The SA Journal Diabetes & Vascular Disease Volume 18 No 2 (November 2021)

26 VOLUME 18 NUMBER 2 • November 2021 Diabetes news SA JOURNAL OF DIABETES & VASCULAR DISEASE Daily handful of walnuts modestly lowers ‘bad’ cholesterol: two-year US study A daily handful of walnuts every day for two years modestly lowered levels of low-density lipoprotein (LDL) cholesterol, known as ‘bad cholesterol’ and reduced the number of total LDL particles and small LDL particles in healthy, older adults, according to a study in the American Heart Association’s flagship journal Circulation . Healthy older adults who ate a handful of walnuts (about half a cup) a day for two years modestly lowered their level of LDL cholesterol levels. Consuming walnuts daily also reduced the number of LDL particles, a predictor of cardiovascular disease risk. Walnuts are a rich source of omega-3 fatty acids (alpha-linolenic acid), which have been shown to have a beneficial effect on cardiovascular health. ‘Prior studies have shown that nuts in general, and walnuts in particular, are associated with lower rates of heart disease and stroke. One of the reasons is that they lower LDL cholesterol levels, and now we have another reason: they improve the quality of LDL particles,’ said study co-author Dr Emilio Ros, director of the Lipid Clinic at the Endocrinology and Nutrition Service of the Hospital Clínic of Barcelona in Spain. ‘LDL particles come in various sizes. Research has shown that small, dense LDL particles are more often associated with atherosclerosis, the plaque or fatty deposits that build up in the arteries. Our study goes beyond LDL cholesterol levels to get a complete picture of all of the lipoproteins and the impact of eating walnuts daily on their potential to improve cardiovascular risk.’ In a sub-study of the Walnuts and Healthy Ageing study, a large, two-year, randomised, controlled trial examining whether walnuts contribute to healthy ageing, researchers evaluated if regular walnut consumption, regardless of a person’s diet or where they live, has beneficial effects on lipoproteins. MedicalBrief 2021 Up to three cups of coffee daily linked to significant health benefits: UK Biobank analysis U p to three cups of coffee per day is associated with a lower risk of stroke, fatal heart disease and all-cause mortality in a population without diagnosed heart disease over 10 to 15 years, according to a large study presented at the European Society of Cardiology Congress 2021. Coffee may reverse some of the detrimental effects of ageing on the heart, said the lead author. Imaging analysis indicated that compared with participants who did not drink coffee regularly, daily consumers had healthier sized and better functioning hearts. ‘To our knowledge, this is the largest study to systematically assess the cardiovascular effects of regular coffee consumption in a population without diagnosed heart disease,’ said study author Dr Judit Simon of the Heart and Vascular Centre, Semmelweis University, Budapest, Hungary. ‘Our results suggest that regular coffee consumption is safe, as even high daily intake was not associated with adverse cardiovascular outcomes and all-cause mortality after a follow up of 10 to 15 years,’ she continued. ‘Moreover, 0.5 to three cups of coffee per day was independently associated with lower risks of stroke, death from cardiovascular disease and death from any cause.’ Even though coffee is among the most consumed beverages in the world, little is known about the long-term impact of regular consumption on cardiovascular health. This study investigated the association between usual coffee intake and incident heart attack, stroke and death. It included 468 629 participants of the UK Biobank with no signs of heart disease at the time of recruitment. The average age was 56.2 years and 55.8% were women. Participants were divided into three groups according to their usual coffee intake: none (did not consume coffee on a regular basis, 22.1%), light to moderate (0.5 to three cups/day, 58.4%) and high (more than three cups/day, 19.5%). The researchers estimated the association of daily coffee consumption with incident outcomes over a median follow up of 11 years using multivariable models. The analyses were adjusted for factors that could influence the relationship including age, gender, weight, height, smoking status, physical activity, high blood pressure, diabetes, cholesterol level, socio-economic status and usual intake of alcohol, meat, tea, fruit and vegetables. Compared with non-coffee drinkers, light-to-moderate consumption was associated with a 12% lower risk of all- cause death [hazard ratio (HR) = 0.88, p < 0.001], 17% lower risk of death from cardiovascular disease (HR = 0.83, p = 0.006), and 21% lower risk of incident stroke (HR = 0.79; p = 0.037). To examine the potential underlying mechanisms, the researchers analysed the association between daily coffee intake and heart structure and function over a median follow up of 11 years. For this, they used data from 30 650 participants who underwent cardiac magnetic resonance imaging (MRI), which is considered the gold standard for the assessment of cardiac structure and function. Simon said: ‘The imaging analysis indicated that compared with participants who did not drink coffee regularly, daily consumers had healthier sized and better functioning hearts. This was consistent with reversing the detrimental effects of ageing on the heart. Our findings suggest that coffee consumption of up to three cups per day is associated with favourable cardiovascular outcomes. While further studies are needed to explain the underlying mechanisms, the observed benefits might be partly explained by positive alterations in cardiac structure and function.’ MedicalBrief 2021