‘Walnuts prevent heart attack, lower cholesterol’
TWO handfuls of walnuts a day could help stave off heart disease, a new study has revealed.
The tree nuts lower total cholesterol levels in the body, thus reducing the chances of a person suffering a heart attack.
Researchers said the snack contains important nutrients such as unsaturated fats, protein, vitamins and minerals.
The study is published in the American Journal of Clinical Nutrition.
Dr. Michael Falk, one of the authors from the Life Sciences Research Organisation, said: “Our study results further support the growing body of research that tree nuts, such as walnuts, can reduce the risk of cardiovascular diseases.
“Tree nuts contain important nutrients. Walnuts are the only nut that provide a significant amount – 2.5g per one ounce serving – of alpha-linolenic (ALA), the plant-based form of omega-3.”
Juglans regia commonly known as walnut tree is a well-known member of Juglans genus, constituting an important species of deciduous trees found primarily in temperate areas.
J. regia belongs to the family Juglandaceae which includes three species: J. nigra, J. cinerea, and J. regia.
The African walnut is botanically known as Tetracarpidium conophorum and belongs to the plant family Euphorbiaceae. In southern Nigerian ethnomedicine, it is used as a male fertility agent and the leaves are used for the treatment of dysentery and to improve fertility in males. It is known as ukpa (Igbo) and awusa or asala (Yoruba). African walnut is known in the littoral and the western Cameroon as kaso or ngak.
Falk and his team conducted a systematic review and meta-analysis of 61 controlled trials to arrive at their conclusions.
They found walnuts are effective in lowering total cholesterol, Low Density Lipo-protein (LDL), so-called ‘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.
Falk said the findings show consuming at least two servings – two ounces – of walnuts each day jas stronger effects of total cholesterol and LDL levels.
Additionally, the 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 reviewed, 61 trials met the eligibility criteria for Dr Falk’s review – incorporating 2,582 people.
Trials directly provided nuts to the intervention group rather than relying solely on dietary advise to consume nuts.
The dose of nuts varied from five to 100g each 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 by nine to 16 per cent, and diastolic blood pressure by 2-3mmHg2.
Studies have also shown the tree nuts can reduce total cholesterol, while increasing levels of High Density Lipo-protein (HDL), or ‘good’ cholesterol, reducing inflammation and improving arterial function.
These factors are major contributors to heart disease risk, and reducing them is a critical step toward a healthier heart.
In addition to providing omega-3s, walnuts also deliver a convenient source of fiber (two grams per ounce) and protein (four grams per ounce).
Indeed, previous studies had shown that African walnut prevents heart disease. They suggested eating walnuts at the end of a meal might help cut the damage that fatty food can do to the arteries.
It is thought that the nuts are rich in compounds that reduce hardening of the arteries, and keep them flexible. Phytochemical analysis indicates that African walnuts contain ingredients such as omega-3 fatty acids, antioxidants and phytosterols that may all reduce the risk of the disease.
Most of the studies on the plant have been on the nutritive value of the seeds, which is a snack and delicacy.