The UK Food Standards Agency convened a group of expert scientists to review current research investigating whether n-3 polyunsaturated fatty acids (PUFA) from plant oils (a-linolenic acid; ALA) were as beneficial to cardiovascular health as the n-3 PUFA from the marine oils, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The workshop also aimed to establish priorities for future research. Dietary intake of ALA has been associated with a beneficial effect on CHD; however, the results from studies investigating the effects of ALA supplementation on CHD risk factors have proved equivocal. The studies presented as part of the present workshop suggested little, if any, benefit of ALA, relative to linoleic acid, on risk factors for cardiovascular disease; the effects observed with fish-oil supplementation were not replicated by ALA supplementation. There is a need, therefore, to first prove the efficacy of ALA supplementation on cardiovascular disease, before further investigating effects on cardiovascular risk factors. The workshop considered that a beneficial effect of ALA on the secondary prevention of CHD still needed to be established, and there was no reason to look further at existing CHD risk factors in relation to ALA supplementation. The workshop also highlighted the possibility of feeding livestock ALA-rich oils to provide a means of increasing the dietary intake in human consumers of EPA and DHA. a-Linolenic acid: Fish oils: Cardiovascular disease: Nutrition researchThe Food Standards Agency (FSA) convened a workshop on 18 March 2002, to examine the role of a-linolenic acid (ALA) in relation to cardiovascular disease. The results from recently completed studies were presented, both FSA-and non-FSA-funded, and the workshop was chaired by Professor Martijn Katan, Wageningen University, The Netherlands. The aim of the workshop was to determine where this work has taken us and where further work should be concentrated, as well as acting as a vehicle for dissemination. The research recommendations emanating from the workshop discussions will feed into the future direction of the UK FSA-funded nutrition research, and may also be of value in guiding other funders internationally. BackgroundThe long chain n-3 polyunsaturated fatty acids (PUFA), eicosapentanoic acid (EPA; 20 : 5n-3) and docosahexaenoic * (GISSI-Prevenzione Investigators, 1999). EPA and DHA also have a variety of beneficial effects on risk factors for CHD. Oily fish is the richest dietary source of EPA and DHA, but fish consumption is low in habitual UK diets (Department of the Environment, Food and Rural Affairs, 2001). An alternative source of n-3 PUFA is the more abundant ALA (18 : 3n-3), which can be elongated and desaturated to its long-chain derivatives EPA and DHA; however, in man the extent and regulation of this conversion is unclear. The question arises, therefore, whether plant oils rich in ALA (for example, linseed, rapeseed and nut oils) could reproduce the beneficial effects of fish consumption on risk for cardiovascular...

Abnormalities of autonomic control of the cardiovascular system are seen in chronic heart failure (CHF) and confer a poor prognosis. Nitric oxide appears to be important in the regulation of baroreflex control in health and in disease states. The antioxidant vitamin C increases nitric oxide bioavailability in CHF. We evaluated the effects of vitamin C on baroreceptor sensitivity (BRS) by sequence analysis in 100 CHF patients and 44 control subjects. Groups of 55 CHF patients and 22 controls were randomly allocated to receive a single intravenous injection of vitamin C (2 g) or placebo. In addition, 45 CHF patients were randomly allocated to receive a 4-week course of oral vitamin C (4 g/day) or placebo. An age-related reference range for BRS was developed in 22 healthy controls matched for age and gender to the CHF group. BRS was significantly impaired in the CHF group compared with age-matched older controls and young controls (6.9 +/- 3.1, 12.5 +/- 4.9 and 21.7 +/- 9.1 mmHg/ms respectively; P < 0.001 between groups). Intravenous vitamin C acutely improved BRS in CHF patients by 24% (by 1.8 +/- 4.1 mmHg/ms; P < 0.05), but not in controls. There was no improvement in BRS in CHF patients given chronic oral vitamin C. Thus acute intravenous, but not chronic oral, vitamin C improved BRS in CHF patients. There was no effect of intravenous vitamin C in healthy subjects, suggesting that the mechanism was either by free radical scavenging or due to central effects.

ED in both diabetic and non-diabetic men is characterized by marked endothelial dysfunction in comparison with non-diabetic control subjects. Response to sildenafil is not predicted by either endothelial function or autonomic function, but in diabetic men appears to be related to the initial degree of erectile dysfunction.

These data uncover a role of endogenous endothelin-1 in the maintenance of basal vasomotor tone in patients with angiographically normal coronary arteries.

Background: Chronic heart failure (CHF) is associated with abnormalities of skeletal muscle metabolism. This may be due to impaired oxygen delivery as a result of endothelial dysfunction. Aims: We postulated that ascorbic acid would improve oxygen delivery to exercising muscle and improve skeletal muscle metabolism. Methods: We studied skeletal muscle metabolism using 31 P magnetic resonance spectroscopy in 39 CHF patients. Endothelial function was assessed by changes in pulse wave velocity. Subjects were randomised to receive 4 g ascorbic acid daily for 4 weeks in a placebo-controlled double-blind study. Results: Ascorbic acid significantly increased phosphocreatine utilization during exercise. In addition, glycolytic ATP synthesis increased in the ascorbic acid group (change in rate of ATP synthesis at 1 min −0.21 ± 0.76 with placebo, 2.06 ± 0.60 following ascorbic acid; p b 0.05). Phosphocreatine and ADP recovery after exercise were not changed. The fall in pulse wave velocity during reactive hyperaemia was increased by ascorbic acid from − 6.3 ± 2.6% to −12.1 ± 2.0% (p b 0.05). Conclusions: These findings suggest that ascorbic acid increased both phosphocreatine utilization and glycolytic ATP synthesis during exercise in patients with CHF implying worsened skeletal muscle metabolism despite improvements in endothelial function.