Walnuts dramatically cut the risk of suffering a heart attack, new research shows.
Nutrition experts said eating whole walnuts or their extracted oil can reduce the chance of cardiovascular damage through a mechanism other than simply lowering cholesterol.
Professor Penny Kris-Etherton, a co-author of the study by American researchers at Penn State, Tufts University and the University of Pennsylvania, said: ‘We already know that eating walnuts in a heart-healthy diet can lower blood cholesterol levels.’
‘But, until now, we did not know what component of the walnut was providing this benefit. Now we understand additional ways in which whole walnuts and their oil components can improve heart health.’
In a controlled trial, the researchers gave 15 participants with high blood cholesterol level one of four treatments – either 85 grams of whole walnuts, six grams of walnut skin, 34 grams of defatted nutmeat, or 51 grams of oil.
The team evaluated biochemical and physiological responses in the participants before the treatments were administered and again 30 minutes, one hour, two hours, four hours and six hours after administering the treatments.
The researchers repeated this process for each of the remaining three treatments.
Results showed that a one-time consumption of the oil component in walnuts improved vascular health.
In addition, consumption of whole walnuts helped good cholesterol perform more effectively in transporting and removing excess cholesterol from the body.
Co-researcher Claire Berryman said: ‘Our study showed that the oil found in walnuts can maintain blood vessel function after a meal, which is very important given that blood vessel integrity is often compromised in individuals with cardiovascular disease.’
She said walnut oil was particularly good at preserving the function of specific cells which play an important role in cardiovascular health.’
According to the researchers, walnuts contain alpha-linolenic acid, gamma-tocopherol and phytosterols, which may explain the positive effects of the walnut oil treatment.
Mr Berryman said: ‘Implications of this finding could mean improved dietary strategies to fight heart disease.
‘The science around good cholesterol functionality is very new, so to see improvements in this outcome with the consumption of whole walnuts is promising and worth investigating further.’
‘Our study indicates that simple dietary changes, such as incorporating walnuts and or their oil in a heart healthy diet, may reduce the risk of heart disease.’
The study is published in the Journal of Nutrition.
Read more: Daily Mail