Ginger and garlic are good for far more than flavoring food. Both have well-documented effects on inflammation, digestion, blood pressure, cholesterol, blood sugar, and immune function. While they share some overlapping benefits, each brings distinct strengths, and understanding what each one does best can help you use them more intentionally in your diet.
Ginger and Digestion
Ginger’s oldest reputation is as a stomach soother, and clinical data backs it up. In patients with functional dyspepsia (chronic indigestion without a clear cause), ginger sped up gastric emptying significantly compared to placebo. The stomach cleared its contents in about 12.3 minutes with ginger versus 16.1 minutes with placebo. That faster transit means less bloating, less fullness, and less of that heavy feeling after eating.
The mechanism involves serotonin receptors in the gut. Ginger’s active compounds bind to the same receptor sites that anti-nausea medications target, which is why it works for motion sickness and morning sickness too. It also increases the rhythmic contractions of the stomach that physically push food along. If you regularly feel sluggish after meals, ginger is one of the better-studied natural options for relief.
Lowering Inflammation
Chronic, low-grade inflammation drives a wide range of health problems, from joint pain to heart disease to metabolic dysfunction. A meta-analysis of randomized controlled trials found that ginger supplementation reduced C-reactive protein (a key blood marker of inflammation) by 0.8 mg/L on average. It also lowered two other major inflammatory signals, interleukin-6 and tumor necrosis factor-alpha, while improving the body’s total antioxidant capacity.
Garlic has its own anti-inflammatory pathway. Its sulfur compounds suppress some of the same inflammatory signaling cascades, though garlic’s strongest evidence is in cardiovascular and immune outcomes rather than general inflammation markers. Together, the two spices target overlapping but distinct parts of the inflammatory response, which is one reason traditional cuisines so often pair them.
Blood Sugar Control
Ginger shows meaningful effects on blood sugar in people with type 2 diabetes. In a 12-week trial, participants taking 2 grams of ginger powder daily saw their fasting blood sugar drop by about 19 mg/dL, while the placebo group’s levels barely moved. More importantly, their HbA1c (a measure of average blood sugar over two to three months) fell from 7.37% to 6.60%. That 0.77 percentage point drop is clinically significant and comparable to what some medications achieve.
These results came from a relatively modest dose, roughly half a teaspoon of dried ginger powder per day. While individual results vary, and these findings are most relevant to people with already elevated blood sugar, the effect size is hard to ignore.
Garlic and Blood Pressure
Garlic’s strongest cardiovascular evidence is in blood pressure reduction. A meta-analysis of clinical trials found that garlic lowered systolic blood pressure by 16.3 mmHg and diastolic by 9.3 mmHg in people who already had elevated readings. To put that in perspective, many first-line blood pressure medications aim for a 10 to 15 mmHg systolic reduction. The effect was specific to people with high blood pressure; those with normal readings didn’t see meaningful changes.
The active compounds in garlic promote the production of a signaling molecule that relaxes blood vessel walls, allowing blood to flow more easily. This effect builds over weeks of consistent intake rather than working like an acute dose.
Garlic and Cholesterol
Regular garlic intake also lowers total cholesterol. A meta-analysis found that garlic-treated subjects had total cholesterol levels 0.77 mmol/L lower than placebo groups, representing about a 12% reduction beyond what placebo achieved. The effect on HDL (“good”) cholesterol was minimal, suggesting garlic primarily works by pulling down the harmful fractions. For someone with borderline-high cholesterol, that 12% reduction could be the difference between a concerning lab result and a normal one.
Immune Function
Garlic has broad antimicrobial and antiviral properties. Pre-clinical research shows its sulfur compounds can block viral entry into cells and inhibit viral replication through several mechanisms. But the immune story goes beyond just killing pathogens directly.
In human studies, aged garlic extract increased the proliferation of two important immune cell types: gamma-delta T cells and natural killer cells. These are your body’s first responders, the cells that detect and destroy infected or abnormal cells before a full immune response kicks in. Participants also showed higher antioxidant levels and lower inflammatory markers. The practical result in these studies was reduced severity and duration of colds and flu, suggesting garlic strengthens both the initial immune response and the adaptive immune system that builds longer-term protection.
How Much to Use
For garlic, the commonly suggested daily intake is 2 to 5 grams of fresh raw garlic (roughly one to two cloves), or 0.4 to 1.2 grams of dried garlic powder. For ginger, the clinical trials showing blood sugar and digestive benefits used about 2 grams of dried ginger powder per day, which translates to roughly a tablespoon of fresh grated ginger.
You don’t need to take supplements to hit these amounts. A stir-fry with two cloves of garlic and a thumb-sized piece of ginger gets you into the therapeutic range for both. Consistency matters more than any single large dose.
Raw vs. Cooked: What You Lose
Garlic’s most studied compound, allicin, is created when you crush or chop a raw clove. Cooking deactivates the enzyme responsible for this conversion, but that doesn’t mean cooked garlic is useless. Roasted garlic retains about 30% of the allicin bioavailability of raw crushed garlic, while boiled garlic retains around 16%. Interestingly, the intensity of cooking matters less than you’d expect: roasting at high heat for a full hour produced nearly the same allicin availability as roasting at a lower temperature for half the time.
Roasting consistently outperformed boiling, delivering roughly twice the active compound availability. If you prefer cooked garlic (and most people do), roasting is your best bet. For maximum potency, crush or mince garlic and let it sit for a few minutes before cooking. This gives the enzyme time to generate allicin before heat shuts it down.
Ginger is more forgiving. Its active compounds, the gingerols and shogaols, are heat-stable. In fact, drying and cooking ginger converts gingerols into shogaols, which have their own anti-inflammatory properties. Fresh ginger, dried ginger, and cooked ginger all deliver meaningful benefits.
Safety and Drug Interactions
Both ginger and garlic are generally safe at food-level doses. The most common concern is their potential to increase bleeding, particularly in people taking blood thinners. However, a review of the evidence on warfarin interactions found that solid proof of a dangerous interaction with either ginger or garlic is actually lacking. A small number of bleeding cases were reported with garlic use, but none involved patients on warfarin, making it difficult to attribute the effect clearly.
That said, if you’re taking anticoagulant medication and plan to use high-dose supplements (not just cooking with these ingredients), it’s worth discussing with your prescriber. The risk from adding garlic and ginger to your meals is negligible. The risk from concentrated supplement capsules at several times the food-level dose is less well characterized. Raw garlic on an empty stomach can also cause heartburn or digestive upset in some people, which is easily avoided by eating it with food.