But if white garlic has impressive health benefits, black garlic could be even better. Produced by naturally fermenting white garlic under carefully controlled conditions, black garlic was originally used in Asian cuisine. In many Eastern cultures, it is still revered as an anti-ageing ingredient.
Research suggests fermented black garlic could have the therapeutic edge over the non-fermented white variety as it’s believed to have four times the antioxidant levels of white garlic. Antioxidants help reduce damage from free radicals, rogue molecules that contribute to cell damage associated with many diseases, and black garlic is being investigated for its role in boosting immunity and potentially reducing cholesterol.
Dr Sarah Brewer says: ‘Black garlic could have even greater medicinal uses than white garlic, particularly when it comes to supporting the immune system and heart health.’
What does black garlic do?
Research suggests black garlic has significantly greater antioxidant properties than white non-fermented garlic, offering at least four times the antioxidant activity per gram (and the antioxidant capacity of raw white garlic is already high).
One compound, S-Allylcysteine, a derivative of the amino acid cysteine has been shown to help lower cholesterol levels.
In laboratory trials, black garlic extracts have been shown to increase the activity of immune cells, including macrophages and natural killer cells. These are white blood cells in the immune system formed in response to an infection, which engulf and digest foreign substances and invading bacteria.
This helps to boost immune defences by targeting abnormal body cells and those infected with a virus. This could suggest a useful preventative health role if similar effects are confirmed in human trials.
Black garlic extracts have been shown to lower total cholesterol and levels of triglycerides, a form of fat found in dietary fats including meat, dairy produce and cooking oils, and also made in the liver. A 12-week study on 60 human volunteers with mildly raised cholesterol compared the effects of aged black garlic extract (6g a day divided in two doses) against a placebo. In the group taking the extract, levels of ‘good’ HDL cholesterol were found to have increased by just over seven per cent. This could help lower the risk of heart attack or stroke.
Getting black garlic from your diet
In the UK, black garlic is becoming increasingly popular. Less pungent than the white variety, it has a soft, caramelised, molasses-like taste with subtle garlic undertones, so not only does it taste sweeter, it will also leave your breath smelling better. It is now available in many supermarkets and health food shops. If cooking with it, add it in towards the end as once any garlic is heated for more than three minutes its medicinal effects are rapidly reduced. If you’re not a fan of the taste of garlic, you can get the beneficial effects from supplements.
Garlic has been eaten safely for thousands of years. Avoid if you have allergies or sensitivity to garlic or other members of the onion family. There are some concerns garlic may increase the risk of bleeding, so avoid if you are taking anticoagulant medication.
There is no recommended daily allowance for black garlic. A typical dose is one tablet of 200mg concentrated extract a day (equivalent to 2,000mg whole garlic).