clinical trials for digestion, joint pain, and cognition at doses around 300–500 mg/day. These deliver concentrated polyphenols beyond what culinary use provides. If you're considering a supplement, choose products from reputable brands with third-party testing and discuss with your healthcare provider. Perilla seed oil is nutritionally distinct from the leaves — it is rich in ALA omega-3 but contains very different amounts of the polyphenols found in shiso leaves. Do not treat them as interchangeable.

There is no established official daily intake for shiso leaves — they are a food, not a supplement, and are eaten to taste and appetite rather than dosed. Here's a practical framework: Culinary range: Most people in Japanese and Korean cooking use anywhere from 2–3 leaves as a garnish up to 10–20 g (roughly 10–20 medium leaves) as a vegetable component of a meal. Eating this amount daily is safe and consistent with longstanding dietary traditions. Start low if new: If you are new to shiso, begin with a few leaves to check for any sensitivity (especially if you react to other mint-family herbs). Increase gradually to your preferred amount. For supplement extracts: Clinical trials have used around 300–500 mg/day of standardized extract for 4–12 weeks. If you're considering an extract for a specific health goal (gut symptoms, joint pain), start with the lowest studied dose and discuss with your healthcare provider. A useful daily target: 6–15 fresh leaves per day (10–20 g) is a reasonable and pleasurable culinary goal. You can easily reach this by using shiso as a wrap at one meal, shredding leaves into a salad, or adding them to a noodle or rice bowl. There is no known upper limit for culinary shiso use. The concerns around high-dose perilla ketone toxicity seen in livestock relate to specific plant parts and concentrated preparations, not to everyday leaf consumption in humans.

Shiso leaves are rich in rosmarinic acid, luteolin, apigenin, and anthocyanins, which provide potent antioxidant and anti-inflammatory effects. These plant compounds help inhibit pro-inflammatory signaling molecules and support vascular health. Additionally, the leaves contain alpha-linolenic acid (ALA), an omega-3 fatty acid that supports cell membrane health.

Shiso leaves can be eaten raw as wraps for sushi, shredded into salads (chiffonade), blended into dressings with sesame oil, or added to hot soups and stir-fries at the end of cooking. Drying and crumbling the leaves also creates a flavorful seasoning for roasted vegetables or popcorn. The herb is highly versatile and requires very little preparation.

Shiso leaves are often paired with sesame or citrus because these ingredients enhance the absorption of shiso's nutrients, such as fat-soluble carotenoids and non-heme iron. Combining shiso with ginger is another traditional pairing used to support digestive health. These combinations balance the herb's fragrance while maximizing its nutritional value.

Shiso is considered very safe for daily culinary consumption for most people, though those with allergies to the mint family (Lamiaceae) should exercise caution. If you are allergic to basil, mint, or lavender, you may also react to shiso. It is recommended to start with a small amount if you have known herb sensitivities.

Shiso leaves contain luteolin and rosmarinic acid, which have been studied for their ability to reduce mast cell activation and inhibit inflammatory responses. While culinary amounts are beneficial, human trials showing significant relief for allergies or joint pain typically utilize concentrated extracts. It is a nutrient-dense addition to an anti-inflammatory diet.

Shiso leaf extracts have been studied for their potential neuroprotective properties and mood-supporting effects, though they are not a replacement for medication. The aromatic compound perillaldehyde may offer mild mood support, and apigenin is being researched for its brain-protecting potential. Always consult a healthcare provider if you are taking CNS-active medications like antidepressants.

People taking blood thinners, antidiabetic medications, or CNS-active drugs should consult a doctor before using concentrated perilla supplements, though culinary amounts are generally fine. High-dose perilla seed oil contains ALA which could theoretically impact bleeding risk. It is also advised to avoid new herbal supplements before surgery.

You can find fresh shiso at H Mart, Mitsuwa Marketplace, and 99 Ranch Market, as well as at local farmers markets in states like California and New York. While rarely stocked at conventional grocers like Kroger or Safeway, it is increasingly available through specialty produce delivery services and upscale natural food co-ops.

In the U.S., shiso is typically in season from late spring through early autumn, particularly in USDA Hardiness Zones 6 through 10. While it thrives in the summer heat of the South and Midwest, greenhouse cultivation allows for a year-round supply in major metropolitan areas with high demand for East Asian produce.

While both are Perilla frutescens, American grocery stores often label the large, rounded Korean variety as "perilla leaves" and the smaller, jagged Japanese variety as "shiso." The Korean type is a staple for BBQ wraps and pickling, whereas the Japanese green or purple varieties are favored for sushi garnishes and tempura.

Look for the USDA Organic seal on shiso packaging to ensure the leaves were grown without synthetic pesticides or fertilizers. Because shiso is a specialty herb, you may also find "Certified Naturally Grown" labels at local farmers markets, which indicates the grower follows organic standards but may not have federal certification.