Going nuts!

Sorry about the title. I couldn’t resist as going nuts seems to provide quite a few health benefits. Nothing completely new, but recently published scientific findings strengthen the case for the benefits of eating nuts. All in moderation of course.

The week started with news that eating almonds on a regular basis may help boost levels of the good (high-density lipoprotein or HDL) cholesterol while also improving the way cholesterol is removed from the body.

And it ended with news of a new brain imaging study showing that consuming walnuts activates an area in the brain associated with regulating hunger and food cravings, thus discouraging overeating by promoting feelings of fullness.

The goodness of almonds

almonds2It has previously been shown that a diet that includes almonds lowers the bad (low-density lipoprotein or LDL) cholesterol, which is a major risk factor for heart disease. But not as much was known about how almonds affect HDL cholesterol, which helps lower the risk of heart disease.

HDL is like a garbage bag that slowly gets bigger and more spherical as it gathers cholesterol molecules from cells and tissues before depositing them in the liver to be broken down and excreted.

The researchers wanted to see if almonds could not just increase the levels but also improve the function of HDL cholesterol.

In a clever trial researchers found that HDL cholesterol levels and functionality improved when participants received 43 grams – about a handful – of almonds a day compared to when the same participants ate a banana muffin instead.

This should reduce the risk of heart disease and in addition almonds also provide a dose of good fats, vitamin E and fibre that might improve health, with the caveat that the research was supported by the Almond Board of California.

The goodness of walnuts

walnuts2Walnuts are not far behind almonds as they too are packed with nutrients linked to better health. Not being enough, it was also previously known that people reported feeling fuller after eating walnuts although not necessarily why.

Now to determine exactly how walnuts stop food cravings scientists used functional magnetic resonance imaging (fMRI) to observe how walnuts could change activity in the brain.

During one five-day session, volunteers consumed daily smoothies containing 48 grams of walnuts and during a separate session they received a walnut-free but nutritionally comparable placebo smoothie, flavoured to taste exactly the same as the walnut-containing smoothie. The order of the two sessions was random.

As in previous observational studies, participants reported feeling less hungry during the week they consumed walnut-containing smoothies than during the week they were given the placebo smoothies. And fMRI tests administered on the fifth day of the experiment revealed for the first time details of the neurocognitive impact these nuts have on the brain.

When participants were shown pictures of highly desirable foods, fMRI imaging revealed increased activity in a part of the brain called the right insula after participants had consumed the five-day walnut-rich diet compared to when they had not.

As this area of the insula is likely involved in cognitive control and salience, it meant that participants were paying more attention to food choices and selecting the less desirable but healthier options over the highly desirable but less healthy options.

But again you should know that this study was supported by commercial interest, this time the California Walnut Commission.

Be careful with the calories

So good news on all fronts but how to handle this information? Binge on almonds and walnuts every day?

Well, it may pay off to be a bit careful with the calorie intake as eating a handful each of both almonds and walnuts in the same day would equate to eating two banana muffins daily. And not many nutritionists would recommend that.

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