Several factors contribute to cataract formation, including physiological factors (age), medications (such as steroids, gout drugs), illnesses (like diabetes, heart disease, hypothyroidism), and lifestyle and environmental factors (smoking, obesity, ultraviolet and heavy-metal exposures). Here are some tips to help you stave off cataracts for as long as possible:
* Stop smoking. Men who smoke over 20 cigarettes a day had the highest risk of developing cataracts; even previously heavy smokers who had given up still ran a greater risk of cataracts (JAMA, 1992; 268: 989-93). It's thought that the cadmium in cigarettes accumulates in the lens, and may enhance the accumulation of harmful lead and copper in the eye (Br J Ophthalmol, 1998; 82: 186-8).
* Sport those sunglasses. Japanese researchers reviewing studies carried out in Japan as well as in Iceland, Australia and Singapore found that those with the highest levels of sun exposure also had the greatest incidence of cataracts (Invest Ophthalmol Vis Sci, 2003; 44: 4210-4).
* Reduce/eliminate heavy-metal exposure. Long-term, low-level exposure to toxic metals - in particular, lead - results in its accumulation in the lens. Such a buildup increases the oxidative burden in the lens, leading to cataracts (JAMA, 2004; 292: 2750-4).
* Lose weight. Researchers at Harvard University discovered that people with a body mass index (BMI) of 30 or more increased their risk of cataract by at least a third compared with those with a BMI of 23 or less (Int J Obes Relat Metab Disord, 2002; 26: 1588-95).
Another study showed that it's not just the weight that counts, but how the fat is distributed. Those whose fat is concentrated around the abdomen (central obesity) are more likely to develop cataracts (Am J Clin Nutr, 2000; 72: 1495-502).
* Build up your antioxidants. The factors already mentioned underscore the importance of maintaining a good antioxidant status in your eyes. Cataract-busting nutrients include:
vitamin A and carotenes. Researchers looking at the 12-year food intake of over 77,000 nurses found that those with more lutein and zeaxanthin in their diets had a 22 per cent lower risk of cataracts (Am J Clin Nutr, 1999; 70: 509-16). Take 30,000-180,000 IU of vitamin A depending on cataract severity
vitamin C. A potent antioxidant, this vitamin also increases the levels and activity of glutathione (GSH), a polypeptide synthesised in the lens that is crucial for maintaining antioxidants in the eye. One study - albeit in chicks and, thus, not necessarily applicable to humans - found that vitamin C slowed the decline of GSH levels (Exp Eye Res, 1985; 40: 445-51). Take at least 2000 mg/day of vitamin C
vitamin E. There is a link between low levels of vitamin E and an increased risk of cataracts. In patients with early-stage cataracts, 100 mg of vitamin E twice daily significantly decreased cataract size and increased levels of GSH compared with a placebo (Ann Nutr Metab, 1999; 43: 286-9). Take 100-450 IU of vitamin E
B vitamins. Folic acid is important for the production and maintenance of new cells. An Italian study found that those who consumed more folic acid were less than half as likely to develop cataracts than those who were deficient in this water-soluble form of vitamin B (Ann Epidemiol, 1996; 6: 41-6). Take 400 or 800 mcg/day of folic acid
Selenium. A deficiency of this trace mineral is seen in the eyes of people with cataracts, indicating a defective antioxidant system leading to lens changes (Acta Ophthalmol Scand, 1995; 73: 329-32). Take 600 mcg/day of this mineral
Riboflavin. This B vitamin (B2) is essential for GSH function. One study found that adding flavin adenine dinucleotide (FAD), a riboflavin derivative, to surgically removed cataracts restored GSH activity (Curr Eye Res, 1987; 6: 1249-56). As B vitamins tend to work together, take B-complex supplements, which usually contain either 50 or 100 mg of riboflavin
Bilberry (Vaccinum myrtillus). Traditionally used for various eye conditions, this herb contains anthocyanosides, potent antioxidants that are particularly beneficial to the eye and blood vessels. A four-month course of bilberry and vitamin E halted the progression of cataracts in 96 per cent of the study patients (Ann Ottalmol Clin Ocul, 1989; 115: 109). Take one to two 60-mg (standardised to 25 per cent anthocyanosides) bilberry capsules three times a day
More information on surgery-free cataract treatment can be found in The WDDTY Good Sight Guide, available from our offices for lb6.95 (UK) or lb8.45 (overseas).