Eating walnuts has been linked to a number of health benefits. These include a reduced risk of heart disease, possible cancer prevention and improved brain function.
Heart disease, or cardiovascular disease, is a broad term used for chronic diseases related to the heart and blood vessels.
In many cases, heart disease may be prevented with healthy lifestyle habits, such as eating nuts
Walnuts are no exception. In fact, many studies have shown that eating walnuts may combat risk factors for heart disease by:
These effects are likely caused by the beneficial fat composition of walnuts as well as their rich antioxidant content.
Cancer is a group of diseases characterized by abnormal cell growth.
Many forms of cancer can be prevented by eating healthy food, exercising and avoiding unhealthy lifestyle habits.
Since they are a rich source of beneficial plant compounds, walnuts could be an effective part of a cancer-preventive diet
Walnuts contain several bioactive components that may have anti-cancer properties. These include:
Observational studies have linked the regular consumption of nuts with a lower risk of colon and prostate cancer
This is supported by animal studies indicating that eating walnuts may suppress cancer growth in the breasts, prostate, colon and kidneys
However, before any stronger claims can be made, these effects need to be confirmed by clinical studies in humans.
Several human studies indicate that eating nuts may improve brain function. They also show that walnuts can help with depression and age-related decline in brain function (55, 56).
A study of elderly people linked regular consumption of walnuts with significant memory improvement (57).
However, these studies were observational and therefore can’t prove that walnuts were the cause of improvements in brain function. Stronger evidence is provided by studies that investigate the effect of eating walnuts directly.
One 8-week study of 64 young, healthy adults, found that eating walnuts improved comprehension. However, significant improvements in non-verbal reasoning, memory and mood were not detected (58).
Nevertheless, walnuts have also been shown to improve brain function in animals.
In another study, mice with Alzheimer’s disease were fed walnuts every day for 10 months. Their memory and learning skills improved significantly (59).
Similarly, studies of elderly rats found that eating walnuts for eight weeks reversed age-related impairments in brain function (60, 61).
These effects are probably due to the high antioxidant content of walnuts. However, their omega-3 fatty acids may also play a role (61, 62).