Diet & Fitness

Bitter herbs are thought to stimulate digestive function by increasing saliva production and promoting both stomach acid and digestive enzyme production.³ As a result, they are particularly used when there is low stomach acid but not in heartburn (where too much stomach acid could initially exacerbate the situation). These herbs literally taste bitter. Some examples of bitter herbs include greater celandine, wormwood, gentian,dandelion, blessed thistle, yarrow, devil’s claw, bitter orange, bitter melon, juniper, andrographis, prickly ash, and centaury.⁴. Bitters are generally taken either by mixing 1–3 ml tincture into water and sipping slowly 10–30 minutes before eating, or by making tea, which is also sipped slowly before eating.

Very little published research is available on the traditional uses of bitter orange as a digestive aid and sedative. The German Commission E has approved the use of bitter orange for loss of appetite and dyspeptic ailments.⁵ One test tube study showed bitter orange to potently inhibit rotavirus (a cause of diarrhea in infants and young children).⁶ Bitter orange, in an herbal combination formula, reportedly normalized stool function and completely eased intestinal pain in 24 people with non-specific colitis and, again in an herbal combination formula, normalized stool function in another 32 people with constipation.^7,8

Citrus and citrus extracts have long been used to promote weight loss, and research suggests, in general, they have small positive effects on body weight and waist circumference.⁹ Bitter orange (Citrus aurantium) and its active constituent, synephrine, are sometimes included in weight-loss formulas. Synephrine has been found to activate a type of nerve receptor that helps regulate carbohydrate and fat metabolism.¹⁰ Studies in healthy adults have noted single doses of bitter orange extract increased fat-burning during exercise in men and women,¹¹ and energy used during digestion, a major avenue for expending calories, in women, but not men.¹² Synephrine is a weak stimulant, and is often combined with stronger central nervous system stimulants, particularly caffeine, which may increase calorie-burning.¹⁰ Two clinical trials examining the effect of combination supplements containing bitter orange extract have noted positive effects on weight loss.^14,15 However, in a randomized controlled trial using bitter orange alone in subjects with overweight and obesity, no weight loss was attributable to the supplement after six weeks.¹⁶

Reports on the possible blood pressure-raising effect of single doses of bitter orange extract in healthy individuals have been mixed.^17,18 An industry-sponsored review of 20 published and unpublished studies with a combined total of approximately 360 subjects concluded taking bitter orange or synephrine, alone or in combination with other ingredients (one of which was usually caffeine), for six to twelve weeks has been associated with slight weight loss and has had no substantial adverse effects on heart rate or blood pressure.¹⁹

Bitter orange has a history of use as a calming agent and to counteract insomnia. There is no clinical trial data to support its efficacy in this regard. The usual amount of tincture used is 2 to 3 ml at bedtime.^19,20