A Review of Nutritional Requirements of Adults Aged ≥65 Years in the UK.

Appropriate dietary choices in later life may reduce the risk of chronic diseases and rate of functional decline, however, there is little well-evidenced age-specific nutritional guidance in the UK for older adults, making it challenging to provide nutritional advice. Therefore, the aim of this critical review was to propose evidence-based nutritional recommendations for older adults (aged ≥65 y). Nutrients with important physiological functions in older adults were selected for inclusion in the recommendations. For these nutrients: 1) recommendations from the UK Scientific Advisory Committee for Nutrition (SACN) reports were reviewed and guidance retained if recent and age-specific, and 2) a literature search conducted where SACN guidance was not sufficient to set or confirm recommendations for older adults, searching Web of Science up to March 2020. Data extracted from a total of 190 selected publications provided evidence to support age-specific UK recommendations for protein (1.2 g·kg-1·d-1), calcium (1000 mg·d-1), folate (400 µg·d-1), vitamin B-12 (2.4 µg·d-1), and fluid (1.6 L·d-1 women, 2.0 L·d-1 men) for those ≥65 y. UK recommendations for carbohydrates, free sugars, dietary fiber, dietary fat and fatty acids, sodium, and alcohol for the general population are likely appropriate for older adults. Insufficient evidence was identified to confirm or change recommendations for all other selected nutrients. In general, significant gaps in current nutritional research among older adults existed, which should be addressed to support delivery of tailored nutritional guidance to this age group to promote healthy aging.

Association between egg consumption and cardiovascular disease events, diabetes and all-cause mortality.

PURPOSE: The association between egg consumption and cardiovascular disease (CVD) or type 2 diabetes (T2D) remains controversial. We investigated the association between egg consumption and risk of CVD (primary outcome), T2D and mortality in the Caerphilly prospective cohort study (CAPS) and National Diet and Nutritional Survey (NDNS). METHODS: CAPS included 2512 men aged 45-59 years (1979-1983). Dietary intake, disease incidence and mortality were updated at 5-year intervals. NDNS included 754 adults aged 19-64 years from 2008 to 2012. RESULTS: Men free of CVD (n = 1781) were followed up for a mean of 22.8 years, egg consumption was not associated with new incidence of CVD (n = 715), mortality (n = 1028) or T2D (n = 120). When stroke (n = 248), MI (n = 477), heart failure (n = 201) were investigated separately, no associations between egg consumption and stroke and MI were identified, however, increased risk of stroke in subjects with T2D and/or impaired glucose tolerance (IGT, fasting plasma glucose ≥ 6.1 mmol/L), adjusted hazard ratios (95% CI) were 1.0 (reference), 1.09 (0.41, 2.88), 0.96 (0.37, 2.50), 1.39 (0.54, 3.56) and 2.87 (1.13, 7.27) for egg intake (n) of 0 ≤ n ≤ 1, 1 < n ≤ 2, 2 < n ≤ 3, 3 < n < 5, and n ≥ 5 eggs/wk, respectively (P = 0.01). In addition, cross-sectional analyses revealed that higher egg consumption was significantly associated with elevated fasting glucose in those with T2D and/or IGT (CAPS: baseline P = 0.02 and 5-year P = 0.04; NDNS: P = 0.05). CONCLUSIONS: Higher egg consumption was associated with higher blood glucose in subjects with T2D and/or IGT. The increased incidence of stroke with higher egg consumption among T2D and/or IGT sub-group warrants further investigation.

Red Wine and Pomegranate Extracts Suppress Cured Meat Promotion of Colonic Mucin-Depleted Foci in Carcinogen-Induced Rats.

Processed meat intake is carcinogenic to humans. We have shown that intake of a workshop-made cured meat with erythorbate promotes colon carcinogenesis in rats. We speculated that polyphenols could inhibit this effect by limitation of endogenous lipid peroxidation and nitrosation. Polyphenol-rich plant extracts were added to the workshop-made cured meat and given for 14 days to rats and 100 days to azoxymethane-induced rats to evaluate the inhibition of preneoplastic lesions. Colons of 100-d study were scored for precancerous lesions (mucin-depleted foci, MDF), and biochemical end points of peroxidation and nitrosation were measured in urinary and fecal samples. In comparison with cured meat-fed rats, dried red wine, pomegranate extract, α-tocopherol added at one dose to cured meat and withdrawal of erythorbate significantly decreased the number of MDF per colon (but white grape and rosemary extracts did not). This protection was associated with the full suppression of fecal excretion of nitrosyl iron, suggesting that this nitroso compound might be a promoter of carcinogenesis. At optimized concentrations, the incorporation of these plant extracts in cured meat might reduce the risk of colorectal cancer associated with processed meat consumption.

Role of flavonoids and nitrates in cardiovascular health.

CVD remain the leading cause of death globally. Effective dietary strategies for their reduction are of high priority. Increasing evidence suggests that phytochemicals, particularly dietary flavonoids and nitrates, are key modulators of CVD risk reduction through impact on multiple risk factors. The aim of this review is to explore the evidence for the impact of flavonoid- and nitrate-rich foods and supplements on CVD risk, with specific reference to their importance as mediators of vascular health and platelet function. There is accumulating evidence to support benefits of dietary flavonoids on cardiovascular health. Dose-dependent recovery of endothelial function and lowering of blood pressure have been reported for the flavanol (-)-epicatechin, found in cocoa, apples and tea, through production and availability of endothelial nitric oxide (NO). Furthermore, flavonoids, including quercetin and its metabolites, reduce in vitro and ex vivo platelet function via inhibition of phosphorylation-dependent cellular signalling pathways, although further in vivo studies are required to substantiate these mechanistic effects. Hypotensive effects of dietary nitrates have been consistently reported in healthy subjects in acute and chronic settings, although there is less evidence for these effects in patient groups. Proposed mechanisms of actions include endothelial-independent NO availability, which is dependent on the entro-salivary circulation and microbial conversion of dietary nitrate to nitrite in the mouth. In conclusion, flavonoid- and nitrate-rich foods show promising effects on vascular function, yet further randomly controlled studies are required to confirm these findings and to determine effective doses.

New perspectives on dairy and cardiovascular health.

CVD are the leading cause of mortality and morbidity worldwide. One of the key dietary recommendations for CVD prevention is reduction of saturated fat intake. Yet, despite milk and dairy foods contributing on average 27 % of saturated fat intake in the UK diet, evidence from prospective cohort studies does not support a detrimental effect of milk and dairy foods on risk of CVD. The present paper provides a brief overview of the role of milk and dairy products in the diets of UK adults, and will summarise the evidence in relation to the effects of milk and dairy consumption on CVD risk factors and mortality. The majority of prospective studies and meta-analyses examining the relationship between milk and dairy product consumption and risk of CVD show that milk and dairy products, excluding butter, are not associated with detrimental effects on CVD mortality or risk biomarkers that include serum LDL-cholesterol. In addition, there is increasing evidence that milk and dairy products are associated with lower blood pressure and arterial stiffness. These apparent benefits of milk and dairy foods have been attributed to their unique nutritional composition, and suggest that the elimination of milk and dairy may not be the optimum strategy for CVD risk reduction.

A central role for heme iron in colon carcinogenesis associated with red meat intake.

Epidemiology shows that red and processed meat intake is associated with an increased risk of colorectal cancer. Heme iron, heterocyclic amines, and endogenous N-nitroso compounds (NOC) are proposed to explain this effect, but their relative contribution is unknown. Our study aimed at determining, at nutritional doses, which is the main factor involved and proposing a mechanism of cancer promotion by red meat. The relative part of heme iron (1% in diet), heterocyclic amines (PhIP + MeIQx, 50 + 25 µg/kg in diet), and NOC (induced by NaNO2+ NaNO2; 0.17 + 0.23 g/L of drinking water) was determined by a factorial design and preneoplastic endpoints in chemically induced rats and validated on tumors in Min mice. The molecular mechanisms (genotoxicity, cytotoxicity) were analyzed in vitro in normal and Apc-deficient cell lines and confirmed on colon mucosa. Heme iron increased the number of preneoplastic lesions, but dietary heterocyclic amines and NOC had no effect on carcinogenesis in rats. Dietary hemoglobin increased tumor load in Min mice (control diet: 67 ± 39 mm²; 2.5% hemoglobin diet: 114 ± 47 mm², P = 0.004). In vitro, fecal water from rats given hemoglobin was rich in aldehydes and was cytotoxic to normal cells, but not to premalignant cells. The aldehydes 4-hydroxynonenal and 4-hydroxyhexenal were more toxic to normal versus mutated cells and were only genotoxic to normal cells. Genotoxicity was also observed in colon mucosa of mice given hemoglobin. These results highlight the role of heme iron in the promotion of colon cancer by red meat and suggest that heme iron could initiate carcinogenesis through lipid peroxidation. .

The effects of dietary nitrate on blood pressure and endothelial function: a review of human intervention studies.

Evidence has accumulated in recent years that suggests that nitrate from the diet, particularly vegetables, is capable of producing bioactive NO in the vasculature, following bioconversion to nitrite by oral bacteria. The aim of the present review was to consider the current body of evidence for potential beneficial effects of dietary nitrate on blood pressure and endothelial function, with emphasis on evidence from acute and chronic human intervention studies. The studies to date suggest that dietary nitrate acutely lowers blood pressure in healthy humans. An inverse relationship was seen between dose of nitrate consumed and corresponding systolic blood pressure reduction, with doses of nitrate as low as 3 mmol of nitrate reducing systolic blood pressure by 3 mmHg. Moreover, the current studies provide some promising evidence on the beneficial effects of dietary nitrate on endothelial function. In vitro studies suggest a number of potential mechanisms by which dietary nitrate and its sequential reduction to NO may reduce blood pressure and improve endothelial function, such as: acting as a substrate for endothelial NO synthase; increasing vasodilation; inhibiting mitochondrial reactive oxygen species production and platelet aggregation. In conclusion, the evidence for beneficial effects of dietary nitrate on blood pressure and endothelial function is promising. Further long-term randomised controlled human intervention studies assessing the potential effects of dietary nitrate on blood pressure and endothelial function are needed, particularly in individuals with hypertension and at risk of CVD.

Acute ingestion of beetroot bread increases endothelium-independent vasodilation and lowers diastolic blood pressure in healthy men: a randomized controlled trial.

Dietary nitrate, from beetroot, has been reported to lower blood pressure (BP) by the sequential reduction of nitrate to nitrite and further to NO in the circulation. However, the impact of beetroot on microvascular vasodilation and arterial stiffness is unknown. In addition, beetroot is consumed by only 4.5% of the UK population, whereas bread is a staple component of the diet. Thus, we investigated the acute effects of beetroot bread (BB) on microvascular vasodilation, arterial stiffness, and BP in healthy participants. Twenty-three healthy men received 200 g bread containing 100 g beetroot (1.1 mmol nitrate) or 200 g control white bread (CB; 0 g beetroot, 0.01 mmol nitrate) in an acute, randomized, open-label, controlled crossover trial. The primary outcome was postprandial microvascular vasodilation measured by laser Doppler iontophoresis and the secondary outcomes were arterial stiffness measured by Pulse Wave Analysis and Velocity and ambulatory BP measured at regular intervals for a total period of 6 h. Plasma nitrate and nitrite were measured at regular intervals for a total period of 7 h. The incremental area under the curve (0-6 h after ingestion of bread) for endothelium-independent vasodilation was greater (P = 0.017) and lower for diastolic BP (DBP; P = 0.032) but not systolic (P = 0.99) BP after BB compared with CB. These effects occurred in conjunction with increases in plasma and urinary nitrate (P < 0.0001) and nitrite (P < 0.001). BB acutely increased endothelium-independent vasodilation and decreased DBP. Therefore, enriching bread with beetroot may be a suitable vehicle to increase intakes of cardioprotective beetroot in the diet and may provide new therapeutic perspectives in the management of hypertension.

Heme-induced biomarkers associated with red meat promotion of colon cancer are not modulated by the intake of nitrite.

Red and processed meat consumption is associated with the risk of colorectal cancer. Three hypotheses are proposed to explain this association, via heme-induced oxidation of fat, heterocyclic amines, or N-nitroso compounds. Rats have often been used to study these hypotheses, but the lack of enterosalivary cycle of nitrate in rats casts doubt on the relevance of this animal model to predict nitroso- and heme-associated human colon carcinogenesis. The present study was thus designed to clarify whether a nitrite intake that mimics the enterosalivary cycle can modulate heme-induced nitrosation and fat peroxidation. This study shows that, in contrast with the starting hypothesis, drinking water added with nitrite to mimic the salivary nitrite content did not change the effect of hemoglobin on biochemical markers linked to colon carcinogenesis, notably lipid peroxidation and cytotoxic activity in the colon of rat. However, ingested sodium nitrite increased fecal nitroso-compounds level, but their fecal concentration and their nature (iron-nitrosyl) would probably not be associated with an increased risk of cancer. We thus suggest that the rat model could be relevant for study the effect of red meat on colon carcinogenesis, in spite of the lack of nitrite in the saliva of rats.

Blood pressure-lowering effects of beetroot juice and novel beetroot-enriched bread products in normotensive male subjects.

A number of vegetables have a high nitrate content which after ingestion can be reduced to nitrite by oral bacteria, and further to vasoprotective NO endogenously. In the present study, two separate randomly controlled, single-blind, cross-over, postprandial studies were performed in normotensive volunteers. Ambulatory blood pressure (BP) was measured over a 24 h period following consumption of either four doses of beetroot juice (BJ), 0, 100, 250 and 500 g (n 18), or three bread products, control bread (0 g beetroot), red beetroot- and white beetroot-enriched breads (n 14). Total urinary nitrate/nitrite (NO(x)) was measured at baseline, and at 2, 4 and 24 h post-ingestion. BJ consumption significantly, and in a near dose-dependent manner, lowered systolic BP (SBP, P < 0·01) and diastolic BP (DBP, P < 0·001) over a period of 24 h, compared with water control. Furthermore, bread products enriched with 100 g red or white beetroot lowered SBP and DBP over a period of 24 h (red beetroot-enriched bread, P <0·05), with no statistical differences between the varieties. Total urinary NO(x) significantly increased following the consumption of 100 g (P < 0·01), 250 g (P <0·001) and 500 g BJ (P <0·001) and after red beetroot-enriched bread ingestion (P <0·05), but did not reach significance for white beetroot-enriched bread compared with the no-beetroot condition. These studies demonstrated significant hypotensive effects of a low dose (100 g) of beetroot which was unaffected by processing or the presence of betacyanins. These data strengthen the evidence for cardioprotective BP-lowering effects of dietary nitrate-rich vegetables.