1.
Dietary phytochemicals in breast cancer research: anticancer effects and potential utility for effective chemoprevention.
Kapinova, A, Kubatka, P, Golubnitschaja, O, Kello, M, Zubor, P, Solar, P, Pec, M
Environmental health and preventive medicine. 2018;23(1):36
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Plain language summary
Bioactive phytochemicals are continually being studied for their role in cancer prevention with increasing evidence for flavonoids, carotenoids, phenolic acids, and organosulfur compounds (found in cruciferous vegetables). This 2018 review explores the protective effects of a broad spectrum of plant-derived substances. In total, more than 5000 individual phytochemicals have been identified in plant-derived foods, such as fruits, vegetables, and grains. These bioactive compounds have been shown to have antitumor activity, reduce inflammation, induce apoptosis (cell death), inhibit the proliferation of aggressive tumour cells, and impact on metastasis (migration of cancer cells). Specifically, in breast cancer, a few studies have examined phytochemicals on cancer stem cells (the originating tumour cells) and found that curcumin, genistein, indol-3-carbinol, c-phycocyanin, resveratrol, and quercetin downregulated their activity. Systematic reviews of dietary patterns and breast cancer show vegetables, and especially fibre, to be consistently protective against reduced risk of mammary carcinogenesis. Dietary polyphenols are considered a cost-effective approach to cancer care however there is still a lack of evidence due to the complex nature of combined phytochemicals versus isolated agents. Wholefood consumption is considered to improve bioavailability compared to supplementation however phytochemicals are a low-dose component of foods. There is also concern that some phytochemicals may act as carcinogens or tumour promoters (for example, beta-carotene). More clinical trials are required to fully understand phytochemicals and breast cancer care.
Abstract
Cancerous tissue transformation developing usually over years or even decades of life is a highly complex process involving strong stressors damaging DNA, chronic inflammation, comprehensive interaction between relevant molecular pathways, and cellular cross-talk within the neighboring tissues. Only the minor part of all cancer cases are caused by inborn predisposition; the absolute majority carry a sporadic character based on modifiable risk factors which play a central role in cancer prevention. Amongst most promising candidates for dietary supplements are bioactive phytochemicals demonstrating strong anticancer effects. Abundant evidence has been collected for beneficial effects of flavonoids, carotenoids, phenolic acids, and organosulfur compounds affecting a number of cancer-related pathways. Phytochemicals may positively affect processes of cell signaling, cell cycle regulation, oxidative stress response, and inflammation. They can modulate non-coding RNAs, upregulate tumor suppressive miRNAs, and downregulate oncogenic miRNAs that synergically inhibits cancer cell growth and cancer stem cell self-renewal. Potential clinical utility of the phytochemicals is discussed providing examples for chemoprevention against and therapy for human breast cancer. Expert recommendations are provided in the context of preventive medicine.
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Cardiovascular Health Benefits of Specific Vegetable Types: A Narrative Review.
Blekkenhorst, LC, Sim, M, Bondonno, CP, Bondonno, NP, Ward, NC, Prince, RL, Devine, A, Lewis, JR, Hodgson, JM
Nutrients. 2018;10(5)
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Diets high in vegetables are linked with a lower incidence of chronic disease. Some vegetables may have much larger health benefits in comparison to others, and therefore dietary guidelines could be developed to include targeted advice on consuming specific types of vegetables with the greatest health benefits. This review of observational studies focused on the cardiovascular health benefits of specific vegetable types. Vegetables discussed in this review were grouped into the following types: leafy green, cruciferous, alliums, yellow-orange-red and legumes. These vegetables contain many nutrients and phytochemicals that have been proposed to have benefits for cardiovascular health. The authors looked at the results from nearly 100 observational studies. Most of the studies were carried out on older adults; some were focussed on a single gender (male or female), and some were mixed. Follow up periods in the studies ranged from 3 years to 28 years. Most of the studies relied on food frequency questionnaires (FFQs) to estimate vegetable consumption, and many did not define the size of a vegetable portion in grams. The percentage of studies demonstrating significant benefits of vegetable consumption on CVD ranged from 25% for legumes to 43% for leafy greens. The strongest beneficial effects on CVD risk were seen for leafy green and cruciferous vegetables. The authors concluded that the evidence in this review suggests intake of leafy green and cruciferous vegetables may confer strong cardiovascular health benefits. Increasing vegetable intake, with a focus on leafy green and cruciferous vegetables may provide the greatest benefits.
Expert Review
Conflicts of interest:
Educator for various organizations, such as Institute for Functional Medicine, American Academy for Anti-Aging Medicine
Take Home Message:
- Green leafy vegetables and cruciferous vegetables were found to most impactful for cardiovascular health.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
This review highlights the role of specific types of vegetables based on color and nutrients for cardiovascular health benefit.
Clinical practice applications:
The authors investigated whether some vegetable types were more relevant for cardiovascular-related issues than others. Based on their review of the scientific literature, green, leafy vegetables and cruciferous vegetables were found to be most impactful.
Considerations for future research:
This review suggests that more research is needed to understand how certain plant foods, vegetables, and phytochemicals may be functionally important for certain organ systems.
Abstract
Adequate vegetable consumption is one of the cornerstones of a healthy diet. The recommendation to increase vegetable intake is part of most dietary guidelines. Despite widespread and long-running public health messages to increase vegetable intake, similar to other countries worldwide, less than 1 in 10 adult Australians manage to meet target advice. Dietary guidelines are predominantly based on studies linking diets high in vegetables with lower risk of chronic diseases. Identifying vegetables with the strongest health benefits and incorporating these into dietary recommendations may enhance public health initiatives around vegetable intake. These enhanced public health initiatives would be targeted at reducing the risk of chronic diseases, such as cardiovascular diseases (CVD). Specific vegetable types contain high levels of particular nutrients and phytochemicals linked with cardiovascular health benefits. However, it is not clear if increasing intake of these specific vegetable types will result in larger benefits on risk of chronic diseases. This review presents an overview of the evidence for the relationships of specific types of vegetables, including leafy green, cruciferous, allium, yellow-orange-red and legumes, with subclinical and clinical CVD outcomes in observational epidemiological studies.