Gamma-Tocopherol – An Underestimated Vitamin?

Wagner, Karl‐Heinz; Kamal‐Eldin, Afaf; Elmadfa, Ibrahim

doi:10.1159/000079555

Cited by 242 publications

(153 citation statements)

References 228 publications

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“…γ-Tocopherol content of the pumpkin seed oils was typically 2-8 times higher than the isomer currently regarded as having the greatest bioavailability, R-tocopherol. However, recent research has found that γ-tocopherol may have greater antioxidant activities than R-tocopherol (104)(105)(106) and that the latter may suppress the bioavailability of the former isomer (107). In which case, the considerably higher γ-tocopherol content of pumpkin seed oils could make the oil even more attractive from a nutritional perspective.…”

Section: Resultsmentioning

confidence: 99%

Oil and Tocopherol Content and Composition of Pumpkin Seed Oil in 12 Cultivars

Stevenson

Eller

Wang

et al. 2007

J. Agric. Food Chem.

324

230

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Twelve pumpkin cultivars (Cucurbita maxima D.), cultivated in Iowa, were studied for their seed oil content, fatty acid composition, and tocopherol content. Oil content ranged from 10.9 to 30.9%. Total unsaturated fatty acid content ranged from 73.1 to 80.5%. The predominant fatty acids present were linoleic, oleic, palmitic, and stearic. Significant differences were observed among the cultivars for stearic, oleic, linoleic, and gadoleic acid content of oil. Low linolenic acid levels were observed (<1%). The tocopherol content of the oils ranged from 27.1 to 75.1 μg/g of oil for α-tocopherol, from 74.9 to 492.8 μg/g for γ-tocopherol, and from 35.3 to 1109.7 μg/g for δ-tocopherol. The study showed potential for pumpkin seed oil from all 12 cultivars to have high oxidative stability that would be suitable for food and industrial applications, as well as high unsaturation and tocopherol content that could potentially improve the nutrition of human diets. Keywords: Pumpkin seed oil; pumpkin seed; oilseed; winter squash; Cucurbitaceae; fatty acid; tocopherol

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Section: Resultsmentioning

confidence: 99%

Oil and Tocopherol Content and Composition of Pumpkin Seed Oil in 12 Cultivars

Stevenson

Eller

Wang

et al. 2007

J. Agric. Food Chem.

324

230

View full text Add to dashboard Cite

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“…(10) High consumption of soybean oil is associated with increased serum gamma-tocopherol levels. (11,29) In addition to gamma-tocopherol, soybean oil is also a dietary source of alpha-tocopherol, (11) vitamin K, (86) and omega-3 fatty acids, (10) which may also have beneficial effects on bone. (87,88) To our knowledge, no human studies have examined the association between soybean oil intake and bone metabolism.…”

Section: Discussionmentioning

confidence: 99%

Effects of vitamin E on bone turnover markers among US postmenopausal women

Hamidi

Corey

Cheung

2012

Journal of Bone and Mineral Research

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Increased oxidative stress and inflammation resulting from aging and declining estrogen levels can lead to increased bone loss in postmenopausal women. Alpha-tocopherol and gamma-tocopherol, the two predominant isomers of vitamin E, have antioxidant and anti-inflammatory properties, but their effects on bone metabolism have not been well studied in humans. We examined the associations between dietary and total (diet and supplements) alpha-tocopherol intake, serum alpha-tocopherol and gamma-tocopherol levels and their ratio, and bone turnover markers (BTMs) among postmenopausal women aged !45 years. We used cross-sectional data from the National Health and Nutrition Examination Survey 1999-2002. Multiple regression models with adjustments for relevant confounders were used to examine the associations between intake and serum levels of tocopherols, and serum bone-specific alkaline phosphatase (BAP), a biomarker of bone formation, and urinary N-telopeptides/creatinine (uNTx/Cr), a biomarker of bone resorption. The study sample included 497 postmenopausal women who were not taking estrogen, steroids, or osteoporosis medications, were free from kidney and liver disease, cancer, and rheumatoid arthritis, and were fasting >9 hours prior to examination. Participants had a mean age of 65.5 AE 0.6 years and over 45% used vitamin E (alpha-tocopherol) supplements in the past month. Vitamin E supplement users had significantly lower serum gamma-tocopherol, higher serum alpha-tocopherol levels, and higher ratio of serum alpha-tocopherol to gamma-tocopherol than nonusers. High serum gamma-tocopherol levels and low ratio of serum alpha-tocopherol to gamma-tocopherol were associated with increased BAP levels (p < 0.01 for both). There were no associations between any of the vitamin E variables and uNTx/Cr. In conclusion, we hypothesize that gamma-tocopherol may uncouple bone turnover, resulting in more bone formation than resorption. Vitamin E supplements in the form of alpha-tocopherol suppress serum gamma-tocopherol levels and may have negative effects on bone formation. Further research is needed to investigate the potential anabolic effect of gamma-tocopherol from food sources on bone. ß

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“…Nuts are also rich sources of antioxidant vitamins (e.g., tocopherols) and phenolic compounds, necessary to protect the germ from oxidative stress and preserve the reproductive potential of the seed, but also bioavailable after consumption and capable of providing a significant antioxidant load [25]. Almonds in particular are especially rich in α-tocopherol, while walnuts contain significant amounts of its isomer γ-tocopherol, which has been investigated much less than α-tocopherol, but is increasingly recognized as a relevant antiatherogenic molecule [31]. Remarkably, in all nuts most of the antioxidants are located in the pellicle or outer soft shell, as shown for almonds [32,33] and peanuts [34], and 50% or more of them are lost when the skin is removed [25].…”

Section: Nutrient Content Of Nutsmentioning

confidence: 99%

Health Benefits of Nut Consumption

2010

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Nuts (tree nuts and peanuts) are nutrient dense foods with complex matrices rich in unsaturated fatty and other bioactive compounds: high-quality vegetable protein, fiber, minerals, tocopherols, phytosterols, and phenolic compounds. By virtue of their unique composition, nuts are likely to beneficially impact health outcomes. Epidemiologic studies have associated nut consumption with a reduced incidence of coronary heart disease and gallstones in both genders and diabetes in women. Limited evidence also suggests beneficial effects on hypertension, cancer, and inflammation. Interventional studies consistently show that nut intake has a cholesterol-lowering effect, even in the context of healthy diets, and there is emerging evidence of beneficial effects on oxidative stress, inflammation, and vascular reactivity. Blood pressure, visceral adiposity and the metabolic syndrome also appear to be positively influenced by nut consumption. Thus it is clear that nuts have a beneficial impact on many cardiovascular risk factors. Contrary to expectations, epidemiologic studies and clinical trials suggest that regular nut consumption is unlikely to contribute to obesity and may even help in weight loss. Safety concerns are limited to the infrequent occurrence of nut allergy in children. In conclusion, nuts are nutrient rich foods with wide-ranging cardiovascular and metabolic benefits, which can be readily incorporated into healthy diets.

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Gamma-Tocopherol – An Underestimated Vitamin?

Cited by 242 publications

References 228 publications

Oil and Tocopherol Content and Composition of Pumpkin Seed Oil in 12 Cultivars

Oil and Tocopherol Content and Composition of Pumpkin Seed Oil in 12 Cultivars

Effects of vitamin E on bone turnover markers among US postmenopausal women

Health Benefits of Nut Consumption

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