Shiso (Perilla Leaf)

Heart and circulation Shiso leaves contain small amounts of ALA, plus antioxidants that may help protect the inner walls of blood vessels (the endothelium) from oxidative damage. However, most of the cardiovascular research around Perilla frutescens focuses on perilla seed oil — which is nutritionally distinct from the leaf — rather than on culinary shiso itself. No well-designed human trials have tested shiso leaves specifically for blood pressure, cholesterol, or other heart outcomes. Any circulatory benefit from eating fresh shiso is likely modest and best understood as part of a broad whole-food plant-based dietary pattern. Digestive health and microbiome This is where the most human clinical evidence exists. A proprietary standardized perilla leaf extract called Benegut has been tested in clinical trials involving adults with functional dyspepsia (a condition involving chronic post-meal discomfort, bloating, and nausea without a clear structural cause). Participants reported statistically significant reductions in digestive symptoms compared to placebo over four-week periods. That said, these trials used concentrated, standardized extracts — not everyday culinary shiso — and sample sizes were modest. Traditional use and mechanistic data also suggest shiso's aromatic oils and rosmarinic acid may reduce mild gut spasms, support the gut barrier, and act against certain foodborne bacteria. Blood sugar and metabolism There are no clinical trials specifically examining shiso leaves for blood glucose, insulin sensitivity, or HbA1c (a three-month average of blood sugar levels). Shiso's antioxidant and anti-inflammatory properties could theoretically support metabolic health, but this remains speculative. People managing blood sugar concerns can safely enjoy shiso in cooking — just don't swap it for established dietary or medical strategies. Inflammation and recovery Rosmarinic acid, luteolin, and shisonin all demonstrate anti-inflammatory activity in lab and animal studies, including the ability to inhibit COX-2 (an enzyme that drives inflammatory responses). But robust controlled human trials testing fresh shiso leaves as an anti-inflammatory intervention don't yet exist. Available human data mostly involve perilla seed oil or mixed herbal formulas. Shiso is best viewed as a supportive food in an anti-inflammatory diet rather than a primary treatment. Allergies and immune support Shiso has a well-documented traditional role in Japanese herbal medicine for hay fever, asthma, and skin allergy. The Japanese Medical Herb Association notes that benefits for these conditions are under investigation but not yet confirmed by large clinical trials. Rosmarinic acid and perillaldehyde have shown mast-cell-stabilizing effects (mast cells are immune cells that trigger allergy symptoms) in experimental systems. Red shiso's anthocyanins may also support general immune resilience. This is a genuinely promising area, but "promising in the lab" is not the same as "proven to work in humans."

The honest answer: use both, for different purposes. Green shiso is higher in aromatic oils, particularly perillaldehyde, which gives it that bright, herbal flavor. It is the go-to for fresh applications — wrapping, garnishing, slicing into salads, or blending into sauces. It provides good amounts of vitamin C and carotenoids. Red shiso is the better source of shisonin and other anthocyanins, making it the stronger antioxidant-pigment option. It is traditionally used in pickling (umeboshi, shiso-pickled ginger) and in infused drinks and teas. Its color is pH-sensitive — it turns bright pink in acidic environments like plum or citrus, which is part of what makes it so striking in Japanese pickled foods. For most people, the practical choice is whichever variety is fresher and available. Both belong in the kitchen.

The digestive-comfort seeker Struggles with mild post-meal bloating or heaviness, especially after large or rich meals. Wants to add aromatic herbs to cooking without turning to supplements. May benefit from shiso tea after meals, or from using fresh shiso in place of heavier sauces and dressings. The antioxidant-curious home cook Interested in eating a more colorful, polyphenol-rich diet without complicated supplementation. Already enjoys Japanese or Asian-style cooking and wants to understand why these ingredients are so prominent. Red shiso pickles, green shiso rice bowls, and shiso-infused dressings are all easy, practical entry points.

There is no official recommended daily intake for shiso as a medicine or supplement. As a culinary herb, typical use looks like this: Fresh leaves: 5–10 leaves per serving (approximately 5–10 g), used as wraps, garnishes, or mixed into dishes. This is considered safe for daily use for most people. Shiso tea: About 5–8 fresh leaves (or 1–2 teaspoons of dried leaf) per 250 ml cup. One to two cups per day is a reasonable starting point. Dried shiso flakes (furikake or yukari): A small pinch to a teaspoon over rice or noodles — these are more concentrated in flavor and often contain added salt, so check labels. Supplements / concentrated extracts: Clinical studies have used standardized extracts in the range of several hundred milligrams per day, but these products vary significantly by manufacturer. If you are considering a supplement (rather than food), look for standardized rosmarinic acid content and consult your healthcare provider for dosing guidance. Start low if you are new to shiso — not because it is risky, but because the flavor is assertive. A few leaves in a bowl is enough to appreciate the aroma; you can build from there based on taste and tolerance.

Shiso leaf contains rosmarinic acid, perillaldehyde, and flavonoids like luteolin, which provide antioxidant and anti-inflammatory effects. These compounds help reduce oxidative stress and cellular damage caused by free radicals while supporting the body's immune signaling and gut microbiome.

Shiso leaf may support digestive health due to the compound perillaldehyde, which has antimicrobial and gut-settling properties. Clinical trials using concentrated perilla leaf extracts have specifically highlighted its potential for providing digestive comfort.

You can use fresh shiso as an edible wrap for fish and rice, thinly slice it for grain bowls and salads, or blend it into miso dressings. Red shiso is commonly used to steep into a vivid pink tea or layered with vinegar to quick-pickle vegetables like daikon and cucumber.

People taking anticoagulant medications like warfarin should be cautious because shiso is high in Vitamin K, which can reduce the effectiveness of blood thinners. It is recommended to keep leafy herb intake consistent and consult a doctor before making significant dietary changes.

Shiso contains oxalates, which are naturally occurring compounds that can contribute to the formation of calcium-oxalate kidney stones in susceptible individuals. While standard culinary portions are unlikely to be a risk, those with a history of stones should moderate their intake and stay hydrated.

Shiso contains rosmarinic acid, a potent polyphenol that research suggests may act as a natural antihistamine to reduce allergy-related immune responses. While culinary amounts are generally safe, these compounds could theoretically enhance the effects of allergy medications at high supplemental doses.

Eating shiso as a culinary herb is generally considered safe during pregnancy, but concentrated supplements or large amounts of tea are not recommended. This precaution is due to a lack of limited safety data regarding high doses of perilla during pregnancy and breastfeeding.

Shiso can be grown as a summer annual in most US USDA Hardiness Zones (2–11) or as a perennial in warmer regions like Florida and Southern California. While it thrives in the heat of July and August, gardeners should be aware that it can become invasive in the Eastern US if allowed to go to seed.

You can typically find fresh shiso at H Mart, Mitsuwa Marketplace, and 99 Ranch Market, or at local farmers markets in cities with significant Japanese or Korean populations. While rarely stocked in conventional supermarkets like Kroger or Publix, it is increasingly available through specialty produce delivery services like Weee! or Misfits Market.

In the United States, Japanese varieties are typically labeled as Shiso, while the larger, milder Korean varieties are often sold as Perilla or Sesame Leaves. Though they are the same species, the Korean variety (Perilla frutescens var. frutescens) is preferred for pickling and BBQ wraps, while the Japanese variety (var. crispa) is prized for sushi.