Consuming about 60 grammes of tree nuts, such as walnuts, daily may lower the risk of cardiovascular disease, a new study has claimed.
After conducting a systematic review and meta-analysis of 61 controlled trials, Michael Falk from Life Sciences Research Organisation in US, found that consuming tree nuts lowers total cholesterol, triglycerides, LDL (bad) cholesterol, and ApoB, the primary protein found in LDL cholesterol.
These are key factors that are used to evaluate a person’s risk of cardiovascular disease. Walnuts were investigated in 21 of the 61 trials, more than any other nut reviewed in this study, researchers said.
“Our study results further support the growing body of research that tree nuts, such as walnuts, can reduce the risk of cardiovascular diseases,” said Falk.
“Tree nuts contain important nutrients such as unsaturated fats, protein, vitamins and minerals. Walnuts are the only nut that provide a significant amount (2.5 grams per one ounce serving) of alpha-linolenic acid (ALA), the plant-based form of omega-3s,” Falk said.
Beyond finding that tree nuts lower total cholesterol, triglycerides, LDL cholesterol and ApoB, researchers also found that consuming at least two servings (two ounces or 57 grammes) per day of tree nuts, such as walnuts, has stronger effects on total cholesterol and LDL.
Additionally, results showed that tree nut consumption may be particularly important for lowering the risk of heart disease in individuals with type 2 diabetes.
Of 1,301 articles surveyed, 61 trials met eligibility criteria for this systematic review and meta-analysis, totalling 2,582 unique participants.
Trials directly provided nuts to the intervention group rather than relying solely on dietary advice to consume nuts.
The dose of nuts varied from 5 to 100g/day and most participants followed their typical diet.
More than two decades of research has shown that walnuts may help lower cardiovascular risk factors by decreasing LDL (bad) cholesterol by 9-16 per cent and diastolic blood pressure by 2-3 mmHg, as well as reducing total cholesterol, raising HDL cholesterol, reducing inflammation as measured by C-reactive protein, and improving arterial function.
These factors are major contributors to heart disease risk, and reducing them is a critical step towards a healthier heart, researchers said.
In addition to providing omega-3s, walnuts also deliver a convenient source of fibre (2 grammes per ounce) and protein (4 grams per ounce).