Natural therapy for glaucoma
Often I am asked: Is there a natural therapy for glaucoma? Is there a miracle cure for glaucoma? Unfortunately, there is not. When you’re at risk for glaucoma, it is vital to focus our attention on glaucoma prevention. In this article, I will discuss 5 nutraceuticals that may be beneficial for your eye health.
Preventing glaucoma naturally
Why we should shift our focus to preventing glaucoma
It is a well-known fact. Surgeons and specialists train many years to become experts in their field. But during their training at medical school and as registrars there is generally a lack of focus on the nutritional and preventive aspects of disease.
On top of that, there is also the lack of gold standard evidence on whether certain lifestyle changes and dietary nutrients have a positive impact on disease.
Randomised clinical trials are the gold standard for scientific medical evidence. The reality is that running a randomised clinical trial on prevention will cost a lot of time, effort and money, with minimal financial reward at the end of it. This is why such trials are rarely conducted. So the next best type of scientific evidence is population-based cohort studies, which unfortunately are not as highly accepted by clinicians compared to randomised clinical trials.
Dr Brian Ang Glaucoma specialist Melbourne
Study: “Consuming 3 or more servings of fruit per day may impact your risk of getting glaucoma”
The results from the major population-based cohort studies worldwide have all shown that a healthy and balanced diet confers greater resilience to our eye health and reduces the risk of chronic eye diseases, such as glaucoma and macular degeneration.
Dr Brian Ang Eye specialist Melbourne
- Data from the Nurses Health Study and Health Professionals Follow-up Study of over 100,000 participants reported that a higher intake of nitrate-rich foods and leafy green vegetables reduced glaucoma risk by over 20%.
- A separate population-based study in the United States (the Study of Osteoporotic Fractures Research Group) reported that those who consumed 3 or more servings of fruit per day were 79% less likely to have glaucoma. Furthermore, those who ate more than one serving per week of leafy green vegetables (collard greens and kale), decreased their odds of having glaucoma by over 50%.
- Daily greens and brightly coloured fresh fruit and vegetables (such as carrots, peppers, berries and citrus fruits), particularly when taken as part of a Mediterranean diet, also reduces the prevalence of macular degeneration. This is thought to be due to the natural antioxidants (such as vitamins A, C & E, zinc and carotenoids) present in these foods that help to protect the eyes from oxidative stress and chronic inflammation.
It is also worth remembering that as we age, the ability to absorb the B vitamins (including vitamin B12 and folate) from food declines. As a result, dietary deficiencies in the B vitamins become more common as we grow older. Deficiency in either vitamin B12 or folate can cause vision loss, anaemia, and cognitive impairment. We should therefore ensure that our diet also includes rich sources of B vitamins, such as whole grains, seafood and eggs.
Is there a natural therapy for glaucoma (and macular degeneration)?
Clinical studies have demonstrated potential neuroprotective benefits of certain nutraceuticals and vitamins against glaucoma.
There are two caveats. Firstly, there is no conclusive data on the benefits and risks of taking these supplements for glaucoma over the long term. Secondly, these supplements are intended to be complementary to, and not as a replacement for, existing glaucoma treatments.
As I mentioned before, I am passionate about this topic and I believe that nutrition plays a pivotal role in preventing disease. So even though we lack conclusive data, as an eye specialist here in Melbourne, I strongly support my patients in their journey to prevent further eye damage.
In this article, I will cover 5 nutraceuticals that may be used to improve your eye health. Just remember, always consult with your family doctor if you are taking supplements.
Vitamins for glaucoma prevention
Natural therapy for glaucoma: 5 nutraceuticals worth taking [Part 1]
Nicotinamide
Nicotinamide is the active form of vitamin B3, a water-soluble vitamin. Being water-soluble means that any excess vitamin is excreted in the urine and is not stored in the body.
It is naturally found in lean meat, milk, fish and nuts, and is commonly added to cereals and other foods.
- Cellular metabolism
- Mitochondrial energy production, and
- DNA repair for cells throughout the body.
Nicotinamide is a natural precursor for the anti-ageing coenzyme NAD+ (nicotinamide adenine dinucleotide). As we grow older, NAD+ supply decreases, leading to metabolic decline of the cells in the body. Nicotinamide increases NAD+ levels to help the cells achieve regular metabolism, reduce mitochondrial dysfunction, and maintain cellular vitality.
In 2020, the Centre for Eye Research Australia published a world-first clinical trial showing that high-dose nicotinamide (vitamin B3) could lead to improvement in inner retinal function in glaucoma patients.
The ideal long-term dose of nicotinamide for glaucoma is still not entirely clear. The trials were short-term and used high doses of 3,000 mg daily. This is way higher than the recommended daily allowance of 16 mg, to the tune of 18,650%!
My clinical experience is that 3,000 mg daily of nicotinamide is actually not very well tolerated and sometimes also affects liver function.
I therefore usually recommend that patients take a lower dose that they can tolerate over the long term.
Finally, you might have heard of two other NAD+ precursors marketed as being the latest, greatest (and expensive) anti-ageing supplement there is: nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN). When it comes to glaucoma, nicotinamide is better than either NR or NMN because it can cross the blood-brain barrier and directly increase NAD+ levels in the retinal ganglion cells.
Folate and Cobalamin
They are two water-soluble B-vitamins that are very closely intertwined with each other: vitamin B9 (folate) and vitamin B12 (cobalamin).
Natural food sources include broccoli, brussel sprouts, dark green leafy vegetables, whole grains, seafood and eggs.
- DNA synthesis and metabolism
- Production of healthy red blood cells
- Healthy functioning of the optic nerve and nervous system in general. Deficiency in either vitamin can cause sight-threatening nutritional optic neuropathy
- Metabolism of homocysteine (an amino acid) to create other molecules that the body needs. High homocysteine levels are associated with increased risk of glaucoma and macular degeneration, dementia, heart disease, and stroke.
Supplementation with vitamin B9 and vitamin B12 can:
- Reduce the risk of macular degeneration, particularly for females over the age of 40.
- Reduce homocysteine levels, thereby reducing glaucoma risk
- Reverse vision loss from nutritional optic neuropathy due to folate and B12 deficiency
- Reduce retinal venous pressure
In addition, vitamin B12 (methylcobalamin) can reduce deterioration in visual defect progression in normal tension glaucoma when taken over the long-term (over 4 years) at a daily dose of 1,500 micrograms.
Now, there are a few things to consider before you rush out to buy these vitamins.
Let’s start with folate or folic acid.
Synthetic folic acid supplements cannot benefit your eyes and nerves without first being converted to the biologically active form.
Unfortunately, genetic mutations (DHFR and MTHFR polymorphism) can hinder this conversion process. These mutations are reasonably common and most of us do not know if we have these mutations or not.
Therefore, it makes sense that the best type of folic acid supplement should be its already biologically active form: L-methylfolate.
So in summary: if you are going to take folic acid supplements, take L-methylfolate (also known as levomefolic acid).
Now, let’s move on to vitamin B12.
Supplemental vitamin B12 is actually better than B12 from food because it is not bound to protein and therefore does not rely on stomach acid releasing the vitamin for absorption in the intestine.
Absorption of B12 from supplements is therefore less affected by stomach and intestinal malabsorption issues.
The two main types of supplemental vitamin B12 are methylcobalamin and cyanocobalamin. Of the two, I’d suggest methylcobalamin because it is the natural, active form used in the body.
So in summary: if you are going to take vitamin B12, take methylcobalamin (also known as mecobalamin).
My view on these two B vitamins for glaucoma? Given that they are essential for the functioning of the nervous system and the optic nerve, my clinical opinion is that taking the active form of the vitamins has far more potential upsides than there are downsides.
Saffron
Saffron is rich in antioxidants, with beneficial effects in reducing oxidative stress and inflammation, as well as protecting against complications of diabetes. The most notable antioxidants contained in saffron are the carotenoids crocin and crocetin.
Unlike the other carotenoids (such as lutein, zeaxanthin, astaxanthin, lycopene and beta-carotene), crocin and crocetin are not present in other foods and are therefore not easily accessible in our daily diets unless you happen to eat a lot of saffron.
A randomised clinical trial from Iran evaluated the role of saffron in stable glaucoma patients who were already on eye pressure-lowering medications. The results found that 30 mg daily of saffron was able to significantly reduce eye pressure within 3 weeks. The eye pressure returned to the original levels once saffron was discontinued.
We know that reducing eye pressure reduces the risk of glaucoma progression. Does this mean that taking saffron will decrease your eye pressure (and by inference, the risk of glaucoma progression) over the long term? This is indeed possible, and hopefully longer term studies will be able to confirm this.
The benefits of saffron are not limited to glaucoma alone. A head to head study of saffron vs lutein and zeaxanthin caused quite the stir when it was published in 2019. The study found that visual function in intermediate macular degeneration (AMD) patients remained stable when taking saffron over a period of 29 months, but not with lutein and zeaxanthin, which showed a deterioration in visual function.
Now, this study had its flaws in terms of design and conduct, so please don’t go thinking that you must take saffron over lutein and zeaxanthin for intermediate AMD.
Rather, it serves to highlight the potential that saffron has when it comes to diseases of the eye.
It is not only intermediate AMD patients that benefit from saffron. Mild AMD patients do as well. An Australian trial in mild AMD patients found that supplementation with 20 mg daily of saffron improved visual function modestly when taken for 3 months. A separate trial from Iran found similar benefits for mild-moderate dry AMD patients at a higher dose of 50 mg daily.
Crocin has also been studied in diabetic macular edema (DME). A randomised clinical trial of patients with DME resistant to conventional medical treatment found that crocin 15 mg daily for 3 months helped to improve vision and reduce the amount of edema at the macula.
Let’s think about this for a bit. The trial showed that crocin from saffron was able to benefit DME patients, where conventional medical treatment had failed. Saffron worked, when conventional medical therapy didn’t. Yes, the trial was only for a short 3 month duration, but I think the results are absolutely eye-opening.