Remember this study?
Being underweight was associated with a significantly increased risk of glaucoma only in females. “Underweight females have less adipose tissue, which is the major place of estrogen production especially for postmenopausal women,” the authors explained. “Recently, activation of G protein-coupled estrogen receptors exhibited neuroprotective effects against retinal ganglion cell degeneration. Thus, we speculate that insufficient plasma estrogen in underweight females could result in retinal ganglion cell degeneration, which is known to play a key role in the pathogenesis of glaucoma.”
In connection with the NeuroFit Diet, I am working on a section on fennel. In this preview, I'm going to show you how fennel could be of interest in regard to the findings above, and I will highlight many other interesting properties of this spice. By the way, the study above is far from the first one to find an association between being underweight and an increased risk of glaucoma in females. Dr. Robert Ritch observed this in his practice and mentioned it to me years ago.
The Romans believed that fennel seed could help supercharge their vision. Today we know its active compounds include anethole, rosmarinic acid, chlorogenic acid, quercetin, and apigenin (1, 2) and that these carry multiple health benefits.
Fennel seed extract has demonstrated antioxidant, anti-inflammatory, and acetylcholinesterase inhibitory activities, contributing to its neuroprotective properties. It has shown memory-enhancing and neuroprotective (3) effects and an ability to mitigate cognitive impairments.
How does fennel relate to the study above?
Fennel's main constituent, anethole, mimics estrogen’s function in the body (1). I don't know of any studies that examine whether fennel reduces glaucoma risk for underweight females, but in principle it could, and it should be studied. If you fall into this category, consider adding some fennel seeds to spice up your cooking.
There are additional interesting research papers on fennel:
The study, "Oculohypotensive effects of foeniculum vulgare in experimental models of glaucoma," concluded that aqueous extract of fennel possesses significant ocular anti-hypotensive activity, which lowered IOP comparable to timolol (4).
Another study showed the protective and therapeutic effects of aqueous extract of fennel seed eye drops (0.5%) against cataract in rabbits. The results showed a highly significant reduction in lens opacity score (5).
Here are more details on fennel's main constituents:
- Anethole: This compound has antimicrobial properties and mimics estrogen, which can be particularly beneficial for postmenopausal women who may have reduced levels of this hormone. Anethole can also increase prolactin levels, which can promote lactation and has been linked to potential anti-cancer effects.
- Flavonoids (e.g., quercetin and apigenin): These compounds have antioxidant, antibacterial, and anti-inflammatory effects. Apigenin, in particular, has been shown to have neuroprotective effects, making it a promising candidate for preventing cognitive decline.
- Phenolic compounds (e.g., rosmarinic acid and chlorogenic acids): These compounds also have antioxidant and anti-inflammatory effects, and may help protect against chronic diseases such as heart disease and diabetes.
- Terpenes (e.g., fenchone, limonene and α-phellandrene): These terpenes are responsible for the characteristic aroma and flavor of fennel. Limonene is considered "uplifting" and it has been associated with reducing anxiety, stress, inflammation, and acid reflux, improving digestion, boosting the immune system, and improving mental focus.
- Water-soluble vitamins (e.g., vitamin C, thiamine, riboflavin, niacin, and pyridoxine): Fennel is a good source of several essential vitamins, which are important for a variety of physiological processes, including immune function and energy metabolism.
- Fat-soluble vitamins (e.g., vitamins A, E, and K): These vitamins are important for vision, skin health, and blood clotting, among other functions.
- Trace minerals and other elements (e.g., calcium, chromium, copper, iron, magnesium, manganese, and zinc): Fennel is also a good source of several essential minerals, which are involved in many bodily processes, including bone health, enzyme function, and immune function.
- Essential amino acids (e.g., leucine, isoleucine, phenylalanine, and tryptophan): These amino acids are the building blocks of proteins, which are essential for growth, repair, and maintenance of tissues throughout the body.