Do you eat soy products daily? Do not exclude them from your diet, especially if you are a woman and want a healthy heart. The key, however, is to begin eating soy early in life.

According to new research, lifelong soy consumption, similar to the diet of women in Asia, produces the least atherosclerosis (hardening and narrowing of the arteries). Switching to a Western diet after menopause leads to atherosclerosis comparable to a lifelong Western diet.

"While switching to soy from a Western diet after menopause helps only if there is not much atherosclerosis already," researchers said in a press statement.

The study was conducted by researchers from Wake Forest School of Medicine in Winston-Salem, North Carolina, on female monkeys before and after surgical menopause. They fed pre-menopausal monkeys a diet with protein derived mainly from animal sources or a diet with protein from soybeans.

After having their ovaries removed, mimicking human menopause, one group of monkeys continued to eat a soy diet, another switched from animal protein to soy and a third group stuck with animal protein,. After 34 months, cholesterol levels were good in the monkeys who ate soy before and after menopause.

For those that switched to a soy protein diet after menopause, cholesterol levels did improve significantly. But when it came to how much plaque progressed in the arteries, there were not any statistically significant differences, despite trends favoring a lifelong soy diet and the switch to soy after menopause.

"But monkeys eating a lifelong soy diet showed a much lower proportion of complicated plaque in the arteries than other monkeys," researchers added.

"This study underscores how important it is for women to get into the best cardiovascular shape they can before menopause. The healthy habits they start then will carry them through the years to come," suggested Margery Gass, executive director of the journal of the North American Menopause Society (NAMS), which published the research.

Soy contains 40 percent protein. As animal protein contains all the essential amino acids, lacking in pulse protein, soy is often used to replace the animal proteins in an individual's diet. Soybean is the only vegetable food that contains all eight essential amino acids. Soyabeans are processed to various soya products namely soy flour, soy milk, cottage cheese like tofu, fermented products like tempeh and miso. Its health benefits include:

• Bone health
• Menopausal symptoms
• Heart health
• Cancer prevention

Soy foods contain isoflavones, an estrogen derived from plants that has been shown to protect against cancer. However, a recent study found no evidence supporting the theory that  suggests soy-based foods reduce the risk of uterine cancer.

The current study was published online in the journal Menopause.