Are walnuts the key to weight loss and improving cholesterol?
Forget salad, there could be another food that is great for shedding those excess pounds, and it might just help to protect your heart in the long run! The key to losing weight could surprisingly be walnuts, according to the findings of a new study, whereby scientists found that a diet rich in both olive oil and walnuts – one of the most popular and versatile of all the nuts - could help boost weight loss as well as increasing the ‘good’ HDL cholesterol levels in overweight people. The weight loss results were comparable to that of being on a lower fat, higher carbohydrate diet and with regards to the findings, the study has recommended people eating even just a handful of them each day. Researchers involved with the study say it is even more beneficial to eat walnuts which are high in polyunsaturated fats, as they will provide extra boost to heart health as well as lower cholesterol. Study author Dr Cheryl Rock, of the San Diego School of Medicine at the University of California, said she was surprised by the results demonstrated in the study. “One of the surprising findings of this study was even though walnuts are higher in fat and calories, the walnut-rich diet was associated with the same degree of weight loss as a lower fat diet. “Considering the results of this study, as well as previous walnut research on heart health and weight, there's something to be said for eating a handful of walnuts a day.” To come to their conclusion, the team of researchers analysed 245 overweight or obese women aged between 22 and 72, all of whom were part of a one-year weight loss programme. The women were randomly assigned to one of three different diets. The first was a lower fat and higher carbohydrate diet, the second was a lower carbohydrate and higher fat diet, whilst the third was a walnut-rich, higher fat and lower carbohydrate diet. Those assigned to the walnut-rich diet would consume around 43g (1.5 ounces) of the nuts a day – which works out at around one and a half handfuls. After a six month follow-up, it was discovered that women across all of the groups had lost an average of nearly 8% of their initial weight. Women given the walnut-rich diet were found to have similar amounts of weight to the two other groups, however also had the added benefit of noticeable improvements in their cholesterol levels compared to the women in the other groups. Specifically, there was a significant decrease noted in the LDL cholesterol (the ‘bad’ cholesterol) and an increase in HDL cholesterol (the ‘good’ cholesterol). This was not evident within the other diet groups. This happened to be particularly noticeable in the women who were insulin-resistant - a precursor of diabetes. The researchers believe this was the case as the low-carb high-fat diet group were urged to eat more foods rich in monounsaturated fats, found in a variety of foods and oils. Foods high in monounsaturated fatty acids are believed to improve blood cholesterol levels, thereby lowering the risk of heart disease. The walnut-rich diet was found to offer a large amount of polyunsaturated fats though, and in fact walnuts are the only nut where the fat is mainly polyunsaturated, which comprises of a high quantity of alpha-linolenic acid (ALA). ALA is a plant-derived form of omega-3 fatty acid, an important part of a healthy working body. Omega 3 must be obtained from a person’s diet due to the body being unable to generate it itself. This ultimately means many have insufficient levels of the fatty acid. Dr Rock admitted as the study only included women, the results may not be the same for men, and did not measure whether the women actually fully stuck to the diets assigned to them, although the women probably adhered to them considering the weight loss experienced. “In addition to these findings, we hope to explore the effect of walnuts on satiety, as we believe satiety is a critical factor for maintaining weight loss,” Dr Rock concluded.