This week’s Nutrition News evaluates three recent studies that have highlighted the potential health benefits of certain nutrients supporting heart health and eye health.
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Omega 3 could support eye health in Alzheimer’s sufferers
A new study has suggested that omega-3 fatty acids could help alleviate visual problems in people with Alzheimer's disease. The study, reported by Healthline, saw researchers develop a new form of the omega-3 fatty acid docosahexaenoic acid (DHA) that can cross into the retina to minimize visual difficulties related to Alzheimer’s disease and other disorders.
After six months, the subjects given the supplements showed a 96 percent improvement in eye health through retinal DHA content and preserved retinal structure and function. DHA is critical to eyesight and is concentrated in the retina; helping maintain photoreceptors, which are cells that convert light into signals sent to the brain. The results of the study suggest that this supplement could help prevent visual difficulties in those with Alzheimer’s and other cognitive health issues and disorders with common DHA deficiency and visual impairment.
Alzheimer's disease can cause visual impairment due to the brain not processing the information sent to it by the eyes. Vision problems in people with Alzheimer’s disease can be due to peripheral field loss, loss of contrast sensitivity, difficulty with depth perception, or problems with glare. Omega 3 has been shown to support normal brain and eye development in the foetus and breastfed babies and now this new research suggests it may have further applications in supporting eye health.
Although the results are promising, it is important to note that further research is needed to establish the efficacy and safety of this new omega 3 supplement formulation.
Amino acids and antioxidants support heart health post-menopause
A study, reported by NutraIngredients, investigated the effects of the amino acid citrulline combined with the antioxidant glutathione on heart health in healthy postmenopausal women. It was hypothesised menopause support could be offered through combining these nutrients as postmenopausal women may experience endothelial dysfunction due to arginine deficiency relative to asymmetric dimethylarginine caused by oxidative stress. This condition may contribute to increased blood pressure responsiveness to sympathetic activation induced by cold pressor test.
The study involved 44 healthy PMW who were given either citrulline (6 g), citrulline and glutathione (2 g + 200 mg), or a placebo for four weeks. The researchers measured brachial artery flow-mediated dilation (FMD), aortic stiffness (pulse wave velocity, PWV), brachial and aortic BP reactivity to cold pressor test, and serum fasting blood glucose (FBG), arginine, and arginine/asymmetric dimethylarginine ratio.
It was found that baseline FBG was higher in citrulline and glutathione vs. placebo. FMD increased after citrulline and glutathione vs. placebo (p < 0.05). Citrulline and citrulline and glutathione increased arginine/asymmetric dimethylarginine (p < 0.05), but did not affect aortic PWV. Citrulline and glutathione attenuated the brachial and aortic systolic BP and mean arterial pressure (MAP) responses to cold pressor test vs. placebo and citrulline (p < 0.05). The improvements in FMD were related to baseline FMD and aortic MAP response to cold pressor test.
The study concluded that citrulline and glutathione supplementation improved FMD and attenuated systolic BP and MAP reactivity in postmenopausal women, suggesting that such supplementation may reduce the risk of cardiovascular events during moments of physiological stress in postmenopausal women.
Heart health benefits of walnuts to come from the gut
We recently looked at the health benefits of walnuts in the 10th March Nutrition News and now a subsequent study has been published that suggests that eating walnuts could lead to changes in gut microbes that contribute to heart-healthy benefit.
According to research reported by Healthline on 25th March and presented at the DiscoverBMB conference by scientists at Texas Tech University, heart health could benefit from increasing the body’s production of the amino acid L-homoarginine which, in turn, alters the gut microbiome. Using metatranscriptomics, which is the study of gene expressions of gut microbes, the researchers analysed how cardiovascular health could be impacted by diet. Faecal samples were collected from 35 participants with a high risk of cardiovascular disease who followed three different diets: one incorporating whole walnuts; another with the same amount of omega-3 and polyunsaturated fatty acids but without walnuts; and a third that partially substituted the fatty acid oleic acid for the same amount that would have been derived from walnuts, but did not include walnuts.
The researchers found that those on the diet with whole walnuts had higher levels of anti-inflammatory activity in their gut and an increase in the body's production of the amino acid L-homoarginine. These changes suggest that walnuts alter the gut microbiome to induce beneficial pathways that could reduce cardiovascular risk factors.
While the study was industry-funded by the California Walnut Commission, and further research is needed to confirm the observations, previous research has indicated that walnuts are a healthy addition to diets due to their omega-3 fats, antioxidants and fibre content, suggesting that there are multiple benefits to including the nut in your diet.
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Alison is Director and Founder of Metabolics who writes about Metabolics updates, events and natural healthcare. Her experience and passion for natural supplements and healthcare comes from her years of experience as a practising osteopath, having founded Metabolics in her search for high quality, natural products in her own work. Alison has been a qualified and practising Osteopath since 1981 and regularly gives seminars on a range of healthcare subjects to the wider practitioner community helping share her knowledge and experience.