Eggs, often regarded as a health risk and a major culprit for heart disease, can actually be quite beneficial -- in fact, they can actually reduce the risk of stroke when they're integrated into a healthy lifestyle.
Eggs are good
Nutritionally, eggs are still an object of heated debate: on the one hand, some studies have shown that eggs can raise the overall cholesterol levels, which can lead to long-term cardiovascular problems. But on the other hand, other studies have found that moderate consumption of eggs doesn't do any harm, and might actually be good for you. This new research falls into the latter category.
In the new study, researchers carried out a systematic review and meta-analysis of studies between 1982 and 2015 focusing on the relationships between consumption of eggs and coronary heart disease (276,000 subjects) and stroke (308,000 subjects). They found that there was no overall association between egg consumption and heart disease, and moderate egg consumption seemed to reduce the risk of a stroke by 12%. This was independent of other health factors.
It's important to note that this study only established a correlation, not causation -- more work is still needed to establish the exact mechanism which causes this effect. However, Dr. Dominik Alexander, the principal investigator of the study, mentions that "eggs do have many positive nutritional attributes, including antioxidants, which have been shown to reduce oxidative stress and inflammation. They are also an excellent source of protein, which has been related to lower blood pressure." Simply stated, they have a lot of healthy nutrients which are good for your body, and if you don't eat too many, then they're probably good for you.
Another potential limitation is that the study was carried out on Chinese participants, so there may be a cultural or genetic component that affects the results of the study. But even so, this is not an isolated study -- there is increasing evidence that seems to suggest that eating eggs is very important for a healthy diet.
"One can deliberate on the many limitations and caveats of nutritional research, but the take-home message of this research from a large study from China is that at the very least up to one egg a day is not linked with raised cardiovascular risk, and at best up to one egg a day may even have health benefits," says Prof Nita Forouhi of the University of Cambridge, commenting on the work.
It's also important to note that doctors are already encouraging people to consume eggs. The US Guidelines for Americans eliminated dietary cholesterol limits, and recommended regular consumption of eggs among lean protein choices. The British NHS writes "although eggs contain some cholesterol, the amount of saturated fat we eat has more of an effect on the amount of cholesterol in our blood than the cholesterol we get from eating eggs".
This raises an important point -- it's not the eggs themselves that can be bad, but rather the saturated fats within, so it's important how you cook them sufficiently. The first thing about cooking eggs is to cook them -- don't let them be runny or improperly cooked, as they can carry dangerous diseases. Cooking eggs thoroughly can eliminate the risk of diseases and food poisoning.
Nutritionally, it's best if you don't fry eggs. I know -- it's the simplest and arguably most delicious way to cook an egg, but it's also the way which adds the most saturated fats, and you don't want that.
Lastly, you don't want to eat too many eggs. It's hard to put an actual limit, but one or two a day should be enough, researchers say.
The study has been published in BMJ.