[HEALTH] Holy basil (Ocimum sanctum), commonly called tulsi (meaning “the indefatigable” in Sanskrit), known as the "tonic of life" has been used for millennia in Ayurvedic medicine as an adaptogen that supports the body’s natural rhythm.
Researchers took a step back to analyze all available studies on holy basil in 2017. Across 70 studies involving almost 4,000 total participants, holy basil consistently showed beneficial effects for modulating stress, immune function, blood sugar, lipid levels, and inflammation with very few adverse effects. Few herbs have been studied this broadly and come away with such a consistent, reassuring track record, so enjoy!
STRESS Holy basil seems to help people handle stress more easily. In a randomized, double-blind, placebo-controlled human study, healthy adults received a standardized holy basil extract for 8 weeks. The researchers measured cortisol levels, physiological responses to mental stress (including blood pressure reactivity), and subjective feelings of stress and relaxation. Compared to a placebo, Tulsi was shown to reduce cortisol levels, help blunt blood pressure responses to stress, and help subjects feel more relaxed. Participants also reported less fatigue and improved sleep quality. Rather than simply sedating the nervous system, Tulsi helped subjects’ bodies adapt to stress.
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IMMUNE HEALTH Holy basil may also interact with the immune system itself. In a randomized, double-blind, placebo-controlled human study, healthy volunteers took holy basil extract daily for 4 weeks. Researchers found significant increases in natural killer cell activity and T-helper cells, two important components of the immune system. This isn’t vague “immune-support” propaganda either—those are objective changes in the immune system that could help the body stay vigilant against threats without encouraging excess inflammation.
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ANXIETY Tulsi supplementation in humans improved anxiety, including nervousness, restlessness, tension/stress in the mind, and general emotional health. Previous randomized trials found significant decreases in anxiety levels as measured on psychological assessments, with anxious adults also noting subjective improvement in how calm and emotionally stable they felt. Reviews on tulsi summarize studies that demonstrated improvements in anxiety separately from overall stress levels, implying an action on mood. Effects on anxiety do not appear to be caused by sedation but rather by promoting a normal baseline from which anxiety (overactivation) can be decreased.
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ANXIETY Tulsi supplementation in humans improved anxiety, including nervousness, restlessness, tension/stress in the mind, and general emotional health. Previous randomized trials found significant decreases in anxiety levels as measured on psychological assessments, with anxious adults also noting subjective improvement in how calm and emotionally stable they felt. Reviews on tulsi summarize studies that demonstrated improvements in anxiety separately from overall stress levels, implying an action on mood. Effects on anxiety do not appear to be caused by sedation but rather by promoting a normal baseline from which anxiety (overactivation) can be decreased.
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METABOLIC HEALTH Tulsi has also been shown to improve blood sugar levels and other markers of metabolic health. In one early human trial, type 2 diabetics were given tulsi or a placebo for 45 days. Compared to a placebo, Tulsi showed reductions in fasting blood glucose, post-meal blood glucose, and triglycerides. A later meta-analysis (statistical analysis that combines the results of many studies) found that consuming tulsi was consistently associated with reductions in blood sugar and improvements in lipid levels among participants with pre-existing metabolic risk factors. Animal and test-tube studies suggest that antioxidant effects and alpha-amylase inhibition (which slows the digestion of carbohydrates) may play a role.
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HOW TO USE:
Most commonly, people drink tulsi as a tea once or twice per day. Tulsi supplements are also available as standardized holy basil extracts, which allow you to take a dose similar to what was used in studies: typically around 300–600 mg per day.