Nuts have been consistently associated with reduced risk of coronary heart disease in epidemiological studies. Evidence of nuts’ cardioprotective effects were originally recognized in the early 1990s, and since then, several human trials have documented improvements in lipid levels in response to including nuts in the diet. Beneficial cardiovascular effects beyond cholesterol lowering have also been identified, particularly for walnuts and almonds.
A review published in Archives of Internal Medicine in 2010 pooled the data from 25 different clinical studies that ran for a minimum of three weeks, comparing a nut eating group to a control group. Most of the studies were done on walnuts or almonds, but studies on macadamias, pistachios, hazelnuts, pecans, and peanuts were also included in the analysis.
This review confirmed that nut consumption has beneficial effects on lipid levels, and it also reached two interesting new conclusions:
1. Dose dependent effect
First, the different studies were on different quantities of nuts, and the review concluded that the cholesterol-lowering effects of nuts are dose-dependent — this means that more nuts consumed translated into greater decreases in LDL and total cholesterol:
|
Quantity of nuts consumed |
Decrease in total cholesterol |
Decrease in LDL |
|
1 oz. |
2.8% |
4.2% |
|
1.5 oz. |
3.2% |
4.9% |
|
2.4 oz. |
5.1% |
7.4% |
For healthy weight individuals, these results suggest that 2.4 ounces may be better than 1 ounce for cardiovascular health.
2. Effects Were Greater in Individuals With Lower BMI
The researchers found that body mass index (BMI) modified the association between nut consumption and cholesterol lowering. The effects of nuts were greater in individuals with lower BMI, meaning that those who were overweight or obese saw less cholesterol-lowering benefit than healthy weight individuals.
Nuts and seeds are critical components of a disease-preventing diet, and I recommend eating them daily. The addition of nuts and seeds benefits cardiovascular health and may even enhance lifespan, according to large, long-term studies; for example, in the Adventist Health Study, those who had a high level of physical activity, followed a vegetarian diet, and ate nuts frequently lived on average 8 years longer than those who did not share those habits. Similarly, in a trial evaluating diets supplemented with either nuts or olive oil, nut consumption (more than 3 servings per week) was associated with a 39% reduced risk of death from all causes. For those that are overweight, nuts are beneficial, but nut and seed intake must also be consistent with weight loss goals. The primary means of decreasing cardiovascular risk in overweight individuals should be eating lots of high micronutrient, low calorie foods. For people who are significantly overweight, nuts should still be included, but their caloric density suggests a limit such as 1 ounce per day for women and 1.5–2 ounces a day for men.
This article was originally published on www.drfuhrman.com. Read the original here.
*Image of “walnut“ via Shutterstock
