For many, choosing a healthy diet is a matter of sacrifice: giving up appetizers, reducing carbohydrates or saturated fats, giving up desserts. But what if there was something that you really loved and it turned out to be good for you? No, I’m not talking about chocolate (even if in small quantities, maybe chocolate isn’t so bad!).
This time it’s crazy in the news. Previous studies have shown that people who consumed more nuts had better cardiovascular risk factors and lower rates of cardiovascular disease. For example, several trials have linked nut consumption to lower blood pressure and cholesterol levels. And nuts make up a significant part of Mediterranean dietwhich has also been shown to be good for heart health.
Studies investigating the health benefits of nuts
A 2018 study suggests that nuts might be a particularly good choice. And this is not the first time that researchers have reached this conclusion. A previous analysis by the same researchers (including 365 study participants in 13 trials) found that nut-enriched diets led to lower total and LDL (“bad”) cholesterol compared to other diets. Since then, other studies involving many more participants and longer follow-up have been published.
This latest analysis combined data from 26 previous trials involving more than 1,000 people; compared to those who followed a regular diet, those who followed a diet enriched with nuts had:
- a decrease in total cholesterol (by approximately 7 mg/dL, which is a 3% greater reduction)
- reduce LDL cholesterol (by approximately 5.5 mg/dL, a greater reduction of 4%)
- a reduction in triglycerides (by approximately 4.7 mg/dL, a greater reduction of 5.5%)
- lower apoprotein B (a protein linked to cardiovascular disease) by almost 4 mg/dL
Although these improvements in blood lipids were rather small, larger improvements (e.g., a 12 mg/dL drop in total cholesterol) were observed when the comparison diet was a typical American or Western diet (this is (i.e. a diet rich in red meats, high-fat dairy products, and artificially sweetened foods).
A diet high in high-fat foods, such as nuts, always raises concerns about the risk of weight gain, but fortunately, those on a high-nut diet did not gain weight.
It should be noted that more recent studies have also highlighted the health benefits of eating nuts, including improvement of blood lipids and a possible protective effect on brain health.
Why are nuts so good for you?
While this research is intriguing, it also raises the question of whether nuts are unique in some way. In fact, it may be the types of oils in nuts that make them special when it comes to cardiovascular health. Nuts contain a lot of polyunsaturated fatty acids, which are healthier than saturated fats. Additionally, nuts contain alpha-linolenic and linoleic acids, which may have anti-inflammatory effects that keep blood vessels healthy, in addition to having favorable effects on blood lipids.
All nuts are not created equal. Many nuts (like my favorites, almonds and cashews) are rich in monounsaturated fats, as well as polyunsaturated fats. These are healthier types of fats than saturated and trans fats, but the specific combination of fats and polyunsaturated fatty acids found in nuts may be particularly good for cardiovascular health.
Not so fast, nut lovers
Before you start stocking up on nuts, there are a few important caveats to keep in mind:
- The improvements in blood lipids observed in these studies were small.
- These studies have not determined the ideal “dose” or duration of nut consumption. In one of the best studies, a mixture of about nine hazelnuts, 12 almonds and six walnuts was eaten daily. That might be more than some people are willing to eat!
- Most studies on nut consumption cannot prove that nuts are the reason a person’s cholesterol levels improved on a nut-enriched diet. It’s possible that those who like nuts also tend to exercise more, smoke less, or have more favorable genes than those who don’t eat them.
- No food in your diet can make you healthy. It’s the bigger picture that matters most. A healthy diet, regular physical activity, avoiding excess weight and not smoking are good starting points. And even with a healthy lifestyle, some people need medications or other treatments to reduce their risk of cardiovascular and other diseases.
The essentials
Researchers analyzing previous studies on the health benefits of nuts have given us reason to include them regularly in our diet and, perhaps, choose them over other nuts. Hopefully this type of research will lead to better food choices and better health.
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