Serum Ascorbic Acid and Other Correlates of Self-Reported Cataract Among Older Americans

doi:10.1016/S0895-4356(99)00110-9

Journal of Clinical Epidemiology

Volume 52, Issue 12, December 1999, Pages 1207-1211

https://doi.org/10.1016/S0895-4356(99)00110-9 Get rights and content

Abstract

The purpose of this study was to examine the correlates of self-reported cataract among older Americans, and specifically, to determine whether serum ascorbic acid levels are associated with a decreased prevalence of cataract. A national probability survey of Americans, the Second National Health and Nutrition Examination Survey (NHANES II), was conducted between 1976 and 1980. A total of 4001 participants were included between the ages of 60 and 74 years with data on serum ascorbic acid level and other variables of interest. A total of 252 women (12%) and 164 men (9%) reported a history of cataract. Serum ascorbic acid level was inversely associated with prevalence of cataract in multiple logistic regression analyses; each 1 mg/dl increase was independently associated with a 26% decrease in cataract (P = 0.03). Other independent correlates of cataract included increasing age, female sex, smoking, and diabetes mellitus (all P < 0.01). We identified four correlates of cataract among older Americans: serum ascorbic acid level, increasing age, smoking, and diabetes mellitus. Ascorbic acid, a water-soluble antioxidant found in high concentrations in the lens, may be of importance for the prevention of cataract among older Americans.

Introduction

Cataracts affect many older Americans and are an important cause of blindness 1, 2. Because oxidative damage to the lens may be related to the development of cataract [3], antioxidant nutrients may have the potential to decrease the risk of cataract formation. Ascorbic acid, an important water-soluble antioxidant, is of particular interest because it is found it high concentrations in the lens and aqueous humor of the eye [4]. The relation of ascorbic acid to cataract is uncertain, however; some studies have found that low ascorbic acid intakes 5, 6, 7 or low ascorbic acid blood levels [8] are a risk factor for cataract,while other studies have not 9, 10, 11, 12. To date, the relation between serum ascorbic acid and cataract has not been examined in a large representative sample of the United States population.

To determine whether serum ascorbic acid levels and other nutrient antioxidants are correlated with prevalence of self-reported cataract, we analyzed data from the Second National Health and Nutrition Examination Survey (NHANES II) that included serum ascorbic acid levels and dietary intake data on over 9000 older Americans.

Section snippets

Study Population

NHANES II was a national probability survey of over 20,000 Americans conducted between 1976 and 1980 that employed a stratified, cluster sampling design to oversample populations of special interest, such as low-income Americans [13]. Adult participants were interviewed and examined by study personnel at two visits [13]. Complete data from 2100 women and 1901 men between the ages of 60 and 74 years were available for multivariate analyses.

Measurements

NHANES II questionnaire data included self-reported age,

Results

The characteristics of the participants included in these analyses are provided in Table 1. The sample was approximately equally divided between women (54%) and men (46%). All variables analyzed were, with the exception of history of smoking, similar in men and women. Men were more likely than women to report a past history of smoking (75% vs. 37%). Approximately 9% of women reported using hormones. Fewer than 1% of all participants reported use of steroid medications in the prior week or use

Discussion

High serum ascorbic acid levels were independently associated with a lower prevalence of cataract among NHANES II participants age 60 to 74 years; each 1 mg/dl increase in serum ascorbic acid level was associated with a 26% reduction in the prevalence of cataract. Other significant correlates of cataract were increasing age, female sex, smoking, and diabetes mellitus. These findings concur with other observational studies that found high plasma levels of ascorbic acid 8, 16, high dietary

Acknowledgements

This study was supported by Public Health Service grant HL53479 and funding from Hoffmann-La Roche, Inc.

References (36)

P.F. Jacques et al.
Nutritional status in persons with and without senile cataractBlood vitamin and mineral levels
Am J Clin Nutr
(1988)
P.F. Jacques et al.
Epidemiologic evidence of a role for the antioxidant vitamins and carotenoids in cataract prevention
Am J Clin Nutr
(1991)
P.F. Jacques et al.
Long-term vitamin C supplement use and prevalence of early age-related lens opacities
Am J Clin Nutr
(1997)
S.D. Varma
Scientific basis for medical therapy of cataracts by antioxidants
Am J Clin Nutr
(1991)
B.E. Klein et al.
Cigarette smoking and lens opacitiesThe Beaver Dam Eye Study
Am J Prev Med
(1993)
F. Ederer et al.
Senile lens changes and diabetes in two populations
Am J Ophthalmol
(1981)
M.C. Leske et al.
The epidemiology of senile cataractsA review
Am J Epidemiol
(1983)
W.G. Hodge et al.
Risk factors for age-related cataracts
Epidemiol Rev
(1995)
P.F. Jacques
Antioxidants and cataracts
Epidemiology
(1993)
S.D. Varma
Ascorbic acid and the eye with special reference to the lens
Ann NY Acad Sci
(1987)

J.M. Robertson et al.

Vitamin E intake and risk of cataracts in humans

Ann NY Acad Sci

(1989)

M.C. Leske et al.

The Lens Opacities Case-Control Study

Arch Ophthalmol

(1991)

S.E. Hankinson et al.

Nutrient intake and cataract extraction in womenA prospective study

BMJ

(1992)

M. Mohan et al.

India-US Case-Control Study of Age-related Cataracts

Arch Ophthalmol

(1989)

Risk factors for age-related cortical, nuclear, and posterior subcapsular cataracts

Am J Epidemiol

(1991)

S. Vitale et al.

Plasma antioxidants and risk of cortical and nuclear cataract

Epidemiology

(1993)

L. Wong et al.

Sunlight exposure, antioxidant status, and cataract in Hong Kong fishermen

J Epidemiol Comm Health

(1993)

Plan and Operation of the Second National Health and Nutrition Examination Survey, 1976–1980. [DHHS publication (PHS) 81-1317]

(1981)

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La carence en vitamine C reste une anomalie biologique sous-évaluée dans la population générale et notamment chez la personne âgée fragile de plus de 75 ans. Les manifestations cliniques d’une carence modérée en vitamine C restent non spécifiques, mais peuvent aller en cas de carence profonde et prolongée, vers un syndrome hémorragique et des manifestations stomatologiques comme les gingivorragies et les pertes de dents. On assiste ainsi à une ré-emergence du scorbut, chez les personnes âgées, qui restent une population à risque. Le traitement consiste en une prise de vitamine C, à une posologie de 1 g/j, pour une durée de 15 jours.
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The oxidized form of vitamin E, i.e., tocotrienoxyl or tocopheroxyl radical can be regenerated to the reduced native state, tocotrienol and tocopherol, through oxidation of vitamin C and glutathione (Fig. 6).48,49 The National Health and Nutrition Examination Survey II study reported the amount of ascorbic acid consumption and its serum levels were inversely associated with the number of cataract cases.46,50 Supporting51,52 and conflicting results53–55 were also reported.
The eyes are exposed to oxidative stress due to light absorption and the high metabolism rate of their tissue cells. Oxidative stress plays an important role in the pathogenesis of many major eye diseases, including ocular inflammation, neovascularization, age-related macular degeneration, glaucoma, and cataracts. Herbal molecules, such as lutein, zeaxanthin, omega-3 fatty acids, vitamin C, and vitamin E, have been tried as ocular aliments. Although there are many positive outcomes for preventive or even therapeutic uses for ocular diseases, the efficacy remains controversial. Nevertheless, traditional Chinese medicine remains the best choice of herbal molecules mining for ocular remedies.
Polymorphisms in sodium-dependent vitamin C transporter genes and plasma, aqueous humor and lens nucleus ascorbate concentrations in an ascorbate depleted setting
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Use of any nutritional supplement is very low in India; in our previous study we found less than 1% use (Ravindran et al., 2011a). In the US and European populations, median plasma ascorbate concentrations are typically 50 μmol/L or greater (Simon et al., 1999; Woodside et al., 2013). There are few studies of ascorbate concentrations in aqueous humor and lens in humans.
We have previously reported low concentrations of plasma ascorbate and low dietary vitamin C intake in the older Indian population and a strong inverse association of these with cataract. Little is known about ascorbate levels in aqueous humor and lens in populations habitually depleted of ascorbate and no studies in any setting have investigated whether genetic polymorphisms influence ascorbate levels in ocular tissues. Our objectives were to investigate relationships between ascorbate concentrations in plasma, aqueous humor and lens and whether these relationships are influenced by Single Nucleotide Polymorphisms (SNPs) in sodium-dependent vitamin C transporter genes (SLC23A1 and SLC23A2). We enrolled sixty patients (equal numbers of men and women, mean age 63 years) undergoing small incision cataract surgery in southern India. We measured ascorbate concentrations in plasma, aqueous humor and lens nucleus using high performance liquid chromatography. SLC23A1 SNPs (rs4257763, rs6596473) and SLC23A2 SNPs (rs1279683 and rs12479919) were genotyped using a TaqMan assay. Patients were interviewed for lifestyle factors which might influence ascorbate. Plasma vitamin C was normalized by a log₁₀ transformation. Statistical analysis used linear regression with the slope of the within-subject associations estimated using beta (β) coefficients. The ascorbate concentrations (μmol/L) were: plasma ascorbate, median and inter-quartile range (IQR), 15.2 (7.8, 34.5), mean (SD) of aqueous humor ascorbate, 1074 (545) and lens nucleus ascorbate, 0.42 (0.16) (μmol/g lens nucleus wet weight). Minimum allele frequencies were: rs1279683 (0.28), rs12479919 (0.30), rs659647 (0.48). Decreasing concentrations of ocular ascorbate from the common to the rare genotype were observed for rs6596473 and rs12479919. The per allele difference in aqueous humor ascorbate for rs6596473 was −217 μmol/L, p < 0.04 and a per allele difference in lens nucleus ascorbate of −0.085 μmol/g, p < 0.02 for rs12479919. The β coefficients for the regression of log₁₀ plasma ascorbate on aqueous humor ascorbate were higher for the GG genotype of rs6596473: GG, β = 1460 compared to carriage of the C allele, CG, β = 1059, CC, β = 1132, p interaction = 0.1. In conclusion we found that compared to studies in well-nourished populations, ascorbate concentrations in the plasma, aqueous humor and lens nucleus were low. We present novel findings that polymorphisms in SLC23A1/2 genes influenced ascorbate concentration in aqueous humor and lens nucleus.
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Age-related cataract is the most common cause of reversible loss of useful vision worldwide. Numerous epidemiologic studies have been conducted on the relationship between intake of antioxidant vitamins and risk of cataract in older people. These studies have produced conflicting findings, but there are few studies about fruit and vegetables, which are rich in antioxidant nutrients, micronutrients, phytochemicals, and fiber. We first reviewed the assessment of fruit and vegetable intake and the association between these factors and the risk of age-related cataract. We then explained the possible correlation mechanisms of dietary fruit and vegetable intake and age-related cataract in detail. Finally, we showed that a diet in concordance with general dietary guidelines may possibly be beneﬁcial to age-related cataract.
Inverse association of vitamin C with cataract in older people in India
2011, Ophthalmology
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By comparison in the India Age-Related Eye Disease Study, the lowest and highest quintile cut points were <2 and >21 μmol/L. In the National Health and Nutrition Examination Survey, a 1 mg/dL increase in serum vitamin C (equivalent to a 58 μmol/L increase) was associated with a 26% reduction in self-reported cataract.21 The average vitamin C levels were 62 μmol/L (standard deviation = 28).
To examine the association between vitamin C and cataract in the Indian setting.
Population-based cross-sectional analytic study.
A total of 5638 people aged ≥60 years.
Enumeration of randomly sampled villages in 2 areas of north and south India to identify people aged ≥60 years. Participants were interviewed for socioeconomic and lifestyle factors (tobacco, alcohol, household cooking fuel, work, and diet); attended a clinical examination, including lens photography; and provided a blood sample for antioxidant analysis. Plasma vitamin C was measured using an enzyme-based assay in plasma stabilized with metaphosphoric acid, and other antioxidants were measured by reverse-phase high-pressure liquid chromatography.
Cataract and type of cataract were graded from digital lens images using the Lens Opacity Classification System III (LOCS III), and cataract was classified from the grade in the worse eye of ≥4 for nuclear cataract, ≥3 for cortical cataract, and ≥2 for posterior subcapsular cataract (PSC). Any cataract was defined as any unoperated or operated cataract.
Of 7518 enumerated people, 5638 (75%) provided data on vitamin C, antioxidants, and potential confounders. Vitamin C was inversely associated with cataract (adjusted odds ratio [OR] for highest to lowest quartile = 0.61; 95% confidence interval (CI), 0.51–0.74; P=1.1×10⁻⁶). Inclusion of other antioxidants in the model (lutein, zeaxanthin, retinol, β-carotene, and α-tocopherol) made only a small attenuation to the result (OR 0.68; 95% CI, 0.57–0.82; P < 0.0001). Similar results were seen with vitamin C by type of cataract: nuclear cataract (adjusted OR 0.66; CI, 0.54–0.80; P < 0.0001), cortical cataract (adjusted OR 0.70; CI, 0.54–0.90; P < 0.002), and PSC (adjusted OR 0.58; CI, 0.45–0.74; P < 0.00003). Lutein, zeaxanthin, and retinol were significantly inversely associated with cataract, but the associations were weaker and not consistently observed by type of cataract. Inverse associations were also observed for dietary vitamin C and cataract.
We found a strong association with vitamin C and cataract in a vitamin C–depleted population.
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Nutrition and eye-related disorders
2008, Food for the Ageing Population: A volume in Woodhead Publishing Series in Food Science, Technology and Nutrition
Age-related cataract and age-related macular degeneration (AMD) are the major causes of visual impairment and blindness in the aging population. There is much interest in the prevention of these two age-related eye diseases. Of particular interest is the possibility that certain dietary components intervention might reduce the incidence or retard the progression of these diseases. The nutrients that may be important in the prevention of these eye diseases are vitamins C and E and the carotenoids, lutein and zeaxanthin, zinc, and omega-3 fatty acids. There is biological plausibility to support a role of these dietary components in the protection of the lens and macula from light damage. Further support comes from epidemiologic studies evaluating dietary intakes and risk of these eye diseases.

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Original articlesSerum Ascorbic Acid and Other Correlates of Self-Reported Cataract Among Older Americans

Abstract

Introduction

Section snippets

Study Population

Measurements

Results

Discussion

Acknowledgements

Am J Clin Nutr

Am J Clin Nutr

Am J Clin Nutr

Am J Clin Nutr

Am J Prev Med

Am J Ophthalmol

The epidemiology of senile cataractsA review

Am J Epidemiol

Risk factors for age-related cataracts

Epidemiol Rev

Antioxidants and cataracts

Epidemiology

Ascorbic acid and the eye with special reference to the lens

Ann NY Acad Sci

Vitamin E intake and risk of cataracts in humans

Ann NY Acad Sci

The Lens Opacities Case-Control Study

Arch Ophthalmol

Nutrient intake and cataract extraction in womenA prospective study

BMJ

India-US Case-Control Study of Age-related Cataracts

Arch Ophthalmol

Risk factors for age-related cortical, nuclear, and posterior subcapsular cataracts

Am J Epidemiol

Plasma antioxidants and risk of cortical and nuclear cataract

Epidemiology

Sunlight exposure, antioxidant status, and cataract in Hong Kong fishermen

J Epidemiol Comm Health

Plan and Operation of the Second National Health and Nutrition Examination Survey, 1976–1980. [DHHS publication (PHS) 81-1317]

Original articles
Serum Ascorbic Acid and Other Correlates of Self-Reported Cataract Among Older Americans