There is no hard evidence that low LDL levels are harmful, but in very rare cases, low LDL may possibly increase the risk of cancer, depression, anxiety and pre-term birth, explains Mayo Clinic. Low LDL levels are considered ideal, since they are associated with a lower risk of heart disease.
High LDL levels contribute to cholesterol accumulation in the arteries, which increases a patient's risk of heart attack, explains Mayo Clinic. Therefore, maintaining a low LDL level is desirable; the lower, the better. Most people should aim to keep their LDL below 130 milligrams per deciliter, but those who are at a high risk of heart disease may be advised by their physicians to keep their LDL below 100 or even 70 milligrams per deciliter in order to avoid heart attacks.
The other primary type of cholesterol is called HDL, explains Mayo Clinic. HDL is commonly known as "good" cholesterol, since higher levels are associated with a lower risk of heart disease. Men and women are advised to keep their HDL levels above 60 milligrams per deciliter for heart attack prevention. Exercise and weight loss are often effective for increasing HDL levels while decreasing LDL levels. Quitting smoking, eating more soluble fiber and eating less fatty meat and dairy products also help many patients re-balance their cholesterol levels.